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Accurately quantifying the spatiotemporal distribution of the biological component of CO2 surface-atmosphere exchange is necessary to improve top-down constraints on China's anthropogenic CO2 emissions. We provide hourly fluxes of CO2 as Net Ecosystem Exchange (NEE; µmol CO2 m-2 s-1) on a 0.25°×0.25° grid by adapting the Vegetation, Photosynthesis, and Respiration Model (VPRM) to the eastern half of China for the time period from 2005-2009; the minimal empirical parameterization of the VPRM-CHINA makes it well-suited for inverse modeling approaches. This study diverges from previous VPRM applications in that it is applied at large scale to China's ecosystems for the first time, incorporating a novel processing framework not previously applied to existing VPRM versions. In addition, the VPRM-CHINA model prescribes methods for addressing dual-cropping regions that have two separate growing season modes applied to the same model gridcell. We evaluate the VPRM-CHINA performance during the growing season and compare to other biospheric models. We calibrate the VPRM-CHINA with ChinaFlux and FluxNet data and scale up regionally using Weather Research and Forecasting (WRF) Model v3.6.1 meteorology and MODIS surface reflectances. When combined with an anthropogenic emissions model in a Lagrangian particle transport framework, we compare the ability of VPRM-CHINA relative to an ensemble mean of global hourly flux models (NASA CMS) to reproduce observations made at a site in Northern China. The measurements are heavily influenced by the Northern China administrative region. Modeled hourly timeseries using vegetation fluxes prescribed by VPRM-CHINA exhibit low bias relative to measurements during the May-September growing season. Compared to NASA CMS subset over the study region, VPRM-CHINA agrees significantly better with measurements. NASA CMS consistently underestimates regional uptake in the growing season. We find that during the peak growing season, when the heavily cropped North China Plain significantly influences measurements, VPRM-CHINA models an CO2 uptake signal comparable in magnitude to the modeled anthropogenic signal. In addition to demonstrating efficacy as a low-bias prior for top-down CO2 inventory optimization studies using ground-based measurements, high spatiotemporal resolution models such as the VPRM are critical for interpreting retrievals from global CO2 remote sensing platforms such as OCO-2 and OCO-3 (planned). Depending on the satellite time-of-day and season of crossover, efforts to interpret the relative contribution of the vegetation and anthropogenic components to the measured signal are critical in key emitting regions such as Northern China -where the magnitude of the vegetation CO2 signal is shown to be equivalent to the anthropogenic signal. [ABSTRACT FROM AUTHOR]

Recent studies show that international trade affects global distributions of air pollution and public health. Domestic interprovincial trade has similar effects within countries, but has not been comprehensively investigated previously. Here we link four models to evaluate the effects of both international exports and interprovincial trade on PM2.5 pollution and public health across China. We show that 50-60% of China's air pollutant emissions in 2007 were associated with goods and services consumed outside of the provinces where they were produced. Of an estimated 1.10 million premature deaths caused by PM2.5 pollution throughout China, nearly 19% (208,500 deaths) are attributable to international exports. In contrast, interprovincial trade leads to improved air quality in developed coastal provinces with a net effect of 78,500 avoided deaths nationwide. However, both international export and interprovincial trade exacerbate the health burdens of air pollution in China's less developed interior provinces. Our results reveal trade to be a critical but largely overlooked consideration in effective regional air quality planning for China. [ABSTRACT FROM AUTHOR]

Stable carbon isotope ratios ([[Delta].sup.13]C) in extant plants can discriminate between [C.sub.3], [C.sub.4], and CAM photosynthesis, estimate water-use efficiency, and detect carbon cycle variations. In fossil plants [[Delta].sup.13]C is typically measured in untreated leaf carbon, which is used to reconstruct the [[Delta].sup.13]C of living tissue. Living plant tissue is a mixture of different chemical components such as cellulose, lignin, and lipids, which differ from each other in their [[Delta].sup.13]C. The ratio of cellulose, lignin, and lipids is altered during fossilization through partial anaerobic decay and thermal maturation, which increase the abundance of isotopically light lignin and cutin relative to isotopically heavy cellulose, Reconstructions of [[Delta].sup.13]C in a fossil can be 5% to 6% too negative if the fossil material consists solely of lignin. Carbon isotope ratios in extant and fossil plant cuticle indicate that isolation of a pure cuticle fraction can overcome biases introduced by fossilization. The [[Delta].sup.13]C of extant angiosperm and gymnosperm cuticle is 3-3.5% more negative than the [[Delta].sup.13]C of whole tissue, an offset that is consistent for [C.sub.3], [C.sub.4], and CAM species. Estimating whole-tissue [[Delta].sup.13]C from cuticle [[Delta].sup.13]C in extant plants has an error of approximately [+ or -]1%, significantly less than the potential error caused by loss of cellulose during fossilization. Comparison of [[Delta].sup.13]C in untreated leaf carbon and cuticle macerated from the same fossil indicates significant loss of cellulose in some fossil specimens. Carbon isotopic differences between [C.sup.3] and [C.sup.4] plants are sufficiently large to be detected in either untreated fossil carbon or cuticle. However, finer-scale differences in fossil-plant [[Delta].sup.13]C, such as those resulting from differences in water-use efficiency or variations in atmospheric C[O.sub.2], probably require the analysis of cuticle for unambiguous detection.

Although capacity credits for wind power have been embodied in power systems in the U.S. and Europe, the current planning framework for electricity in China continues to treat wind power as a nondispatchable source with zero contribution to firm capacity. This study adopts a rigorous reliability model for the electric power system evaluating capacity credits that should be recognized for offshore wind resources supplying power demands for Jiangsu, China. Jiangsu is an economic hub located in the Yangtze River delta accounting for 10% of the total electricity consumed in China. Demand for electricity in Jiangsu is projected to increase from 331 TWh in 2009 to 800 TWh by 2030. Given a wind penetration level of 60% for the future additional Jiangsu power supply, wind resources distributed along the offshore region of five coastal provinces in China (Shandong, Jiangsu, Shanghai, Zhejiang, and Fujian) should merit a capacity credit of 12.9%, the fraction of installed wind capacity that should be recognized to displace coal-fired systems without violating the reliability standard. In the high-coal-price scenario, with 60% wind penetration, reductions in CO2 emissions relative to a business as usual reference could be as large as 200.2 million tons of CO2 or 51.8% of the potential addition, with a cost for emissions avoided of $29.0 per ton. [ABSTRACT FROM AUTHOR]

China is the largest atmospheric mercury (Hg) emitter in the world. Its Hg emissions and environmental impacts need to be evaluated. In this study, China's Hg emission inventory is updated to 2007 and applied in the GEOS-Chem model to simulate the Hg concentrations and depositions in China. Results indicate that simulations agree well with observed background Hg concentrations. The anthropogenic sources contributed 35–50% of THg concentration and 50–70% of total deposition in polluted regions. Sensitivity analysis was performed to assess the impacts of mercury emissions from power plants, non-ferrous metal smelters and cement plants. It is found that power plants are the most important emission sources in the North China, the Yangtze River Delta (YRD) and the Pearl River Delta (PRD) while the contribution of non-ferrous metal smelters is most significant in the Southwest China. The impacts of cement plants are significant in the YRD, PRD and Central China. [Copyright &y& Elsevier]