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Snow bacterial abundance and diversity at the Guoqu Glacier and the East Rongbuk Glacier located in the central and southern Tibetan Plateau were investigated using a 16S rRNA gene clone library and flow cytometry approach. Bacterial abundance was observed to show seasonal variation, with different patterns, at the two glaciers. High bacterial abundance occurs during the monsoon season at the East Rongbuk Glacier and during the non-monsoon season at the Guoqu Glacier. Seasonal variation in abundance is caused by the snow bacterial growth at the East Rongbuk Glacier, but by bacterial input from the dust at the Guoqu Glacier. Under the influence of various atmospheric circulations and temperature, bacterial diversity varies seasonally at different degrees. Seasonal variation in bacterial diversity is more distinct at the Guoqu Glacier than at the East Rongbuk Glacier. Bacterial diversity at the two glaciers exhibits different responses to various environmental conditions. More bacteria at the Guoqu Glacier are connected with those from a soil environment, while more bacteria affiliated with a marine environment occur at the East Rongbuk Glacier.

The Atmospheric Infrared Sounder (AIRS) and MODerate-Resolution Imaging Spectroradiometer (MODIS) on board NASA Earth Observing System (EOS) Aqua spacecraft measure the upwelling infrared radiance used for numerous remote-sensing- and climate-related applications. AIRS provides high spectral resolution infrared radiances, while MODIS provides collocated high spatial resolution radiances at 16 broad infrared bands. An optimal algorithm for cloud-clearing has been developed for AIRS cloudy soundings at the University of Wisconsin-Madison, where the spatially and spectrally collocated AIRS and MODIS data has been used to analyze the characteristic of this algorithm. An analysis and characterization of the global AIRS cloud-cleared radiances using the bias and the standard deviation between the cloud-cleared and the nearby clear measurements are studied. Scene inhomogeneity for both land- and water-surface types has been estimated to account for the assessed error. Both monthly and seasonal changes of global AIRS/MODIS cloud-clearing performance also have been analyzed.

The construction of roads has direct and indirect impacts on soil erosion, with spatio-temporal variations existing among different levels of road zones. Aiming to quantitatively analyze the soil loss, this paper explored the relationship between the erosion of soil and its distance from the road in Fengqing county, Southwest China in 1987 and 2004, respectively. The average soil erosion was calculated and expressed with grid map using universal soil loss equation (USLE) model based on GIS and RS. Along the different levels of roads classified as trunk, county, town, village and unpaved road, the buffer zones were subdivided into five stripes, each of which was 200 meters wide. The average soil erosion modulus of each buffer zone was also counted. Results show that the soil loss decreases with increasing distance to the road except rare trunk roads in the region. In addition, the declined intensity varies with the different levels of roads. Soil erosion was more serious along the lower level road than the higher ones. And soil erosion was more severe for all levels of roads in 1987 than those in 2004 because much more rainfalls affected the situation of soil erosion in 1987.

The comprehensive study of the tectonics-sequence stratigraphic-petroleum system shows that five sets of major regional and some local source rocks were developed in the tectonic evolution of South China, including the Lower Cambrian and Lower Silurian in the Caledonian cycle, the Middle Permian and Upper Permian in the Hercynian cycle, and the Lower Triassic in the Indo-Sinian cycle. Due to the inhomogeneous maturity of source rocks in this area, gas exploration would mainly be carried out in the Lower Paleozoic areas, while oil and gas exploration would be in the Upper Paleozoic ones. The reformation from the Indo-Sinian cycle to the Himalayan cycle exerted decisive influence on the hydrocarbon accumulation in the Mesozoic-Cenozoic basin and marine sequences in southern China. The petroleum systems formed in the medium-late period of the superimposed basins are of the greatest potential. The distribution of primary and secondary oil-gas pools was mainly affected by favorable sedimentary facies, ancient uplift and slope. The comprehensive evaluation concluded that the focuses for petroleum exploration in the marine sequences of southern China will be in the superimposed basins along the margin of Yangtze landmass, the Subei-southern South Yellow Sea basin and the marine sequences preserved under the over-thrust nappe along the northern margin of the Jiangnan uplift.

The global weather of today is growing significantly warmer; this is an indisputable fact. However, the scientific community has not yet reached consensus on the causes of global warming and its possible consequences. This paper introduces the causes of global warming and summarizes its results, which both involve a series of huge and complex system issues. Our top priority is to pinpoint the main reason and the interrelated links between causative factors by adopting a macro-approach, or comprehensive comparison analysis. Its physical mechanism was then determined and its digital model established after quantitative study.

We conducted rock magnetic and paleomagnetic research on two deep-sea sediment cores from the west Philippine Sea, located to the east of Benham Rise with the length of 4 m and water depth of over 5000 m. At the bottom of core 146 occurs a reversal of inclination and deflection of relative declination, which is recognized as Brunhes-Matuyama Polarity Boundary (MBPB). No reversal occurs in core 89, which implies a younger bottom age than that of core 146. Rock magnetic results reveal magnetic uniformities in mineralogy, concentration and grain size along the two cores, thus relative paleointensity variations are acquired. The three normalizers-anhysteresis remanent magnetization (ARM), magnetic susceptibility (k) and saturation isothermal remanent magnetization (SIRM) are used for normalization to obtain relative paleointensities. The three normalization results are averaged to indicate the paleoitensity of the cores and are further stacked together to get a synthetic curve for west Philippine Sea (named asWPS800 in this paper). Based on the magnetic correlation between cores and paleointensity to Sint800, we transfer the changes of rock magnetic parameters from depth to time. Furthermore, the astronomically tuned oxygen isotope from ODP site 1143 in the south China Sea is used for the glacial and interglacial indicator. Three concentration proxies (ARM, k and SIRM) and grain size indicators (k ARM/SIRM, k ARM/k) are examined according to the paleointensity-assisted chronology. The grain size changes in the two cores display a consistent pattern with the climatic changes embodied by oxygen isotope. The magnetic sizes are usually coarser in glacial periods and finer in interglacial times, which may reflect the influence of chemical erosion rather than fining from sea level rising on the source sediment. Furthermore, the sub-peaks and sub-troughs in interglaciations almost correspond with that of oxygen isotope records, which means sedimentation can reflect the subtle changes in interglaciations. This kind of revelation of climatic fluctuation by magnetic size is also found in the South China Sea, which shows a common pattern of magnetic signals to climate at least within East Asia. The concentration of ARM (representing more about fine grain) also shows similar response to glacial and interglacial cycles, that is, high in interglacial cycle and low in glacial cycle; but k and SIRM (reflecting more about coarse grain) lack the response to the climatic cycles. At the same time, S-ratio lacks the correlation with aeolian dust record and rhythmic changes, indicating the dominant source of main magnetic carrier (low coercivity magnetite) is the suspended matter instead of dust. The decreasing trend of sedimentation rate from west to east also reveals that the sediments are mainly from west Luzon and adjacent land. Grain sizes first became coarse and then stable around 400 ka B.P., and at the same time all the magnetic contents lowered and amplitude of magnetic mineral changes increased. The magnetic transition around 400 ka B.P. is simultaneous with the decreases of carbonate content, reflecting a global carbonate dissolution event, i.e. mid Brunhes event. The synchronization of magnetic content and grain size with climatic cycles of glacials and interglacials imply the validity of paleointesnityassisted chronology. Also, the response of rock magnetic signals to stable oxygen isotope changes and carbonate variation reveals that rock magnetismmethod can be an effective tool for paleoclimatic and paleoceanographic research.

Due to the multiplicity of factors including weather, the underlying surface and human activities, the complexity of parameter optimization for a distributed hydrological model of a watershed land surface goes far beyond the capability of traditional optimization methods. The genetic algorithm is a new attempt to find a solution to this problem. A genetic algorithm design on the Distributed-Hydrology-Soil-Vegetation model (DHSVM) parameter optimization is illustrated in this paper by defining the encoding method, designing the fitness value function, devising the genetic operators, selecting the arithmetic parameters and identifying the arithmetic termination conditions. Finally, a case study of the optimization method is implemented on the Lushi Watershed of the Yellow River Basin and achieves satisfactory results of parameter estimation. The result shows that the genetic algorithm is feasible in optimizing parameters of the DHSVM model.

The Cenozoic sedimentation in the Tianshui basin, which is located at the junction of the liupanshan and West Qinling, northeast margin of the Tibetan plateau, provides a record for the regional tectonism and exhumation history of the surrounding mountains. Thermochronologic study on the detrital apatite grains from sandstones at Yaodian, near Tianshui, has revealed two rapid tectonic uplift-exhumation events of the source area, which happened at 23.7 and 14.1 Ma, respectively. The fast exhumation (0.34 mm/a) at 23.7 Ma, which recorded the tectonic uplift of West Qinling, led to the formation of the Neogene Tianshui basin and initiated the reception of alluvial deposits. This event is most likely in response to the synchronous tectonism of the Tibetan plateau. The source region experienced another rapid exhumation (1.05 mm/a) at 14.1 Ma, when the Tianshui basin began to depress broadly and fluvial-lacustrine sediments dominated the Late Miocene.