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From 1970s, the climate system has been studied as a whole by considering the coupled atmosphere-ocean-cryosphere-land surface physical system. Beginning from early 2000s, coupling between the physical climate system processes and biogeochemical processes has been one of the most important research focuses. This is because that the biogeochemical processes such as the carbon cycle and nitrogen cycle plays very important roles on the climate and environmental changes. Therefore, there have been great efforts to develop numerical models to simulate the above processes in the coupled earth system. There numerical models are the so-called earth system models. The simulations are performed by numerical integrations in the supercomputers. The earth system model is the most complex one in natural science numerical models, reflecting the comprehensive expressions of the earth system knowledge, and is the pacemaker of the earth science advances in different countries and groups. The earth system model is the most important tool for the earth system science development. This paper discusses the scientific background, application demands, the scientific achievements in China, and the future objectives and tasks.

Continuous in situ measurements of aerosol optical properties have been conducted since March 2010 at a semi-arid rural site in Northeastern China - Tongyu (44.56°N, 122.92°N, elevation 151 m), a reference site of Coordinate Water and Energy cycle Observation Project (CEOP). Aerosol optical properties derived from the measurements during two spring seasons in 2010 and 2011 are analyzed and presented here. Mean values (and standard deviation) of light absorption coefficient (αab) and scattering coefficient (αsc) at 520 nm were 7.61 Mm–1 (6.17 Mm–1) and 89.22 Mm–1 (88.37 Mm–1), respectively, in spring of 2010, and were 7.01 Mm–1 (5.60 Mm–1) and 85.34 Mm–1 (116.11 Mm–1), respectively, in spring 2011. These values are lower than the majority of measurements made in other areas of China. The mean single scattering albedo (ω) was 0.90, greater than values found in some developed areas in China, indicating more scattering or less absorbing aerosols at Tongyu site. Mean values (and standard deviation) of the Angstrom exponent of absorption (αab) were 1.61 (0.27) and 1.64 (0.28) for spring of 2010 and 2011, respectively, and of the scattering (αsc) were 1.48 (0.50) and 1.10 (0.50), respectively. The values of αab were higher than those of pure BC, implying the presence of other light absorbing materials having larger αab values. The moderate values of αsc indicated that considerable amount of coarse particles presented at Tongyu site. Distinct diurnal variations of aerosol optical properties were observed. ω, αab and αsc had nearly opposite diurnal variations compared to those of αab and αsc. Dust aerosols from the northwest and anthropogenic aerosols from the south were major sources contributing to the episodic aerosol events and thus, unusual aerosol optical properties, in spring at Tongyu site. High levels of PM2.5, if mainly caused by dust particles, do not necessarily introduce high values of αab and αsc.

The Models-3 Community Multi-scale Air Quality (CMAQ) modeling system with meteorological fields calculated by the Regional Atmospheric Modeling System (RAMS) was applied to East Asia to investigate the transport and photochemical transformation of tropospheric ozone during the Transport and Chemical Evolution over the Pacific (TRACE-P) field campaign. Modeled concentrations of hydroxyl radical, hydroperoxyl radical, nitric oxide, nitrogen dioxide, ethene, ethane, carbon monoxide, and ozone were compared with observations obtained onboard of two aircrafts in order to evaluate the model performance. Comparison indicates that the model reproduced the tempo-spatial distributions of ozone and its related chemical species reasonably well, and most model results were within a factor of 2 of the observations.

Increasingly severe forest fires in the west have triggered a high demand for accurate and timely information on forest fuel attributes. There is great interest in the potential for using recent advances in high spectral resolution remotely sensed imagery to estimate fuel characteristics. We combined field forest inventory and field spectroscopy in the Colorado Front Range with airborne imaging spectrometer measurements of the region to test their capacity to estimate fire related forest attributes including canopy cover, forest type, and burn severity in ponderosa pine ( Pinus ponderosa ) and Douglas-fir ( Pseudotsuga menziesii var. glauca ) dominated forests. Spectral angle mapper and mixture-tuned matched filtering techniques were tested for mapping fuel attributes. Estimates of canopy cover using spectral angle mapper techniques found 61% agreement with observed values, while mixture-tuned matched filtering estimates of forest canopy cover matched 78% with field observations. The distinction of ponderosa pine versus Douglas-fir is crucial for predicting fire spread in the Rocky Mountains; we found that spectral discrimination of these species was also promising, with an accuracy of 53–57%. The average canopy cover of mixed conifer forest in the area is 38.6%, 24.7% contributed by ponderosa pine and 13.9% by Douglas-fir. The values of canopy cover ranged from 53% to 56% in US Forest Service planned fuel treatment areas, among the highest in the region. Recent forest fires have created approximately 684 km 2 of burned area, with very low canopy cover (13–22%).

▪ Abstract Fossil fuels account for about 80% of energy consumption in Asia. Because of its abundance and easy recoverability, especially in India and China, coal will remain the fuel of choice in the foreseeable future. If current trends continue, sulfur dioxide emissions from Asia may soon equal the emissions from North America and Europe combined. These trends portend a variety of local, regional, and global environmental impacts. Acid rain damages human health, ecosystems, and built surfaces. Many ecosystems will be unable to absorb these increased acidic depositions, leading to irreversible ecosystem damage with far-reaching implications for health, forestry, agriculture, fisheries, and tourism. RAINS-ASIA is a scenario-generating tool used to estimate the extent of damages caused by acid rain and to review the costs and impacts of alternatives to provide a look into the future. Its use extends from national-, regional-, and city-scale evaluation and inputs for cost-effective options analyses, to international negotiations on transboundary pollution.