Science Serving Maryland's Coasts

Alexander Davies, Millersville University of Pennsylvania

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Project Title: 

An Analysis of Future Climate Predicted for the Chesapeake Bay by the IPCC AR4 Models


The purpose of this study is to analyze the projected climate over the Chesapeake Bay Watershed by the IPCC AR4 models.  As a mean of doing this the A2 and B1 emission scenarios were chosen because they represent the largest range of direction in all the emission scenarios.  The mean model is the average of all individual models and is often used as a tool for the most accurate future climate projections. By removing some poorly performing models versus the 20th century data, the mean model was able to undergo a statistically significant improvement.  With an improved mean model, it is projected that mean annual temperature will increase across the watershed by 4.65 degrees Celsius under the A2 emissions scenario and 2.49 degrees Celsius under the B1 scenario.  Additionally, annual precipitation is projected to increase by 5.04% under the B1 scenario and 7.18% under the A2 scenario with the greatest increases projected for winter and spring.  With no concrete relationship exists between precipitation and streamflow, it is possible only to speculate that changes in precipitation may alter the time and duration of the spring freshet.  Flooding events and drought conditions could be an even greater future concern as there appears to be an upward trend for the amount of 5 day rain fall, consecutive dry days, and extreme temperature events—particularly under the A2 scenario.