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Greenland ice sheet melt from MODIS and associated atmospheric variability

Daily June-July melt fraction variations over the Greenland ice sheet (GIS) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) (2000–2013) are associated with atmospheric blocking forming an omega-shape ridge over the GIS at 500 hPa height. Blocking activity with a range of time...

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Autores principales: Häkkinen, Sirpa, Hall, Dorothy K, Shuman, Christopher A, Worthen, Denise L, DiGirolamo, Nicolo E
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Blackwell Publishing Ltd 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4373136/
https://www.ncbi.nlm.nih.gov/pubmed/25821277
http://dx.doi.org/10.1002/2013GL059185
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author Häkkinen, Sirpa
Hall, Dorothy K
Shuman, Christopher A
Worthen, Denise L
DiGirolamo, Nicolo E
author_facet Häkkinen, Sirpa
Hall, Dorothy K
Shuman, Christopher A
Worthen, Denise L
DiGirolamo, Nicolo E
author_sort Häkkinen, Sirpa
collection PubMed
description Daily June-July melt fraction variations over the Greenland ice sheet (GIS) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) (2000–2013) are associated with atmospheric blocking forming an omega-shape ridge over the GIS at 500 hPa height. Blocking activity with a range of time scales, from synoptic waves breaking poleward (<5 days) to full-fledged blocks (≥5 days), brings warm subtropical air masses over the GIS controlling daily surface temperatures and melt. The temperature anomaly of these subtropical air mass intrusions is also important for melting. Based on the years with the greatest melt (2002 and 2012) during the MODIS era, the area-average temperature anomaly of 2 standard deviations above the 14 year June-July mean results in a melt fraction of 40% or more. Though the summer of 2007 had the most blocking days, atmospheric temperature anomalies were too small to instigate extreme melting. KEY POINTS: Short-term atmospheric blocking over Greenland contributes to melt episodes. Associated temperature anomalies are equally important for the melt. Duration and strength of blocking events contribute to surface melt intensity.
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spelling pubmed-43731362015-03-27 Greenland ice sheet melt from MODIS and associated atmospheric variability Häkkinen, Sirpa Hall, Dorothy K Shuman, Christopher A Worthen, Denise L DiGirolamo, Nicolo E Geophys Res Lett Research Letters Daily June-July melt fraction variations over the Greenland ice sheet (GIS) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) (2000–2013) are associated with atmospheric blocking forming an omega-shape ridge over the GIS at 500 hPa height. Blocking activity with a range of time scales, from synoptic waves breaking poleward (<5 days) to full-fledged blocks (≥5 days), brings warm subtropical air masses over the GIS controlling daily surface temperatures and melt. The temperature anomaly of these subtropical air mass intrusions is also important for melting. Based on the years with the greatest melt (2002 and 2012) during the MODIS era, the area-average temperature anomaly of 2 standard deviations above the 14 year June-July mean results in a melt fraction of 40% or more. Though the summer of 2007 had the most blocking days, atmospheric temperature anomalies were too small to instigate extreme melting. KEY POINTS: Short-term atmospheric blocking over Greenland contributes to melt episodes. Associated temperature anomalies are equally important for the melt. Duration and strength of blocking events contribute to surface melt intensity. Blackwell Publishing Ltd 2014-03-16 2014-03-10 /pmc/articles/PMC4373136/ /pubmed/25821277 http://dx.doi.org/10.1002/2013GL059185 Text en ©2014. The Authors. http://creativecommons.org/licenses/by-nc-nd/3.0/ This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
spellingShingle Research Letters
Häkkinen, Sirpa
Hall, Dorothy K
Shuman, Christopher A
Worthen, Denise L
DiGirolamo, Nicolo E
Greenland ice sheet melt from MODIS and associated atmospheric variability
title Greenland ice sheet melt from MODIS and associated atmospheric variability
title_full Greenland ice sheet melt from MODIS and associated atmospheric variability
title_fullStr Greenland ice sheet melt from MODIS and associated atmospheric variability
title_full_unstemmed Greenland ice sheet melt from MODIS and associated atmospheric variability
title_short Greenland ice sheet melt from MODIS and associated atmospheric variability
title_sort greenland ice sheet melt from modis and associated atmospheric variability
topic Research Letters
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4373136/
https://www.ncbi.nlm.nih.gov/pubmed/25821277
http://dx.doi.org/10.1002/2013GL059185
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