Universidad Complutense de Madrid
E-Prints Complutense

Influence of the quasi-biennial oscillation and El Niño-Southern Oscillation on the frequency of sudden stratospheric warmings

Impacto

Downloads

Downloads per month over past year

Richter, Jadwiga H. and Matthes, Katja and Calvo Fernández, Natalia and Gray, Lesley J. (2011) Influence of the quasi-biennial oscillation and El Niño-Southern Oscillation on the frequency of sudden stratospheric warmings. Journal of geophysical research-atmospheres, 116 . ISSN 0148-0227

[img]
Preview
PDF
247kB

Official URL: http://dx.doi.org/10.1029/2011JD015757




Abstract

Stratospheric sudden warmings (SSWs) are a major source of variability during Northern Hemisphere winter. The frequency of occurrence of SSWs is influenced by El Nino-Southern Oscillation (ENSO), the quasi-biennial oscillation (QBO), the 11 year solar cycle, and volcanic eruptions. This study investigates the role of ENSO and the QBO on the frequency of SSWs using the National Center for Atmospheric Research's Whole Atmosphere Community Climate Model, version 3.5 (WACCM3.5). In addition to a control simulation, WACCM3.5 simulations with different combinations of natural variability factors such as the QBO and variable sea surface temperatures (SSTs) are performed to investigate the role of QBO and ENSO. Removing only one forcing, variable SSTs or QBO, yields a SSW frequency similar to that in the control experiment; however, removing both forcings results in a significantly decreased SSW frequency. These results imply nonlinear interactions between ENSO and QBO signals in the polar stratosphere during Northern Hemisphere winter. This study also suggests that ENSO and QBO force SSWs differently. The QBO forces SSW events that are very intense and whose impact on the stratospheric temperature can be seen between December and June, whereas ENSO forces less intense SSWs whose response is primarily confined to the months of January, February, and March. The effects of SSWs on the stratospheric background climate is also addressed here.


Item Type:Article
Additional Information:

We thank C. Kadow for the technical assistance with Figures 1 and 2. The National Center for Atmospheric Research (NCAR) is sponsored by the National Science Foundation. N. Calvo was partially supported by the Advanced Study Program (ASP) at NCAR. K. Matthes is supported within the Helmholtz-University Young Investigators Group NATHAN funded by the Helmholtz Association through the President's Initiative and Networking Fund, GFZ Potsdam, and Freie Universitat Berlin. Copyright 2011 by the American Geophysical Union. L. Gray is supported by the U.K. Natural Environment Research Council (NERC) through its National Centre for Atmospheric Science (NCAS).

Uncontrolled Keywords:11-Year solar-cycle; Northern-hemisphere; Winter stratosphere; Model; Circulation; QBO; Variability; Simulations; Atmosphere; Regimes
Subjects:Sciences > Physics > Astrophysics
Sciences > Physics > Astronomy
Sciences > Physics > Atmospheric physics
ID Code:25520
Deposited On:23 May 2014 08:17
Last Modified:10 Dec 2018 15:05

Origin of downloads

Repository Staff Only: item control page