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Titel |
Estimations of climate sensitivity based on top-of-atmosphere radiation imbalance |
VerfasserIn |
B. Lin, L. Chambers, P. Jr. Stackhouse, B. Wielicki, Y. Hu, P. Minnis, N. Loeb, W. Sun, G. Potter, Q. Min, G. Schuster, T.-F. Fan |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1680-7316
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Chemistry and Physics ; 10, no. 4 ; Nr. 10, no. 4 (2010-02-19), S.1923-1930 |
Datensatznummer |
250008125
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Publikation (Nr.) |
copernicus.org/acp-10-1923-2010.pdf |
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Zusammenfassung |
Large climate feedback uncertainties limit the accuracy in predicting the
response of the Earth's climate to the increase of CO2 concentration
within the atmosphere. This study explores a potential to reduce
uncertainties in climate sensitivity estimations using energy balance
analysis, especially top-of-atmosphere (TOA) radiation imbalance. The
time-scales studied generally cover from decade to century, that is,
middle-range climate sensitivity is considered, which is directly related to
the climate issue caused by atmospheric CO2 change. The significant
difference between current analysis and previous energy balance models is
that the current study targets at the boundary condition problem instead of
solving the initial condition problem. Additionally, climate system memory
and deep ocean heat transport are considered. The climate feedbacks are
obtained based on the constraints of the TOA radiation imbalance and surface
temperature measurements of the present climate. In this study, the TOA
imbalance value of 0.85 W/m2 is used. Note that this imbalance value
has large uncertainties. Based on this value, a positive climate feedback
with a feedback coefficient ranging from −1.3 to −1.0 W/m2/K is
found. The range of feedback coefficient is determined by climate system
memory. The longer the memory, the stronger the positive feedback. The
estimated time constant of the climate is large (70~120 years)
mainly owing to the deep ocean heat transport, implying that the system may
be not in an equilibrium state under the external forcing during the
industrial era. For the doubled-CO2 climate (or 3.7 W/m2 forcing),
the estimated global warming would be 3.1 K if the current estimate of 0.85
W/m2 TOA net radiative heating could be confirmed. With accurate
long-term measurements of TOA radiation, the analysis method suggested by
this study provides a great potential in the estimations of middle-range
climate sensitivity. |
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