Impacts of active satellite sensors' low-level cloud detection limitations on cloud radiative forcing in the Arctic
<p>Previous studies revealed that satellites sensors with the best detection capability identify 25 %–40 % and 0 %–25 % fewer clouds below 0.5 and between 0.5–1.0 km, respectively, over the Arctic. Quantifying the impacts of cloud detection limitations on the radiation flux are critical especi...
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2022-06-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/22/8151/2022/acp-22-8151-2022.pdf |
| _version_ | 1818250171694186496 |
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| author | Y. Liu |
| author_facet | Y. Liu |
| author_sort | Y. Liu |
| collection | DOAJ |
| description | <p>Previous studies revealed that satellites sensors with the best detection capability identify 25 %–40 % and 0 %–25 % fewer clouds below 0.5 and between 0.5–1.0 km, respectively, over the Arctic. Quantifying the impacts of cloud detection limitations on the radiation flux are critical especially over the Arctic Ocean considering the dramatic changes in Arctic sea ice. In this study, the proxies of the space-based radar, CloudSat, and lidar, CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations), cloud masks are derived based on simulated radar reflectivity with QuickBeam and cloud optical thickness using retrieved cloud properties from surface-based radar and lidar during the Surface Heat Budget of the Arctic Ocean (SHEBA) experiment. Limitations in low-level cloud detection by the space-based active sensors, and the impact of these limitations on the radiation fluxes at the surface and the top of the atmosphere (TOA), are estimated with radiative transfer model Streamer. The results show that the combined CloudSat and CALIPSO product generally detects all clouds above 1 km, while detecting 25 % (9 %) fewer in absolute values below 600 m (600 m to 1 km) than surface observations. These detection limitations lead to uncertainties in the monthly mean cloud radiative forcing (CRF), with maximum absolute monthly mean values of 2.5 and 3.4 Wm<span class="inline-formula"><sup>−2</sup></span> at the surface and TOA, respectively. Cloud information from only CALIPSO or CloudSat lead to larger cloud detection differences compared to the surface observations and larger CRF uncertainties with absolute monthly means larger than 10.0 Wm<span class="inline-formula"><sup>−2</sup></span> at the surface and TOA. The uncertainties for individual cases are larger – up to 30 Wm<span class="inline-formula"><sup>−2</sup></span>. These uncertainties need to be considered when radiation flux products from CloudSat and CALIPSO are used in climate and weather studies.</p> |
| first_indexed | 2024-12-12T15:48:09Z |
| format | Article |
| id | doaj.art-eb788f82b933468982e0679b19b1773a |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-12T15:48:09Z |
| publishDate | 2022-06-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-eb788f82b933468982e0679b19b1773a2022-12-22T00:19:42ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242022-06-01228151817310.5194/acp-22-8151-2022Impacts of active satellite sensors' low-level cloud detection limitations on cloud radiative forcing in the ArcticY. Liu<p>Previous studies revealed that satellites sensors with the best detection capability identify 25 %–40 % and 0 %–25 % fewer clouds below 0.5 and between 0.5–1.0 km, respectively, over the Arctic. Quantifying the impacts of cloud detection limitations on the radiation flux are critical especially over the Arctic Ocean considering the dramatic changes in Arctic sea ice. In this study, the proxies of the space-based radar, CloudSat, and lidar, CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations), cloud masks are derived based on simulated radar reflectivity with QuickBeam and cloud optical thickness using retrieved cloud properties from surface-based radar and lidar during the Surface Heat Budget of the Arctic Ocean (SHEBA) experiment. Limitations in low-level cloud detection by the space-based active sensors, and the impact of these limitations on the radiation fluxes at the surface and the top of the atmosphere (TOA), are estimated with radiative transfer model Streamer. The results show that the combined CloudSat and CALIPSO product generally detects all clouds above 1 km, while detecting 25 % (9 %) fewer in absolute values below 600 m (600 m to 1 km) than surface observations. These detection limitations lead to uncertainties in the monthly mean cloud radiative forcing (CRF), with maximum absolute monthly mean values of 2.5 and 3.4 Wm<span class="inline-formula"><sup>−2</sup></span> at the surface and TOA, respectively. Cloud information from only CALIPSO or CloudSat lead to larger cloud detection differences compared to the surface observations and larger CRF uncertainties with absolute monthly means larger than 10.0 Wm<span class="inline-formula"><sup>−2</sup></span> at the surface and TOA. The uncertainties for individual cases are larger – up to 30 Wm<span class="inline-formula"><sup>−2</sup></span>. These uncertainties need to be considered when radiation flux products from CloudSat and CALIPSO are used in climate and weather studies.</p>https://acp.copernicus.org/articles/22/8151/2022/acp-22-8151-2022.pdf |
| spellingShingle | Y. Liu Impacts of active satellite sensors' low-level cloud detection limitations on cloud radiative forcing in the Arctic Atmospheric Chemistry and Physics |
| title | Impacts of active satellite sensors' low-level cloud detection limitations on cloud radiative forcing in the Arctic |
| title_full | Impacts of active satellite sensors' low-level cloud detection limitations on cloud radiative forcing in the Arctic |
| title_fullStr | Impacts of active satellite sensors' low-level cloud detection limitations on cloud radiative forcing in the Arctic |
| title_full_unstemmed | Impacts of active satellite sensors' low-level cloud detection limitations on cloud radiative forcing in the Arctic |
| title_short | Impacts of active satellite sensors' low-level cloud detection limitations on cloud radiative forcing in the Arctic |
| title_sort | impacts of active satellite sensors low level cloud detection limitations on cloud radiative forcing in the arctic |
| url | https://acp.copernicus.org/articles/22/8151/2022/acp-22-8151-2022.pdf |
| work_keys_str_mv | AT yliu impactsofactivesatellitesensorslowlevelclouddetectionlimitationsoncloudradiativeforcinginthearctic |