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Long-term measurements of atmospheric mass concentrations of black carbon (BC) are needed to investigate changes in its emission, transport, and deposition. However, depending on instrumentation, parameters related to BC such as aerosol absorption coefficient (babs) have been measured instead. Most ground-based measurements of babs in the Arctic have been made by filter-based absorption photometers, including particle soot absorption photometers (PSAP), continuous light absorption photometer (CLAP), Aethalometers, and multi-angle absorption photometers (MAAP). The measured babs can be converted to mass concentrations of BC (MBC) by assuming the value of the mass absorption cross section (MAC; MBC = babs/MAC). However, the accuracy of conversion of babs to MBC has not been adequately assessed. Here, we introduce a systematic method for deriving MAC values from babs measured by these instruments and independently measured MBC. In this method, MBC was measured with a filter-based absorption photometer with a heated inlet (COSMOS). COSMOS-derived MBC (MBC (COSMOS)) is traceable to a rigorously calibrated single particle soot photometer (SP2) and the absolute accuracy of MBC (COSMOS) has been demonstrated previously to be about 15 % in Asia and the Arctic. The necessary conditions for application of this method are a high correlation of the measured babs with independently measured MBC, and long-term stability of the regression slope, which is denoted as MACcor (MAC derived from the correlation). In general, babs–MBC (COSMOS) correlations were high (r2 = 0.76–0.95 for hourly data) at Alert in Canada, Ny-Ålesund in Svalbard, Barrow in Alaska, Pallastunturi in Finland, and Fukue in Japan, and stable for up to 10 years. We successfully estimated MACcor values (10.6–15.2 m2 g−1 at a wavelength of 550 nm) for these instruments and these MACcor values can be used to obtain error-constrained estimates of MBC from babs measured at these sites even in the past, when COSMOS measurements were not made. Because the absolute values of MBC in these Arctic sites estimated by this method are consistent with each other, they are applicable to the study of spatial and temporal variation of MBC in the Arctic and to evaluation of the performance of numerical model calculations.

©2018. American Geophysical Union. All Rights Reserved. Aerosol and tropospheric ozone transport to North America has important implications for regional air quality and climate. We present data from Chews Ridge, a remote mountaintop site in California, in February–September 2012, which identifies separate Asian dust and Asian combustion aerosol signals and quantifies exogenous ozone. We use positive matrix factorization of size-fractionated aerosol X-ray fluorescence data and206Pb/207Pb and208Pb/207Pb isotope measurements to isolate aerosol signals of Asian origins and find good agreement between both types source attribution techniques. Power spectra of Asian dust and Asian combustion signals reveal two distinct peaks, one seasonal (~90 days) and one monthly (~25–30 days). Overall, 89% of the Asian dust signal occurs in March–May, compared with June–September, whereas only 51% of the Asian combustion signal occurs in March–May. Nearly half the Pb observed at Chews Ridge was derived from Asia (46%; 8.3% from Asian dust, 23% from Asian combustion, and 15% of the Asian Pb signal was not explained by the positive matrix factorization). A positive correlation between deseasonalized ozone concentrations and the Asian factors suggests that ozone is elevated by 6.3 ± 0.8 ppb due to transpacific transport. Scanning mobility particle size spectra were also measured from May to September and indicate that new particles are often produced and grow throughout the afternoon during onshore flow. We hypothesize that particle nucleation on the windward edge of the continent is an important source of new particles.

The phytoplankton of Lake Ulungur was investigated seasonally from November, 2006 to July, 2007. A total of 164 phytoplankton species (including a number of unconfirmed species) was detected, which belonged to 90 genera, 8 phylum. Among them, Anabaena bergii was a new record species of cyanophyta in Xinjiang Uygur Autonomous Region, and two species of bacillariophyta, Chaetoceros sp. and Thalassionema sp., belonged to marine algal. In each season, the phytoplankton composition was dominated by Chlorophyta and Bacillariophyta, secondly dominated by Cyanophyta, Euglenophyta, Xanthophyta, Chrysophyta, Cryptophyta and Pyrrophyta. The number of phytoplankton species was the highest in autumn (141 species), followed by the summer (128 species) and spring (121 species), the lowest in winter (95 species). There was an obvious seasonal characteristiscs for the dominant species. Raphidiopsis sinensia, Teraёdron minimum, Selenastrum minutum, Chlorella vulgaris and Synedra acus were dominant species in the whole year, while Synedra ulna could only be found in spring, summer and autumn. Kirchneriella contorta and Chlorella ellipsoidea dominated in summer, and Chlorococcum infusionum and Treubaria crassispina dominated in winter. The standing crop of phytoplankton peaked only in summer with a biomass of 6.77mg/L and the minimum biomass of 1.45mg/L occurred in winter. Compared with historical data, the phytoplankton composition had remarkable changes. The growth of green alga and diatom were most notable, while the number of the phytoplankton increased many fold in the past 30 years.

We conducted a case-control study to investigate the association between three common SNPs in IL-10 gene (rs1800896, rs1800871 and rs1800872) and the development of liver cirrhosis in a Chinese population. Between January 2013 and December 2014, a total of 318 patients with liver cirrhosis and 318 health control subjects were enrolled into our study. The IL-10 rs1800896, rs1800871 and rs1800872 polymorphisms were analyzed using polymerase chain reaction (PCR) coupled with restriction fragment length polymorphism (RFLP). By multivariate logistic regression analysis, we found that individuals with the AA genotype and GA+AA genotype of IL-10 rs1800896 were more likely to have an increased risk of liver cirrhosis when compared with the GG genotype, and the ORs (95% CI) for the AA genotype and GA+AA genotype were 2.04 (1.20-3.50) and 1.41 (1.02-1.96), respectively. We found that the GA+AA genotype of IL-10 rs1800896 had higher risk of liver cirrhosis in individuals with chronic hepatitis B when compared with the GG genotype (OR = 1.95, 95% CI = 1.01-3.59). In conclusion, we found that IL-10 rs1800896 polymorphism was correlated with an increased risk of liver cirrhosis, especially in individuals with chronic hepatitis B.

The effectiveness of the breeding method in determining growth and decay characteristics of certain solutions to the Kortweg-de Vries (KdV) equation and the Nonlinear Schrödinger equation is investigated. Bred vectors are a finite amplitude, finite time generalization of Leading Lyapunov Vectors (LLV), and breeding has been used to predict large impending fluctuations in many systems, including chaotic systems. Here, the focus is on predicting fluctuations associated with extreme waves. The bred vector analysis is applied to the KdV equation with two types of initial conditions: soliton collisions, and a Gaussian distribution which decays into a group of solitons. The soliton solutions are stable, and the breeding analysis enables tracking of the growth and decay during the interactions. Furthermore, this study with a known stable system helps validate the use of breeding method for waves. This analysis is also applied to characterize rogue wave type solutions of the NLSE, which have been used to describe extreme ocean waves. In the results obtained, the growth rate maxima and the peaks of the bred vector always precede the rogue wave peaks. This suggests that the growth rate and bred vectors may serve as precursors for predicting energy localization due to rogue waves. Finally, the results reveal that the breeding method can be used to identify numerical instabilities. Effective simulation of diurnal variability is an important aspect of many geophysical data assimilation systems. For the Martian atmosphere, thermal tides are particularly prominent and contribute much to the Martian atmospheric circulation, dynamics and dust transport. To study the Mars diurnal variability (or thermal tides), the GFDL Mars Global Climate Model (MGCM) with the 4D-Local Ensemble Transform Kalman Filter (4D-LETKF) is used to perform a reanalysis of spacecraft temperature retrievals. We find that the use of a "traditional" 6-hr assimilation cycle induces spurious forcing of a resonantly-enhanced semi-diurnal Kelvin waves represented in both surface pressure and mid-level temperature by forming a wave 4 pattern in the diurnal averaged analysis increment that acts as a "topographic" stationary forcing. Different assimilation window lengths in the 4D-LETKF are introduced to remove the artificially induced resonance. It is found that short assimilation window lengths not only remove the spurious resonance, but also push the migrating semi-diurnal temperature variation at 50 Pa closer to the estimated "true" tides even in the absence of a radiatively active water ice cloud parameterization. In order to compare the performance of different assimilation window lengths, short-term to long-term forecasts based on the hour 00 and 12 assimilation are evaluated and compared. Results show that during NH summer, it is not the assimilation window length, but the radiatively active water ice cloud that influences the model prediction. A "diurnal bias correction" that includes bias correction fields dependent on the local time is shown to effectively reduce the forecast root mean square differences (RMSD) between forecasts and observations, compensate for the absence of water ice cloud parameterization, and enhance Martian atmosphere prediction. The implications of these results for data assimilation in the Earth's atmosphere are also discussed.

A field evaluation of versatile aerosol concentration enrichment system (VACES) coupled to a rapid single- particle mass spectrometer (RSMS-3) was conducted as part of the U. S. Environmental Protection Agency Supersite program in Pittsburgh during March 2002. RSMS- 3 hit rate increases were measured, and possible particle composition changes introduced by the VACES were examined in the single- particle mass spectra. The hit rates increased by 5 - 20 times at particle sizes ranging from 40 to 640 nm. VACES only enhances the hit rate by about a factor of 2 for large particle sizes because the RSMS-3 flow rates for these particles did not match the optimum operating condition of VACES. During the 3 days of measurements most of the particles were a mixture of carbonaceous material and ammonium nitrate with a variation across the spectrum from particles that were mostly carbonaceous to particles that were mostly ammonium nitrate. Both ambient and concentrated carbonaceous and ammonium nitrate composition distributions were indistinguishable with RSMS-3, suggesting that VACES introduces an insignificant artifact for those particles.