Brief communication: Recent changes in summer Greenland blocking captured by none of the CMIP5 models
<p>Recent studies note a significant increase in high-pressure blocking over the Greenland region (Greenland Blocking Index, GBI) in summer since the 1990s. Such a general circulation change, indicated by a negative trend in the North Atlantic Oscillation (NAO) index, is generally highligh...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-10-01
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| Series: | The Cryosphere |
| Online Access: | https://www.the-cryosphere.net/12/3287/2018/tc-12-3287-2018.pdf |
| _version_ | 1828516816300802048 |
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| author | E. Hanna X. Fettweis R. J. Hall |
| author_facet | E. Hanna X. Fettweis R. J. Hall |
| author_sort | E. Hanna |
| collection | DOAJ |
| description | <p>Recent studies note a significant increase in
high-pressure blocking over the Greenland region (Greenland Blocking Index,
GBI) in summer since the 1990s. Such a general circulation change, indicated
by a negative trend in the North Atlantic Oscillation (NAO) index, is
generally highlighted as a major driver of recent surface melt records
observed on the Greenland Ice Sheet (GrIS). Here we compare reanalysis-based
GBI records with those from the Coupled Model Intercomparison Project 5
(CMIP5) suite of global climate models over 1950–2100. We find that the
recent summer GBI increase lies well outside the range of modelled past
reconstructions and future GBI projections (RCP4.5 and RCP8.5). The models
consistently project a future decrease in GBI (linked to an increase in NAO),
which highlights a likely key deficiency of current climate models if the
recently observed circulation changes continue to persist. Given
well-established connections between atmospheric pressure over the Greenland
region and air temperature and precipitation extremes downstream, e.g. over
northwest Europe, this brings into question the accuracy of simulated North
Atlantic jet stream changes and resulting climatological anomalies over
densely populated regions of northern Europe as well as of future projections
of GrIS mass balance produced using global and regional climate models.</p> |
| first_indexed | 2024-12-11T18:32:10Z |
| format | Article |
| id | doaj.art-00c54314280444569b6e6107b3fa8071 |
| institution | Directory Open Access Journal |
| issn | 1994-0416 1994-0424 |
| language | English |
| last_indexed | 2024-12-11T18:32:10Z |
| publishDate | 2018-10-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | The Cryosphere |
| spelling | doaj.art-00c54314280444569b6e6107b3fa80712022-12-22T00:54:52ZengCopernicus PublicationsThe Cryosphere1994-04161994-04242018-10-01123287329210.5194/tc-12-3287-2018Brief communication: Recent changes in summer Greenland blocking captured by none of the CMIP5 modelsE. Hanna0X. Fettweis1R. J. Hall2School of Geography and Lincoln Centre for Water and Planetary Health, University of Lincoln, Lincoln, UKLaboratory of Climatology, Department of Geography, University of Liège, Liège, BelgiumSchool of Geography and Lincoln Centre for Water and Planetary Health, University of Lincoln, Lincoln, UK<p>Recent studies note a significant increase in high-pressure blocking over the Greenland region (Greenland Blocking Index, GBI) in summer since the 1990s. Such a general circulation change, indicated by a negative trend in the North Atlantic Oscillation (NAO) index, is generally highlighted as a major driver of recent surface melt records observed on the Greenland Ice Sheet (GrIS). Here we compare reanalysis-based GBI records with those from the Coupled Model Intercomparison Project 5 (CMIP5) suite of global climate models over 1950–2100. We find that the recent summer GBI increase lies well outside the range of modelled past reconstructions and future GBI projections (RCP4.5 and RCP8.5). The models consistently project a future decrease in GBI (linked to an increase in NAO), which highlights a likely key deficiency of current climate models if the recently observed circulation changes continue to persist. Given well-established connections between atmospheric pressure over the Greenland region and air temperature and precipitation extremes downstream, e.g. over northwest Europe, this brings into question the accuracy of simulated North Atlantic jet stream changes and resulting climatological anomalies over densely populated regions of northern Europe as well as of future projections of GrIS mass balance produced using global and regional climate models.</p>https://www.the-cryosphere.net/12/3287/2018/tc-12-3287-2018.pdf |
| spellingShingle | E. Hanna X. Fettweis R. J. Hall Brief communication: Recent changes in summer Greenland blocking captured by none of the CMIP5 models The Cryosphere |
| title | Brief communication: Recent changes in summer Greenland blocking captured by none of the CMIP5 models |
| title_full | Brief communication: Recent changes in summer Greenland blocking captured by none of the CMIP5 models |
| title_fullStr | Brief communication: Recent changes in summer Greenland blocking captured by none of the CMIP5 models |
| title_full_unstemmed | Brief communication: Recent changes in summer Greenland blocking captured by none of the CMIP5 models |
| title_short | Brief communication: Recent changes in summer Greenland blocking captured by none of the CMIP5 models |
| title_sort | brief communication recent changes in summer greenland blocking captured by none of the cmip5 models |
| url | https://www.the-cryosphere.net/12/3287/2018/tc-12-3287-2018.pdf |
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