Spatial Pattern of Precipitation in GPM-Era Satellite Products against Rain Gauge Measurements over Nepal

Authors

  • Bharat Badayar Joshi Institute of Tibetan Plateau Research, Beijing 100049, China
  • Munawar Ali Institute of Tibetan Plateau Research, Beijing 100049, China
  • Dibit Aryal Institute of Tibetan Plateau Research, Beijing 100049, China
  • Laxman Paneru Tribhuvan University, Kirtipur, Nepal
  • Bhaskar Shrestha University of Chinese Academy of Sciences, Beijing 100049, China

DOI:

https://doi.org/10.3126/jalawaayu.v1i2.41009

Keywords:

Satellite Precipation, IMERG, GSMaP, Nepal, Mountains

Abstract

Precipitation in a mountainous region is highly variable due to the complex terrain. Satellite-based precipitation estimates are potential alternatives to gauge measurements in these regions, as these typical measurements are not available or are scarce in high elevation areas. However, the accuracy of these gridded precipitation datasets need to be addressed before further usage. In this study, an evaluation of the spatial precipitation pattern in satellite-based precipitation products is provided, including satellite-only (Integrated Multi satellite Retrievals for GPM IMERG-UCORR and Global Satellite Mapping of Precipitation (GSMaP-MVK) and gauge calibrated (IMERG-CORR and GSMaP-Gauge) products, with a spatial resolution of 0.1°, which is compared to 387-gauge measurements in Nepal from April 2014 to December 2016. The major results are as follows: (1) The gauge calibrated version 5 IMERG-CORR and version 6 GSMaP-Gauge are relatively better than the satellite-only datasets, although they all underestimate the observed precipitation. (2) The daily gauge calibrated GSMaP-Gauge performs fairly well in low and mid-elevation areas, whereas the monthly gauge calibrated IMERG-C performs better in high-elevation areas. (3) For the daily time scale, IMERG-CORR shows a better ability to detect the true precipitation (higher Probability of Detection (POD)) and (lowest False Alarm Ratio (FAR)) events among all datasets. However, all four satellite-based precipitation datasets accurately detect (Critical Success Index (CSI) >40%) precipitation and no-precipitation events. The results of this work provide the systematic quantification of IMERG and GSMaP of satellite precipitation products over Nepal using station observations and delivers a helpful statistical basis for the selection of these datasets for future scientific research.

Downloads

Download data is not yet available.
Abstract
132
PDF
1

Author Biographies

Bharat Badayar Joshi, Institute of Tibetan Plateau Research, Beijing 100049, China

Kathmandu Center for Research and Education, CAS-TU, Kirtipur, Nepal

Laxman Paneru, Tribhuvan University, Kirtipur, Nepal

Central Department of Hydrology and Meteorology

Bhaskar Shrestha, University of Chinese Academy of Sciences, Beijing 100049, China

State Key Laboratory of Remote Sensing Science, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100049, China

Downloads

Published

2021-12-02

How to Cite

Joshi, B. B., Ali, M., Aryal, D., Paneru, L., & Shrestha, B. (2021). Spatial Pattern of Precipitation in GPM-Era Satellite Products against Rain Gauge Measurements over Nepal. Jalawaayu, 1(2), 39–56. https://doi.org/10.3126/jalawaayu.v1i2.41009

Issue

Section

Research Article