A decadal microwave record of tropical air temperature from AMSU-A/aqua observations
A decadal microwave record of tropical air temperature from AMSU-A/aqua observations
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DOI：
10.1007/s00382-013-1696-x
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发表时间：
2013-02
期刊：
影响因子：
4.6
通讯作者：
Yu Shi;King‐Fai Li;Y. Yung;H. Aumann;Zuoqiang Shi;T. Hou
中科院分区：
文献类型：
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作者：
Yu Shi;King‐Fai Li;Y. Yung;H. Aumann;Zuoqiang Shi;T. Hou
大气温度是最重要的气候变量之一。这项观测研究详细描述了自2002年9月以来在热带海洋上空由Aqua号上的高级微波探测单元-仪器A（AMSU-A）获得的9年亮温数据中的温度变化。一个非线性的，自适应的方法，称为包围联合多重提取已被用来提取的AMSU-A/Aqua数据的变异性的主要模式。成功地恢复了对流层和平流层的半年、年、准两年振荡（QBO）模态和QBO年拍频。厄尔尼诺/南方涛动（ENSO）在对流层中的调制被发现，并与多变量ENSO指数很好地相关。2002-2011年期间的长期变化揭示了热带平流层的冷却趋势（-0.5 K/10 hPa）;由于我们的数据长度，热带对流层顶以下的趋势在统计上不显着。在对流层中还发现了一个新的对流层近年模态（周期约为1.6年），其存在得到了国家环境预测中心再分析气温数据的证实。在对流层中的近年度模式被发现占主导地位，在东太平洋地区，是相干的近年度模式在暖池地区，以前已经报道的观测到的海表温度。气候模型模拟本工作报告的自然变率趋势和主要模式仍然是一个挑战。
Atmospheric temperature is one of the most important climate variables. This observational study presents detailed descriptions of the temperature variability imprinted in the 9-year brightness temperature data acquired by the Advanced Microwave Sounding Unit-Instrument A (AMSU-A) aboard Aqua since September 2002 over tropical oceans. A non-linear, adaptive method called the Ensemble Joint Multiple Extraction has been employed to extract the principal modes of variability in the AMSU-A/Aqua data. The semi-annual, annual, quasi-biennial oscillation (QBO) modes and QBO–annual beat in the troposphere and the stratosphere have been successfully recovered. The modulation by the El Niño/Southern oscillation (ENSO) in the troposphere was found and correlates well with the Multivariate ENSO Index. The long-term variations during 2002–2011 reveal a cooling trend (−0.5 K/decade at 10 hPa) in the tropical stratosphere; the trend below the tropical tropopause is not statistically significant due to the length of our data. A new tropospheric near-annual mode (period ~1.6 years) was also revealed in the troposphere, whose existence was confirmed using National Centers for Environmental Prediction Reanalysis air temperature data. The near-annual mode in the troposphere is found to prevail in the eastern Pacific region and is coherent with a near-annual mode in the observed sea surface temperature over the Warm Pool region that has previously been reported. It remains a challenge for climate models to simulate the trends and principal modes of natural variability reported in this work.