Variability of temperature in the Tibetan Plateau based on homogenized surface stations and reanalysis data
Variability of temperature in the Tibetan Plateau based on homogenized surface stations and reanalysis data
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DOI：
10.1002/joc.3512
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发表时间：
2013-05
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影响因子：
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通讯作者：
Qinglong You;K. Fraedrich;G. Ren;N. Pepin;Shi-chang Kang
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文献类型：
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作者：
Qinglong You;K. Fraedrich;G. Ren;N. Pepin;Shi-chang Kang
青藏高原（TP）平均海拔超过4000米。是世界上最高最广的高原。气候观测的缺乏限制了我们对该地区地表气温变化的了解。因此，我们比较了71个均匀化的地面站（海拔2000米以上）的温度及其趋势。1961-2004年期间，与美国国家环境预报中心/美国国家大气研究中心（NCEP/NCAR）再分析（NCEP/NCAR）和欧洲中期天气预报中心（ECMWF）再分析（ERA-40）在TP东部和中部进行了研究。对于当前气候学，ERA-40比NCEP/NCAR更类似于地面站。与地面站相比，NCEP/NCAR和ERA-40再分析都存在冷偏差，这主要是地形高度、站高和坡度差异的结果。平均而言，地面站的变暖趋势比两次再分析都要强，但ERA-40比NCEP/NCAR更清楚地捕捉到了每年和季节的地面变暖。由于ERA-40更能代表TP中部和东部的地表温度及其趋势，因此选择ERA-40预测来检查TP西部的变化，因为那里的地表站很少。另一方面，NCEP/NCAR更能代表自由空气温度条件。“观测减再分析”（OMR）方法可以通过计算地面观测与NCEP/NCAR（只包含影响同化大气趋势的强迫）之间的差异来估计地面变化对气候的影响。OMR的趋势是显着增加，但在何种程度上在当地环境的变化是负责任的需要进一步研究。皇家气象学会
The Tibetan Plateau (TP) with an average elevation of over 4000 m a.s.l. is the world's highest and most extensive highland. The scarcity of climatic observations limits our understanding of surface air temperature change in the region. Thus, we compare temperatures and their trends from 71 homogenized surface stations (with elevations above 2000 m a.s.l.) with National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) Reanalysis (NCEP/NCAR hereafter) and European Centre for Medium‐Range Weather Forecasts (ECMWF) reanalysis (ERA‐40 hereafter) in the eastern and central TP during 1961–2004. For current climatology, ERA‐40 is more similar to the surface stations than NCEP/NCAR. Compared with surface stations, both NCEP/NCAR and ERA‐40 reanalyses have cold biases, which are mainly a result of differences in topographical height, and station aspect and slope. Warming trends at the surface stations are on average stronger than in both reanalyses, but ERA‐40 captures the surface warming more clearly than NCEP/NCAR on an annual and seasonal basis. Since ERA‐40 more closely represents the surface temperatures and their trends in the central and eastern TP, ERA‐40 predictions are selected to examine change in the western TP where there are few surface stations. NCEP/NCAR, on the other hand, is more representative of free air temperature conditions. The ‘observation minus reanalysis’ (OMR) method can be used to estimate the impact of surface changes on climate by computing the difference between surface observations and NCEP/NCAR (which only contains the forcing influencing the assimilated atmospheric trends). The OMR trend is significantly increasing but the extent to which the changes in local environment are responsible needs further study. Copyright © 2012 Royal Meteorological Society