Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

IF value: 5.414
IF5.414
IF 5-year value: 5.958
IF 5-year
5.958
CiteScore value: 9.7
CiteScore
9.7
SNIP value: 1.517
SNIP1.517
IPP value: 5.61
IPP5.61
SJR value: 2.601
SJR2.601
Scimago H <br class='widget-line-break'>index value: 191
Scimago H
index
191
h5-index value: 89
h5-index89
Volume 14, issue 11
Atmos. Chem. Phys., 14, 5251–5269, 2014
https://doi.org/10.5194/acp-14-5251-2014
© Author(s) 2014. This work is distributed under
the Creative Commons Attribution 3.0 License.
Atmos. Chem. Phys., 14, 5251–5269, 2014
https://doi.org/10.5194/acp-14-5251-2014
© Author(s) 2014. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 02 Jun 2014

Research article | 02 Jun 2014

On the detection of the solar signal in the tropical stratosphere

G. Chiodo1, D. R. Marsh2, R. Garcia-Herrera3,1, N. Calvo1, and J. A. García4 G. Chiodo et al.
  • 1Dpto. de Astrofísica y CC de la Atmósfera, Universidad Complutense de Madrid, Madrid, Spain
  • 2Atmospheric Chemistry Division, National Center for Atmospheric Research, Boulder, CO, USA
  • 3Instituto de Geociencias IGEO (CSIC-UCM), Madrid, Spain
  • 4Dpto. de Física, Universidad de Extremadura, Badajoz, Spain

Abstract. We investigate the relative role of volcanic eruptions, El Niño–Southern Oscillation (ENSO), and the quasi-biennial oscillation (QBO) in the quasi-decadal signal in the tropical stratosphere with regard to temperature and ozone commonly attributed to the 11 yr solar cycle. For this purpose, we perform transient simulations with the Whole Atmosphere Community Climate Model forced from 1960 to 2004 with an 11 yr solar cycle in irradiance and different combinations of other forcings. An improved multiple linear regression technique is used to diagnose the 11 yr solar signal in the simulations. One set of simulations includes all observed forcings, and is thereby aimed at closely reproducing observations. Three idealized sets exclude ENSO variability, volcanic aerosol forcing, and QBO in tropical stratospheric winds, respectively. Differences in the derived solar response in the tropical stratosphere in the four sets quantify the impact of ENSO, volcanic events and the QBO in attributing quasi-decadal changes to the solar cycle in the model simulations. The novel regression approach shows that most of the apparent solar-induced lower-stratospheric temperature and ozone increase diagnosed in the simulations with all observed forcings is due to two major volcanic eruptions (i.e., El Chichón in 1982 and Mt. Pinatubo in 1991). This is caused by the alignment of these eruptions with periods of high solar activity. While it is feasible to detect a robust solar signal in the middle and upper tropical stratosphere, this is not the case in the tropical lower stratosphere, at least in a 45 yr simulation. The present results suggest that in the tropical lower stratosphere, the portion of decadal variability that can be unambiguously linked to the solar cycle may be smaller than previously thought.

Publications Copernicus
Download
Citation
Altmetrics
Final-revised paper
Preprint