Meteorological Conditions and Cloud Effects on Surface Radiation Balance Near Helheim Glacier and Jakobshavn Isbræ (Greenland) Using Ground-Based Observations
The surface radiation budget is an essential component of the total energy exchange between the atmosphere and the Earth’s surface. Measurements of radiative fluxes near/on ice surfaces are sparse in the polar regions, including on the Greenland Ice Sheet (GrIS), and the effects of cloud on radiativ...
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ftdoajarticles:oai:doaj.org/article:931e1846310242f78bc15f3d59423f0e 2023-05-15T16:21:30+02:00 Meteorological Conditions and Cloud Effects on Surface Radiation Balance Near Helheim Glacier and Jakobshavn Isbræ (Greenland) Using Ground-Based Observations G. Djoumna S. H. Mernild D. M. Holland 2021-01-01T00:00:00Z https://doi.org/10.3389/feart.2020.616105 https://doaj.org/article/931e1846310242f78bc15f3d59423f0e EN eng Frontiers Media S.A. https://www.frontiersin.org/articles/10.3389/feart.2020.616105/full https://doaj.org/toc/2296-6463 2296-6463 doi:10.3389/feart.2020.616105 https://doaj.org/article/931e1846310242f78bc15f3d59423f0e Frontiers in Earth Science, Vol 8 (2021) surface radiation longwave-equivalent cloudiness cloud transmittance factor meteorological conditions cloud effects on radiation Science Q article 2021 ftdoajarticles https://doi.org/10.3389/feart.2020.616105 2022-12-31T06:38:32Z The surface radiation budget is an essential component of the total energy exchange between the atmosphere and the Earth’s surface. Measurements of radiative fluxes near/on ice surfaces are sparse in the polar regions, including on the Greenland Ice Sheet (GrIS), and the effects of cloud on radiative fluxes are still poorly studied. In this work, we assess the impacts of cloud on radiative fluxes using two metrics: the longwave-equivalent cloudiness, derived from long-wave radiation measurements, and the cloud transmittance factor, obtained from short-wave radiation data. The metrics are applied to radiation data from two automatic weather stations located over the bare ground near the ice front of Helheim (HG, 66.3290°N, 38.1460°W) and Jakobshavn Isbræ(JI, 69.2220°N, 49.8150°W) on the GrIS. Comparisons of meteorological parameters, surface radiation fluxes, and cloud metrics show significant differences between the two sites. The cloud transmittance factor is higher at HG than at JI, and the incoming short-wave radiation in the summer at HG is about 50.0 W m−2 larger than at JI. Cloud metrics derived at the two sites reveal partly cloudy conditions were frequent (42 and 65% of the period at HG and JI) with a high dependency on the wind direction. The total cloud radiative effect (CREnet) generally increases during melt season at the two stations due to long-wave CRE enhancement by cloud fraction. CREnet decreases from May to June and increases afterward, due to the strengthened short-wave CRE. The annually averaged CREnet were 3.0 ± 7.4 W m−2 and 1.9±15.1 W m−2 at JI and HG. CREnet estimated from AWS indicates that clouds cool the JI and HG during melt season at different rates. Article in Journal/Newspaper glacier Greenland Ice Sheet Jakobshavn Jakobshavn isbræ Directory of Open Access Journals: DOAJ Articles Greenland Jakobshavn Isbræ ENVELOPE(-49.917,-49.917,69.167,69.167) Frontiers in Earth Science 8 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
surface radiation longwave-equivalent cloudiness cloud transmittance factor meteorological conditions cloud effects on radiation Science Q |
spellingShingle |
surface radiation longwave-equivalent cloudiness cloud transmittance factor meteorological conditions cloud effects on radiation Science Q G. Djoumna S. H. Mernild D. M. Holland Meteorological Conditions and Cloud Effects on Surface Radiation Balance Near Helheim Glacier and Jakobshavn Isbræ (Greenland) Using Ground-Based Observations |
topic_facet |
surface radiation longwave-equivalent cloudiness cloud transmittance factor meteorological conditions cloud effects on radiation Science Q |
description |
The surface radiation budget is an essential component of the total energy exchange between the atmosphere and the Earth’s surface. Measurements of radiative fluxes near/on ice surfaces are sparse in the polar regions, including on the Greenland Ice Sheet (GrIS), and the effects of cloud on radiative fluxes are still poorly studied. In this work, we assess the impacts of cloud on radiative fluxes using two metrics: the longwave-equivalent cloudiness, derived from long-wave radiation measurements, and the cloud transmittance factor, obtained from short-wave radiation data. The metrics are applied to radiation data from two automatic weather stations located over the bare ground near the ice front of Helheim (HG, 66.3290°N, 38.1460°W) and Jakobshavn Isbræ(JI, 69.2220°N, 49.8150°W) on the GrIS. Comparisons of meteorological parameters, surface radiation fluxes, and cloud metrics show significant differences between the two sites. The cloud transmittance factor is higher at HG than at JI, and the incoming short-wave radiation in the summer at HG is about 50.0 W m−2 larger than at JI. Cloud metrics derived at the two sites reveal partly cloudy conditions were frequent (42 and 65% of the period at HG and JI) with a high dependency on the wind direction. The total cloud radiative effect (CREnet) generally increases during melt season at the two stations due to long-wave CRE enhancement by cloud fraction. CREnet decreases from May to June and increases afterward, due to the strengthened short-wave CRE. The annually averaged CREnet were 3.0 ± 7.4 W m−2 and 1.9±15.1 W m−2 at JI and HG. CREnet estimated from AWS indicates that clouds cool the JI and HG during melt season at different rates. |
format |
Article in Journal/Newspaper |
author |
G. Djoumna S. H. Mernild D. M. Holland |
author_facet |
G. Djoumna S. H. Mernild D. M. Holland |
author_sort |
G. Djoumna |
title |
Meteorological Conditions and Cloud Effects on Surface Radiation Balance Near Helheim Glacier and Jakobshavn Isbræ (Greenland) Using Ground-Based Observations |
title_short |
Meteorological Conditions and Cloud Effects on Surface Radiation Balance Near Helheim Glacier and Jakobshavn Isbræ (Greenland) Using Ground-Based Observations |
title_full |
Meteorological Conditions and Cloud Effects on Surface Radiation Balance Near Helheim Glacier and Jakobshavn Isbræ (Greenland) Using Ground-Based Observations |
title_fullStr |
Meteorological Conditions and Cloud Effects on Surface Radiation Balance Near Helheim Glacier and Jakobshavn Isbræ (Greenland) Using Ground-Based Observations |
title_full_unstemmed |
Meteorological Conditions and Cloud Effects on Surface Radiation Balance Near Helheim Glacier and Jakobshavn Isbræ (Greenland) Using Ground-Based Observations |
title_sort |
meteorological conditions and cloud effects on surface radiation balance near helheim glacier and jakobshavn isbræ (greenland) using ground-based observations |
publisher |
Frontiers Media S.A. |
publishDate |
2021 |
url |
https://doi.org/10.3389/feart.2020.616105 https://doaj.org/article/931e1846310242f78bc15f3d59423f0e |
long_lat |
ENVELOPE(-49.917,-49.917,69.167,69.167) |
geographic |
Greenland Jakobshavn Isbræ |
geographic_facet |
Greenland Jakobshavn Isbræ |
genre |
glacier Greenland Ice Sheet Jakobshavn Jakobshavn isbræ |
genre_facet |
glacier Greenland Ice Sheet Jakobshavn Jakobshavn isbræ |
op_source |
Frontiers in Earth Science, Vol 8 (2021) |
op_relation |
https://www.frontiersin.org/articles/10.3389/feart.2020.616105/full https://doaj.org/toc/2296-6463 2296-6463 doi:10.3389/feart.2020.616105 https://doaj.org/article/931e1846310242f78bc15f3d59423f0e |
op_doi |
https://doi.org/10.3389/feart.2020.616105 |
container_title |
Frontiers in Earth Science |
container_volume |
8 |
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1766009509900189696 |