西北干旱区绿洲—戈壁资料同化数据集的建立与分析  

Establishment and Analysis of Assimilation Dataset of Oasis-Gobi System over an Arid Region in Northwestern China

作　　者：文小航[1,2] 吕世华[2] 董文杰[1] 奥银焕[2] 

机构地区：[1]北京师范大学地表过程与资源生态国家重点实验室,北京100875 [2]中国科学院寒区旱区环境与工程研究所寒旱区陆面过程与气候变化重点实验室,兰州730000

出　　处：《高原气象》2014年第1期66-79,共14页Plateau Meteorology

基　　金：国家重点基础研究发展规划项目(2010CB950503;2010CB950504);寒旱区陆面过程与气候变化重点实验室开放基金(LPCC201101);国家高技术研究发展计划(2013AA122003)

摘　　要：利用美国气象环境预报中心和美国国家大气研究中心(NCEP/NCAR)共同开发的天气研究和预报系统WRF模式3.1版本,结合地球观测系统的中分辨率成像光谱仪EOS-MODIS反演的下垫面土地利用/植被类型资料,并同化2008年夏季金塔绿洲野外观测试验所取得的气象资料,对绿洲系统陆—气水热交换过程进行模拟,最终生成金塔高分辨率资料同化再分析数据集。此数据集包括黑河流域金塔绿洲2008年6-8月逐时水平分辨率1 km的土地利用类型、19层风温湿压、4层土壤温湿度以及地表植被覆盖、辐射分量、热通量等资料。同时,利用金塔绿洲观测期内的地表气压、地面气温和相对湿度实测值对该数据集进行初步验证,并分析了绿洲—戈壁系统的"冷湿岛效应"、平均大气环流特征和空气温湿度长期变化规律。结果表明,绿洲和戈壁下垫面的热力差异明显,绿洲和戈壁平均地表温度白天和夜间分别相差21℃和3℃;10 cm土壤温度白天最大相差17℃,并且绿洲比戈壁滞后3 h达到峰值;戈壁相对湿度比绿洲平均约低11%;白天绿洲的"冷岛效应"和"湿岛效应"影响高度平均可达2000 m和1500 m;夜间绿洲的近地层500 m以下则表现出弱的"冷岛效应";夜间绿洲上空的平均垂直气流为上升气流,白天出现大范围下沉气流,平均最大下沉气流速度可达-0.3 m·s-1。The water-energy exchange process and land-atmospheric interaction were simulated by Weather Re- search and Forecasting （WRF） model version 3. 1, which developed by the National Center for Atmospheric Re- search. The underlying surface land use and vegetation types with MODIS data and the meteorological data which were acquired in Jinta experiment during summer in 2008 were also assimilated in the WRF model. Further, the Jinta high resolution data assimilation reanalysis dataset was produced by WRF model. This dataset includes land- use types with 1 km horizontal resolution for each hour, wind, temperature, humidity and pressure at 19 levels, soil temperature and moisture at 4 levels, vegetation fractional coverage, radiation and heat fluxes on land surface from June to August 2008 over heihe river basin in Jinta Oasis. The surface pressure, temperature and relative humility were verified by observations in this study and the cold-wet land effects＇, characteristics of mean atmos- pheric circulation, and long-period variation of air temperature and relative humidity were analyzed by using this dataset. The result showed that the thermal difference was obviously between oasis and Gobi, and the differences of land surface temperature in the day and night time was 21℃ and 3℃ in oasis and Gobi, respectively. The differences of soil temperature at 10 cm depth during daytime was 17℃ at the most, and the peek value of soil temperature in oasis occurred 3 hours later than in Gobi. The averaged relative humidity in oasis was 11% lower than that in Gobi. The ＇ clod island effect＇ and ＇ wet island effect＇ could affect the atmospheric layer up to 2000 m and 1500 m height during the day, respectively. It showed that a weak cold island effect＂ appeared below 500m near surface layer at night. In the upper layer over oasis, updraft appeared during nighttime and downdraft occurred during daytime on a large scale, and the maximum vertical velocity downwards could reach to -0.3 m. s-1. This reanalysis dataset c

关 键 词：绿洲-戈壁系统 WRF模式 小气候效应 金塔高分辨率资料同化再分析数据集 

分 类 号：P463.2[天文地球—大气科学及气象学]