Water temperature variations resulting from hurricanes

Abstract

Daily variations in sea surface temperature at several coastal and lightship stations and the Nomad buoy during the passages of ten hurricanes are presented. The temperature variations are given for the coastal stations and Nomad buoy for a period from 10 days before to 36 days after the hurricane passed. Generally, marked cooling of the sea surface occurred during the passage of a hurricane. However, examples are noted where a rise in temperature occurred. A comparison was made of the daily temperature variation due to hurricanes as recorded at the coastal and deep water sites. The mean temperatures decrease for the eleven coastal examples and for the thirteen lightship examples was 3.1°F, and for the three Nomad examples was 6.4°F. The extent of cooling of the surface water appears to be related to storm intensity and orientation with respect to the recording station. The temperature decreases at the Nomad buoy during the passage of hurricanes were quite large compared with the changes at other times during the 47-day periods, but factors other than hurricanes appear to cause larger temperature variations at the coastal sites. The length of time for the water temperature to return to normal after passage of a hurricane was computed for all stations. For the coastal and lightship stations the temperature returned to normal in less than one month, with mean time of 13 and 10 days, respectively. At the Nomad buoy, near prehurricane surface temperature conditions were recorded within 10 days. These observations indicate the rapidity with which hurricane effects are modified by subsequent environmental events.