elib
DLR-Header
DLR-Logo -> http://www.dlr.de
DLR Portal Home | Impressum | Datenschutz | Kontakt | English
Schriftgröße: [-] Text [+]

The Millennium water vapour drop in chemistry-climate model simulations

Brinkop, Sabine und Dameris, Martin und Jöckel, Patrick und Garny, Hella und Lossow, Stefan und Stiller, Gabriele (2016) The Millennium water vapour drop in chemistry-climate model simulations. Atmospheric Chemistry and Physics (ACP), Seiten 8125-8140. Copernicus Publications. doi: 10.5194/acp-16-8125-2016. ISSN 1680-7316.

[img] PDF
3MB

Offizielle URL: http://www.atmos-chem-phys.net/16/8125/2016/

Kurzfassung

This study investigates the abrupt and severe water vapour decline in the stratosphere beginning in year 2000 (the ``millennium water vapour drop'') and other similarly strong stratospheric water vapour reductions by means of various simulations with the state-of-the-art Chemistry-Climate Model (CCM) EMAC (ECHAM/MESSy Atmospheric Chemistry Model). The model simulations differ with respect to the prescribed sea surface temperatures (SSTs) and whether nudging is applied or not. The CCM EMAC is able to most-closely reproduce the signature and pattern of the water vapour drop in agreement with those derived from satellite observations, if the model is nudged. Model results confirm that this extraordinary water vapour decline is in particular obvious in the tropical lower stratosphere and is related to a large decrease in cold point temperature. The drop signal propagates under dilution to the higher stratosphere and to the poles via the Brewer-Dobson circulation (BDC). We found that the driving forces for this significant decline in water vapour mixing ratios are tropical sea surface temperature (SST) changes due to a coincidence with a preceding strong El Nino--Southern Oscillation event (1997/98) followed by a~strong La Nina event (1999/2000) and supported by the change of the westerly to the easterly phase of the equatorial stratospheric quasi-biennial oscillation (QBO) in 2000. Correct (observed) SSTs are important to trigger the strong decline in water vapour. There are indications, that at least partly, SSTs contribute to the long period of low water vapour values from 2001 to 2006. For this period, the specific dynamical state of the atmosphere (overall atmospheric large-scale wind and temperature distribution) is important as well, as it causes the observed persistent low cold point temperatures. These are induced by a period of increased upwelling, which, however, has no corresponding pronounced signature in SSTs anomalies in the tropics. Our free-running simulations do not capture the drop as observed, because a) the cold point temperature has a low bias and thus the water vapour variability is reduced and b) because they do not simulate the appropriate dynamical state. Large negative water vapour declines are also found in other years, and seem to be a~feature, which can be found after strong combined El Nino/La Nina events, if the QBO west phase during La Nina changes to the east phase.

elib-URL des Eintrags:https://elib.dlr.de/104656/
Dokumentart:Zeitschriftenbeitrag
Titel:The Millennium water vapour drop in chemistry-climate model simulations
Autoren:
AutorenInstitution oder E-Mail-AdresseAutoren-ORCID-iDORCID Put Code
Brinkop, SabineDLR, IPANICHT SPEZIFIZIERTNICHT SPEZIFIZIERT
Dameris, MartinDLR, IPANICHT SPEZIFIZIERTNICHT SPEZIFIZIERT
Jöckel, PatrickDLR, IPANICHT SPEZIFIZIERTNICHT SPEZIFIZIERT
Garny, HellaDLR, IPANICHT SPEZIFIZIERTNICHT SPEZIFIZIERT
Lossow, Stefanstefan.lossow (at) kit.eduNICHT SPEZIFIZIERTNICHT SPEZIFIZIERT
Stiller, Gabrielegabriele.stiller (at) kit.eduNICHT SPEZIFIZIERTNICHT SPEZIFIZIERT
Datum:6 Juli 2016
Erschienen in:Atmospheric Chemistry and Physics (ACP)
Referierte Publikation:Ja
Open Access:Ja
Gold Open Access:Ja
In SCOPUS:Ja
In ISI Web of Science:Ja
DOI:10.5194/acp-16-8125-2016
Seitenbereich:Seiten 8125-8140
Verlag:Copernicus Publications
ISSN:1680-7316
Status:veröffentlicht
Stichwörter:stratospheric water vapour variability, tropopause
HGF - Forschungsbereich:Luftfahrt, Raumfahrt und Verkehr
HGF - Programm:Raumfahrt
HGF - Programmthema:Erdbeobachtung
DLR - Schwerpunkt:Raumfahrt
DLR - Forschungsgebiet:R EO - Erdbeobachtung
DLR - Teilgebiet (Projekt, Vorhaben):R - Atmosphären- und Klimaforschung
Standort: Oberpfaffenhofen
Institute & Einrichtungen:Institut für Physik der Atmosphäre > Erdsystem-Modellierung
Hinterlegt von: Brinkop, Dr. Sabine
Hinterlegt am:17 Jun 2016 16:36
Letzte Änderung:03 Nov 2023 07:40

Nur für Mitarbeiter des Archivs: Kontrollseite des Eintrags

Blättern
Suchen
Hilfe & Kontakt
Informationen
electronic library verwendet EPrints 3.3.12
Gestaltung Webseite und Datenbank: Copyright © Deutsches Zentrum für Luft- und Raumfahrt (DLR). Alle Rechte vorbehalten.