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Exploring the Effects of Atmospheric Forcings on Evaporation: Experimental Integration of the Atmospheric Boundary Layer and Shallow Subsurface
Published on: June 8, 2015
Tropical drying trends in global warming models and observations.
1Department of Atmospheric and Oceanic Sciences and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA 90095, USA. neelin@atmos.ucla.edu
Summary
Global warming simulations show models agree on drying trends in tropical rainfall, particularly at convective zone margins. Observed rainfall data supports these drying trends in the Caribbean and Central America.
Area of Science:
- Climate Science
- Atmospheric Science
- Global Environmental Change
Background:
- Anthropogenic global warming influences tropical rainfall patterns.
- Latest-generation climate models exhibit discrepancies in simulating spatial precipitation changes.
- Understanding these changes is crucial for climate change impact assessments.
Purpose of the Study:
- To evaluate anthropogenic changes in tropical rainfall using a multimodel ensemble of global warming simulations.
- To identify areas of agreement and uncertainty in model predictions of precipitation changes.
- To compare model projections with observed rainfall trends.
Main Methods:
- Analysis of a multimodel ensemble of global warming simulations.
- Evaluation of global and local measures of precipitation change.
- Definition and application of a precipitation climate sensitivity metric.
- Comparison of model-predicted trends with observed rainfall data sets.
Main Results:
- Major discrepancies exist in the spatial distribution of precipitation changes across models.
- Models show agreement on drying trends (negative precipitation anomalies) at convective zone margins.
- Agreement is found on precipitation climate sensitivity and differential moisture changes.
- Observed rainfall trends confirm summer drying in the Caribbean/Central-American region, a key area of model agreement.
Conclusions:
- Despite spatial uncertainties, models provide reliable projections for certain tropical rainfall changes, particularly drying trends.
- The findings support a hypothesized causal path for precipitation changes linked to moisture dynamics.
- Observed data validates model agreement in specific regions, enhancing confidence in climate change projections.
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