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The integrated analysis of the data from a C-band frequency-modulated continuous-wave (C-FMCW) radar site in Naqu obtained during a rainstorm over the middle and lower reaches of the Yangtze River and the data concerning the three-dimensional structure of the circulation of the precipitation system that occurred over the lower reaches of the Yangtze River Basin during the Third Tibetan Plateau (TP) Atmospheric Experiment from August 15th to 19th, 2014, was carried out. The changes in the echo intensity at the C-FMCW radar site in Naqu were of regional indicative significance for the characteristics of the whole-layer apparent heat source Q1 in local areas and the region of the adjacent river source area, including the Yangtze River, Yellow River, and Lancang River (hereinafter referred to as the “source area of three rivers”), as well as to the vertical speeds due to the development of convection. This study indicates that the C-FMCW radar echo intensity of the plateau convection zone and the related power structures of the coupled dipole circulations in the middle layer of the atmosphere, as well as in the upper atmospheric level divergence and lower atmospheric level convergence, are important stimuli for convective clouds in this region. Furthermore, these radar data provided a physical image of the development and maintenance mechanisms of an eastward-moving heavy rainstorm belt. This study also shows that changes in the echo intensities at the C-FMCW radar site of Naqu can provide strong signals related to heavy rainstorm processes in the upper reaches of the Yangtze River.

This study evaluates total cloud fraction (TCF) and top-of-the-atmosphere cloud radiative effects (CREs) in five widely used reanalyses (CFSR, ERA-Interim, JRA55, MERRA2, and NCEP1) using satellite-based observations for the period 2001–2014, with the emphasis on the Asian monsoon region (AMR) including East Asia (EA) and South Asia (SA). The results indicate that despite certain biases, most reanalyses (especially CFSR and ERA-Interim) broadly capture global spatial patterns of TCF and CREs, with pattern correlations with the observations being greater than 0.7, and also generally reproduce the pronounced contrast of the winter and summer means over EA and SA. In contrast, biases and differences in TCF and CREs in reanalyses are significantly larger over the AMR, particularly in summer. Over EA, the reanalyses underestimate annual and winter mean TCF, shortwave CRE (SWCRE), and net CRE (NCRE), with negative biases of 0–40%. Over SA, the reanalyses broadly reproduce the observed annual cycles of each CRE component, but most of them have considerable biases in magnitude, with an overestimation of NCRE by up to 90%, and an unrealistic ratio of longwave (LWCRE) to SWCRE. Such an unrealistic relationship between LWCRE and SWCRE in some reanalyses may produce an unrealistic annual mean state, annual cycle, and inter-annual variation of NCRE over SA. Comparatively, ERA-Interim and JRA55 give better performance in the annual cycle and inter-annual variations of CREs over EA. The inter-annual biases of TCF and NCRE in CFSR are substantially larger over SA while its TCF reproducibility over EA is the best of the reanalyses. The examination of TCF in MERRA2 with the satellite simulator shows that larger TCF biases occur over the AMR region relative to original satellite and MERRA2 products. It requires more quantitative comparison among reanalyzed and satellite-retrieved cloud properties to identify and improve cloud parameterization.

The CO2 and CH4 fluxes at the water-air interface were measured in shrimp (Marsupenaeus japonicus) monoculture ponds (S) with feed supply and shrimp-sea cucumber (Apostichopus japonicus) polyculture ponds (SS) without feed supply. During farming seasons of the whole year, cumulated CO2-C fluxes were -5.69 g m(-2) (S) and 11.23 g m(-2) (SS), respectively. The cumulated CO2 emissions from S and SS did not differ significantly. The cumulated CH4-C emissions from S (0.57 g m(-2)) were significantly higher than those from SS (0.068 g m(-2)). S absorbed C from the atmosphere with a mean absorption rate of -5.12 g m(-2), whereas SS emitted C to the atmosphere with a mean emission rate of 11.30 g m(-2). Over 20-year horizon, the compressive global warming potentials (cGWPs) were 33.55 (S) and 47.71 (SS), respectively, indicating both feeding and no-feeding mariculture ponds could promote global warming.

The regional features of long-term changes in total and extreme precipitations over eight China domains and their seasonality and relationships with large-scale and local atmospheric and oceanic factors are investigated. A newly compiled data set of 917 China stations from the China National Meteorological Information Center with strict quality control is analysed. Wintertime extreme precipitation has increased persistently in all China domains, together with an obvious wetting tendency except in North China. In spring, an increase in extreme precipitation is also seen except in South China, but total precipitation increases only in half of China. A ‘northern drying and southern wetting’ (NDSW) pattern is found over eastern China for both extreme and total precipitations in summer when precipitation increases significantly in Northwest China (NWCH). Different features are found in autumn when negative trends are found in most of the China domains for total precipitation (except in NWCH and the Tibetan Plateau) and half of the domains for extreme precipitation. Overall, the frequency of extreme precipitation plays a dominant role in determining the extreme precipitation trend compared to the intensity of precipitation. The long-term changes in total precipitation and extreme ratio (extreme precipitation to total precipitation) are both strongly linked to the sea surface temperatures (SSTs) from the Indian Ocean to the Maritime Continent, the Kuroshio, the central-eastern Pacific, and part of the Atlantic Ocean. In summer, the NDSW pattern is closely associated with the weakening of East Asian monsoon circulation and the increase in land surface temperature of 40°–60°N. Local warming trends also contribute to the trends of extreme ratio in several domains in particular seasons.

Experiments of biomass char combustion in 10%O2/90%CO2, 21%O2/79%CO2, 10%O2/90%N2 and 21%O2/79%N2 atmospheres were performed in the fixed-bed reactor system at the temperature of 800°C-1200°C. The results show that at the same temperature, NO emission is higher in O2/N2 atmosphere than that in O2/CO2 atmosphere. The higher the O2 concentration is, the higher the NO yield is. As the temperature rises, the NO yield rises at first and then decreases at the same O2 concentration and atmosphere.

We have performed the first-principles calculations on the structural, electronic, and magnetic properties of 3d transition-metal nanowires (TMNW4s), Fe4, Co4, and Ni4, encapsulated inside GaN nanotubes (GaNNTs). The results show that, all three types of the TMNW4 encapsulated inside the narrower (6,6) and broader (8,8) GaNNTs are both exothermic. The spin polarization and magnetic moment of the TMNW4@(8,8) systems are larger than those of the TMNW4@(6,6) systems due to more weak restriction of the broader (8,8) GaNNT, but those of these two combined systems are smaller than those of the corresponding freestanding TMNW4. Our results reveal that either the TMNW4@(6,6) or TMNW4@(8,8) systems have high spin polarization and magnetic moment and stably exist in atmosphere for long time and thus can be expected to have potential applications in building nanodevices.

We investigate the variations of total and extreme precipitations over China and the United States, focusing on long-term changes. We also explain the features of precipitation by changes in sea surface temperature (SST) and atmospheric circulation. Features of total precipitation and the ratio of extreme to total precipitation are different between China and the United States, and differences occur in both annual and seasonal means. Both total precipitation and precipitation ratio show large seasonal and regional variations over China, but change modestly over the United States Annually, China total precipitation changes insignificantly and the ratio shows only a slight positive trend. However, the US annual total precipitation increases significantly, although the ratio decreases moderately. In China, the ratio exhibits positive trends in all seasons and total precipitation shows small positive trends except a negative trend in fall. The US total precipitation increases remarkably in all seasons except winter when a slight decrease occurs, and the ratio decreases in winter and summer but increases in spring and fall. The change in China precipitation ratio has a strong link to SSTs around the Indian Ocean and the South and East China Seas, and the change in US total precipitation is associated with changes in the Indian Ocean and eastern Pacific SSTs. These relationships become weaker when the trend of total precipitation or precipitation ratio is removed, indicating an impact of SST on the long-term change in precipitation. The trends of US total precipitation and China precipitation ratio are also linked to the long-term changes inatmospheric circulation including the trade wind, the North Pacific anticyclone, and the circulation patternsover Asia. In most cases, the total and extreme precipitations are associated with similar SST and atmospheric patterns, except in China where the annual extreme precipitation is associated with SST and circulation features as is the precipitation ratio.

A summary of the development of the high-resolution climate system model, version 2 of the Beijing Climate Center Climate System Model (BCC_CSM2.0), is presented. It is an atmospheric and oceanic fully coupled climate model system with a horizontal resolution of T266 (approximately 45 × 45 km) in the atmosphere and 30 × 30 km in the tropical ocean. It was developed on the basis of a lower resolution version of the model (BCC_CSM1.1) [T42 (approximately 280 × 280 km)]. A more sophisticated atmospheric dynamics framework and physical parameterizations are employed in BCC_CSM2.0, and these improvements enabled the increase in the model’s horizontal resolution. Preliminary evaluations of BCC_CSM2.0 indicate better performance in reproducing regional climate features and the seasonal march of East Asian precipitation, as compared with lower resolution versions. Thirty-year simulations show some improvements in capturing the ITCZ, especially in winter (December to February), the spatial structure and details of East Asian summer monsoon precipitation and surface air temperature, the annual SST cycle in the eastern Pacific, the semiannual cycle in the Western Pacific and their transition phases in the central Pacific.

The abilities of 27 Atmospheric Model Intercomparison Projection models to simulate the radiation budget (RB) over the East Asian monsoon region (EAMR) are analyzed based on Clouds and the Earth's Radiant Energy System Energy Balanced and Filled, hereafter CERES, products. The regional mean values of annual top of the atmosphere (TOA) net RB in the simulations are constantly larger than the CERES values in the majority of the models (24 of 27), due mainly to the overestimation of its shortwave (SW) component. The TOA SW RB overestimation in most models (25 of 27) is due mainly to the insufficient SW absorption by the atmosphere and the consequent superfluous downwelling shortwave radiation reaching and being absorbed by the surface. Both the intensity underestimation of SW cloud radiative forcing (CRF) and the inadequate clear-sky atmospheric SW absorption contribute to the overestimation of TOA SW RB in the models. The underestimation of SW CRF intensity is mainly due to the reduced total cloud cover simulated in most of the models compared with the general circulation model-oriented CALIPSO Cloud Product. Black carbon explains the greatest part of the clear-sky atmospheric SW absorption biases in most of the models. The persistent underestimation of TOA SW CRF intensity over the EAMR across all seasons largely explains the seasonally constant overestimation of TOA SW RB. The seasonal variation in clear-sky longwave (LW) RB demonstrates the remarkable seasonal variation in atmospheric and surface LW RB biases.

Many species have been found to be capable of foliar water uptake, but little research has focused on this in desert plants.Tamarix ramosissimawas investigated to determine whether its leaves can directly absorb water from high humidity atmosphere and, if they can, to understand the magnitude and importance of foliar water uptake. Various techniques were adopted to demonstrate foliar water uptake under submergence or high atmospheric humidity. The mean increase in leaf water content after submergence was 29.38% and 20.93% for mature and tender leaves, respectively. In the chamber experiment, obvious reverse sap flow occurred when relative humidity (RH) was persistently above 90%. Reverse flow was recorded first in twigs, then in branches and stems. For the stem, the percentage of negative sap flow rate accounting for the maximum value of sap flow reached 10.71%, and its amount accounted for 7.54% of diurnal sap flow. Small rainfall can not only compensate water loss of plant by foliar uptake, but also suppress transpiration. Foliar uptake can appear in the daytime under certain rainfall events. High atmospheric humidity is beneficial for enhancing the water status of plants. Foliar uptake should be an important strategy of water acquisition for desert plants.

Hazardous air pollutants have been noticed in Taiwan recently, they are known not only to endanger human health but also to diminish the air quality. The primary objective of this investigation is to determine the concentration levels and to explore the characterizations of air pollutants in metropolitan areas of northern Taiwan. Air samples were collected from Oct. 1989 to March 1993 in five sampling stations, located in northern Taiwan. The 24-hour suspended particulate matter samples were obtained by using Hi-vol samplers. The analysis of chemical elemental components was conducted with XRF & ICP-AES; the content of ionic species was analyzed by using IC; the amount of fourteen PAHs was measured with GC/MS; and the mutagenicity levels embraced on the particles was examined from the bioassay. The result of this study reveals that the BaP/BghiPr ratio in downtown stations ranged from 0.1 to 0.3. Examination of the results from EF and FA, suggest that the soil dust, residual oil combustion, traffic, photochemical reactions, oceanic processes, coal-burning, biomass burning, fertilizer factory, waste incinerator, foundry and limestone industry are the predominant pollution sources. Moreover, on the basis of the good relationship existing between the elemental and PAHs data, introduction of PAHs information into the original inorganic data set not only improves the resolvable performance of the modeling, but also establishes better credibility.