Merged Statistical Analyses of Historical Monthly Precipitation Anomalies Beginning 1900

An improved land-ocean global monthly precipitation anomaly reconstruction is developed for the period beginning in 1900. Reconstructions use the available historical data and statistics developed from the modern satellite-sampled period to analyze variations over the historical pre-satellite period. This paper documents the latest in a series of precipitation reconstructions developed by the authors. Although the reconstruction principle is still the minimization of mean-squared error, this latest reconstruction includes the following three major improvements over previous reconstructions: (i) an improved method that first produces an annual first guess, which is then adjusted using a monthly increment analysis; (ii) improved use of oceanic observations in the annual first guess using a canonical correlation analysis; and (iii) reinjection of gauge data where those data are available. These improvements allow more confident analyses and evaluations of global precipitation variations over the reconstruction period.

(Abstract excerpted from Smith et al. 2012.)

本研究针对1900年以来的陆地与海洋全球月度降水异常重建进行了改进。该重建过程利用了现有历史数据，并结合现代卫星采样时期所发展出的统计数据，以分析历史卫星前时期的变动情况。本文记录了作者们开发的一系列降水重建工作的最新进展。尽管重建原理仍基于均方误差的最小化，但此次最新重建相较于先前版本具有以下三项主要改进：(一)首先采用一种改进的方法生成年度初步估计值，随后利用月度增量分析进行调整；(二)通过典范相关分析，在年度初步估计值中更有效地利用海洋观测数据；(三)在数据可用的情况下，重新注入气象观测数据。这些改进使得对重建时期全球降水变率的分析和评估更加自信。(摘要摘自Smith等，2012年。)