Important role of the mid-tropospheric atmospheric circulation in the recent surface melt increase over the Greenland ice sheet
Since 2007, there has been a series of surface melt records over the Greenland ice sheet (GrIS), continuing the trend towards increased melt observed since the end of the 1990's. The last two decades are characterized by an increase of negative phases of the North Atlantic Oscillation (NAO) fav...
Saved in:
Main Authors | , , , , , |
---|---|
Format | Web Resource |
Language | English |
Published |
Copernicus
07.02.2013
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Abstract | Since 2007, there has been a series of surface melt records over the Greenland ice sheet (GrIS), continuing the trend towards increased melt observed since the end of the 1990's. The last two decades are characterized by an increase of negative phases of the North Atlantic Oscillation (NAO) favouring warmer and drier summers than normal over GrIS. In this context, we use a circulation type classification based on daily 500 hPa geopotential height to evaluate the role of atmospheric dynamics in this surface melt acceleration for the last two decades. Due to the lack of direct observations, the interannual melt variability is gauged here by the summer (June–July–August) mean temperature from reanalyses at 700 hPa over Greenland; analogous atmospheric circulations in the past show that ~70% of the 1993–2012 warming at 700 hPa over Greenland has been driven by changes in the atmospheric flow frequencies. Indeed, the occurrence of anticyclones centred over the GrIS at the surface and at 500 hPa has doubled since the end of 1990's, which induces more frequent southerly warm air advection along the western Greenland coast and over the neighbouring Canadian Arctic Archipelago (CAA). These changes in the NAO modes explain also why no significant warming has been observed these last summers over Svalbard, where northerly atmospheric flows are twice as frequent as before. Therefore, the recent warmer summers over GrIS and CAA cannot be considered as a long-term climate warming but are more a consequence of NAO variability affecting atmospheric heat transport. Although no global model from the CMIP5 database projects subsequent significant changes in NAO through this century, we cannot exclude the possibility that the observed NAO changes are due to global warming. |
---|---|
AbstractList | Since 2007, there has been a series of surface melt records over the Greenland ice sheet (GrIS), continuing the trend towards increased melt observed since the end of the 1990's. The last two decades are characterized by an increase of negative phases of the North Atlantic Oscillation (NAO) favouring warmer and drier summers than normal over GrIS. In this context, we use a circulation type classification based on daily 500 hPa geopotential height to evaluate the role of atmospheric dynamics in this surface melt acceleration for the last two decades. Due to the lack of direct observations, the interannual melt variability is gauged here by the summer (June–July–August) mean temperature from reanalyses at 700 hPa over Greenland; analogous atmospheric circulations in the past show that ~70% of the 1993–2012 warming at 700 hPa over Greenland has been driven by changes in the atmospheric flow frequencies. Indeed, the occurrence of anticyclones centred over the GrIS at the surface and at 500 hPa has doubled since the end of 1990's, which induces more frequent southerly warm air advection along the western Greenland coast and over the neighbouring Canadian Arctic Archipelago (CAA). These changes in the NAO modes explain also why no significant warming has been observed these last summers over Svalbard, where northerly atmospheric flows are twice as frequent as before. Therefore, the recent warmer summers over GrIS and CAA cannot be considered as a long-term climate warming but are more a consequence of NAO variability affecting atmospheric heat transport. Although no global model from the CMIP5 database projects subsequent significant changes in NAO through this century, we cannot exclude the possibility that the observed NAO changes are due to global warming. |
Author | Belleflamme, Alexandre Gallée, Hubert Hanna, Edward Erpicum, Michel Lang, Charlotte Fettweis, Xavier |
Author_xml | – sequence: 1 fullname: Fettweis, Xavier – sequence: 2 fullname: Hanna, Edward – sequence: 3 fullname: Lang, Charlotte – sequence: 4 fullname: Belleflamme, Alexandre – sequence: 5 fullname: Erpicum, Michel – sequence: 6 fullname: Gallée, Hubert |
BookMark | eNo9jD1PwzAURT0UibYwsvsPGPwVJxlRBaVSJRaYrRfnpTVy7cpxu_LXCS1iule6554FmcUUkZAHwR8r0eqn4ljNpBZMcqFmZC7aVjOupb4li3H84tzIlus5-d4cjikXiIXmFJCmgZY90oPvWcnpmMbjHrN3FMrhvzuf3SlA8SlSHy98RoeTYjzlAdx0x1CmyWWEcXKeMV-odUaMAWJP_QSNe8RyR24GCCPe_-WSfL6-fKze2PZ9vVk9b1kQsi2s0gDQQV0NStRdL3teuVr3SqM2jauGbuAVSg2GDw0YJbTqfh-8NaZuXINqSdTVGzzu0KbceXuWNoG_9lPYWXC2QyulaaxQQtat-gEnQmjG |
ContentType | Web Resource |
DBID | Q33 |
DOI | 10.5194/tc-7-241-2013 |
DatabaseName | Université de Liège - Open Repository and Bibliography (ORBI) |
DatabaseTitleList | |
DeliveryMethod | fulltext_linktorsrc |
Discipline | Geography Meteorology & Climatology |
ExternalDocumentID | oai_orbi_ulg_ac_be_2268_131279 |
GroupedDBID | 29F 2WC 3V. 5GY 5VS 7XC 8CJ 8FE 8FH 8R4 8R5 AAFWJ ABDBF ABUWG ADBBV AENEX AFKRA AFPKN AHGZY ALMA_UNASSIGNED_HOLDINGS ATCPS BBORY BCNDV BENPR BFMQW BHPHI BKSAR BPHCQ CCPQU D1J D1K E3Z ESX GROUPED_DOAJ GX1 H13 HCIFZ IAO IEA IPNFZ ISR ITC K6- KQ8 LK5 M7R MM- M~E OK1 P2P PATMY PCBAR PIMPY PQQKQ PROAC PYCSY Q2X Q33 RIG RKB RNS TR2 TUS ZBA ~02 |
ID | FETCH-LOGICAL-l129t-54aaaba75f317bd2d05c74d34e468c5fbf05e24a60f8a63143b4aaa096678c8e3 |
ISSN | 1994-0424 1994-0416 |
IngestDate | Fri Sep 27 12:33:50 EDT 2024 |
IsDoiOpenAccess | true |
IsOpenAccess | true |
IsPeerReviewed | true |
IsScholarly | true |
Language | English |
LinkModel | OpenURL |
MergedId | FETCHMERGED-LOGICAL-l129t-54aaaba75f317bd2d05c74d34e468c5fbf05e24a60f8a63143b4aaa096678c8e3 |
Notes | scopus-id:2-s2.0-84874077692 |
OpenAccessLink | http://dx.doi.org/10.5194/tc-7-241-2013 |
ParticipantIDs | liege_orbi_v2_oai_orbi_ulg_ac_be_2268_131279 |
PublicationCentury | 2000 |
PublicationDate | 2013-02-07 |
PublicationDateYYYYMMDD | 2013-02-07 |
PublicationDate_xml | – month: 02 year: 2013 text: 2013-02-07 day: 07 |
PublicationDecade | 2010 |
PublicationYear | 2013 |
Publisher | Copernicus |
Publisher_xml | – name: Copernicus |
RestrictionsOnAccess | open access |
SSID | ssj0062904 |
Score | 2.4326992 |
Snippet | Since 2007, there has been a series of surface melt records over the Greenland ice sheet (GrIS), continuing the trend towards increased melt observed since the... |
SourceID | liege |
SourceType | Open Access Repository |
SubjectTerms | Earth sciences & physical geography Physical, chemical, mathematical & earth Sciences Physique, chimie, mathématiques & sciences de la terre Sciences de la terre & géographie physique |
Title | Important role of the mid-tropospheric atmospheric circulation in the recent surface melt increase over the Greenland ice sheet |
URI | http://orbi.ulg.ac.be/handle/2268/131279 |
hasFullText | 1 |
inHoldings | 1 |
isFullTextHit | |
isPrint | |
link | http://utb.summon.serialssolutions.com/2.0.0/link/0/eLvHCXMwnV1Nb9QwELWgHEBcSgFRCpUPiBOGbWJns-eqpSCVUyv2FtnOmEbKJlXqBbWX_nVmnM-uEKJcrGzkjSzPsz2eeTPD2Dszd05JI4VOFOAFRVuxMItcGGs0pUtPXHAXnH5LTs7l16VajoTMEF3izUd788e4kv-RKr5DuVKU7D0kO3wUX-AzyhdblDC2_yTjL6ugPVd-IAmSGrkqcuGp-MEVpQygfKx-NTzborFdxa6e4oh7HhECrtaN07jKV1BS2QDSJsnOj5MSegWCThlcDZSV9gLGyOlj8P4XtMkKlpoO2nFfq9qYs7Y29MD-6YzUwddf91yjLloIXEnW9En0TcfP7WwTVCeCqKwjRai-hKYq7Hpid2xzEcs2cHpz_0Z1UuKkeyvmAlULQd8cD6reOb9xft3JlF03psjW5Y9M28xAhsplmh3EB9F88ZA9wlYR7e_zcqABJdFi1jIPwrBCqdxhiG1OVhrUpztDwotMSZSGiSZyts2efgfDe6fLM_YAqh32uCtlf3G9w3ZP8RpUN8Fbwt_zw7LAO0n49ZzdDoDhBBheO46i5ZuA4RPA8AlgeFGF_i1geAcYToDhPWA4ASb0GgDDETA8AOYFOz8-Ojs8EV0FDlGiHuiFklprXLTKoZpp8iifKTuXeSxBJqlVzriZgkjqZOZSncSoexv6B16LUQeyKcQv2VZVV_CKcVr3OjdxbCPASzkYAzj5NqEzRqWx2WUfwpy2EvwZZX-X5uv7dd9jT0Z8vmFbvlnDW9QmvdkPVpj9AIrf8Id9gQ |
link.rule.ids | 230,786,790,870,891,27958 |
linkProvider | Geneva Foundation for Medical Education and Research |
openUrl | ctx_ver=Z39.88-2004&ctx_enc=info%3Aofi%2Fenc%3AUTF-8&rfr_id=info%3Asid%2Fsummon.serialssolutions.com&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.atitle=Important+role+of+the+mid-tropospheric+atmospheric+circulation+in+the+recent+surface+melt+increase+over+the+Greenland+ice+sheet&rft.au=Fettweis%2C+Xavier&rft.au=Hanna%2C+Edward&rft.au=Lang%2C+Charlotte&rft.au=Belleflamme%2C+Alexandre&rft.date=2013-02-07&rft.pub=Copernicus&rft.issn=1994-0424&rft_id=info:doi/10.5194%2Ftc-7-241-2013&rft.externalDBID=n%2Fa&rft.externalDocID=oai_orbi_ulg_ac_be_2268_131279 |
thumbnail_l | http://covers-cdn.summon.serialssolutions.com/index.aspx?isbn=/lc.gif&issn=1994-0424&client=summon |
thumbnail_m | http://covers-cdn.summon.serialssolutions.com/index.aspx?isbn=/mc.gif&issn=1994-0424&client=summon |
thumbnail_s | http://covers-cdn.summon.serialssolutions.com/index.aspx?isbn=/sc.gif&issn=1994-0424&client=summon |