Effects of the Land/Sea Breeze Circulation

Analyze the wind direction at the time of 18z on September 1st (1 PM EST) in comparison with the temperature contrasts, upward motion and time of day.  The Bundle should like like Figure 3 at that time.

Sea Breeze

Figure 3

Click on the link to the bundle called “sat_seabreeze.xidv”. Two main windows should appear; the Display Window and the Data Selector Window. Various Parameter Windows will also appear. Use the zoom buttoms and arrow buttons on the left side of the Display window to zoom in on Florida and Move ahead to 17:15Z on September 1st (12:15pm). Once you load the bundle and zoom in, you should be able to view an image similar to Figure 5. Click on the play button to loop the images. Notice that there are afternoon sea breeze thunderstorms in Florida. Think back to the upward motion that is occurring due to the converging sea breezes at this time.

Figure 6

The inland or offshore extent of the land/sea breeze is greater in the tropics compared to the mid-latitudes (about 100 km compared to about 10 km). This is because a circulation such as the sea breeze in the tropics can have a much larger horizontal extent without being turned by the Coriolis acceleration (Coriolis is weaker in the tropics).  Therefore, the circulations greatly influence the weather in tropical towns.  For instance, enhanced rainfall at night and early morning on the east coasts of Brazil and the Ivory Coast are a result of the land breeze circulation. Also, large mountainous islands (such as Puerto Rico) often have a clear ring of suppressed cloudiness surrounding them in the afternoon. This is due to the compensating subsidence from the convection and thunderstorms over the interior.

The Pacific coast of the U.S. also is affected by sea breezes. In this region, strong gusty winds lead to the onshore advection of marine stratus clouds and fog.

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