全球日尺度AMSR-E和AMSR2全天候大气可降水数据集（2002-2017）

大气水汽是研究水循环的重要参数，在全球气候变暖的背景下，为了更好地研究大气水汽对水循环的影响，构建了空间分辨率为0.25°的全球日尺度AMSR-E/AMSR2全天候大气可降水（Total Precipitable Water，TPW）数据集。数据集中，陆地上空的TPW主要有我们新开发的基于AMSR-E、AMSR2的18.7和23.8GHz亮温数据反演算法获取；海洋上空TPW数据融合了AMSR-E/AMSR2官方TPW产品。作为后处理，为了消除AMSR-E TPW和AMSR2 TPW之间的系统性偏差，以AIRSX2RET TPW为基准，使用直方图匹配方法分别对AMSR-E和AMSR2的TPW数据在全球尺度上进行了系统偏差校正，保证数据的连续性，最终得到全球日尺度AMSR-E和AMSR2 TPW全天候数据集。其中，AMSR-E数据时间范围为2002年7月8日至2011年9月27日，AMSR2数据时间范围为2013年1月1日至2017年8月31。每个日期下均包含升轨和降轨两个文件，数据格式为Geotiff。数据层数为2，第一个层为TPW数据，单位为mm，第二层为时间信息，表示以UTC为时间基准的像元观测时间距离当天0时0分0秒所经过的秒数。数据集具有可靠的质量，通过与全球SuomiNET GPS TPW验证分析，数据集的均方根误差为3.5-5.2mm。由于大气可降水是影响地表遥感重要的地球物理参数，对地球的气候变化也有重要影响，故此数据可用于气候变暖的背景下大气水汽对水循环的影响、大气水资源的评估以及大气校正等方面的研究。

Atmospheric water vapor is a critical parameter for water cycle research. Against the backdrop of global warming, a global daily-scale all-weather Total Precipitable Water (TPW) dataset from AMSR-E/AMSR2 with a spatial resolution of 0.25° was developed to better investigate the impacts of atmospheric water vapor on the water cycle. Within this dataset, TPW over land is mainly retrieved using a newly developed retrieval algorithm based on 18.7 and 23.8 GHz brightness temperature data from AMSR-E and AMSR2; TPW over ocean is fused with the official TPW products of AMSR-E/AMSR2. As a post-processing step, to eliminate the systematic biases between AMSR-E TPW and AMSR2 TPW, we performed global-scale systematic bias correction on the TPW data of AMSR-E and AMSR2 respectively using the histogram matching method, with AIRSX2RET TPW as the reference, to ensure data continuity, and finally obtained the global daily-scale all-weather AMSR-E and AMSR2 TPW dataset. Specifically, the time range of AMSR-E data is from July 8, 2002 to September 27, 2011, and that of AMSR2 data is from January 1, 2013 to August 31, 2017. Each date contains two files corresponding to the ascending and descending orbits respectively, and the data format is Geotiff. The dataset has 2 bands: the first band is TPW data with the unit of mm, and the second band is time information, which represents the number of seconds elapsed between the pixel's observation time and 00:00:00 of the same day based on UTC time. This dataset has reliable quality. Through validation analysis against global SuomiNET GPS TPW data, the root mean square error (RMSE) of the dataset is 3.5–5.2 mm. Since total precipitable water is an important geophysical parameter affecting surface remote sensing and also exerts significant impacts on Earth's climate change, this dataset can be applied to researches on the impacts of atmospheric water vapor on the water cycle, atmospheric water resource assessment, and atmospheric correction under the background of global warming.

搜集汇总

背景与挑战

背景概述

该数据集提供了2002年至2017年全球日尺度全天候大气可降水（TPW）数据，空间分辨率为0.25°，基于AMSR-E和AMSR2传感器数据构建，并通过偏差校正保证数据连续性。数据集质量可靠（均方根误差3.5-5.2mm），适用于研究气候变暖下大气水汽对水循环的影响、大气水资源评估及遥感大气校正等领域。