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To explore the autoimmune response and outcome in the central nervous system (CNS) at the onset of viral infection and correlation between autoantibodies and viruses.MethodsA retrospective observational study was conducted in 121 patients (2016–2021) with a CNS viral infection confirmed via cerebrospinal fluid (CSF) next-generation sequencing (cohort A). Their clinical information was analysed and CSF samples were screened for autoantibodies against monkey cerebellum by tissue-based assay. In situ hybridisation was used to detect Epstein-Barr virus (EBV) in brain tissue of 8 patients with glial fibrillar acidic protein (GFAP)-IgG and nasopharyngeal carcinoma tissue of 2 patients with GFAP-IgG as control (cohort B).ResultsAmong cohort A (male:female=79:42; median age: 42 (14–78) years old), 61 (50.4%) participants had detectable autoantibodies in CSF. Compared with other viruses, EBV increased the odds of having GFAP-IgG (OR 18.22, 95% CI 6.54 to 50.77, p<0.001). In cohort B, EBV was found in the brain tissue from two of eight (25.0%) patients with GFAP-IgG. Autoantibody-positive patients had a higher CSF protein level (median: 1126.00 (281.00–5352.00) vs 700.00 (76.70–2899.00), p<0.001), lower CSF chloride level (mean: 119.80±6.24 vs 122.84±5.26, p=0.005), lower ratios of CSF-glucose/serum-glucose (median: 0.50[0.13-0.94] vs 0.60[0.26-1.23], p=0.003), more meningitis (26/61 (42.6%) vs 12/60 (20.0%), p=0.007) and higher follow-up modified Rankin Scale scores (1 (0–6) vs 0 (0–3), p=0.037) compared with antibody-negative patients. A Kaplan-Meier analysis revealed that autoantibody-positive patients experienced significantly worse outcomes (p=0.031).ConclusionsAutoimmune responses are found at the onset of viral encephalitis. EBV in the CNS increases the risk for autoimmunity to GFAP.

Pangenomes provide access to an accurate representation of the genetic diversity of species, both in terms of sequence polymorphisms and structural variants (SVs). Here we generated the Saccharomyces cerevisiaeReference Assembly Panel (ScRAP) comprising reference-quality genomes for 142 strains representing the species’ phylogenetic and ecological diversity. The ScRAP includes phased haplotype assemblies for several heterozygous diploid and polyploid isolates. We identified circa (ca.) 4,800 nonredundant SVs that provide a broad view of the genomic diversity, including the dynamics of telomere length and transposable elements. We uncovered frequent cases of complex aneuploidies where large chromosomes underwent large deletions and translocations. We found that SVs can impact gene expression near the breakpoints and substantially contribute to gene repertoire evolution. We also discovered that horizontally acquired regions insert at chromosome ends and can generate new telomeres. Overall, the ScRAP demonstrates the benefit of a pangenome in understanding genome evolution at population scale.

Subauroral red (SAR) arcs are commonly observed ionospheric red line emissions. They are usually attributed to subauroral electron heating by inner magnetospheric heat flux (IMHF). However, the role of IMHF in changing the ionosphere‐thermosphere (IT) still remains elusive. We conduct controlled numerical experiments with the Thermosphere‐Ionosphere Electrodynamic General Circulation Model (TIEGCM). Coulomb collisional heat flux derived with the Comprehensive Inner Magnetosphere Ionosphere (CIMI) model and empirical subauroral polarization streams (SAPS) are implemented in TIEGCM. The heat flux causes electron temperature enhancement, electron density depletion, and consequently SAR arcs formed in the dusk‐to‐midnight subauroral ionosphere region. SAPS cause more substantial plasma and neutral heating and plasma density variations in a broader region. The maximum enhancement of subauroral red line emission rate is comparable to that caused by the heat flux. However, the visibility of SAR arcs also depends on the relative enhancement to the background brightness. The Earth's topside atmosphere is subject to energy inputs from the magnetosphere and solar wind. In addition to the Joule heating generated by high latitude plasma convection and energy flux carried by precipitating magnetospheric particles, magnetospheric energy can be also deposited in the ionosphere‐thermosphere via heat flux, that is, energy flows carried by low‐energy thermal electrons. When hot ions in the ring current collide with the cold plasma in the plasmasphere, heat conduction occurs and the resultant heat flux is transported along geomagnetic field lines to the footprint ionosphere. The additional heating raises the electron temperature in the subauroral ionosphere and modifies the ionosphere‐thermosphere states. This study uses first‐principles inner magnetosphere model and ionosphere‐thermosphere model to illustrate the thermodynamic coupling effects between the topside ionosphere and the magnetosphere, and compare the relative significance between the heat flux and plasma convection due to electrodynamic coupling. The numerical experiments show that the heat flux primarily increases electron temperature while subauroral plasma flow heats up both plasma and neutrals. Despite different physical mechanisms, the heat flux and subauroral plasma convection make comparable contributions to red line emission rates in the subauroral region. Inner magnetospheric heat flux increases subauroral ionospheric electron temperature and depletes the density to form subauroral red arcsCompared to subauroral polarization streams, the heat flux heating effects are only confined to electrons in the subauroral regionThe heat flux produces negligible impacts on ions and neutrals compared to subauroral polarization streams Inner magnetospheric heat flux increases subauroral ionospheric electron temperature and depletes the density to form subauroral red arcs Compared to subauroral polarization streams, the heat flux heating effects are only confined to electrons in the subauroral region The heat flux produces negligible impacts on ions and neutrals compared to subauroral polarization streams

The January 2022 Hunga Tonga–Hunga Ha’apai eruption was one of the most explosive volcanic events of the modern era1,2, producing a vertical plume that peaked more than 50 km above the Earth3. The initial explosion and subsequent plume triggered atmospheric waves that propagated around the world multiple times4. A global-scale wave response of this magnitude from a single source has not previously been observed. Here we show the details of this response, using a comprehensive set of satellite and ground-based observations to quantify it from surface to ionosphere. A broad spectrum of waves was triggered by the initial explosion, including Lamb waves5,6propagating at phase speeds of 318.2 ± 6 m s−1at surface level and between 308 ± 5 to 319 ± 4 m s−1in the stratosphere, and gravity waves7propagating at 238 ± 3 to 269 ± 3 m s−1in the stratosphere. Gravity waves at sub-ionospheric heights have not previously been observed propagating at this speed or over the whole Earth from a single source8,9. Latent heat release from the plume remained the most significant individual gravity wave source worldwide for more than 12 h, producing circular wavefronts visible across the Pacific basin in satellite observations. A single source dominating such a large region is also unique in the observational record. The Hunga Tonga eruption represents a key natural experiment in how the atmosphere responds to a sudden point-source-driven state change, which will be of use for improving weather and climate models.

Graphical Abstract:

In recent years, LoRa has been extensively researched in the satellite Internet of Things (IoT). However, the multiple access technology of LoRa is still one of the bottlenecks of satellite IoT. To improve the multiple access performance of LoRa satellite IoT, based on the orthogonality of LoRa symbols in the fractional domain, this paper proposes a low complexity Orthogonal LoRa Multiple Access (OLMA) algorithm for multiple LoRa users occupying the same frequency bandwidth. The algorithm introduces the address code to divide the fractional bandwidth into multiple parts, and the OLMA users with different address codes occupy different parts to transmit the information code, thus avoiding mutual interference caused by collisions in the same frequency bandwidth. The multiple access capability of OLMA can be flexibly configured only by simply adjusting the length of the address code according to the actual application requirements of data transmission. Theoretical analysis and simulation results show that the OLMA algorithm can greatly improve the multiple access capability and the total transmission bit rate of LoRa IoT without changing the existing LoRa modulation parameters and process.

Genome introgressions drive evolution across the animal1, plant2and fungal3kingdoms. Introgressions initiate from archaic admixtures followed by repeated backcrossing to one parental species. However, how introgressions arise in reproductively isolated species, such as yeast4, has remained unclear. Here we identify a clonal descendant of the ancestral yeast hybrid that founded the extant Saccharomyces cerevisiaeAlpechin lineage5, which carries abundant Saccharomyces paradoxusintrogressions. We show that this clonal descendant, hereafter defined as a ‘living ancestor’, retained the ancestral genome structure of the first-generation hybrid with contiguous S. cerevisiaeand S. paradoxussubgenomes. The ancestral first-generation hybrid underwent catastrophic genomic instability through more than a hundred mitotic recombination events, mainly manifesting as homozygous genome blocks generated by loss of heterozygosity. These homozygous sequence blocks rescue hybrid fertility by restoring meiotic recombination and are the direct origins of the introgressions present in the Alpechin lineage. We suggest a plausible route for introgression evolution through the reconstruction of extinct stages and propose that genome instability allows hybrids to overcome reproductive isolation and enables introgressions to emerge.

The global atmospheric static stability (N2) in the middle atmosphere and its relation to gravity waves (GWs) were investigated by using the temperature profiles measured by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument from 2002 to 2018. At low latitudes, a layer with enhanced N2occurs at an altitude of ~20 km and exhibits annual oscillations caused by tropopause inversion layers. Above an altitude of ~70 km, enhanced N2exhibits semiannual oscillations at low latitudes caused by the mesosphere inversion layers and annual oscillations at high latitudes resulting from the downward shift of the summer mesopause. The correlation coefficients between N2and GW amplitudes can be larger than 0.8 at latitudes poleward of ~40°N/S. This observation provides factual evidence that a large N2supports large‐amplitude GWs and indicates that N2plays a dominant role in maintaining GWs at least at high latitudes of the middle atmosphere. This evidence also partially explains the previous results regarding the phase changes of annual oscillations of GWs at high latitudes.

Aging varies among individuals due to both genetics and environment, but the underlying molecular mechanisms remain largely unknown. Using a highly recombined Saccharomyces cerevisiaepopulation, we found 30 distinct quantitative trait loci (QTLs) that control chronological life span (CLS) in calorie-rich and calorie-restricted environments and under rapamycin exposure. Calorie restriction and rapamycin extended life span in virtually all genotypes but through different genetic variants. We tracked the two major QTLs to the cell wall glycoprotein genes FLO11and HPF1. We found that massive expansion of intragenic tandem repeats within the N-terminal domain of HPF1was sufficient to cause pronounced life span shortening. Life span impairment by HPF1was buffered by rapamycin but not by calorie restriction. The HPF1repeat expansion shifted yeast cells from a sedentary to a buoyant state, thereby increasing their exposure to surrounding oxygen. The higher oxygenation altered methionine, lipid, and purine metabolism, and inhibited quiescence, which explains the life span shortening. We conclude that fast-evolving intragenic repeat expansions can fundamentally change the relationship between cells and their environment with profound effects on cellular lifestyle and longevity.

This special issue reports the latest results on long‐term variations and trends in the middle and upper atmosphere, in particular, in the mesosphere and thermosphere. The issue is based on selected papers from the 10th IAGA/ICMA/SCOSTEP workshop on Long‐term changes and trends in the atmosphere, held in Hefei, China, 14–18 May 2018. This introduction highlights recent progress in key science areas of long‐term changes in the upper atmosphere. Long‐term change in the middle and upper atmosphere is caused by increasing carbon dioxide and ozone changeLong‐term decrease in thermosphere density increases risks of space trafficThis introduction highlights of recent progress on long‐term changes in the middle and upper atmosphere

Triarylamine-alt-fluorene (TAF) copolymers are widely used for hole injection and transport in organic electronics. Despite suggestions to planarize the triphenylamine moiety, little research has been conducted. Here, we report a comprehensive investigation of the effects of planarization on the electronic and transport properties of a model TAF polymer semiconductor core. We compared the conventional twisted-propeller N-4-methoxyphenyl-N,N-diphenylamine-4′,4″-diyl (TA) unit and its planarized bridged analogue (bTA) where adjacent o,o′-positions are linked by 1,1-dimethylmethylene. We studied both polyelectrolyte and non-polyelectrolyte forms of this core in both doped and undoped states. We found that planarization leads to an unprecedented trap-free transport of holes, and a pronounced enhancement of their mobility in the undoped state though less so in the doped state. Planarization also induces a slight reduction in the ionization energy of the undoped polymer, consequently lowering the work function of the doped polymer. This is accompanied by small spectral shifts: a red shift in the first absorption band of the undoped polymer and a blue shift in the first absorption band of the polaron. Furthermore, this study unveils new fundamental features of TAF polymers: (i) Doping induces the formation of three polaron bands within the subgap. (ii) Absorption of both neutral and polaron segments exhibit a linear intensity relationship with doping level. (iii) Electrical conductivity reaches a maximum at the half-doped state, varying as σ ∼ (x(1 – x))3for 0.1 ≲ x≲ 0.9, where xis the doping level. Finally, we demonstrate the successful integration of these self-compensated hole-doped TAF polymers as efficient hole injection layers in organic semiconductor diodes.

Nanopore direct RNA sequencing (DRS) provides the direct access to native RNA strands with full-length information, shedding light on rich qualitative and quantitative properties of gene expression profiles. Here with NanoTrans, we present an integrated computational framework that comprehensively covers all major DRS-based application scopes, including isoform clustering and quantification, poly(A) tail length estimation, RNA modification profiling, and fusion gene detection. In addition to its merit in providing such a streamlined one-stop solution, NanoTrans also shines in its workflow-orientated modular design, batch processing capability, all-in-one tabular and graphic report output, as well as automatic installation and configuration supports. Finally, by applying NanoTrans to real DRS datasets of yeast, Arabidopsis, as well as human embryonic kidney and cancer cell lines, we further demonstrated its utility, effectiveness, and efficacy across a wide range of DRS-based application settings.

The Gravity Field and Steady‐State Ocean Circulation Explorer (GOCE) and CHAllenging Minisatellite Payload (CHAMP) satellites measure in‐situ thermospheric density and cross‐track wind. When propagating obliquely to the satellite track in a horizontal plane (i.e., not purely along‐track or cross‐track), gravity waves (GWs) can be observed both in the density and cross‐track wind perturbations. We employ the Wavelet Analysis, red noise model, dissipative dispersion and polarization relations for thermospheric GWs, and specific criteria to determine whether a quiet‐time (Kp < 3) thermospheric traveling atmospheric disturbances (TADs) event is a GW or not. The first global morphology of thermospheric GWs instead of TADs is reported. The fast intrinsic horizontal phase speed (cIH> 600 m/s) of most GWs suggests that they are not generated in the lower/middle atmosphere (where cIH< 300 m/s). A second population of GWs with slower speeds (cIH= 50–250 m/s) in GOCE are likely from the lower/middle atmosphere, but they occur much less frequently in CHAMP. GW hotspots occur during the high‐latitude and the winter midlatitude regions. GW amplitudes exhibit semi‐annual and annual variations. These findings suggest that most GOCE and CHAMP GWs are higher‐order GWs from primary GW sources in the lower/middle atmosphere. Finally, the average propagation direction of the CHAMP GWs exhibits a clear diurnal cycle, with clockwise (counterclockwise) occurring in the northern (southern) hemisphere and equatorward propagation occurring at ∼13 LST. This suggests that the predominant GW propagation direction is opposite to the background wind direction. Gravity waves (GWs) are challenging to measure in many parts of the thermosphere. Still, the GOCE and CHAMP missions offer an opportunity to observe GWs by measuring thermospheric density and cross‐track wind perturbations. However, the absence of along‐track wind perturbations in these data sets hinders the direct determination of intrinsic GW parameters. To address this, we employ Wavelet Analysis and red noise processes to quantify the along‐track parameters, including phases and amplitudes, of intermittent and localized thermospheric traveling atmospheric disturbance (TAD) events of varying scales. Subsequently, we utilize the transformed dissipative dispersion and polarization relations for thermospheric GWs to determine intrinsic parameters of GWs in those TAD events. By examining the resulting GW solutions (e.g., propagation directions, horizontal wavelengths, periods, etc.), we investigate the characteristics of thermospheric GWs during geomagnetic quiet time. We present first statistics on global thermospheric GW properties across different latitudes, local times, and months. The high phase speeds of most GWs suggest that they cannot be directly generated in the lower/middle atmosphere. Our findings reveal an evident seasonal variation of GW amplitudes, and their diurnal cycle in predominant propagation directions are opposite to the background wind direction. The strongest gravity wave (GW) events occur most often in the summer polar region during geomagnetic quiet timesGWs in the winter hemisphere at midlatitudes during quiet times and 12–24 local solar time (LST) are possible due to the polar vortexCHAllenging Minisatellite Payload observes a clockwise (counterclockwise) rotation of GW azimuth in the northern (southern) hemisphere over LST The strongest gravity wave (GW) events occur most often in the summer polar region during geomagnetic quiet times GWs in the winter hemisphere at midlatitudes during quiet times and 12–24 local solar time (LST) are possible due to the polar vortex CHAllenging Minisatellite Payload observes a clockwise (counterclockwise) rotation of GW azimuth in the northern (southern) hemisphere over LST

Water vapor (H2O) measurements made by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument between 2002 and 2018 and by the Aura Microwave Limb Sounder (MLS) instrument between 2004 and 2018 are analyzed to determine the linear trend and solar cycle response of H2O in the stratosphere and mesosphere. Both SABER and MLS show a rapid global H2O increase of 5–6% per decade in the lower stratosphere after the 2001 drop. The increasing zonal mean H2O at 40°N in SABER and MLS is consistent with the Boulder frost point hygrometer data in the lower stratosphere. The global distribution of SABER and MLS H2O trends are positive at most altitudes and latitudes, and they peak in the tropical lower stratosphere. In the mesosphere the SABER H2O trend is 0.1–0.2 ppmv per decade and the MLS H2O trend is 0.2–0.3 ppmv per decade. The trend and solar cycle response derived from the observations are compared against the Whole Atmosphere Community Climate Model (WACCM). The solar cycle response of H2O from WACCM agrees with SABER and MLS. The linear H2O trend from WACCM does not show the observed increase in the lower stratosphere. SABER and MLS show a rapid global water vapor increase of 5‐6% per decade in the lower stratosphere after 2002.SABER and MLS water vapor show positive trend and strong negative correlation with solar cycle in the mesosphere.SABER H2O time series and trend at 40N are consistent with the Boulder frost point hygrometer measurements after 2002.

We use Whole Atmosphere Community Climate Model simulations made under various climate change scenarios to study the evolution of the global‐mean temperature trend in the late twentieth century and the twenty‐first century. Results are compared with available satellite observations, including new trend estimates derived from the Sounding of the Atmosphere using Broadband Emission Radiometry instrument on NASA's TIMED spacecraft. Modeled and observed trends are shown to be consistent throughout the entire middle atmosphere, from near the tropopause (~16 km) to the lower thermosphere (~95 km) in the period covered by the satellite data. Simulations are extended into the twenty‐first century to document the evolution of the global‐mean temperature trend profile. We find, consistent with previous studies, a marked change in the trend profile at the turn of the twenty‐first century, which is driven by the recovery of stratospheric ozone following the adoption of the Montreal Protocol. In the twenty‐first century, the trend profile becomes more uniform with altitude, but its overall shape and magnitude are conditioned by the scenario adopted for future emissions of greenhouse gases. Our results suggest that the vertical profile of temperature trends in the middle atmosphere will remain an important signature of global climate change, and they underscore the importance of global, continuous monitoring of this region of the atmosphere. WACCM is used to calculate global‐mean temperature trends in the middle atmosphere through the end of the twenty‐first centuryModeled trends are compared against existing satellite observations and found to be consistentEvolution of the trend profiles in the early twenty‐first century is influenced by changes in both CO2and ozone; afterward, CO2dominates the response

We analyze quiet‐time data from the Gravity Field and Ocean Circulation Explorer satellite as it overpassed the Southern Andes at z≃275 km on 5 July 2010 at 23 UT. We extract the 20 largest traveling atmospheric disturbances from the density perturbations and cross‐track winds using Fourier analysis. Using gravity wave (GW) dissipative theory that includes realistic molecular viscosity, we search parameter space to determine which hot spot traveling atmospheric disturbances are GWs. This results in the identification of 17 GWs having horizontal wavelengths λH= 170–1,850 km, intrinsic periods τIr= 11–54 min, intrinsic horizontal phase speeds cIH= 245–630 m/s, and density perturbations ρ′/ρ¯∼0.03–7%. We unambiguously determine the propagation direction for 11 of these GWs and find that most had large meridional components to their propagation directions. Using reverse ray tracing, we find that 10 of these GWs must have been created in the mesosphere or thermosphere. We show that mountain waves (MWs) were observed in the stratosphere earlier that day and that these MWs saturated at z∼ 70–75 km from convective instability. We suggest that these 10 Gravity Field and Ocean Circulation Explorer hot spot GWs are likely tertiary (or higher‐order) GWs created from the dissipation of secondary GWs excited by the local body forces created from MW breaking. We suggest that the other GW is likely a secondary or tertiary (or higher‐order) GW. This study strongly suggests that the hot spot GWs over the Southern Andes in the quiet‐time middle winter thermosphere cannot be successfully modeled by conventional global circulation models where GWs are parameterized and launched in the troposphere or stratosphere. The GW dissipative dispersion and polarization relations were used to uniquely characterize the hot spot GWsThe hot spot GWs were medium to large scale, had periods <1 hr, and had horizontal intrinsic phase speeds cIH= 245–630 m/sAll of the hot spot GWs were likely secondary, tertiary, or higher‐order GWs from MW breaking

The precision of array of laser applications and manipulation on smaller scales are limited by the so-called 200 nm wall, and breakthroughs rely on the discovery of new materials with transparency and phase matchability in the ultraviolet and deep ultraviolet region. Herein, we discover an unprecedented alignment of the asymmetric non-π-conjugated species [PO3F] in NaNH4PO3F·H2O, which allows the best uniform P–F bond orientation that generates a remarkable enhancement of the (010) in-plane anisotropy that yields the largest birefringence (obv.: 0.053) to date in the phosphate and fluorophosphate families. The substance produces second harmonic generation lasers through direct frequency doubling with incident Yb:KGW femtosecond lasers on an as-synthesized (010) wafer with a size of 14 × 10 × 2.1 mm3. According to the calculated refractive index dispersion curve, the shortest second-harmonic generation (SHG) wavelength is estimated to be 194 nm, the shortest among phosphates and monofluorophosphate. These insights may help to design other high-performance non-π-conjugated deep-UV nonlinear optical materials.

Thermosphere Ionosphere Mesosphere Electrodynamics General Circulation Model (TIMEGCM) simulations are diagnostically analyzed to investigate the causes of mesosphere and lower thermosphere (MLT) wind changes at middle latitudes during the 17 April 2002 storm. In the early phase of the storm, middle‐latitude upper thermospheric wind changes are greater and occur earlier than MLT wind changes. The horizontal wind changes cause downward vertical wind changes, which are transmitted to the MLT region. Adiabatic heating and heat advection associated with downward vertical winds cause MLT temperature increases. The pressure gradient produced by these temperature changes and the Coriolis force then drive strong equatorward meridional wind changes at night, which expand toward lower latitudes. Momentum advection is minor. As the storm evolves, the enhanced MLT temperatures produce upward vertical winds. These upward winds then lead to a decreased temperature, which alters the MLT horizontal wind pattern and causes poleward wind disturbances at higher latitudes. In a recent work, we found that in the mesosphere and lower thermosphere (MLT) region at middle latitudes, adiabatic heating/cooling and vertical heat advection, both associated with vertical wind changes, are the dominant processes that determine the temperature responses to storms. However, the cause of MLT vertical wind changes during storms has not been elucidated. Thus, there is a compelling need to understand how and why the wind changes during storms in the MLT region. Here we address this question by exploring theoretically the processes that determine the MLT wind response to storms at middle latitudes. During the early phase of the storm, the middle‐latitude upper thermospheric wind changes are greater and occur earlier than those in the MLT region. The horizontal wind changes cause vertical wind changes, which are transmitted to the MLT region. The pressure gradient produced by the temperature changes associated with vertical wind changes and the Coriolis force are the dominant processes that drive storm time MLT wind changes at middle latitudes. Momentum advection is minor. As the storms evolve, the enhanced temperatures produce upward vertical winds. The upward vertical winds then lead to a depleted temperature, which consequently alters the MLT horizontal wind pattern. Pressure gradient produced by temperature changes and the Coriolis force drive the storm‐time MLT wind changes at middle latitudesDownward vertical winds from the upper thermosphere enhance MLT temperatures, which drive equatorward winds in the storm early phaseAs storms progress, enhanced MLT temperatures create a divergent flow at middle latitude, making disturbance winds poleward and upward

During 30 September to 9 October 2016, Hurricane Matthew traversed the Caribbean Sea to the east coast of the United States. During its period of greatest intensity, in the central Caribbean, Matthew excited a large number of concentric gravity waves (GWs or CGWs). In this paper, we report on hurricane‐generated CGWs observed in both the stratosphere and mesosphere from spaceborne satellites and in the ionosphere by ground Global Positioning System receivers. We found CGWs with horizontal wavelengths of ~200–300 km in the stratosphere (height of ~30–40 km) and in the airglow layer of the mesopause (height of ~85–90 km), and we found concentric traveling ionospheric disturbances (TIDs or CTIDs) with horizontal wavelengths of ~250–350 km in the ionosphere (height of ~100–400 km). The observed TIDs lasted for more than several hours on 1, 2, and 7 October 2016. We also briefly discuss the vertical and horizontal propagation of the Hurricane Matthew‐induced GWs and TIDs. This study shows that Hurricane Matthew induced significant dynamical coupling between the troposphere and the entire middle and upper atmosphere via GWs. It is the first comprehensive satellite analysis of gravity wave propagation generated by hurricane event from the troposphere through the stratosphere and mesosphere into the ionosphere. Concentric gravity waves generated by Hurricane Matthew were seen from the tropopause to the ionosphere on October 2016These concentric gravity waves had horizontal wavelengths of ~200–350 kmSmall and large concentric gravity waves observed in airglow layer and ionosphere correlated with Hurricane Matthew's strongest period

The seasonal and height dependencies of the orographic primary and larger‐scale secondary gravity waves (GWs) have been studied using the temperature profiles measured by Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) from 2002 to 2017. At ~40°S and during Southern Hemisphere winter, there is a strong GW peak over the Andes mountains that extend to z~ 55 km. Using wind and topographic data, we show that orographic GWs break above the peak height of the stratospheric jet. At z~ 55–65 km, GW breaking and momentum deposition create body forces that generate larger‐scale secondary GWs; we show that these latter GWs form a wide peak above 65 km with a westward tilt. At middle latitudes during summer in the respective hemisphere, orographic GW breaking also generates larger‐scale secondary GWs that propagate to higher altitudes. Both orographic primary and larger‐scale secondary GWs are likely responsible for most of the non‐equatorial peaks of the persistent global distribution of GWs in SABER. It is important to characterize orographic primary gravity waves (GWs) and the larger‐scale secondary GWs via both observations and numerical modeling because of their role in dynamics of the atmosphere. We present the global distributions of GWs and the associated larger‐scale secondary GWs in the middle atmosphere (z~ 30–100 km) from temperature profiles measured by the SABER instrument over the past 16 years (2002–2017). We show that the peaks of the primary and the associated secondary GWs coincide with topographic peaks and that these associations depend on latitude and season. The polar stratospheric jet and the lower stratospheric wind reversal cause the orographic GWs break. The breaking GWs deposit their momentum and induce body forces that generate larger‐scale secondary GWs; these secondary GWs are responsible for the GWs peaks observed above the mountain wave breaking height. Orographic primary and larger‐scale secondary gravity waves are observed in the middle atmosphere using SABER observations from 2002–2017Over the southern Andes, secondary GWs are generated from MW breaking in the upper stratosphere from April to October and have a westward tilt with heightAt around 40°N and 20°N in the NH summer and 20°S in the NH winter and autumn, the GW peaks coincide with topographic peaks

The Global UltraViolet Imager (GUVI) onboard the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite provides a data set of vertical thermospheric composition (O, N2, and O2densities) and temperature profiles from 2002–2007. Even though GUVI sampling is limited by orbital constraint, we demonstrated that the GUVI data set can be used to derive the altitude profiles of the amplitudes and phases of annual oscillation (AO) and semiannual oscillation (SAO), thereby providing important constraints on models seeking to explain these features. We performed a seasonal and interannual analysis of GUVI limb O, O2, and N2densities and volume number density ratio O/N2at constant pressure levels. These daytime observations of O and O/N2in the lower thermosphere show a strong AO at midlatitudes and a clear SAO at lower latitudes. The global mean GUVI O/N2number density ratio shows the AO, with slightly larger values in January than in July and a SAO with O/N2greater during equinoxes than at the solstices. O and N2densities on fixed pressure levels in the upper thermosphere are anticorrelated with solar extreme ultraviolet flux. On the other hand, O/N2is smaller during solar minimum and larger during solar maximum. The thermospheric AO and SAO in composition have a constant phase with altitude throughout the thermosphere. The global mean GUVI O/N2shows both an annual variation and a semiannual variation with O/N2greater during equinoxes than at the solsticesO and N2densities on fixed pressure levels in the upper thermosphere are anticorrelated with solar EUV flux, but O/N2positively correlates with solar cycleGUVI reveals that phases of AO and SAO in thermospheric O and N2densities at different heights are consistent

A mesospheric bore event was observed in the airglow layers of both OH and OI (557.7 nm) bands by two all‐sky airglow imagers in Lhasa (29.66°N, 90.98°E) on the Tibetan Plateau and the Day Night Band (DNB) of the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar‐orbiting Partnership (NPP) satellite on the night of 16–17 December 2014. Simultaneous temperature and OH intensity observations from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument onboard the TIMED satellite and wind measurement by a Doppler meteor radar were used to characterize the environment of the bore propagation. A large mesospheric inversion layer was identified from the temperature measured by the SABER instrument. The observed winds in the height range of the OH layer were almost orthogonal to the propagation direction of the mesospheric bore. Both hydraulic jump theory and observations showed that the duct initially shrank followed by an expansion. The duct mainly existed in the OH layer but was weak in the OI layer, as revealed by the double‐layer imaging and satellite observations. The horizontal wavelengths and observed phase speeds of the bore packet decreased as the duct shrank and increased as the duct expanded. The intensity amplitude of the bore packet decreased slowly and then decreased sharply after dissipation. With the variation of the depth of the duct, the bore may have leak out of the duct. The presented study advances the understanding of mesospheric bore evolution and how the ducted environment influences the propagation of the bore. The evolution process of both mesospheric bore and duct layer are shown based on observations over the Tibetan PlateauThe duct depth variations estimated from hydraulic jump theory were consistent well with the observationsThe duct layer and bore were mainly in the OH layer as revealed from double‐layer imaging and satellite observations

The Hunga Tonga Hunga‐Ha'apai (HTHH) volcanic eruption on 15 January 2022 injected water vapor and SO2into the stratosphere. Several months after the eruption, significantly stronger westerlies, and a weaker Brewer‐Dobson circulation developed in the stratosphere of the Southern Hemisphere and were accompanied by unprecedented temperature anomalies in the stratosphere and mesosphere. In August 2022, the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) satellite instrument observed record‐breaking temperature anomalies in the stratosphere and mesosphere that alternate signs with altitude. Ensemble simulations carried out with the Whole Atmosphere Community Climate Model (WACCM6) indicate that the strengthening of the stratospheric westerlies explains the mesospheric temperature changes. The stronger westerlies cause stronger westward gravity wave drag in the mesosphere. Although the enhanced gravity wave drag is partly balanced by a weakening of planetary wave forcing, the net result is an acceleration of the mesospheric mean meridional circulation. The stronger mesospheric circulation, in turn, plays a dominant role in driving the changes in mesospheric temperatures. This study highlights the impact of large volcanic eruptions on middle atmospheric dynamics and provides insight into their long‐term effects in the mesosphere. On the other hand, we could not discern a clear mechanism for the observed changes in stratospheric circulation. In fact, an examination of the WACCM ensemble reveals that not every member reproduces the large changes observed by SABER. We conclude that there is a stochastic component to the stratospheric response to the HTHH eruption. This work studies the impact of the Hunga Tonga‐Hunga Ha'apai volcanic eruption, which took place on 15 January 2022, on the earth's mesosphere (55–80 km). The eruption injected water vapor and SO2into the stratosphere, which was followed by changes in the wind patterns in the stratosphere (16–55 km). Concurrent with these changes, we observed unprecedented temperature changes in the mesosphere, with record high and low temperature anomalies in August that alternate signs with altitude. We used climate model simulations to show that the changes in stratospheric winds were ultimately responsible for these record‐breaking mesospheric temperatures. We found that the stronger winds in the stratosphere enhanced gravity wave breaking in the mesosphere, which led to changes in the circulation and thus the temperature. However, we could not find a clear mechanism for the changes observed in the stratosphere. Sounding of the Atmosphere using Broadband Emission Radiometry observed unprecedented mesospheric temperature variations in the Southern Hemisphere in August 2022 after the Hunga Tonga Hunga‐Ha'apai eruptionWhole Atmosphere Community Climate Model simulations indicate that changes in the mesospheric temperature are due to a stronger mesospheric meridional circulationStronger stratospheric westerlies after eruption enhance westward gravity wave drag in the mesosphere, thus a stronger circulation Sounding of the Atmosphere using Broadband Emission Radiometry observed unprecedented mesospheric temperature variations in the Southern Hemisphere in August 2022 after the Hunga Tonga Hunga‐Ha'apai eruption Whole Atmosphere Community Climate Model simulations indicate that changes in the mesospheric temperature are due to a stronger mesospheric meridional circulation Stronger stratospheric westerlies after eruption enhance westward gravity wave drag in the mesosphere, thus a stronger circulation

As a companion study of the Part 1 (J. C. Wang et al., 2022, https://doi.org/10.1029/2022JA030948), the impact of the lower‐thermospheric circulation on atomic oxygen (O) in the mesosphere and lower thermosphere (MLT) region is investigated in this Part 2 using Specified Dynamics Configuration Runs of the Whole Atmosphere Community Climate Model eXtended (SD‐WACCMX) output. The asymmetry of the O profile in the summer and winter MLT region is mainly driven by local vertical advection, which is associated with the lower‐thermospheric winter‐to‐summer circulation and middle‐to‐upper thermospheric summer‐to‐winter circulation. It is found that meridional transport and eddy diffusion only weakly modulate the O budget within this altitude range. The globally and annually averaged transport effect due to the vertical advection is quantitatively estimated. It is shown that the vertical advection is the dominant mechanism in redistributing O at altitudes between 84 and 103 km, suggesting the vertical wind can efficiently transport O between its source and sink region within the vertical column. This study demonstrates that whole atmosphere coupling on seasonal time scales is a complex interaction involving multiple underlying mechanisms within the space‐atmosphere interaction region. Vertical advection is the dominant mechanism acting to transport O in the mesosphere and lower thermosphere (MLT)A Hemispheric asymmetry in MLT O number density is driven by local vertical advectionInterhemispheric mass transport and eddy diffusion only play a minor role in controlling O at higher latitudes in the MLT Vertical advection is the dominant mechanism acting to transport O in the mesosphere and lower thermosphere (MLT) A Hemispheric asymmetry in MLT O number density is driven by local vertical advection Interhemispheric mass transport and eddy diffusion only play a minor role in controlling O at higher latitudes in the MLT

In this article, we consider a three species Lotka–Volterra food web reaction–diffusion model with cycle, in which the intensity of the rate of preying on species 1 by species 2, the rate of preying on species 2 by species 3 and the rate of preying on species 3 by species 1 are in general asymmetrical. By suitably choosing cross diffusion coefficients as the bifurcation parameter, a spatially inhomogeneous Hopf bifurcation at a positive constant steady state is proved to occur for a sequence of critical values of the bifurcation parameter. In addition, we demonstrate that these spatially inhomogeneous bifurcating periodic solutions are stable when diffusion coefficients are located in suitable ranges. Our results show that cross diffusion plays a key role in the formation of spatially inhomogeneous periodic oscillatory patterns. • A three species Lotka–Volterra food web reaction–diffusion model with cycle is established. • The Existence of spatially inhomogeneous Hopf bifurcation near the positive steady state solution is studied. • The stability of spatially inhomogeneous bifurcating periodic solutions is studied. • The findings show that the spatially inhomogeneous Hopf bifurcation can be triggered by the effect of cross diffusion factors. [ABSTRACT FROM AUTHOR]

This work uses Sounding of the Atmosphere using Broadband Emission Radiometry CO2data from 2002 to 2015 and Specified Dynamics‐Whole Atmosphere Community Climate Model (SD‐WACCM) outputs from 1979 to 2014 to show, for the first time, the solar cycle response of CO2in the Austral winter mesosphere and lower thermosphere region. Both Sounding of the Atmosphere using Broadband Emission Radiometry and SD‐WACCM show that CO2experiences a decrease during solar maximum throughout the Austral winter mesosphere and lower thermosphere region. This work highlights the regions where CO2experiences its strongest and weakest solar cycle responses as modeled by SD‐WACCM. The region with the strongest solar cycle response experiences around 5% reduction in CO2between solar maximum and solar minimum. The region with weakest solar cycle response experiences less than 1% reduction in CO2between solar maximum and solar minimum. It is shown that the region of the strongest CO2response is driven by photodissociation, downwelling, and reduced eddy diffusion. On the other hand, the region of the weakest CO2response is driven by the opposing effects of photodissociation and enhanced eddy diffusion. This is the first work to show that the solar cycle could affect the Austral winter lower thermosphere circulation and eddy diffusion processes. These anomalies in the lower thermospheric circulation and eddy diffusion are found to be related to the solar cycle response in the Austral winter mesosphere wave‐mean flow dynamics. This work therefore concludes that the solar cycle affects lower thermospheric CO2via modulations of the lower thermospheric circulation and eddy diffusion processes. Response of CO2in the Austral winter MLT to the 11‐year solar cycle is presentedSolar cycle response of CO2in the Austral winter MLT is driven by photochemistry and transportThe residual circulation and eddy diffusion in the Austral winter lower thermosphere respond to the 11‐year solar cycle

The Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on board the TIMED satellite has been continuously operating for more than 16 years, since 2002, monitoring the CO2concentration on nearly a global scale in the middle and upper atmosphere (from 65 km up to 110 km). A recent reanalysis (Qian et al., 2017, https://doi.org/10.1002/2016JA023825) concluded that different deseasonalizing methodologies may have a strong impact on long‐term trend analysis, ultimately yielding different altitude profiles of the global mean CO2trend. In this work, we aim to understand how the nonuniform spatial and temporal sampling inherent in the SABER CO2data set affects the determination of the long‐term trends. In addition, our goal is to disentangle reported differences in SABER CO2trends due to different time averaging windows and methodologies used for trend estimation. The Whole Atmosphere Community Climate Model is used for synthetic studies of the time series. We demonstrate that, due to the time varying data gaps and nonuniform sampling of local times, different time binning of the SABER CO2data may indeed bias the long‐term trend estimation. We show and discuss how the 60‐day averaging reduces the bias in relative trends. We also conclude that different deseasonalizing methodologies (averaged over the same temporal bins) yield negligible differences on the trend determination. Taking this into account the global mean CO2relative trend does not deviate statistically from the tropospheric value below 1 × 10−3mb (90 km). Above about 90 km, there is a positive slope in the global CO2trend profile, but with substantially reduced magnitude for 60‐day binned data. The Level2C SABER daytime CO2data set has a nonuniform spatial and temporal sampling, and also shows strong local time variationA forward modeling study using SD‐WACCM outputs shows that time averaging data into 60‐day bins partially compensates for this effectThe reanalysis of the SABER CO2yields a nearly constant up to 90 km, however reaching 8% per decade at 105 km

The first‐principles three‐dimensional ionosphere model Naval Research Laboratory SAMI3/ESF is used to study the low‐latitude nighttime medium‐scale traveling ionospheric disturbances (MSTIDs) triggered by the typhoon‐induced concentric gravity waves (CGWs) for the first time. Simulation results demonstrate that the electrodynamic coupling between CGWs and Perkins instability can initiate the rarely observed low‐latitude nighttime MSTIDs by accelerating their growth rates. Both the simulations and observations show that the westward and westward/equatorward propagating CGWs with similar wavefront alignments to the Perkins instability could enhance the generation of MSTIDs rather than the northward propagating CGWs. The CGWs penetrating to the ionospheric Flayer without severe dissipation can induce greater polarization electric fields to accelerate the Perkins instability via E× Bdrifts. Nighttime medium‐scale traveling ionospheric disturbances (MSTIDs) are electrodynamical structures, which are primarily observed in the midlatitude ionosphere over the Asian, European, and American regions. These structures have typical wavelengths of a few hundred kilometers and propagate westward and equatorward with a unique frontal alignment along northwest‐southeast and northeast‐southwest in the Northern and Southern Hemispheres, respectively. Recently, low‐latitude nighttime MSTIDs were observed over the Taiwan Strait when Super Typhoon Nepartak swept toward Taiwan on 7 July 2016. It is suggested that the typhoon‐induced concentric gravity waves (CGWs) could play an important role to seed the low‐latitude MSTIDs. To confirm this hypothesis, we used a SAMI3/ESF ionosphere model to identify the interconnection between CGWs and MSTIDs. Simulations demonstrate that the CGWs can modulate the ionospheric electrodynamics and electron density distribution through wind perturbation, leading to the generation of low‐latitude nighttime MSTIDs. CGWs propagating upward into the ionosphere without severe dissipation could efficiently initiate the MSTIDs. The study confirms the impact of CGWs on the nighttime equatorial ionosphere, providing important implications for the electrodynamic coupling between the meteorological events and ionospheric instabilities. Numerical modeling shows the initiation of low‐latitude nighttime MSTIDs by typhoon‐induced concentric gravity wavesElectrodynamical coupling of Perkins instability and CGW‐induced electric fields drives the low‐latitude nighttime MSTIDsThe westward/southwestward propagating CGWs penetrating to the ionospheric Flayer initiate the MSTIDs most efficiently

SpaceX launched its Falcon Heavy demonstration mission at 20:45 UT on 6 February 2018 at NASA Kennedy Space Center in Florida. Short‐period northward propagating traveling ionospheric disturbances (TIDs) were observed following the shock waves in the ionospheric total electron content over East Florida‐Atlantic region. These TIDs have the periods of ~6–8 min, amplitude of ~0.05 total electron content unit, horizontal phase velocities of ~420–488 m/s, and horizontal wavelengths of ~164–240 km. They lasted for ~100 min and propagated a long distance of about 1,450 km, exhibiting a nearly coherent wave pattern and near‐constant phase velocity. The theoretical dispersion relation suggests that the short‐period TIDs were likely associated with the ducted gravity waves which became evanescent at altitudes around 170 km. Additional simulations were conducted in the Naval Research Laboratory SAMI3/ESF model using analytical expressions to approximate these gravity waves. Simulations reveal that modulations of the ionospheric electric fields through gravity wave wind dynamo perturbation can lead to weak ionospheric disturbances as observed. SpaceX launched its Falcon Heavy demonstration mission at 20:45 UT on 6 February 2018 at NASA Kennedy Space Center in Florida. The most powerful operational rocket consists of three Falcon‐9 nine‐engine cores in the first stage, however, produced relative weak traveling ionosphere disturbances in comparison with other Falcon‐9 launches. The weak traveling ionospheric disturbances had the short period but could travel a long distance of ~1,450 km (from off coast Florida to Lake Ontario). These characteristics suggest that the rocket induced atmospheric gravity waves that were guided along the lower thermosphere ~115–170 km altitude. The guided gravity waves may not affect the ionospheric plasma directly, but on the other hand, created electrodynamic perturbations in the ionosphere. Numerical simulations confirm that the electrodynamic perturbations could transmit to the upper part of ionosphere or even the opposite hemisphere. The powerful Falcon‐Heavy rocket induced surprisingly weak traveling ionospheric disturbances compared to previous Falcon‐9 rocket launchesThe short‐period and long‐distance propagating TIDs likely originate from the ducted gravity waves in the lower thermosphereNumerical simulations suggest that the ducted gravity waves induce the TIDs through electrodynamic coupling

Long-read sequencing technologies have become increasingly popular due to their strengths in resolving complex genomic regions. As a leading model organism with small genome size and great biotechnological importance, the budding yeast Saccharomyces cerevisiae has many isolates currently being sequenced with long reads. However, analyzing long-read sequencing data to produce high-quality genome assembly and annotation remains challenging. Here, we present a modular computational framework named long-read sequencing data analysis for yeasts (LRSDAY), the first one-stop solution that streamlines this process. Starting from the raw sequencing reads, LRSDAY can produce chromosome-level genome assembly and comprehensive genome annotation in a highly automated manner with minimal manual intervention, which is not possible using any alternative tool available to date. The annotated genomic features include centromeres, protein-coding genes, tRNAs, transposable elements (TEs), and telomere-associated elements. Although tailored for S. cerevisiae, we designed LRSDAY to be highly modular and customizable, making it adaptable to virtually any eukaryotic organism. When applying LRSDAY to an S. cerevisiae strain, it takes ∼41 h to generate a complete and well-annotated genome from ∼100× Pacific Biosciences (PacBio) running the basic workflow with four threads. Basic experience working within the Linux command-line environment is recommended for carrying out the analysis using LRSDAY.

The altitude‐ and latitude‐dependent responses of neutral temperature in the lower thermosphere to the 2013 St. Patrick's Day geomagnetic storm have been studied using neutral temperature measurements from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument onboard the TIMED satellite and the Solar Occultation For Ice Experiment (SOFIE) instrument onboard the AIM satellite. Both SABER and SOFIE observations revealed that both temperature increase (having peaks of ~15–25 K) and decrease (having peak of ~15 K), which were associated with the storm, occurred in the two hemispheres. The magnitudes of temperature variations changed with latitude, altitude, and the phase of the storm. The peaks of the temperature increase occurred 0.5–1.5 days later than the peak of the AE index, depending on latitude and height. Global circulation changes initiated due to heating and ion drag in the auroral region are likely responsible for the temperature increases or decreases in the lower thermosphere. Geomagnetic storms play important roles in changing the lower thermospheric state through the storm time changes of global wind circulation and the associated heat transfer. There were both either warming or cooling of the temperature in the lower thermosphere responding to storms. Using the neutral temperature measurements from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument onboard the TIMED satellite and the Solar Occultation For Ice Experiment (SOFIE) instrument onboard the AIM satellite, we show that both temperature increase and decrease occurred in two hemispheres and are related to the phase of the storm. Global circulation changes initiated by heating and ion drag in the auroral region are likely responsible for the temperature increases or decreases in the lower thermosphere. Temperatures measured by SABER and SOFIE in the lower thermosphere have prominent responses to the 2013 St. Patrick's Day geomagnetic stormBoth temperature increase and decrease are seen during the storm and extended downward below 100 km over a wide range of latitudeThe peak of temperature change varied with latitudes and occurred about 0.5–1.5 days after the storm main phase, depending on height

Large-scale population genomic surveys are essential to explore the phenotypic diversity of natural populations. Here we report the whole-genome sequencing and phenotyping of 1,011 Saccharomyces cerevisiaeisolates, which together provide an accurate evolutionary picture of the genomic variants that shape the species-wide phenotypic landscape of this yeast. Genomic analyses support a single ‘out-of-China’ origin for this species, followed by several independent domestication events. Although domesticated isolates exhibit high variation in ploidy, aneuploidy and genome content, genome evolution in wild isolates is mainly driven by the accumulation of single nucleotide polymorphisms. A common feature is the extensive loss of heterozygosity, which represents an essential source of inter-individual variation in this mainly asexual species. Most of the single nucleotide polymorphisms, including experimentally identified functional polymorphisms, are present at very low frequencies. The largest numbers of variants identified by genome-wide association are copy-number changes, which have a greater phenotypic effect than do single nucleotide polymorphisms. This resource will guide future population genomics and genotype–phenotype studies in this classic model system.

Polar mesospheric clouds (PMC), or noctilucent clouds, can be observed over high latitudes with the naked eye from the ground or from space near the summer solstice. PMC are considered a direct and sensitive indicator of climate change and have been reported to appear more frequently in recent decades. How PMC will change in the future under the influence of natural variability and anthropogenic forcing is uncertain. In this study, we utilize model output from the Whole Atmosphere Community Climate Model under several shared socioeconomic pathway (SSP) scenarios and input the water vapor, temperature, and pressure information into a 0‐d PMC model to project the trend and variation of PMC over the 21st century, and their relationship to future changes of temperature, water vapor, and the solar cycle. The 0‐d model calculations indicate that PMC ice water content (IWC) will increase and PMC will extend to lower latitudes under high SSP scenarios. Under these scenarios, more mesospheric water vapor leads to an increased IWC of PMC over the polar region, and colder mesopause temperature leads to more PMC over the mid‐latitudes. There is a significant anti‐correlation between the solar cycle and PMC IWC over the 21st century, but the anti‐correlation is not always significant on the decadal scale. Finally, methane oxidation in the stratosphere and water vapor entering from the troposphere are both responsible for future changes in mesospheric water vapor and thus PMC. Polar mesospheric clouds (PMC), also known as noctilucent clouds, are a direct and sensitive indicator of climate change and have been reported to appear more frequently in recent decades. Our numerical model projection of future changes in PMC indicates a possible increase in their ice water content (IWC) with higher future greenhouse gas emissions and a decrease with lower greenhouse gas emissions. The IWC of the PMC can be influenced by the solar cycle, mesospheric water vapor, and temperature. With more greenhouse gas emissions and global surface warming, more water vapor will enter the middle atmosphere or form via the oxidation of methane, thus increasing PMC IWC over the polar region. The associated middle atmospheric cooling increases the IWC of PMC over the mid‐latitudes, and PMC can extend to lower latitudes where PMC have not been commonly seen before. Future projections of Polar mesospheric clouds (PMC) for high greenhouse gas emission scenarios indicate an increasing ice water content (IWC) over the 21st centuryThe variation of PMC is mainly determined by mesospheric water vapor over polar region and by mesospheric temperature over mid‐latitudesOver the 21st century, PMC IWC anti‐correlates with the solar cycle. The correlation is not always significant on a decadal time scale Future projections of Polar mesospheric clouds (PMC) for high greenhouse gas emission scenarios indicate an increasing ice water content (IWC) over the 21st century The variation of PMC is mainly determined by mesospheric water vapor over polar region and by mesospheric temperature over mid‐latitudes Over the 21st century, PMC IWC anti‐correlates with the solar cycle. The correlation is not always significant on a decadal time scale

The satellite‐based Cloud Imaging and Particle Size (CIPS) instrument and Atmospheric Infrared Sounder (AIRS) observed concentric gravity waves (GWs) generated by Typhoon Yutu in late October 2018. This work compares CIPS and AIRS nadir viewing observations of GWs at altitudes of 50–55 and 30–40 km, respectively, to simulations from the high‐resolution European Centre for Medium‐Range Weather Forecasting Integrated Forecasting System (ECMWF‐IFS) and ECMWF reanalysis v5 (ERA5). Both ECMWF‐IFS with 9 km and ERA5 with 31 km horizontal resolution show concentric GWs at similar locations and timing as the AIRS and CIPS observations. The GW wavelengths are ∼225–236 km in ECMWF‐IFS simulations, which compares well with the wavelength inferred from the observations. After validation of ECMWF GWs, five category five typhoon events during 2018 are analyzed using ECMWF to obtain characteristics of concentric GWs in the Western Pacific regions. The amplitudes of GWs in the stratosphere are not strongly correlated with the strength of typhoons, but are controlled by background wind conditions. Our results confirm that amplitudes and shapes of concentric GWs observed in the stratosphere and lowermost mesosphere are heavily influenced by the background wind conditions. Atmospheric gravity waves (GWs) have an important role in coupling the different atmospheric layers. One of the main sources of GWs is convection such as typhoons. In the stratosphere, these GWs frequently appear as concentric (or ring‐shaped) patterns in nadir‐viewing satellite measurements. In this work, data from two such nadir viewing satellite instruments, the Cloud Imaging and Particle Size (CIPS) instrument and Atmospheric Infrared Sounder (AIRS), are analyzed to study the GWs generated by Typhoon Yutu, which occurred in late October 2018. CIPS and AIRS observe at altitudes of 50–55 and 30–40 km, respectively, providing us a unique opportunity to study concentric GWs at two different altitudes. The satellite observations are then used to validate the GW‐resolving high‐resolution European Centre for Medium‐Range Weather Forecasting (ECMWF) model. Utilizing ECMWF simulations, four more typhoon events were analyzed. The results indicate that the amplitudes of concentric GWs in the stratosphere are not correlated with the strength of typhoons. However, the amplitudes and shapes of concentric GWs observed in the stratosphere and lower mesosphere are found to be influenced by the background wind conditions. This work provides an understanding of the relative importance of GW source strength and background wind conditions. Cloud Imaging and Particle Size (CIPS) and Atmospheric Infrared Sounder (AIRS) measurements of concentric gravity waves (GWs) generated by Typhoon Yutu are used to verify European Centre for Medium‐Range Weather Forecasting (ECMWF) GWs in the altitude range of 30–55 kmAnalysis of GW observations from CIPS and AIRS as well as ECMWF data provides detailed characteristics of concentric GWsDifferences in GW amplitudes among five typhoon cases grow as GWs propagate upward, indicating the importance of background winds Cloud Imaging and Particle Size (CIPS) and Atmospheric Infrared Sounder (AIRS) measurements of concentric gravity waves (GWs) generated by Typhoon Yutu are used to verify European Centre for Medium‐Range Weather Forecasting (ECMWF) GWs in the altitude range of 30–55 km Analysis of GW observations from CIPS and AIRS as well as ECMWF data provides detailed characteristics of concentric GWs Differences in GW amplitudes among five typhoon cases grow as GWs propagate upward, indicating the importance of background winds

A microbial ecosystem is a complex community of multiple bacterial interactions. The potential role of gut microbiota in human health has already attracted the attention of many researchers. Dysregulation of the gut microbial community has been suggested to be closely associated with the progression of various chronic diseases. Malignant neoplasms represent a major global health burden and are now the leading cause of death. The formation of tumors is often thought to be influenced by genetic and environmental factors. Recent research advances have indicated that multiple malignancies may also be attributed to the gut microbiota. In this review, we highlight the complex interactions between gut microbes and their metabolites, as well as the potential impact of gut microecology on the occurrence and development of tumors. In addition, potential strategies for targeted therapy of tumors using gut microecology are discussed. In the near future, intestinal microecology is likely to be used for early screening of tumors and subsequent clinical treatment.

Numerical studies have shown that there is a lower thermospheric winter‐to‐summer circulation that is driven by wave dissipation and that it plays a significant role in trace gas distributions in the mesosphere and lower thermosphere, and in the composition of the thermosphere. However, the characteristics of this circulation are poorly known. Direct observations of it are difficult, but it leaves clear signatures in tracer distributions. The Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) onboard the Thermosphere Ionosphere Mesosphere Energetics and Dynamics satellite has obtained CO2concentration from 2002 to present. This data set, combined with simulations by the Whole Atmosphere Community Climate Model, provides an unprecedented opportunity to infer the morphology of this circulation in both the summer and winter hemispheres. Our study show that there exists a maximum vertical gradient of CO2at summer high latitudes, driven by the convergence of the upwelling of the mesospheric circulation and the downwelling of the lower thermospheric circulation; in the winter hemisphere, the maximum vertical gradient of CO2is located at a higher altitude, driven by the convergence of the upwelling of the lower thermospheric circulation and the downwelling of the solar‐driven thermospheric circulation; the bottom of the lower thermospheric circulation is located between ~ 95 km and 100 km, and it has a vertical extent of ~10 km. Analysis of the SABER CO2and temperature at summer high latitudes showed that the bottom of this circulation is consistently higher than the mesopause height by ~10 km. The mean meridional circulation in the lower thermosphere is difficult to observe but can be derived from trace species distributionMaximum vertical gradient of CO2at summer high latitudes shows vertical wind convergence of mesosphere and lower thermosphere circulationsMaximum vertical gradient of CO2at winter high latitudes reflects vertical wind convergence of the two thermospheric circulations

We report the first observation of concentric traveling ionospheric disturbances (CTIDs) triggered by the launch of a SpaceX Falcon 9 rocket on 17 January 2016. The rocket‐triggered ionospheric disturbances show shock acoustic wave signature in the time rate change (time derivative) of total electron content (TEC), followed by CTIDs in the 8–15 min band‐pass filtering of TEC. The CTIDs propagated northward with phase velocity of 241–617 m/s and reached distances more than 1000 km away from the source on the rocket trajectory. The wave characteristics of CTIDs with periods of 10.5–12.7 min and wavelength ~ 200–400 km agree well with the gravity wave dispersion relation. The optimal wave source searching and gravity wave ray tracing technique suggested that the CTIDs have multiple sources which are originated from ~38–120 km altitude before and after the ignition of the second‐stage rocket, ~200 s after the rocket was launched. First observation of concentric traveling ionospheric disturbances triggered by CGWs associated with a SpaceX Falcon 9 rocket launchThe horizontal velocities, wavelengths, and periods of CTIDs agree with the gravity wave dispersion relationThe reverse ray tracing shows that multiple concentric waves were most likely generated around and above the mesosphere region We observed circular ripples in the space plasma 125 mile height above Earth during the SpaceX rocket launch. These ripple disturbances are indicators of the atmospheric gravity waves that are important to altering the winds in the upper atmosphere. The rocket launches could be another anthropogenic source of upper atmosphere disturbances if space travels become widely available.

Two remarkable typhoon‐induced traveling ionospheric disturbances (TIDs) with concentric and northwest‐southeast (NW‐SE) alignments, respectively, associated with concentric gravity waves (CGWs) and ionosphere instabilities possibly seeded by CGWs, were observed in total electron content (TEC) derived from ground‐based Global Navigation Satellite System networks in Taiwan and Japan when the Category 5 Super Typhoon Nepartak approached Taiwan on 7 July 2016. The concentric TIDs (CTIDs) first appear with horizontal phase velocities of ~161–200 m/s, horizontal wavelengths of ~160–270 km, and periods of ~15–22 min during 08:00–11:20 UT. Following the CTIDs, the NW‐SE aligned nighttime medium‐scale TIDs (MSTIDs) are formed on the west edge of the CTIDs over the Taiwan Strait during 11:30–14:00 UT. It is suggested that the MSTIDs are produced by the electrodynamical coupling of Perkins instability and CGW‐induced polarization electric fields. This study proposes connections of typhoon‐induced CTIDs and subsequently occurring MSTIDs in the low‐latitude ionosphere. Concentric and medium‐scale traveling ionosphere disturbances excited by Super Typhoon Nepartak (2016) are observed in GNSS TECNighttime MSTIDs with NW‐SE alignment of wavefronts occurred on the west edge of CTIDsElectrodynamical coupling of Perkins instability and CGWs‐induced electric fields could explain the typhoon‐induced nighttime MSTID

Using the thermosphere‐ionosphere‐mesosphere electrodynamics general circulation model simulations, we investigate the short‐term ionospheric variability due to the child waves and altered tides produced by the nonlinear interaction between the 6 day wave and migrating tides. Via the Fourier spectral diagnostics and least squares fittings, the [21 h, W2] and [13 h, W1] child waves, generated by the interaction of the 6 day wave with the DW1 and SW2, respectively, are found to play the leading roles on the subdiurnal variability (e.g., ±10 m/s in the ion drift and ~50% in the NmF2) in the Fregion vertical ion drift changes through the dynamo modulation induced by the low‐latitude zonal wind and the meridional wind at higher latitudes. The relatively minor contribution of the [11 h, W3] child wave is explicit as well. Although the [29 h, W0] child wave has the largest magnitude in the Eregion, its effect is totally absent in the vertical ion drift due to the zonally uniform structure. But the [29 h, W0] child wave shows up in the NmF2.It is found that the NmF2short‐term variability is attributed to the wave modulations on both Eregion dynamo and in situ Fregion composition. Also, the altered migrating tides due to the interaction will not contribute to the ionospheric changes significantly. The 6 day wave interacts significantly in the mesosphere, generating the child waves, which leads to the ionospheric subdiurnal variabilityThe child waves impact the ionospheric vertical ion drifts via modulating the Eregion dynamo induced by zonal and meridional windsThe child waves impact the NmF2via the modulations on both the Eregion dynamo and in situ Fregion composition

The global gravity wave (GW) potential energy (PE) per unit mass is derived from SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) temperature profiles over the past 14 years (2002–2015). Since the SABER data cover longer than one solar cycle, multivariate linear regression is applied to calculate the trend (means linear trend from 2002 to 2015) of global GW PE and the responses of global GW PE to solar activity, to QBO (quasi‐biennial oscillation) and to ENSO (El Niño–Southern Oscillation). We find a significant positive trend of GW PE at around 50°N during July from 2002 to 2015, in agreement with ground‐based radar observations at a similar latitude but from 1990 to 2010. Both the monthly and the deseasonalized trends of GW PE are significant near 50°S. Specifically, the deseasonalized trend of GW PE has a positive peak of 12–15% per decade at 40°S–50°S and below 60 km, which suggests that eddy diffusion is increasing in some places. A significant positive trend of GW PE near 50°S could be due to the strengthening of the polar stratospheric jets, as documented from Modern Era Retrospective‐analysis for Research and Applications wind data. The response of GW PE to solar activity is negative in the lower and middle latitudes. The response of GW PE to QBO (as indicated by 30 hPa zonal winds over the equator) is negative in the tropical upper stratosphere and extends to higher latitudes at higher altitudes. The response of GW PE to ENSO (as indicated by the Multivariate ENSO Index) is positive in the tropical upper stratosphere. Gravity waves (GWs) are disturbances of the atmosphere with horizontal wavelengths of several kilometers to several thousand kilometers. GWs can be generated by many sources, e.g., wind jets, deep convection, and flow over topography. The global GW potential energy (PE) per unit mass is derived from SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) temperature profiles over the past 14 years (2002–2015). We find a significant positive trend of GW PE at around 50°N during July from 2002 to 2015. Both the monthly and the deseasonalized trends in of GW PE are significant near 50°S. Specifically, the deseasonalized trend of GW PE has a positive peak of 12–15% per decade at 40°S–50°S and below 60 km, which suggests that eddy diffusion is increasing in some places. The response of GW PE to solar activity is negative in the lower and middle latitudes. The response of GW PE to QBO (as indicated by 30 hPa zonal winds over the equator) is negative in the tropical upper stratosphere and extends to higher latitudes at higher altitudes. The response of GW PE to ENSO (as indicated by the MEI index) is positive in the tropical upper stratosphere. Linear trends of gravity wave (GW) potential energy (PE) from 2002 to 2015 are significant near 50°S and peak of 12–15% per decade in the height range of 40–60 kmThe increase in GW PE near 50°S could be due to a stronger polar stratospheric jet and tropopause jetThe response of GW PE to F10.7and QBO is negative and, to ENSO, it is positive

Structural rearrangements have long been recognized as an important source of genetic variation, with implications in phenotypic diversity and disease, yet their detailed evolutionary dynamics remain elusive. Here we use long-read sequencing to generate end-to-end genome assemblies for 12 strains representing major subpopulations of the partially domesticated yeast Saccharomyces cerevisiae and its wild relative Saccharomyces paradoxus. These population-level high-quality genomes with comprehensive annotation enable precise definition of chromosomal boundaries between cores and subtelomeres and a high-resolution view of evolutionary genome dynamics. In chromosomal cores, S. paradoxus shows faster accumulation of balanced rearrangements (inversions, reciprocal translocations and transpositions), whereas S. cerevisiae accumulates unbalanced rearrangements (novel insertions, deletions and duplications) more rapidly. In subtelomeres, both species show extensive interchromosomal reshuffling, with a higher tempo in S. cerevisiae. Such striking contrasts between wild and domesticated yeasts are likely to reflect the influence of human activities on structural genome evolution.

Gravity wave forcing near the mesopause drives a summer-to-winter residual circulation in the mesosphere and a reversed, lower thermospheric winter-to-summer residual circulation. We conducted modeling studies to investigate how this lower thermospheric residual circulation impacts thermospheric composition (O/N2). We found that the upwelling associated with the residual circulation significantly decreases O/N2in winter and the downwelling in summer slightly increases O/N2. Consequently, the residual circulation reduces the summer-to-winter latitudinal gradient of O/N2, which causes the simulated latitudinal gradient of O/N2to be more consistent with observations. The smaller summer-to-winter latitudinal gradient of O/N2would decrease the ionosphere winter anomaly in model simulations, which would bring the simulated winter anomaly into better agreement with ionospheric observations. The lower thermospheric residual circulation may be a process that has been largely ignored but is very important to the summer-to-winter latitudinal gradients, as well as annual/semiannual variations in the thermosphere and ionosphere. The lower thermospheric residual circulation reduces the summer-to-winter latitudinal gradient of thermospheric compositionConsequently, it reduces the ionosphere winter anomalyIt may be a process that has been largely ignored but is important to the summer-winter latitudinal gradient in the thermosphere/ionosphere

The quasi 2 day wave (QTDW) is a traveling planetary wave that can be enhanced rapidly to large amplitudes in the mesosphere and lower thermosphere (MLT) region during the northern winter postsolstice period. In this study, we present five case studies of QTDW events during January and February 2005, 2006 and 2008–2010 by using the Thermosphere‐Ionosphere‐Mesosphere Electrodynamics‐General Circulation Model (TIME‐GCM) nudged with the Navy Operational Global Atmospheric Prediction System‐Advanced Level Physics High Altitude (NOGAPS‐ALPHA) Weather Forecast Model. With NOGAPS‐ALPHA introducing more realistic lower atmospheric forcing in TIME‐GCM, the QTDW events have successfully been reproduced in the TIME‐GCM. The nudged TIME‐GCM simulations show good agreement in zonal mean state with the NOGAPS‐ALPHA 6 h reanalysis data and the horizontal wind model below the mesopause; however, it has large discrepancies in the tropics above the mesopause. The zonal mean zonal wind in the mesosphere has sharp vertical gradients in the nudged TIME‐GCM. The results suggest that the parameterized gravity wave forcing may need to be retuned in the assimilative TIME‐GCM. The quasi 2 day wave is well resolved by TIME‐GCM nudged with NOGAPS‐ALPHASignificant low‐latitude discrepancies between the nudged TIME‐GCM and NOGAPS‐ALPHA and the nudged TIME‐GCM and the horizontal wind modelThe low‐latitude discrepancies may be due to the different gravity wave parameterizations used in the TIME‐GCM and NOGAPS‐ALPHA

A recent 31 year simulation (1979–2010) by extended Canadian Middle Atmosphere Model (eCMAM30) and the 14 year (2002–2015) observation by the Thermosphere Ionosphere Mesosphere and Dynamics/Sounding of the Atmosphere using Broadband Emssion Radiometry (TIMED/SABER) are utilized to investigate the temperature response to the 11 year solar cycle on the mesosphere. Overall, the zonal mean responses tend to increase with height, and the amplitudes are on the order of 1–2 K/100 solar flux unit (1 sfu = 10−22W m−2Hz−1) below 80 km and 2–4 K/100 sfu in the mesopause region (80–100 km) from the eCMAM30, comparatively weaker than those from the SABER except in the midlatitude lower mesosphere. A pretty good consistence takes place at around 75–80 km with a response of ~1.5 K/100 sfu within 10°S/N. Also, a symmetric pattern of the responses about the equator agrees reasonably well between the two. It is noteworthy that the eCMAM30 displays an alternate structure with the upper stratospheric cooling and the lower mesospheric warming at midlatitudes of the winter hemisphere, in favor of the long‐term Rayleigh lidar observation reported by the previous studies. Through diagnosing multiple dynamical parameters, it is manifested that this localized feature is induced by the anomalous residual circulation as a consequence of the wave‐mean flow interaction during the solar maximum year. The extended CMAM reasonably reproduced the 11 year solar cycle effect on the temperature in the mesosphereThe simulated alternate structure in the temperature response at midlatitudes is in favor of the previous ground‐based observationThe alternate structure in temperature is attributed to the anomalous residual circulation generated by the wave‐mean flow interaction

In this study, the Thermosphere Ionosphere Electrodynamics Global Circulation Model and the extended Canadian Middle Atmosphere Model are utilized to investigate the seasonal variations of the upward propagation of the migrating terdiurnal tide from the mesosphere and lower thermosphere (MLT). Three main conclusions are drawn from a series of controlled simulations: (1) The background thermospheric zonal and meridional winds and neutral temperature can affect the upward propagation of the terdiurnal tide. (2) The background zonal winds can play an important role in the variation of the vertical advection and adiabatic cooling/heating, especially in the low thermosphere, and as a consequence, the upward propagation of the terdiurnal tide is modulated. (3) The terdiurnal tide in the MLT has influences not only on the latitudinal distributions and magnitudes of the terdiurnal tide in the upper thermosphere but also on the effect of the background winds on the upward propagation of the terdiurnal tide. The background thermospheric zonal and meridional winds and neutral temperature can affect the upward propagation of the terdiurnal tideThe background zonal winds modulate the vertical advection and adiabatic cooling/heating and further affect the tidal propagationThe latitudinal distribution of tide in the low atmosphere plays an important role in the tidal upward propagation in the upper thermosphere

Concentric traveling ionosphere disturbances (CTIDs) in total electron content triggered by Super Typhoon Meranti on 13 September 2016 are detected by using the ground‐based Global Navigation Satellite Systems network in Taiwan. The CTIDs emanated outward before the typhoon landfall and lasted for more than 10 h. The characteristics of CTIDs agree with the gravity wave theory and exhibit spatial and temporal scales in wave periods of ~8–30 min, horizontal wavelengths of ~160–200 km, and horizontal phase velocities of ~106–220 m/s. We also observe the CTIDs showing the stationary wave character. Broad spectra of CTIDs are excited after the rainbands of typhoon impinged on Central Mountain Range of Taiwan. The ray‐tracing technique confirms that the CTIDs were excited by convective clouds, spiral rainbands, and the eyewall of Typhoon Meranti. This study provides new evidence of typhoon‐induced concentric gravity waves in the ionosphere. Concentric traveling ionosphere disturbances (CTIDs) in total electron content (TEC) are observed during Super Typhoon Meranti (2016)The CTIDs agree with the gravity wave dispersion relation suggesting the upward propagation of typhoon‐induced gravity wavesComparison between CTIDs and meteorological radar refractivity reveals multiple sources of excited waves

It is well‐known that equatorial plasma bubbles (EPBs) are highly correlated to the post‐sunset rise of the ionosphere on a climatological basis. However, when proceeding to the daily EPB development, what controls the day‐to‐day/longitudinal variability of EPBs remains a puzzle. In this study, we investigate the underlying physics responsible for the day‐to‐day/longitudinal variability of EPBs using the Sami3 is A Model of the Ionosphere (SAMI3) and the Specified Dynamics Whole Atmosphere Community Climate Model with thermosphere‐ionosphere eXtension (SD‐WACCM‐X). Simulation results on October 20, 22, and 24, 2020 were presented. SAMI3/SD‐WACCM‐X self‐consistently generated midnight EPBs on October 20 and 24, displaying irregular and regular spatial distributions, respectively. However, EPBs are absent on October 22. We investigate the role of gravity waves on upwelling growth and EPB development and discuss how gravity waves contribute to the distributions of EPBs. We found the westward wind associated with solar terminator waves and gravity waves induces polarization electric fields that map to the equatorial ionosphere from higher latitudes, resulting in midnight vertical drift enhancement and retrograde plasma flow. The upward vertical drift and retrograde flow further lead to shear flow instability and midnight plasma vortex, creating background conditions identical to the post‐sunset ionosphere. This provides conditions favorable for the upwelling growth and EPB development. The converging and diverging winds associated with solar terminator waves and midnight temperature maximum also affect the longitudinal distribution of EPBs. The absence of EPBs on October 22 is related to the weak westward wind associated with solar terminator waves. Plasma bubbles are a particular space weather phenomenon mainly occurring in the nighttime equatorial region. After sunset, the ionosphere becomes unstable due to the upward motion of vertitical ion drift. Bubbles can develop from the bottomside ionospheric F layere and stretch into the topside ionosphere (above 500 km), like wax bubbles in a lava lamp. Bubbles significantly reduce the plasma density in the ionosphere, displaying turbulent plume structures that can disrupt radio wave communications and GPS navigation. Understanding and predicting the development of plasma bubbles has baffled scientists for more than 80 years, especially in understanding the day‐to‐day variability. In this study, we aim to understand what controls the day‐to‐day variability of plasma bubbles by using the physics‐based SAMI3/SD‐WACCM‐X model. We found that gravity waves are ubiquitous and play a vital role in seeding and determining the spacing between plasma bubbles. The longitudinal distribution of plasma bubbles is affected by meridional wind. The most striking finding is that daily dusk solar terminator waves significantly impact neutral wind and electrodynamics, controlling the presence or absence of plasma bubbles at midnight. This study reveals that the day‐to‐day variability of plasma bubbles is considerably linked to the variations in the lower atmosphere. The regular and irregular spatial distributions of equatorial plasma bubbles (EPBs) are determined by the zonal wavelength and wavefront orientation of gravity wavesSolar terminator/gravity waves contribute to midnight vertical drift enhancement and retrograde flow, creating midnight plasma vortexThe absence of midnight EPBs is related to weak westward winds associated with solar terminator/gravity waves The regular and irregular spatial distributions of equatorial plasma bubbles (EPBs) are determined by the zonal wavelength and wavefront orientation of gravity waves Solar terminator/gravity waves contribute to midnight vertical drift enhancement and retrograde flow, creating midnight plasma vortex The absence of midnight EPBs is related to weak westward winds associated with solar terminator/gravity waves