Refinement of Surface Precipitation Estimates for the Dual-frequency Precipitation Radar on the GPM Core Observatory Using Near-Nadir Measurements

• HIROSE Masafumi

  Faculty of Science and Technology, Meijo University, Nagoya, Japan

• SHIGE Shoichi

  Graduate School of Science, Kyoto University, Kyoto, Japan

• KUBOTA Takuji

  Earth Observation Research Center, Japan Aerospace Exploration Agency, Tsukuba, Japan

• FURUZAWA Fumie A.

  Institute for Space-Earth Environmental Research, Nagoya University, Nagoya, Japan

• MINDA Haruya

  Institute for Space-Earth Environmental Research, Nagoya University, Nagoya, Japan

• MASUNAGA Hirohiko

  Institute for Space-Earth Environmental Research, Nagoya University, Nagoya, Japan

Bibliographic Information

Other Title

• Refinement of Surface Precipitation Estimates for the Dual-frequency Precipitation Radar on the GPM Core Observatory Using Near-Nadir Measurements : Special Edition on Global Precipitation Measurement (GPM) : 5th Anniversary

Abstract

 Precipitation statistics from Global Precipitation Measurement Core Observatory Dual-frequency Precipitation Radar (GPM DPR) are underestimated due to systematic bias depending on the scanning angle. Over five years of GPM DPR KuPR Version 06A data, the precipitation anomaly is −7% and −2% over land and ocean, respectively. This study improves the estimation of low-level precipitation-rate profiles and the detection of shallow storms (with top heights of ≤2.5 km), using reference datasets of near-nadir measurements.   First, the low-level precipitation profile (LPP) is updated using an a priori near-nadir database generated from structural-characteristics related variables of the precipitation and environmental parameters. The LPP correction increases precipitation over areas where downward-increasing precipitation profiles are dominant below 2 km, such as at high elevations and at middle and high latitudes. Globally, the LPP correction increases precipitation by 5%. Second, the effect on precipitation data of missing shallow storms is estimated using the angle-bin difference in the detectability of storms with a top height of ≤2.5 km. The effect of the shallow-precipitation deficiency (SPD) is comparable in magnitude to that of the LPP correction. A priori lookup tables for the SPD correction, constrained by the clutter-free bottom level and spatially averaged shallow-precipitation fractions, are constructed so that the correction applies to gridded statistics at 0.1° and three-month scales. The SPD correction enhances precipitation by 50% over specific low-rainfall oceans in the sub-tropics and at high latitudes, where shallow precipitation dominates. Based on these two corrections, precipitation increases by 8% and 11% over land and ocean, respectively. At latitudes between 60° N and 60° S, the difference in KuPR compared with satellite-gauge blended products is reduced from −17% to −9%, whereas with gauge-based products is reduced from −19% to −15% over land.

Journal

• Journal of the Meteorological Society of Japan. Ser. II

  Journal of the Meteorological Society of Japan. Ser. II advpub (0), 1231-1252, 2021

  Meteorological Society of Japan

Keywords

• spaceborne precipitation radar
• retrieval error
• low-level precipitation profile
• shallow storm
• surface-clutter mask
• incidence-angle dependence

Details

• CRID: 1390288292974938880
• NII Article ID: 130008112052
• NII Book ID: AA00702524
• DOI: 10.2151/jmsj.2021-060
• ISSN: 21869057
• ISSN: 00261165
• NDL BIB ID: 031774280
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I031774280
• Web Site: https://www.jstage.jst.go.jp/article/jmsj/99/5/99_2021-060/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed