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Chang (2024, https://doi.org/10.1029/2024gl110011) challenged the methodology proposed recently by Okajima et al. for evaluating cyclonic and anticyclonic contributions to Eulerian eddy statistics and atmospheric energetics based on the local flow curvature. He argued that using the local wind curvature to separate energetic contributions from cyclones and anticyclones is not physically meaningful. Here we argue that his claims are based on an unrealistic assumption of monopolar relative vorticity in an entire storm‐track domain and a meridionally uniform zonal background flow atypical to midlatitudes. We also demonstrate that the error in attributing eddy statistics to cyclones and anticyclones is significantly smaller than his estimation. Rather, we further demonstrate that the curvature‐based methodology effectively eliminates the shear influence to identify cyclonic and anticyclonic regions, which is dismissed in his argument. We conclude that the curvature‐based methodology is beneficial in evaluating distinct cyclonic and anticyclonic contributions to atmospheric energetics in realistic conditions. Plain Language Summary: Chang (2024, https://doi.org/10.1029/2024gl110011) raised a question about the effectiveness of the recent method by Okajima et al. for evaluating cyclonic and anticyclonic contributions separately to eddy statistics based on the local flow curvature. He brings idealized cases to claim that the method by Okajima et al. is not physically meaningful. Here we show that Chang's arguments rely on an unrealistic assumption that an entire storm‐track region contains only one or two isolated cyclonic vorticity patches placed within horizontally uniform westerlies, which are atypical of midlatitudes. We also reveal that the error in attributing eddy statistics to cyclones and anticyclones is much smaller than Chang's result. The curvature‐based method effectively removes the influence of shear vorticity to determine cyclonic and anticyclonic regions, which is overlooked in his argument. We conclude that our curvature‐based method is useful for evaluating the separate contributions of cyclones and anticyclones to atmospheric energetics in realistic conditions in midlatitudes. Key Points: The error in attributing eddy statistics to cyclones and anticyclones is significantly smaller than that presented by Chang (2024, https://doi.org/10.1029/2024gl110011)The arguments of Chang (2024, https://doi.org/10.1029/2024gl110011) are based on the unrealistic assumptions of monopolar vorticity and an atypical background flowThe curvature‐based evaluation of cyclonic and anticyclonic contributions is a practical, beneficial method for realistic flow fields [ABSTRACT FROM AUTHOR]

Climate change is associated with the modification of the polar jet stream, cyclone tracks and corresponding circulation patterns over midlatitudes. To apply these synoptic changes on regional climate, the changing sensitivity of a specific location to different pressure centre regions must be studied. An automated, objective circulation pattern detection method was developed to investigate the evolution of cyclonic and anticyclonic influence at any specific point within the European domain. The algorithm was used to assign each location to influencing low‐ or high‐pressure centres within the domain. Pressure centre displacements and the frequency redistribution among different centres were studied for each location. The 180‐year (January 1836–December 2015) mean sea level pressure dataset on the European domain with a 0.703° × 0.702° spatial and daily temporal resolution was obtained from NOAA 20th Century Reanalysis project. The presented method can apply the continental‐scale changes to specific locations. A significant increase of anticyclonic influence was found in southern and central Europe, in line with the northward displacement of Atlantic cyclones. Hundred and eighty year (180‐year) change of the number of days with anticyclonic versus cyclonic influence was found to be between +10% and 15% in the Mediterranean and +2% and 10% in most of Europe. The increasing anticyclonic influence in central Europe was strongest in the spring and the winter and was most attributable to the eastern European anticyclone. Results highlight the importance of research on the dynamical climate response of anticyclonic pressure systems. [ABSTRACT FROM AUTHOR]

Interannual variability of summer monsoon depressions (MDs) over the Bay of Bengal (BoB) is investigated with special emphasis on developing and decaying El Niño phases during the period 1979–2020. Previous studies have overlooked the relationship between MDs frequency and El Niño phenomena, despite of their stronger association with Indian Summer Monsoon (ISM) rainfall. Our analysis revealed that the number of MDs has reduced remarkably by a factor of 2 during El Niño decay summers (more than half) as compared to climatology and in fact, no such decline is depicted in developing El Niño years. The strong easterlies extending from the southern flank of the Western North Pacific (WNP) anticyclone to the southern BoB cause negative low-level vorticity anomalies and reduce the Barotropic instability during El Niño decay summers. These conditions are unfavourable for the formation of MDs in the BoB. It is also noted that the Genesis Potential Parameter (GPP) for the MDs over the BoB and WNP region is weaker in the El Niño decay summers compared to developing El Niño and normal years. Moreover, during the El Niño decay summers less number of Tropical Cyclones (TCs) over WNP due to weak GPP, reduced the chances of westward propagating remnants of TCs from the Philippine Sea to the BoB, which is not favourable for the formation of MDs. Essentially, the reduction in the frequency of MDs would influence the seasonal rainfall distribution over the Indian subcontinent and largely impacts the regional agriculture activities and water management sector. Further, the Indo-western Pacific capacitor (IPOC) effect, which is strongly tied to decaying El Niño phase plays a critical role in altering the number of MDs by maintaining WNP anticyclone. Thus, predicting IPOC pattern during the decay phase of El Niño would provide useful insights on a number of MDs and ISM rainfall prediction. [ABSTRACT FROM AUTHOR]

Abstract Chang (2024, https://doi.org/10.1029/2024gl110011) challenged the methodology proposed recently by Okajima et al. for evaluating cyclonic and anticyclonic contributions to Eulerian eddy statistics and atmospheric energetics based on the local flow curvature. He argued that using the local wind curvature to separate energetic contributions from cyclones and anticyclones is not physically meaningful. Here we argue that his claims are based on an unrealistic assumption of monopolar relative vorticity in an entire storm‐track domain and a meridionally uniform zonal background flow atypical to midlatitudes. We also demonstrate that the error in attributing eddy statistics to cyclones and anticyclones is significantly smaller than his estimation. Rather, we further demonstrate that the curvature‐based methodology effectively eliminates the shear influence to identify cyclonic and anticyclonic regions, which is dismissed in his argument. We conclude that the curvature‐based methodology is beneficial in evaluating distinct cyclonic and anticyclonic contributions to atmospheric energetics in realistic conditions.

The Kuroshio‐Oyashio Extension and Gulf Stream oceanic frontal zones are characterized by enhanced activity of synoptic‐scale cyclones and anticyclones and vigorous air‐sea heat and moisture exchange in the cold season. However, the time‐mean air‐sea exchange attributed separately to cyclones and anticyclones has not been assessed. Here we quantify cyclonic and anticyclonic contributions around the frontal zones to surface turbulent heat fluxes, precipitation, and the associated hydrological cycle using atmospheric general circulation model experiments with observed and artificially smoothed sea‐surface temperature gradients. The evaluation reveals that precipitation exceeds evaporation climatologically within cyclonic domains while evaporation dominates within anticyclonic domains. These features as well as the net moisture transport from anticyclonic to cyclonic domains are all enhanced by the sharpness of the frontal zones. Oceanic frontal zones thus climatologically act to strengthen the hydrological cycle. These findings aid our understanding of the relationship between midlatitude air‐sea interactions on synoptic‐ and longer‐time scales. Plain Language Summary: Two regions with pronounced sea surface temperature gradients over the North Pacific and North Atlantic are known as major oceanic frontal zones that are important for air‐sea interactions with vigorous heat and moisture release from the ocean to the atmosphere. Recent studies found that day‐to‐day variations, due to migratory low‐ and high‐pressure systems, are essential for the time‐mean air‐sea interaction over these frontal zones. However, the relative importance of those low‐ and high‐pressure systems has not been quantified. Using atmospheric general circulation model experiments with observed and artificially smoothed sea‐surface temperature gradients, we show that contributions of high‐pressure systems are important for the enhanced heat and moisture supply from the ocean in response to realistic oceanic frontal zones, while contributions of low‐pressure systems are crucial for the changes in rainfall. We further demonstrate that the moisture transport from high‐ to low‐pressure systems is strengthened climatologically with the sharpness of midlatitude oceanic frontal zones, indicative of a strengthening of the hydrological cycle. Our findings indicate that synoptic‐scale migratory low‐ and high‐pressure systems play an important role in midlatitude air‐sea interactions. These results bridge the gap between our understanding of midlatitude air‐sea interactions from day‐to‐day to climatic time scales. Key Points: Cyclonic and anticyclonic contributions to air‐sea heat and moisture exchange are quantified around midlatitude oceanic frontal zonesOceanic frontal zones enhance surface turbulent heat fluxes within anticyclones and precipitation within cyclones, respectivelySharpness of midlatitude oceanic frontal zones strengthens the net moisture transport from anticyclones to cyclones [ABSTRACT FROM AUTHOR]

The discovery of smoke‐induced dynamical anomalies in the stratosphere associated with the 2019/2020 Australian New Year pyrocumulonimbus (pyroCb) super outbreak initiated a new field of study involving aerosol/weather anomalies. This paper documents the dynamical anomalies associated with the February 2009 Australian Black Saturday pyroCb outbreak. Positive potential vorticity anomalies (indicating anticyclonic rotation) with horizontal extent ∼1000 km and vertical thickness ∼2 km are associated with the plume, which we classify as a Smoke With Induced Rotation and Lofting (SWIRL). The SWIRL initially formed east of Australia, but then moved westward, crossing over Australia, and continuing to Africa. The SWIRL lasted for nearly three weeks (13 February–4 March), traveling ∼27,000 km and rising from potential temperatures of ∼410–500 K (altitudes ∼18–21 km). The altitude of the SWIRL is corroborated with coincident satellite‐based profiles of H2O, CO, HCN, O3, and aerosol extinction. A vertical temperature dipole (±3 K) accompanied the PV anomaly, as verified with coincident Global Navigation Satellite System radio occultation temperatures. The SWIRL dissipated as it passed over Africa. Operational ECMWF forecasts with early initialization (13 February) and late initialization (21 February) are examined. In the early case, the forecasted PV anomaly disappeared within 4 days, as expected due to lack of smoke heating in the forecast model. In the late case, while the forecasted PV anomaly was weaker than in the reanalyzes, a remnant anomaly remained out to 10 days. Plain Language Summary: Large bushfires in February 2009 in Australia led to large thunderstorms called pyrocumulonimbus (pyroCb) that injected significant amounts of smoke high into the atmosphere. When this smoke was warmed by absorbing sunlight it became buoyant and started to rise and rotate. This feature has been named a Smoke With Induced Rotation and Lofting (SWIRL) and had previously been observed in large pyroCbs that occurred around New Year's Day 2020 and in Canadian fires that occurred in 2017. The February 2009 SWIRL was a pancake‐like structure 1000 km across and 2 km thick. It lasted for three weeks, traveling over 27,000 km, and rising from 18 to 21 km in altitude. The SWIRL was observed both in weather maps and in satellite observations of gases such as water vapor, carbon monoxide, and ozone. Forecasting the SWIRL is difficult because current numerical weather models either do not consider smoke heating or lack inputs of pyroCb events as they are occurring in real time. Key Points: The February 2009 Australian Black Saturday pyroCbs injected a smoke plume into the stratosphere that induced a mesoscale anticycloneThe anticyclone was 1000 km across and 2 km thick and traveled 27,000 km in three weeks as it rose from 18 to 21 km in altitudeSatellite trace gas and aerosol anomalies coincide with potential vorticity anomalies, confirming smoke‐induced dynamical perturbations [ABSTRACT FROM AUTHOR]

Dynamical understandings of midlatitude transient eddy activity, especially its midwinter minimum over the North Pacific, are still limited, partly because conventional Eulerian eddy statistics are incapable of separating cyclonic and anticyclonic contributions. Here we evaluate the two contributions separately based on local curvature of instantaneous flow fields to compare their seasonality between the North Pacific and North Atlantic storm‐tracks. The anticyclonic contribution is found crucial for the midwinter minimum of the North Pacific transient eddy activity. Eddy energetics reveals that the net efficiency of the anticyclonic contribution in replenishing total transient eddy energy over the North Pacific exhibits a pronounced midwinter minimum leading to net energy loss, while that of its cyclonic counterpart does not, in harmony with a precipitation peak around midwinter. This study suggests that more attention should be paid to anticyclones in studying midlatitude storm‐track dynamics. Plain Language Summary: Our understanding of the dynamics of midlatitude transient eddy activity, especially its midwinter minimum over the North Pacific, is still limited. This is partly because conventional local statistics based on temporal filtering, which are commonly used as a measure of transient eddy activity, are unable to treat contributions from cyclones and anticyclones separately. Here we evaluate cyclonic and anticyclonic contributions to local eddy statistics separately based on local curvature of instantaneous flow fields, to compare their seasonality between the North Pacific and North Atlantic storm‐tracks. The anticyclonic contribution is found crucial for the midwinter minimum of the North Pacific transient eddy activity. We then apply eddy energetics to assess the relative importance of various processes relevant to the seasonality of eddy activity. The net efficiency of the relevant processes associated with the anticyclonic contribution in replenishing total transient eddy energy over the North Pacific exhibits a pronounced midwinter minimum leading to net energy loss. By contrast, that of the cyclonic counterpart does not, in harmony with a precipitation peak around midwinter. This study suggests that more attention should be paid to anticyclones in studying midlatitude storm‐track dynamics. Key Points: Anticyclonic contribution is crucial for the midwinter minimum of the North Pacific transient eddy activityThis minimum is consistent with net energy loss for anticyclonic regions in midwinter in energy conversion/generation termsMore attention should be paid to anticyclones in studying midlatitude storm‐track activity and their interaction with a time‐mean flow [ABSTRACT FROM AUTHOR]

Abstract The Kuroshio‐Oyashio Extension and Gulf Stream oceanic frontal zones are characterized by enhanced activity of synoptic‐scale cyclones and anticyclones and vigorous air‐sea heat and moisture exchange in the cold season. However, the time‐mean air‐sea exchange attributed separately to cyclones and anticyclones has not been assessed. Here we quantify cyclonic and anticyclonic contributions around the frontal zones to surface turbulent heat fluxes, precipitation, and the associated hydrological cycle using atmospheric general circulation model experiments with observed and artificially smoothed sea‐surface temperature gradients. The evaluation reveals that precipitation exceeds evaporation climatologically within cyclonic domains while evaporation dominates within anticyclonic domains. These features as well as the net moisture transport from anticyclonic to cyclonic domains are all enhanced by the sharpness of the frontal zones. Oceanic frontal zones thus climatologically act to strengthen the hydrological cycle. These findings aid our understanding of the relationship between midlatitude air‐sea interactions on synoptic‐ and longer‐time scales.

Abstract Dynamical understandings of midlatitude transient eddy activity, especially its midwinter minimum over the North Pacific, are still limited, partly because conventional Eulerian eddy statistics are incapable of separating cyclonic and anticyclonic contributions. Here we evaluate the two contributions separately based on local curvature of instantaneous flow fields to compare their seasonality between the North Pacific and North Atlantic storm‐tracks. The anticyclonic contribution is found crucial for the midwinter minimum of the North Pacific transient eddy activity. Eddy energetics reveals that the net efficiency of the anticyclonic contribution in replenishing total transient eddy energy over the North Pacific exhibits a pronounced midwinter minimum leading to net energy loss, while that of its cyclonic counterpart does not, in harmony with a precipitation peak around midwinter. This study suggests that more attention should be paid to anticyclones in studying midlatitude storm‐track dynamics.

The peculiarities of the troposphere and stratosphere dynamic processes that accompanied cooling events (cold waves) with a duration of more than a week in the northwest of European Russia (on the example of St. Petersburg) and in its north and center (on the example of Moscow) in early and late December 2021, respectively, are analyzed using reanalysis data, station observations, and trajectory modeling. In both cases the daily temperatures dropped below −10°C, and cold waves were accompanied by the air mass transport from the northeast [ABSTRACT FROM AUTHOR]

The anomalous post-monsoon tropical cyclone (TC) Jawad has been simulated using the Coupled Ocean–Atmosphere Wave Sediment Transport (COAWST) model using Global Forecasting System (GFS) Analyses and Forecasts as the atmospheric initial and boundary conditions (IC and BC) along with two contrasting ocean IC and BCs, viz., HYCOM (experiment name GFS-HYCOM) and INCOIS (experiment name GFS-INCOIS), to evaluate the influence of TC Jawad on the ocean surface and sub-surface characteristics. Both experiments captured the track of the simulated TC, including its recurvature, with significant accuracy. Validation of surface and sub-surface temperatures from two buoys, (1) BD11 (west of the TC track) and (2) BD13 (east of the TC track) suggests that a proper contrast in temperature exists in the buoy observations between the two sides of the TC track with the eastern side—showing higher sub-surface warming, which is captured by GFS-HYCOM but with significant overestimation. The lower temperature on the western side of the TC track can be attributed to the weak upwelling associated with the cyclonic circulation caused by the interaction of the TC with the southward coastal currents. The vertical distribution of the temperature across the longitudes showed an unusually higher downwelling on the eastern side of the TC track suggesting the existence of a strong clockwise circulation near the location of BD13. This circulation was found to be more rigorous in GFS-HYCOM, which also simulated higher current magnitude in the sub-surface than GFS-INCOIS. Further analysis showed that the interaction of the cyclonic wind flow of TC Jawad (westerly) near the surface with the easterly flow caused the generation of the clockwise circulation over the ocean surface on the eastern side of the TC track leading to intense downwelling and warming of sub-surface temperature. This study highlights the importance of the employment of coupled ocean–atmosphere models to simulated TCs for a better understanding of the air–sea interaction processes and their responses to the passage of an anomalous TC like Jawad. [ABSTRACT FROM AUTHOR]

In this work, we took into account the evolution of the production of the main crops grown in the area of Iermata, Seleus commune, Arad county, over a period of four years, between 2020-2023. In order to correlate the production data with certain meteorological indicators, we took into account the meteorological data provided by the Banat Crisana Regional Meteorological Center, for Arad county, Chisineu Cris meteorological station. Seleus commune is located in the eastern part of the Crişului Alb Plain, on the course of the Cigher river. It is located 12 km from Ineu, 6 km from Pâncota and 45 km from the municipality of Arad. It is also crossed by the Cigher river, the Morilor canal, to the north is Crisul Alb and to the west the Matca Canal. The Seleus commune is composed of three localities: Seleus, Moroda and Iermata. The area is characterized by a temperate climate with moderate continental accents, with warm summers and mild winters, characteristic of the Western Plain. It can be appreciated that the influences of the Mediterranean climate are easily felt. The multiannual air temperature average is 10.6°C. The warmest month is July (20.7°C) and the coldest is January (-1.1°C). The absolute maximum and minimum temperatures (+40.4°C and -30.1°C, respectively) demonstrate the possibility of recording a very hot summer or rather cold winter and mark the climatic continentalism. In general, the winters are moderate, without strong frosts due to the western climatic influence and due to the fact that the area has a more sheltered position from the polar-continental air invasions from the east and northeast. In the spring, under the influence of the western circulation and the extension of the ridges of the Azorean anticyclone over the south of Europe, the de-spring is faster than in the eastern part of the country. In the summer months, the air temperature is not too high, due to the western influences. It is between 18.9°C in June and 20.7°C in July. In autumn, the multiannual averages of these months vary between 16.2°C in September and 6.2°C in November. This decrease in temperature is due to the advection of cold air under the action of the ridge of the Euro-Asian anticyclone. The area being frequently subject to warm air invasions from the south-western sector, means that even in this season the temperature is 1°-2° higher than in the eastern part of the country. [ABSTRACT FROM AUTHOR]

Synoptic anticyclones are a common feature of subtropical and midlatitude climate and are associated with descending air and clear conditions, while associated anticyclonic circulation anomalies can contribute to temperature extremes. When anticyclones are tracked in both the ERA5 reanalysis and 10 global climate models from the 5th Coupled Model Intercomparison Project (CMIP5) using a common grid, the CMIP5 models consistently underestimate the observed frequency of anticyclones in the southern hemisphere, while overestimating anticyclone frequencies in the northern hemisphere. Under a high emissions scenario, the overall frequency of anticyclones is projected to decline over the twenty-first century. Declines are largest in the southern hemisphere subtropics, where projected changes in anticyclone frequency can be linked to the projected poleward shift in the Southern Annular Mode. Stronger and more robust declines are projected for the subset of quasi-stationary anticyclones that move less than 4° over 24 h. Using the Australian region as a case study, regionally downscaled models show very similar projected changes to the driving CMIP5 models, adding little additional value for understanding projected changes in anticyclones. [ABSTRACT FROM AUTHOR]

Data from the AIRS satellite infrared spectrometer and NCEP reanalysis are used to study the formation of the ozone miniholes (OMHs) and their influence on the levels of UV radiation (UVR) from May 22 to 24, 2021, in the middle and southern parts of the Volga region and the south of Urals and Western Siberia, and from March 16 to 18, 2022, in the northwest of the European Russia. These OMHs form due to the anticyclone-caused tropopause rise and the transport of ozone-depleted air masses from the subtropics. In the former period, in the OMH region with negative total ozone (TO) anomalies up to ~20% of the average values over 2003 to 2021, the positive UVR anomalies attained 40–60%, and the UV index increased from ~6 to ~8. In the latter period, in the OMH region with negative TO anomalies up to ~ −40%, the positive UVR anomalies attained 40–60%, and the UV index increased from ~1 to ~2. The UVR flux calculations with an original radiation model confirmed the UVR increase in the OMH region revealed using satellite observations. [ABSTRACT FROM AUTHOR]

This study investigates the Arctic sea ice concentration trend during 1979–2021 and explores why the autumn Arctic sea ice loss is accelerated after 2002 and its trend declining center shifts from the Chukchi Sea to the Barents-Kara-Laptev Seas. Attribution analysis reveals that the enhanced summer sea ice concentration negative trend in large part explains the autumn sea ice concentration accelerating reduction, whereas it is the trend center shift of increased downward longwave radiation that accounts for mostly of the autumn sea ice concentration decline center shift. Further analysis suggests the downward longwave radiation trend is closely related to large-scale atmospheric circulation changes. A tendency towards a dipole structure with an anticyclonic circulation over Greenland and the Arctic Ocean and a cyclonic circulation over Barents-Kara Seas enhances (suppresses) the downward longwave radiation over Western (Eastern) Arctic by warming and moistening (cooling and drying) the lower troposphere during 1979–2001. In comparison, a tendency towards a stronger Ural anticyclone combined with positive phase of the North Atlantic Oscillation pattern significantly promotes the increase of downward longwave radiation over Barents-Kara-Laptev Seas during 2002–2021. Our results set new insights into the Arctic sea ice variability and deepen our understanding of the climate change.

The Asian tropopause aerosol layer (ATAL) has emerged in recent decades with aerosol accumulation near tropopause above Asian Summer Monsoon region. Although ATAL effects on surface and top‐of‐atmosphere (TOA) radiation budgets are well established, the magnitude and variability of ATAL effects on radiative transfer within the tropopause layer remain poorly constrained. Here, we investigate the impacts of various aerosol types and layer structures on clear‐sky shortwave radiative heating in the Asian monsoon tropopause layer using reanalysis products and offline radiative transfer simulations. ATAL effects on shortwave radiative heating based on the Modern‐Era Retrospective Analysis for Research and Applications, version 2 aerosol reanalysis are on the order of 15% of mean clear‐sky radiative heating within the tropopause layer, although discrepancies among recent reanalysis and forecast products suggest that this ratio could be as small as ∼10% or as large as ∼70%. Uncertainties in surface and TOA flux effects are also large, with values spanning one order of magnitude at the TOA. ATAL effects on radiative heating peak between 150 and 80 hPa (360–400 K potential temperature) along the southern flank of the anticyclone. Clear‐sky and all‐sky shortwave heating are at local minima in this vertical range, which is situated between the positive influences of monsoon‐enhanced water vapor and the negative influence of the "ozone valley" in the monsoon lower stratosphere. ATAL effects also extend further toward the west, where diabatic vertical velocities remain upward despite descent in pressure coordinates. Plain Language Summary: Every summer, a layer of polluted air laden with aerosol particles collects above the convective storms of the Asian monsoon as part of a broad upper‐level circulation centered over the Tibetan Plateau. Researchers have developed a working understanding of how the dynamical environment shapes this Asian tropopause aerosol layer (ATAL). The motivating question for this work is: How might the aerosol layer reshape its environment? Aerosols can absorb and scatter sunlight, affecting both the amount of sunlight transmitted through the layer and the magnitude of solar heating within the layer. These effects depend on aerosol species and their vertical distribution within the layer, both of which are highly variable. In this paper, we translate variations and uncertainties in the amount, composition, and vertical distribution of aerosols near the Asian monsoon tropopause into variations and uncertainties in the absorption and scattering of solar radiation by the aerosol layer. We find that aerosols account for a substantial part (10%–70%) of heating by solar radiation near the tropopause in the region of ATAL. The vertical location and horizontal extent of the aerosol effects are distinct from those of other radiative effects. Key Points: The Asian tropopause aerosol layer produces a 10%–70% direct enhancement of clear‐sky shortwave heating above the summer monsoonEffects are largest where shortwave heating is weakest, with similar magnitudes to water vapor and ozone effects near the monsoon tropopauseDiscrepancies across recent aerosol analysis and forecast products cause large uncertainties in aerosol forcing of heating and fluxes [ABSTRACT FROM AUTHOR]

This study adopts a novel dynamic index of the westward ridge point (WRP) of the western Pacific subtropical high (WPSH) to investigate the interannual variation of the WPSH in boreal winter. The WRP index based on the theory of gradient wind approximation is particularly suitable for boreal winters. The WRP index comprises two dimensions that depict the zonal and meridional movement of the WPSH, respectively. There is a significant positive correlation between the zonal WRP index and the meridional WRP index. When the WPSH gets stronger, the WRP and the WPSH shift equatorward while advancing westward, and vice versa. The zonal and meridional shifts of the WPSH have distinct impact on the climate anomalies in the western North Pacific and East Asia. The northward shift of the WPSH characterizes a cyclonic-anticyclonic pair over western North Pacific, whereas the eastward shift of the WPSH characterizes a cyclonic anomaly over the subtropical western North Pacific. The anomalies of precipitation and surface air temperature vary accordingly. The meridional shift of the WPSH is closely associated with the El Niño-Southern Oscillation (ENSO) Sea Surface Temperature (SST) anomalies. The WRP index also demonstrates robust predictability in the hindcast data from ENSEMBLES, suggesting its far-reaching potential for climate prediction. • The westward ridge point index effectively measures the shift of western Pacific subtropical high in winter. • The zonal and meridional shifts of the western Pacific subtropical high have distinct climatic effect. • The westward ridge point index holds a high predictive potential for East Asian winter climate. [ABSTRACT FROM AUTHOR]

We assess temperature and moisture transport in and around the Antarctic Peninsula (AP) associated with atmospheric blocking over two domains, one located to the west (150–90°W, 50–70°S, Western AP (WAP)) and the other over and to the east (90–30°W, 50–70°S, Eastern AP (EAP)) of the AP. We make use of surface meteorological observations, ERA5 reanalysis data, and a state-of-the-art atmospheric river (AR) database. Observed temperature anomalies indicate that the WAP and EAP blocking patterns are characterized by significant cold and warm anomalies over the AP, respectively, particularly in austral autumn, winter and spring. Consistent with these changes, cold anomalies depicted by ERA5 are associated with the transport of cold and dry air from the Antarctic continent by southerly and southeasterly flow over the eastern flank of the WAP blocking. ERA5 results highlight the importance of blocking days over the EAP domain (largely centered over the Drake Passage) to the occurrence of warm events associated with northerly and northwesterly warm air transport. Significant increases in integrated vapor transport (IVT) and AR frequency are also evident during the EAP blocking, particularly on the windward side of the AP. During the most extreme blocking days in this domain, there exist significant increases in latent and sensible heat fluxes on the windward side of the AP and the Larsen C Ice Shelf, respectively, indicating the contribution of foehn events to warm anomalies, especially in austral autumn and winter. The co-occurrences between landfalling ARs and blocking are found to amplify foehn effect due to higher IVT and associated latent heat condensation compared to blocking days without ARs. We conclude that blocking patterns are important to understand the occurrence of extremely warm events and landfalling ARs in the AP and their potential impacts on the surface cryospheric processes.

Under global warming, the frequent occurrence of Eurasian extreme cold events in the Northern Hemisphere in recent years has attracted widespread attention. Winter Eurasia near‐surface anticyclone activities are closely related to low temperatures. This study uses a new objective anticyclone identification algorithm based on a Mask region‐based convolutional neural network (Mask R‐CNN) to detect long‐term winter Eurasian anticyclone activities. We found that most tracks of Eurasian anticyclones (30.5%) pass Siberia in winter. Anticyclone tracks over Siberia can be well separated into the eastward moving type, the northwest–southeast type, and the local type, with distinct associated circulation patterns. The energy dispersions of upstream Rossby waves have an important influence on the movement, maintenance and intensification of the three types. In association with anticyclones intensifying in Siberia, surface air temperatures in the mid‐latitudes of Eurasia, especially Siberia, are significantly lower. In particular, the local type is the most active (56.1%) and is significantly correlated with the winter temperature anomaly in most areas of East Asia. Further research indicates that the preceding autumn sea ice condition in the Barents Sea can be used as a precursor factor to modulate the local type anticyclone activity and winter temperature anomaly in East Asia. In years of less ice, a quasi‐meridional wave activity flux originating from the Barents Sea is more active, and the centre SLP of the local type anticyclone is higher with more cold air mass carried, which in turn results in colder weather in Siberia, the Mongolian Plateau and East Asia. [ABSTRACT FROM AUTHOR]

Using Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) data in the northern hemisphere at the 10 hPa level, we compared the stratospheric evolution of temperature and geopotential height during two major sudden stratosphere warming events (SSWs) that occurred in the Arctic winter of 2018 and 2019. In the prewarming period, poleward temperature-enhanced regions were mainly located around 120°E with a displaced vortex and around 120°E and 60°W with splitting vortices. The evolution of geopotential height indicated that these temperature-enhanced regions were both on the western side of high-latitude anticyclones. In the postwarming period, the polar vortex turned from splitting to displacement in the 2018 SSW but from displacement to splitting in the 2019 SSW. Both transitions were observed over the Atlantic region, which may have been caused by anticyclones moving through the polar region. Our findings revealed that the evolution of the anticyclone is important during SSWs and is closely related to temperature-enhanced regions in the prewarming periods and to transitions of the polar vortices in postwarming periods.

Sea surface cooling induced by tropical cyclones (TCs) is an important component of air-sea interactions. Using coordinate transformation and composite analysis methods, we examined the interannual variability in TC-induced sea surface cooling (TCSSC) in the South China Sea (SCS). The frequency of surface cooling cases was over 86% and that of surface warming cases was less than 14%. The magnitude of TCSSC was defined as the absolute value of TCSSC. The maximum magnitude of TCSSC occurred on the right side of the TC track, and the mean magnitude of TCSSC decreased by 0.04°C/a from 2006 to 2018. The interannual variability in TCSSC was highly correlated with the TC translation speed and pre-TC mixed layer depth. Notably, TCSSC got enhanced in El Nino years of 2007, 2010, and 2015. The El Nino types were suggested to determine the occurring periods of strong TCSSC via controlling the positions of SCS anticyclones, which brought pre-TC shallow mixed layer and caused strong TCSSC via vertical mixing process during El Nino events. To quantify how the anticyclone influences TCSSC, we need to use mixed layer heat balances model in the next study. [ABSTRACT FROM AUTHOR]

A mathematical model of a magnetic tornado in a magnetohydrodynamic plasma, based on the apparatus of continuum mechanics and Maxwell's electrodynamics, is proposed. In the context of two specific examples, the mutual influence of plasma and magnetic field dynamics, which gives rise to a magnetic tornado, is studied. Of particular interest is the interaction of a plasma and a magnetic field when an ideal plasma moves along the magnetic field lines. In this case, the study of a magnetic tornado is reduced to a purely hydrodynamic case of a tornado in atmospheric air. The numerical results obtained give theoretical confirmation of the existence of vortical formations observed in the chromosphere of the solar plasma, identified with a magnetic super-tornado. [ABSTRACT FROM AUTHOR]

The features of regional atmosphere circulation, which are accompanied simultaneously by two high impact hydrometeorological phenomena (such as droughts and dry winds) in the Black Sea Steppe zone of Ukraine were considered. Dry wind as a complex phenomenon is widespread throughout Ukraine during the warm season of the year. Dry winds often accompany a drought, but they appear as peripheral processes in contrast to the droughts, which are usually formed in the central parts of anticyclones. The number of days with dry winds at the Steppe stations varies on average from 10 to 20 cases to 40–50 cases per warm season, while in the coastal zone the number of days decreases sharply due to a common increase of air atmospheric relative humidity. Analysis of the interannual dynamics of dry winds showed that the number of days with dry winds increases significantly in seasons characterized by a high aridity, according to values of the drought index used. Two time intervals with high and low frequency of seasonal droughts and dry winds were detected during the considered period: 1995–2015. These phenomena have become more intense after 2004, compared to the previous decade. Backward trajectories of air particles showed that the most cases of dry winds originate in air masses, which form up to 5 days previously at the surface level to the east or north-east outside of the territory of Ukraine and then pass into the study area within 5 days.

Extremely high concentrations of dust particles are occasionally generated from the riverbeds of Taiwan, affecting the visibility and traffic safety of the local and nearby areas. The condition is most severe during the winter monsoon when surface wind is strong. This study analyzes the concentration of particulate matter of 10 µm or less (PM10), wind direction, wind speed, temperature, and humidity of riverbed stations adjacent to the Daan, Dajia, Dadu, Zhuoshui, and Beinan Rivers in Taiwan for a period of two years. The weather conditions that cause the high concentration of PM10 are classified into typhoon and non-typhoon types, and the latter type is further classified into three stages: ahead of front, ahead of anticyclone, and behind anticyclone. The associated meteorological influences of these weather types on high-concentration events in the riverbed are explored. The monitoring data show that the hourly PM10 concentration of the four riverbed stations exceeded 125 µg m−3 for 35–465 h per year, and the maximum PM10 in the Daan (and Dajia), and Zhuoshui Rivers was more than 800 µg m−3. Weather analysis showed that the extreme PM10 concentration on the riverbed was caused by weather types: typhoon and ahead of anticyclone, in which the peak hourly concentration reached average values of more than 600 and 400 µg m−3, respectively. The high PM10 caused by the typhoon type mainly occurred in October, with an average wind speed of 6 m s−1, high temperature of 25 °C, and mostly northeasterly winds. The ahead of anticyclone type mainly occurred in December, with an average wind speed of 5 m s−1, and northeasterly and northwesterly winds. Both weather types of riverbed events were observed during the daytime, especially at noon time, when strong wind speed, high temperature, and low relative humidity is favorable for riverbed dust generation. On the other hand, the main months of the high PM10 concentrations of the ahead of front and behind anticyclone stages are February and April. The peak PM10 concentrations of these two types of riverbed events are both about 300 µg m−3, but sporadic riverbed dust in these weather stages is mixed with Asian dust or pollution transported to the rivers through weak northwesterly and northeasterly winds. The high concentrations of these two types of riverbed events can occur at any time; but for the Dadu River, the high concentrations are often observed in the morning, when land breezes from the southeast bring local pollutants to the river.

The reason for aridization in the desert-steppe zone lies in the strengthening of the winter Asian anticyclone, which prevents the Mediterranean and Caspian cyclones from passing into the zone of desert steppes. These conditions provoke cold and snowless winters. The impact of aridization on soils consists in the accumulation of salts in the upper layers, the increase of carbonates and gypsum proportion, and in the intensification of soil erosion. Such conditions were very favorable for ancient cattle breeders, since they could allow the livestock to graze throughout the year and did not have to store fodder. The reverse process – increased humidization is associated with the weakening of the Asian winter anticyclone and the penetration of precipitation cyclones into the region of desert steppes. In such periods, toxic salts are washed out from the soils, humus content increases, segregation of soil carbonate begins, and the reserve of moisture for plants is created. Winter precipitation, though, leads to the formation of a thick snow cover, icing of the plants and the creation of an ice crust. In these conditions grazing was impossible, and herds were subject to depletion and death. Thus, during the periods of aridization, the most favorable conditions for pasturing developed in the desert steppe, while in humid periods, which were previously considered to be the most favorable, there was no opportunity for traditional pastoral farming. So, in the conditions of sharply arid climate in the middle – second half of the 3rd millennium BC, the catacomb cultures and post-catacomb cultural communities prospered in the desert steppe. The increase in the atmospheric humidity in the 19th – 18th cc. BC resulted in the increase in winter precipitation, which made impossible the winter grazing. This was the reason for a well-known period of depopulation of the desert steppe in the Late Bronze Age. The presented material is the result of the authors’ joint research work: А. V. Borisov has developed the general conception of the research, reviewed literary sources and prepared the manuscript’s text; M. V. Eltsov has conducted paleoclimatic reconstructions for the investigated region; S. N. Udaltsov has carried out the chemicalanalytical studies of the selected paleo-soil samples, and the general editing of the manuscript; A. V. Bukhonov has taken an active part in the field part of the study and discussed the proposed conception.

Australia experienced its driest calendar year on record in 2019. A number of factors contributed to the persistently dry conditions, including a record‐low number of cyclones in the Australian region south of 30°S as well as very high numbers of anticyclones during the southern wet season (April–September). The record year is likely a result of natural climate variability together with an underlying trend. The number of cyclones in southern Australia has decreased since 1979, and the number of cool season anticyclones has increased, although large interannual variability means that these trends currently cannot be distinguished from natural variability. However, the longer NCEP1 and JRA55 reanalyses provide evidence of a long‐term decline in cyclone frequency in southern Australia since the 1950s. Plain Language Summary: In southern Australia, low pressure systems are very important for rainfall, and high pressure systems usually bring dry weather. During 2019, southern Australia had the fewest low pressure systems in at least 50 years and more high pressure systems than normal. This may have contributed to the very low rainfall totals experienced that year. Key Points: Southern Australia had record‐low numbers of cyclones in 2019Anticyclones were also more common than normal in southern Australia, especially between April–SeptemberThere is a long‐term increase in anticyclones and decrease in cyclones [ABSTRACT FROM AUTHOR]

Tropical cyclones play a significant role in the formation of the hydrodynamic regime of the South China Sea, including its western part, which is bordered by the coast of Vietnam. In this region, the main hydrodynamic structure is the Vietnamese (western boundary) Current. Its structure depends on both seasonal monsoons and tropical cyclones. Therefore, the study of this dependence is an important task for Vietnamese scientists. The results of these studies are not only of scientific, but also of great practical importance, because the social and economic development of Vietnam largely depends on the activity and variability of synoptic and hydrodynamic processes in this region. This paper presents the results of joint Russian–Vietnamese studies on the dependence of the vertical structure of the Vietnamese current on tropical Pacific cyclones in the north of the South China Sea during the interseasonal winter–summer period. This study is based on numerical modeling. The calculations were performed for April–June 1999, for which the necessary initial field data are available. The simulation results indicated that the Vietnamese Current during this time period is not a uniform stream of water masses. Instead, the structure of water masses in this region is governed by a strong anticyclonic circulation and a deep cyclonic circulation, which are responsible for the complex pattern of the Vietnamese Current. The Vietnamese Current transfers coastal water masses in the summer mode (from south to north) within the anticyclonic circulation and in the winter mode (from north to south) within the cyclonic circulation. [ABSTRACT FROM AUTHOR]

Flow on a beta‐plane driven by a steady localised anticyclonic forcing of potential vorticity (or equivalently a mass source) is considered as a simple model of the Asian monsoon flow in the upper troposphere. Previous authors have noted that the response may be steady, or unsteady, according to the magnitude of the forcing, with the unsteadiness manifested as westward eddy shedding. A detailed study of the transition between steady and eddy‐shedding regimes reveals a third regime ('break up'), for intermediate forcing magnitude, where the flow is steady in the neighbourhood of the forcing, but the westward extending plume of low potential vorticity breaks up into isolated anticyclonic vortices some distance away from the forcing region. A related spatio‐temporal instability problem for flow on a beta plane is specified and analysed. The flow can be stable, convectively unstable or absolutely unstable. It is argued that these three stability regimes correspond to the steady, break‐up and eddy‐shedding regimes for the forced flow and good quantitative correspondence between the regimes is demonstrated by explicit solution of the spatio‐temporal stability problem. [ABSTRACT FROM AUTHOR]

This study investigates the relationship between the summer high temperature in northern China and the northern North Atlantic (NNA) sea surface temperature anomalies (SSTAs) in the previous winter and spring during the period 1981–2017. In northern China, mean maximum temperature (Tmax) above 31°C and high frequencies of hot days are concentrated in June–July. SSTAs in the NNA in the previous December–April have a significant positive relationship with the mean Tmax from the Yellow River Basin to the north of the Yangtze River in June–July, and this significant positive correlation still exists after removing the trends. Correlation and composition analysis suggests that the NNA SST and high temperature in northern China are connected by the mid‐latitude wave‐train circulation anomalies across the Atlantic and Europe. Warm SSTAs in the NNA in winter and spring favour anticyclonic circulations in the NNA, Western Europe and the south of Lake Baikal, and cyclonic circulations in the northeastern North Atlantic and the Ural Mountains. The positive height anomaly and anticyclonic circulation in the south of Lake Baikal tend to result in downward motion and high temperature in northern China. The linkage between winter–spring North Atlantic SST and high temperature can be used to facilitate seasonal prediction of extreme high temperature in China. [ABSTRACT FROM AUTHOR]

Presented are the results from investigating the atmospheric self-purification capacity over the cities of Irkutsk, Beijing and Ulaanbaatar for the summer and winter seasons of 2017–2018. The meteorological potential of the atmosphere (MPA) was used as the criterion for assessing the atmospheric self-purification. It is shown that in the summer season of 2017 the favorable meteorological conditions for the dispersion of air pollutants were dominant over the territory of Irkutsk and Ulaanbaatar. In the summer, MPA was 0.99 and 0.78 in Irkutsk and in Ulaanbaatar, respectively. MPA varied from 2.14 to 4.66 in Beijing in the summer. For the winter months in the three cities, MPA > 1, which indicates an accumulation of pollutants in the atmosphere for that season. In Ulaanbaatar there were unfavorable conditions for self-purification: the maximum MPA index (9.5) was observed in December. The largest contribution to impairment of the atmospheric diffusing capacity over Ulaanbaatar in the wintertime was made by wind velocities of 0–1 m/s. It was found that the maximum accumulation of pollutants in the atmosphere over Beijing occurs in the winter. MPA varied from 15.0 in February to 19.0 in December, averaging 16.68. Fogs made the largest contribution to the unfavorable meteorological conditions of Beijing in December-February. The characteristic properties of the atmospheric circulation, wind regime, fog and atmospheric precipitation were responsible for MPA of Irkutsk, Ulaanbaatar and Beijing for the period under consideration. [ABSTRACT FROM AUTHOR]

The existence of the Asian Summer Monsoon Anticyclone (ASMA) during the summer in the northern hemisphere, upper troposphere and lower stratosphere (UTLS) region plays a significant role in confining the trace gases and aerosols for a long duration, thus affecting regional and global climate. Though several studies have been carried out, our understanding of the trace gases and aerosols variability in the ASMA is limited during different phases of the Indian monsoon. This work quantifies the role of Indian Summer Monsoon (ISM) activity on the tropopause, trace gases (Water Vapor (WV), Ozone (O3), Carbon Monoxide (CO)) and aerosols (Attenuated Scattering Ratio (ASR)) obtained from the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC), Microwave Limb Sounder (MLS), Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite observations, respectively, during the period 2006–2016. Enhancement in the tropopause altitude, WV, CO, ASR and low tropopause temperatures, O3 in the ASMA region is clearly noticed during peak monsoon months (July and August) with large inter-annual variability. Further, a significant increase in the WV and CO, and decrease in O3 during the active phase of the ISM, strong monsoon years and strong La Niña years in the ASMA is noticed. An enhancement in the ASR values during the strong monsoon years and strong La Niña years is also observed. In addition, our results showed that the presence of deep convection spreading from India land regions to the Bay of Bengal with strong updrafts can transport the trace gases and aerosols to the upper troposphere during active spells, strong monsoon years and La Niña years when compared to their counterparts. Observations show that the ASMA is very sensitive to active spells, strong monsoon years and La Niña years compared to break spells, weak monsoon years and El Niño years. It is concluded that the dynamics play a significant role in constraining several trace gases and aerosols in the ASMA and suggested considering the activity of the summer monsoon while dealing with them at sub-seasonal scales.

Daily Peczely circulation types are investigated over 140 years (1881–2020). After presenting monthly mean frequencies and durations of the 13 circulation types, two further questions are investigated: (i) How do the circulation types influence local weather extremes?; (ii) Are there significant trends in the frequency of the original and the grouped circulation types in the recent monotonically warming 50 year period (1971–2020)? The answers are as follows: (i) Four local weather extremes were investigated in nine grid-points of the Pannonian Basin and analyzed in the central months of the seasons. It was established that high precipitation and wind maxima occur in almost all circulation types and months, whereas for both high temperature maxima and low temperature minima, there are six circulation types, where no extremity occurred in one, two, or three investigated months. (ii) In the last 50 years, 37% of the linear seasonal frequency trends have been significant. However, these trends are rarely significant in the shorter monotonously warming (1911–1940) and cooling (1941–1970) 30-year periods. Therefore, the significant trends of the last 50 years are unlikely to be the direct consequences of the monotonous hemispherical warming. Since these hemispherical temperature trends are most likely caused by different sets of physical reasons, the reality of the presented circulation frequency trends needs to be validated by climate models.

Anticyclones are one of the main synoptic features of the global midlatitudes, where they are associated with dry, settled conditions. Previous studies have identified southern Australia as a region where significant long-term changes have occurred in recent decades, including a decline in cool season rainfall and an increase in the frequency of anticyclones. This paper uses several reanalyses to assess the climatology, variability, trends and impacts of anticyclones in southern Australia and several subregions. A robust increase in the frequency of anticyclones in southern Australia is demonstrated between 1960–1979 and 1997–2014, particularly in southeast Australia and the Tasman Sea during the cool months of the year. At least 30% of the recent cool season rainfall decline in southeast Australia can be associated with an increased frequency of anticyclones in this region. However, there are no clear trends in anticyclone frequency near southwestern Western Australia, where long-term rainfall declines are due to changes in other weather systems. [ABSTRACT FROM AUTHOR]

Barotropic geostrophic flows are investigated using rectangular and polar coordinate systems. It is shown that, for the analysis of geostrophic flows with radial symmetry, the use of a polar coordinate system is preferable. Relations between the hydrodynamic characteristics, including the expressions of the fluid particle velocity components and vorticity through pressure, are obtained. It is established that, in the case of stationary barotropic flows, isobaths coincide with current lines. Stationary radially symmetric geostrophic flows are considered. [ABSTRACT FROM AUTHOR]

In the Caribbean Sea, mesoscale anticyclonic ocean eddies impact the local ecosystem by mixing of low salinity river outflow with the nutrient‐rich waters upwelling along the Venezuelan and Colombian coast. To gain insight into the physics and the ecological impact of these anticyclones, we performed a combined hydrographic and biological survey of one Caribbean anticyclone in February 2018. We found that the anticyclone had a radius of 90 km and was surface intensified with the strongest velocities (0.72 m/s) in the upper 150 m of the water column. Below, isopycnal displacements were found down to 700 dbar. The core of the anticyclone entrained waters from the Orinoco River plume and contained slightly elevated chlorophyll concentrations compared to the surroundings. At the edge of the anticyclone we observed higher densities of flying fish but not higher densities of predators like seabirds and cetaceans. Below the surface, a strong temperature inversion (0.98 °C) was present within a barrier layer. In addition, we found thermohaline staircases that originated from double diffusion processes within Tropical Atlantic Central Water. Key Points: Observed velocities (0.72 m/s) of the 180‐km‐wide eddy are strongly surface intensifiedAt the front, higher densities of flying fish but no species at higher trophic levels were observedThe eddy core contained river water and a strong subsurface temperature inversion (0.98°C) [ABSTRACT FROM AUTHOR]

A global climatology of anticyclones identified at mean sea level pressure is presented based on multiple reanalyses over the period 1960–2016, including assessment of regional and seasonal variations, interannual variability, and long-term trends. Interannual variability is associated with the El Niño-Southern Oscillation (ENSO), particularly in the Pacific region during November–April. Anticyclones vary in phase with the strength and intensity of the local mean subtropical ridge, with anticyclone variability also associated with the Southern Annular Mode (SAM) in the Southern Hemisphere and the Arctic Oscillation (AO) in parts of the Northern Hemisphere, particularly during the cooler months of the year. Long-term climatological trends in anticyclone occurrence are presented, including back to 1960 using 20CR reanalysis data. The strongest trends occur in the Southern Hemisphere, including increases in anticyclone frequency in the latitudes 30–40 S and decreases for adjacent latitudes in both seasons, which can be partially attributed to changes in SAM during November–April. [ABSTRACT FROM AUTHOR]

Synoptic processes that occurred in the Tomsk region between 1993 and 2016 are analyzed. A significant decrease in the difference between the frequency of cyclones and anticyclones over the past decade is revealed. There are tendencies to a decrease in the frequency of Arctic air mass invasion, and to an increase, of subtropical and tropical air masses. [ABSTRACT FROM AUTHOR]