An evaluation of GPM-IMERG and ERA5 quantitative precipitation estimates over the Southern Ocean using shipborne observations
Quantitative precipitation estimates over the Southern Ocean (SO) continue to suffer from a high degree of uncertainty for both satellite-based and reanalysis products with large differences present amongst them. This uncertainty arises from the absence of long-term, high-quality observations of pre...
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ftgfzpotsdam:oai:gfzpublic.gfz-potsdam.de:item_5017253 2023-08-27T04:12:10+02:00 An evaluation of GPM-IMERG and ERA5 quantitative precipitation estimates over the Southern Ocean using shipborne observations Montoya Duque, E. Huang, Y. May, P. Siems, S. 2023 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5017253 eng eng info:eu-repo/semantics/altIdentifier/doi/10.57757/IUGG23-1338 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5017253 XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) info:eu-repo/semantics/conferenceObject 2023 ftgfzpotsdam https://doi.org/10.57757/IUGG23-1338 2023-08-06T23:41:22Z Quantitative precipitation estimates over the Southern Ocean (SO) continue to suffer from a high degree of uncertainty for both satellite-based and reanalysis products with large differences present amongst them. This uncertainty arises from the absence of long-term, high-quality observations of precipitation suitable for evaluation across a range of temporal and spatial scales. Recent voyages on the Australian RV Investigator, however, have provided new observations of precipitation across this region made with both the OceanRAIN maritime disdrometer and a dual-polarized C-band weather radar (OceanPOL). The present study employs these unprecedented observations to evaluate the Global Precipitation Mission (GPM) Integrated Multi-satellitE Retrievals (GPM-IMERG) and the ECMWF reanalysis (ERA5) precipitation products. Working at a resolution of 60 minutes and 0.25° (~25 km), the GPM-IMERG product overestimated precipitation intensity when evaluated against the OceanRAIN but captured the frequency well. Looking at the synoptic/process scale, GPM-IMERG was found to be least accurate (overestimate frequency and accumulation) under warm frontal and high-latitude cyclone conditions when cloud-top heights (CTT) were commonly between 6-8 km. In comparison, ERA5’s skill was more consistent across various synoptic conditions, except for high-pressure conditions where the precipitation frequency was highly overestimated. Using the OceanPOL radar, an area-to-area analysis (fractional skill score) finds that ERA5 has greater skill than the GPM-IMERG. Conference Object Southern Ocean GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) Southern Ocean |
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Open Polar |
collection |
GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) |
op_collection_id |
ftgfzpotsdam |
language |
English |
description |
Quantitative precipitation estimates over the Southern Ocean (SO) continue to suffer from a high degree of uncertainty for both satellite-based and reanalysis products with large differences present amongst them. This uncertainty arises from the absence of long-term, high-quality observations of precipitation suitable for evaluation across a range of temporal and spatial scales. Recent voyages on the Australian RV Investigator, however, have provided new observations of precipitation across this region made with both the OceanRAIN maritime disdrometer and a dual-polarized C-band weather radar (OceanPOL). The present study employs these unprecedented observations to evaluate the Global Precipitation Mission (GPM) Integrated Multi-satellitE Retrievals (GPM-IMERG) and the ECMWF reanalysis (ERA5) precipitation products. Working at a resolution of 60 minutes and 0.25° (~25 km), the GPM-IMERG product overestimated precipitation intensity when evaluated against the OceanRAIN but captured the frequency well. Looking at the synoptic/process scale, GPM-IMERG was found to be least accurate (overestimate frequency and accumulation) under warm frontal and high-latitude cyclone conditions when cloud-top heights (CTT) were commonly between 6-8 km. In comparison, ERA5’s skill was more consistent across various synoptic conditions, except for high-pressure conditions where the precipitation frequency was highly overestimated. Using the OceanPOL radar, an area-to-area analysis (fractional skill score) finds that ERA5 has greater skill than the GPM-IMERG. |
format |
Conference Object |
author |
Montoya Duque, E. Huang, Y. May, P. Siems, S. |
spellingShingle |
Montoya Duque, E. Huang, Y. May, P. Siems, S. An evaluation of GPM-IMERG and ERA5 quantitative precipitation estimates over the Southern Ocean using shipborne observations |
author_facet |
Montoya Duque, E. Huang, Y. May, P. Siems, S. |
author_sort |
Montoya Duque, E. |
title |
An evaluation of GPM-IMERG and ERA5 quantitative precipitation estimates over the Southern Ocean using shipborne observations |
title_short |
An evaluation of GPM-IMERG and ERA5 quantitative precipitation estimates over the Southern Ocean using shipborne observations |
title_full |
An evaluation of GPM-IMERG and ERA5 quantitative precipitation estimates over the Southern Ocean using shipborne observations |
title_fullStr |
An evaluation of GPM-IMERG and ERA5 quantitative precipitation estimates over the Southern Ocean using shipborne observations |
title_full_unstemmed |
An evaluation of GPM-IMERG and ERA5 quantitative precipitation estimates over the Southern Ocean using shipborne observations |
title_sort |
evaluation of gpm-imerg and era5 quantitative precipitation estimates over the southern ocean using shipborne observations |
publishDate |
2023 |
url |
https://gfzpublic.gfz-potsdam.de/pubman/item/item_5017253 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.57757/IUGG23-1338 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5017253 |
op_doi |
https://doi.org/10.57757/IUGG23-1338 |
_version_ |
1775356029283860480 |