학술논문

Long‐Term Precipitation Estimates Generated by a Downscaling‐Calibration Procedure Over the Tibetan Plateau From 1983 to 2015
Document Type
article
Source
Earth and Space Science, Vol 6, Iss 11, Pp 2180-2199 (2019)
Subject
precipitation
PERSIANN‐CDR
data mining
calibration
long term
Tibetan Plateau
Astronomy
QB1-991
Geology
QE1-996.5
Language
English
ISSN
2333-5084
Abstract
Abstract The World Meteorological Organization stipulates a minimum of 30 years of historical data is needed to obtain meaningful results in climatological research. However, large numbers of studies have explored downscaling approaches based on the TRMM Multi‐Satellite Precipitation Analysis (TMPA) data, which span only from 1998 to the present, to obtain the precipitation estimates (~1‐km resolution). The main aim of the present study was to develop a new method for obtaining long‐term (>30 years) precipitation estimates at ~1‐km resolution and to apply that method to a region with complex topography, the Tibetan Plateau. First, PERSIANN‐CDR (Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks—Climate Data Record) data were used for downscaling. Considering the characteristics of the PERSIANN‐CDR data, a new downscaling‐calibration procedure utilizing a combination of a spatial data mining downscaling algorithm (Cubist) and a geographical ratio analysis calibration method was proposed. We found that (1) both the original PERSIANN‐CDR data (Bias ~40.79%) and the downscaled results before calibration (Bias ~26.78%) overestimated the precipitation compared with ground observations; (2) the final downscaled results based on the PERSIANN‐CDR data after calibration were close to the ground observations (Bias ~5%); (3) compared to the results interpolated based on the PERSIANN‐CDR data (E