Investigating the roles of the stratosphere in recent observed multi-decadal climate variations
Abstract
We examine the role of the stratosphere in driving recent observed multi-decadal climate variations using GFDL's coupled model LOAR2. We conduct suites of simulations, in which the model's winds and temperature in the stratosphere are restored towards observed values using MERRA2 reanalysis data. In the stratosphere-constrained coupled simulations, the low-frequency surface climate variations (e.g., North Atlantic Oscillation(NAO)) are well correlated with observations. Fpr example, for the perod from 1980 to the present the correlation coefficient for NAO is 0.73 when the model stratosphere (but not the troposphere) is restored to observations. Consequently, the stratosphere-constrained simulations also show significant correlations with observations for surface air temperature over the northern Eurasian continent, the Pacific, and North Atlantic ocean basins. In addition, the multi-decadal trends of the Arctic sea ice extent in March and September are well simulated in comparison with observations. Interestingly, the stratosphere-constrained experiment is able to simulate the recent global warming hiatus, including aspects of its spatial pattern. The mechanisms of how stratospheric variations can induce multi-decadal surface climate changes will be discussed in this presentation.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2017
- Bibcode:
- 2017AGUFM.A53D2290Z
- Keywords:
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- 3305 Climate change and variability;
- ATMOSPHERIC PROCESSES;
- 3339 Ocean/atmosphere interactions;
- ATMOSPHERIC PROCESSES;
- 4504 Air/sea interactions;
- OCEANOGRAPHY: PHYSICAL;
- 4513 Decadal ocean variability;
- OCEANOGRAPHY: PHYSICAL