Unprecedented atmospheric conditions (1948–2019) drive the 2019 exceptional melting season over the Greenland ice sheet
<p>Understanding the role of atmospheric circulation anomalies on the surface mass balance of the Greenland ice sheet (GrIS) is fundamental for improving estimates of its current and future contributions to sea level rise. Here, we show, using a combination of remote sensing observations, regi...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2020-04-01
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| Series: | The Cryosphere |
| Online Access: | https://www.the-cryosphere.net/14/1209/2020/tc-14-1209-2020.pdf |
| _version_ | 1818312688942448640 |
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| author | M. Tedesco M. Tedesco X. Fettweis |
| author_facet | M. Tedesco M. Tedesco X. Fettweis |
| author_sort | M. Tedesco |
| collection | DOAJ |
| description | <p>Understanding the role of atmospheric circulation anomalies on the surface
mass balance of the Greenland ice sheet (GrIS) is fundamental for improving
estimates of its current and future contributions to sea level rise. Here,
we show, using a combination of remote sensing observations, regional
climate model outputs, reanalysis data, and artificial neural networks, that
unprecedented atmospheric conditions (1948–2019) occurring in the summer
of 2019 over Greenland promoted new record or close-to-record values of
surface
mass balance (SMB), runoff, and snowfall. Specifically, runoff in 2019 ranked second within
the 1948–2019 period (after 2012) and first in terms of surface mass
balance negative anomaly for the hydrological year 1 September 2018–31 August 2019. The summer of 2019 was characterized by an exceptional
persistence of anticyclonic conditions that, in conjunction with low albedo
associated with reduced snowfall in summer, enhanced the melt–albedo
feedback by promoting the absorption of solar radiation and favored
advection of warm, moist air along the western portion of the ice sheet
towards the north, where the surface melt has been the highest since 1948.
The analysis of the frequency of daily 500 hPa geopotential heights obtained
from artificial neural networks shows that the total number of days with the
five most frequent atmospheric patterns that characterized the summer of
2019 was 5 standard deviations above the 1981–2010 mean, confirming the
exceptional nature of the 2019 season over Greenland.</p> |
| first_indexed | 2024-12-13T08:21:50Z |
| format | Article |
| id | doaj.art-ca2f9ca80f0b4850bd9c4f1465d63faa |
| institution | Directory Open Access Journal |
| issn | 1994-0416 1994-0424 |
| language | English |
| last_indexed | 2024-12-13T08:21:50Z |
| publishDate | 2020-04-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | The Cryosphere |
| spelling | doaj.art-ca2f9ca80f0b4850bd9c4f1465d63faa2022-12-21T23:53:59ZengCopernicus PublicationsThe Cryosphere1994-04161994-04242020-04-01141209122310.5194/tc-14-1209-2020Unprecedented atmospheric conditions (1948–2019) drive the 2019 exceptional melting season over the Greenland ice sheetM. Tedesco0M. Tedesco1X. Fettweis2Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, USANASA Goddard Institute for Space Studies, New York, NY 10025, USADepartment of Geography, University of Liège, Liège 4000, Belgium<p>Understanding the role of atmospheric circulation anomalies on the surface mass balance of the Greenland ice sheet (GrIS) is fundamental for improving estimates of its current and future contributions to sea level rise. Here, we show, using a combination of remote sensing observations, regional climate model outputs, reanalysis data, and artificial neural networks, that unprecedented atmospheric conditions (1948–2019) occurring in the summer of 2019 over Greenland promoted new record or close-to-record values of surface mass balance (SMB), runoff, and snowfall. Specifically, runoff in 2019 ranked second within the 1948–2019 period (after 2012) and first in terms of surface mass balance negative anomaly for the hydrological year 1 September 2018–31 August 2019. The summer of 2019 was characterized by an exceptional persistence of anticyclonic conditions that, in conjunction with low albedo associated with reduced snowfall in summer, enhanced the melt–albedo feedback by promoting the absorption of solar radiation and favored advection of warm, moist air along the western portion of the ice sheet towards the north, where the surface melt has been the highest since 1948. The analysis of the frequency of daily 500 hPa geopotential heights obtained from artificial neural networks shows that the total number of days with the five most frequent atmospheric patterns that characterized the summer of 2019 was 5 standard deviations above the 1981–2010 mean, confirming the exceptional nature of the 2019 season over Greenland.</p>https://www.the-cryosphere.net/14/1209/2020/tc-14-1209-2020.pdf |
| spellingShingle | M. Tedesco M. Tedesco X. Fettweis Unprecedented atmospheric conditions (1948–2019) drive the 2019 exceptional melting season over the Greenland ice sheet The Cryosphere |
| title | Unprecedented atmospheric conditions (1948–2019) drive the 2019 exceptional melting season over the Greenland ice sheet |
| title_full | Unprecedented atmospheric conditions (1948–2019) drive the 2019 exceptional melting season over the Greenland ice sheet |
| title_fullStr | Unprecedented atmospheric conditions (1948–2019) drive the 2019 exceptional melting season over the Greenland ice sheet |
| title_full_unstemmed | Unprecedented atmospheric conditions (1948–2019) drive the 2019 exceptional melting season over the Greenland ice sheet |
| title_short | Unprecedented atmospheric conditions (1948–2019) drive the 2019 exceptional melting season over the Greenland ice sheet |
| title_sort | unprecedented atmospheric conditions 1948 2019 drive the 2019 exceptional melting season over the greenland ice sheet |
| url | https://www.the-cryosphere.net/14/1209/2020/tc-14-1209-2020.pdf |
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