摘要
利用1982—2006年NOAA系列卫星观测的中国西北地区各气象站所在区域归一化植被指数(NDVI)多年平均最大值(IMAX),给出了判定气象站所代表区域下垫面类型的一个标准:0.45≤IMAX<1为绿洲;0.20≤IMAX<0.45为戈壁;0<IMAX<0.20为沙漠。根据这一标准选择张掖、阿拉善右旗和山丹常规气象站分别为绿洲、沙漠和戈壁代表站与HEIFE试验相同的3种下垫面观测的气象要素进行了对比分析,结果显示:(1)常规气象站与野外站观测的地—气温差的比较显示,两者在绿洲下垫面秋、冬、春三季的变化趋势一致,而夏季前者明显高于后者,且变化位相相反;沙漠下垫面的变化趋势基本一致,前者比后者略偏大;戈壁下垫面最为接近。夏季绿洲下垫面两者地—气温差不同,受下垫面状况和太阳直接辐射作用的共同影响,每日14时的地温有很大不同;两者气温的日变化形式相同,但前者全年都略高于后者。(2)气象站与野外站地面风速的比较发现,绿洲和沙漠下垫面上两者观测的10 m风速值全年均相近,戈壁下垫面前者的值要比后者小很多,气象站年平均风速只有2.3 m.s-1,而野外站达到4.9 m.s-1。本文主要对影响地面感热定量计算的几个气象要素进行讨论,以期能对气象站和野外站观测资料之间的异同以及气象站观测的气象要素对其所在区域的代表性等问题有一个基本了解,从而为气象站与野外站资料相结合的研究提供一个基本认识。
A standard were given to distinguish the underlaying surface types for the representative areas of the meteorological stations in northwestern China using the multi-annual mean maximum value of NDVI（I MAX） observed by NOAA series satellite from 1982 to 2006,that is to say,if 0.45≤ I MAX 1,the underlaying surface is Oasis,0.20≤ I MAX 0.45 is Gobi and 0 I MAX 0.20 is Desert.According to this standard,three conventional meteorological stations that Zhangye,Alashan Right Banner and Shandan were chosen to represent the Oasis,Desert and Gobi underlaying surfaces,respectively,then carried on the contrastive analysis to the meteorological elements with the same underlaying surfaces of HEIFE experiment.The results indicated that the change forms of land-atmosphere temperature difference of conventional meteorological and field stations on the oasis underlaying surface are consistent in autumn,spring and winter,but the former is higher than the latter obviously,and the change phase is opposite in summer.On the Desert underlaying surface,the change tendency is basic consistent,the former is slightly bigger than the latter,and it is closest on the Gobi underlaying surface.The change forms of the land-atmosphere temperature difference were influenced by both the surface conditions and the direct solar radiation,they were mainly caused by daily ground temperature of 14：00 on the oasis underlaying surface in summer,and the air temperature′s diurnal variation form of conventional meteorological station is same as the field station′s,but the former is higher slightly than the latter in a whole year.The wind speed in the heights of 10 m of the conventional meteorological station is close to the field station′s on the Oasis and Desert underlaying surfaces in a whole year,and the annual mean wind speed in the heights of 10 m of the conventional meteorological station is only 2.3 m·s-1,but the field station has 4.9 m·s-1,that is to say,the former′s wind speed is smaller obviously than the latter on the Gobi underlaying surface.The main purpose of this paper is to discuss several meteorological elements which affect the quantitative calculation of sensible heat,in order to have a basic understanding to the problems such as the differences between the conventional meteorological stations and field stations observation data and the regional representative of the meteorological elements that conventioral meteorological station observed,thus provide some knowledge for the research of the meteorological stations combine with field station data.
出处
《高原气象》
CSCD
北大核心
2010年第2期514-522,共9页
Plateau Meteorology
基金
国家自然科学基金项目(40875059)
干旱气象科学研究基金项目(IAM200801)共同资助
关键词
西北干旱区
归一化植被指数
气象站观测
黑河试验
地—气温差
Northwest dry area of China
NDVI
Meteorological station observation
HEIFE
Land-atmosphere temperature difference
