RS AND GIS-BASED FOREST FIRE RISK ZONE MAPPING IN DA HINGGAN MOUNTAINS

1INTRODUCTIONForests are one of the major natural resources that per-form important environmental and recreational func-tions (COSTANZA and GROOT, 1997). It is well known that forests can absorb atmospheric carbon, maintain a certain degree of humidity in atmosphere, regulate rainfall, moderate temperature, and restrain soil erosion, etc. (AURELIA, 2003). So, the health of a forest in any given area is a very important indicator of the ecological conditions. But fire is the great…     

The Effect of Tide on the Global Climate Change

The differential rotation between the solid and fluid spheres caused by tidal force could explain the 1500 to 1800 - year cycle of the worlds temperature. Strong tide increases the vertical and horizontal mixing of water in the oceans,dra-wing the cold Pacific water from the depths to the surface and the warm water from the west to the east, where it cools or warms the atmosphere above, absorbs or releases CO2 to decrease or increase greenhouse effect and to make La Nina or El Nino occur in the global. The moons declination and obliquity of the ecliptic affect the tidal intensity. The exchange of tidal energy and tide -generating force caused by the sun, moon and major planets makes the earths layers rotate in different speeds. The differenti-al rotation between solid and fluid of the earth is the basic reason for El Nino and global climate change.     

LUCC and Accompanied Soil Degradation in China from 1960''''s to 1990''''s

This paper tries to qualitatively analyze land use and cover changes (LUCC) and accompanied soil degradation in China, the data of World Atlas of Agriculture in 1969, Land Cover Data of Asia in 1992 and Global Assessment of Human Induced Soil Degradation in 1992, etc. have been used. From 1960' s to 1990's, the area of forestland had increased, ara-ble land and paddy as well as grassland had significantly decreased in China. The major type of soil degradation is due to wa-ter erosion, which is widely distributed especially in Loess Plateau and in Southeast and Southwest China, this happened in forestland, grassland and arable land and mainly resulted from deforestation. The secondary type is wind erosion, which is mainly distributed in Northwest China, it happened in arable land and grassland and was caused by overgrazing. Chemical deterioration is distributed in North and Northwest China, which happened in paddy, arable land and grassland. Physical de-terioration only concentrated in local area in North     

ASSIMILATION OF REAL OBSERVATIONAL DATA WITH THE GSI-HYBRID DATA ASSIMILATION SYSTEM TO IMPROVE TYPHOON FORECAST

A hybrid GSI (Grid-point Statistical Interpolation)-ETKF (Ensemble Transform Kalman Filter) data assimilation system has been recently developed for the WRF (Weather Research and Forecasting) model and tested with simulated observations for tropical cyclone (TC) forecast. This system is based on the existing GSI but with ensemble background information incorporated. As a follow-up, this work extends the new system to assimilate real observations to further understand the hybrid scheme. As a first effort to explore the system with real observations, relatively coarse grid resolution (27 km) is used. A case study of typhoon Muifa (2011) is performed to assimilate real observations including conventional in-situ and satellite data. The hybrid system with flow-dependent ensemble covariance shows significant improvements with respect to track forecast compared to the standard GSI system which in theory is three dimensional variational analysis (3DVAR). By comparing the analyses, analysis increments and forecasts, the hybrid system is found to be potentially able to recognize the existence of TC vortex, adjust its position systematically, better describe the asymmetric structure of typhoon Muifa and maintain the dynamic and thermodynamic balance in typhoon initial field. In addition, a cold-start hybrid approach by using the global ensembles to provide flow-dependent error is tested and similar results are revealed with those from cycled GSI-ETKF approach.     

华东地区气温变化对居住建筑能源消耗的影响研究

基于1961-2007年华东478个测站和2010-2039年RegCM3模式模拟的日平均气温资料,分析了华东采暖度日和制冷度日时空变化特征及其与气温变化的关系。结果表明,1961-2007年期间,华东采暖度日呈先增加后减少的变化趋势,制冷度日则呈先减少后增加的变化趋势。在2010-2039年期间,华东采暖度日将继续减...     

National Basic Research Program of China(973 Program) Indo-Pacific Oceanic Channel Project Special Issue

正1 INTRODUCTION The tropical Indo-Pacific Oceans span over twothirds of the global tropical oceans.A major warm pool with the highest large-scale sea surface temperature of the global oceans is located in the western Pacific and eastern Indian Oceans.The climate systems over the tropical Pacific and Indian Oceans are subject to strong ocean-atmosphere coupling at multiple scales from intraseasonal to interannual,and to centennial.The strongest     

IPCC-AR4全球气候模式在华东区域气候变化的预估能力评价与不确定性分析

本文分析了IPCC第四次评估报告中的全球气候模式在华东区域的气候预估能力与不确定性.以均方根误差作为衡量预估能力的标准,比较了IPCC-AR4中21个气候模式在中等排放情景下的预估能力,结果表明气候模式对华东区域气候变化的模拟能力差异较大,模式NCAR-CCSM3和MRI_CGCM2_3.2在年平均气温和年降水2个要素的均方根误差均较小.说明它们对华东区域的气候预估能力比其他模式强.在中等排放情景下,气候模式能够模拟出接近观测实况的年平均气温与降水的空间分布特征,但是由于空间分辨率较低,模式不能模拟出局部细致的结构:多模式集合平均对华东区域气温预估存在明显系统偏差,比观测实况偏低1.6℃以上,偏低幅度超过了不确定性(一倍的模式间标准偏差)能涵盖的范围;华东区域年降水模式间标准偏差占模式集合平均百分比为26.7%,表明直接用AR4多模式集合平均的结果难以准确反映华东区域该要素的未来变化.     

浙江省气候变化事实研究

为了区分不均一与局地气候的突变,采用功效不同的SNHT、Buishand、Pettitt 三种均一性检验法对浙江省41 个气象观测站1960—2007 年的温度和降水的观测序列进行检验。通过对三种方法检验的站点数据做气候变化事实研究发现,近50 年浙江省与全球呈现一致的气温年代际变化特征,0.19 ℃/(10 a)的平均气温倾向率比0.13 ℃/(10 a)的全球平均值高,略低于0.22 ℃/(10 a)的全国平均值。全省年平均降水量呈上升趋势,这与中国降水量总体下降的变化趋势相反,但与长江流域以南的变化趋势一致;强降水、高温热浪等极端天气事件频率增大,城市局地气候趋于“ 热干” 化;≥10 ℃的初日提早10 天左右,而终日推迟了近10 天,在持续日数增加的同时,有效积温也相应增大。