IRUS Total

A 1D RCE study of factors affecting the tropical tropopause layer and surface climate

File Description SizeFormat 
1d-rce-study (1).pdfAccepted version334.43 kBAdobe PDFView/Open
Title: A 1D RCE study of factors affecting the tropical tropopause layer and surface climate
Authors: Dacie, S
Kluft, L
Schmidt, H
Stevens, B
Buehler, SA
Nowack, PJ
Dietmüller, S
Abraham, NL
Birner, T
Item Type: Journal Article
Abstract: There are discrepancies between global climate models regarding the evolution of the tropical tropopause layer (TTL) and also whether changes in ozone impact the surface under climate change. We use a 1D clear-sky radiative-convective equilibrium model to determine how a variety of factors can affect the TTL and how they influence surface climate. We develop a new method of convective adjustment, which relaxes the temperature profile towards the moist adiabat and allows for cooling above the level of neutral buoyancy. The TTL temperatures in our model are sensitive to CO2 concentration, ozone profile, the method of convective adjustment and the upwelling velocity, which is used to calculate a dynamical cooling rate in the stratosphere. Moreover, the temperature response of the TTL to changes in each of the above factors sometimes depends on the others. The surface temperature response to changes in ozone and upwelling at and above the TTL is also strongly amplified by both stratospheric and tropospheric water vapour changes. With all these influencing factors, it is not surprising that global models disagree with regard to TTL structure and evolution and the influence of ozone changes on surface temperatures. On the other hand, the effect of doubling CO2 on the surface, including just radiative, water vapour and lapse rate feedbacks, is relatively robust to changes in convection, upwelling or the applied ozone profile.
Issue Date: 15-Oct-2019
Date of Acceptance: 1-Jul-2019
URI: http://hdl.handle.net/10044/1/72259
DOI: 10.1175/jcli-d-18-0778.1
ISSN: 0894-8755
Publisher: American Meteorological Society
Start Page: 6769
End Page: 6782
Journal / Book Title: Journal of Climate
Volume: 32
Copyright Statement: © 2019 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses)
Keywords: Science & Technology
Physical Sciences
Meteorology & Atmospheric Sciences
Radiative-convective equilibrium
Climate sensitivity
Single column models
0401 Atmospheric Sciences
0405 Oceanography
0909 Geomatic Engineering
Meteorology & Atmospheric Sciences
Publication Status: Published
Article Number: JCLI-D-18-0778.1
Online Publication Date: 2019-09-11
Appears in Collections:Centre for Environmental Policy
Faculty of Natural Sciences