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题名 三江源湿地消长对区域气候影响的数值模拟
姓名 马艳
院系 大气科学学院
专业 气象学
学位名称 理学硕士
外文题名 Modelling on Impacts of Three River Source Region''''s changed area on the regional climate
第一导师姓名 靳立亚
关键词 区域气候模式;气候模拟;RegCM3;三江源;湿地
外文关键词 Regional Climate Model,;Climate Simulation,;RegCM_3;Three River Source Region,;Wetland
学科 理学
摘要 本文运用1995年5月-9月的NNRP2再分析每日4时次资料驱动RegCM3模拟 三江源及其周边地区,并用ECMWF再分析每日4时次资料中的ECT42与模拟 结果相比较,得到验证区域气候模式RegCM3是适合运用于该区域。然后,运 行区域气候模式RegCM3研究三江源湿地的消长对该区及其周边地区气候的影 响。共设计了三组试验:控制试验(A),即采用NOAA的OISST和美国地理 调查局提供的地形及全球植被资料,以1995年5月1日06时的NCEP资料作初 始场,积分至1995年9月1日00时;三江源湿地面积扩大试验(B),即将三江 源区的土地覆盖/利用类型11即半荒漠换成类型14即内陆水,其余都跟第一组 实验相同;湿地面积缩小试验(C),即将三江源区的土地覆盖/利用类型2、9、 12、13和14即草甸、冻土、冰川、沼泽和内陆水换成类型8即沙漠,其余都跟 第一组实验相同。通过对比分析发现,三江源湿地的扩大和缩小都能影响地 表温度、高度场和流场、以及降水的强度,还能影响到土壤含水量和蒸发量。 对于湿地增加(减少)产生的影响,主要有以下模拟结果: 当湿地增加后,青藏高原夏季平均温度降低,降水减小。这是因为当三 江源湿地增加,使得地面反照率降低,热容量增加,感热输送减弱,对大气 的湍流加热减小,从而导致该区域上空的大气温度降低,对应的上升运动减 弱,近地层等压面高度也就随之升高,降水就减少。高原气温降低致使高原 上空的气旋性环流加强,长江中下游地区降水增多。同时,季风区的季风加 强,降水增多。新疆温度降低,降水增多。 当湿地减少后,主要变化与湿地增加后基本相反。 由以上可以看出,三江源湿地的消长对该区及其周边地区的气候产生了 深刻的影响。
外文摘要 Impacts of Three River Source Region''''s changed area on the regional climate and environment, were studied and analyzed by using the latest Regional Climate Model (RegCM_3). Experiment was designed, to indicate the conclusion that RegCM_3 has the ability to simulate the climate of the Three River Source Region, in this way: The four times daily reanalysis data during the period of May to September in year 1995, offered by NCEP, was first used to initiate the Regional Climate Model, then the result of simulation was compared with the reanalysis data collected from ECMWF. There were three groups of experiment designed to study the influence of the growth and degradation of Three River Source Region''''s wetland on the climate of the studying region and the regions around. The first experiment is Controlled Experiment (A): run the model from 1st May, 1995 to 1st September, by using datasets of OISST, Topography, and Global Vegetation, offered by NOAA and US Geological Survey respectively. The second one was defined as Expanded Experiment(B) over Three River Source Region''''s wetland, as it just changed the Land Cover/Vegetation Classes over River Source Region from type 11—Semi-desert to type 14—Inland water. The final group is named as Miniature Experiment (C). It was done by substituting type 2, 9, 12, 13 and 14 of Land Cover/Vegetation Classes over River Source Region, which is Short grass, Tundra, Ice cap/glacier, Bog or marsh and Inland water respectively, with type 8—Desert, while keeping the other types unchanged. The comparing analysis indicated that: expansion and degradation of Three River Source Region''''s wetland can both impose impacts on Surface Temperature, Potential Height Field, Wind Field, and intensity of precipitation, as well as the vapor rate and containing water of soil. The main simulating results about the impacts imposed by increase or reduction of wetland area include the following: First, the average temperature in summer over Tibet Plateau falls down and precipitation decreases as the wetland areas increase. This can be explained by the fact that decreased surface reflective rate, increased thermal capacity, weakened sensitive heat flux and decreased heat on atmospheric turbulence, all resulted from the expansion of wetland, can lead the atmospheric temperature over this region to fall, and its rising movement to weaken, and then rise the geopotential height near the surface, as well, the rainfall reduce. The falling te...
研究领域 气候动力与气候预测
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