Global Warming Enhances Ozone Transport from the Stratosphere to the Troposphere
Further Accelerates Global Warming
Outline
Hajime Akimoto (Director of Atmospheric Composition Research Program),
Masaaki Takahashi (Group Leader, joint appointment of professor at
Center for Climate System Research, University of Tokyo), and Kengo
Sudo (Research Fellow) at Frontier Research System for Global Change
(FRSGC: joint project of JAMSTEC and JAXA), has found that ozone
transport from the stratosphere (Note 1) to the troposphere will be
enhanced by global warming as studied by chemical/climate model
experiment (Figure 1 and 2). It is suggested that the enhanced
intrusion of ozone to the troposphere will further accelerates
global warming.
This research outcome was published in Geophysical Research Letter
(Vol. 30, No. 24), by American Geophysical Union, and distributed in
Japan at the end of February.
Background
Impact of climate change induced by global warming, on chemical
species formed in the atmosphere such as ozone, and its feedback
of the chemistry change to the climate is called chemistry-climate
interaction, which is becoming one of the major concerns in various
sectors. Particularly, tropsopheric ozone (Note 2) is recognized as
the third most important greenhouse gas in the IPCC Third Assessment
Report, and its relevance to global warming/climate change attracts
much attention.
In order to study climate change accompanied by the increase of
greenhouse gasses, FRSGC has developed a chemical climate model,
"CHASER" (Note 3), jointly with Center for Climate System Research,
University of Tokyo (CCSR), and National Institute for Environmental
Studies (NIES), which can calculate chemical processes in the
troposphere and its impact on climate on a global scale. So far,
future change of distribution of air pollutants such as ozone, and
their climate effect have been predicted.
Results
Using the A2 Scenario of IPCC (Reference 1), increase of tropopsheric
ozone has been calculated, and it was elucidated that there will be a
big difference in vertical distribution of ozone between the cases
with and without considering global warming. Result of experiment
considering warming shows great enhancement of ozone in the upper
troposphere at mid and low latitude. The reason was found to be due
to the enhancement of atmospheric circulation both in the stratosphere
and troposphere, resulting the increase of stratospheric intrusion of
ozone to the troposphere (Ref. 2).
It is known that ozone in the upper troposphere has a strong greenhouse
effect and its increase has marked effect on the increase of earth
surface temperature (Reference 3). Therefore, the present result
implies that global warming enhances ozone in the upper troposphere,
the ozone enhancement possibly further accelerates warming.
Contacts
Frontier Research System for Global Change
Contact: Ms. Ota
Tel: +81 (0)45-778-5687 (direct)
URL: http://www.jamstec.go.jp/frsgc/eng/index.html
JAXA, Public Affairs Department
Tel: +81-3-3438-6107/6108/6109
URL: http://www.jaxa.jp/index_e.html
JAMSTEC, Public Relations Office, General Affairs Department
Tel: +81 (0)46-867-9066
URL: href=”http://www.jamstec.go.jp/jamstec-e/index-e.html”>http://www.jamstec.go.jp/jamstec-e/index-e.html
This page URL:
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