Will the temperature of the seawater fall after Hurricane Dean passes ? If so, by how much ?

Question

Water temperature plays a major role in determining the strength of a hurricane. Will the passage of Hurricane Dean reduce the water temperature such that following storms may be less powerful ? How much time is required for the water to return to its pre-Dean temperature ?

Answer 1

Yes the hurricane will indeed leave a cooler footprint in its wake. This is verified by looking at detailed sea surface temperature (SST) maps after the storm has passed. Normally the stronger and slower moving of the storm over the water the more the SST is lowered. In many cases it will lower it by as much as 2 to 3 degrees F. and can have an affect on tropical storms that follow later in the wake of the original storm. There are several reasons for the cooling. As stated by another answer, wave action brings cooler water from greater depths and mixes it with the warmer surface water. Increased evaporation of the sea water takes heat from the ocean. Evaporation is increase by larger surface area exposed to the air by the wave action and wind which aids in carring the evaporated water away from the surface quickly. To see this in action, pour a glass of water on yourself and have a fan blow air on you. When you turn the fan on the breeze increases the evaporation rate and you can even becom chilled that way. There also is some lowering by the rain being produced by the storm itself. The rain is nomally cooler that the sea temperature and cools it as mixes with it. Now to tackle the time required to return to pre storm conditions. It depends a lot on exactly when the storm occurrs. In the case of Dean I think it will be close whether or not temperatures reach the pre storm temperature. If it had occurred in late June or July it would about 2 weeks unless another storm or area of cloudiness comes along the same path. If storm were to happen pass the second week of September, I doubt it would completely recover since the sun angle is starting to get to the point where there is not enough energy to maintain the late summer SST. If there are no storms SST normally peaks the last week of August or the first week of September.

Answer 2

The reason warm sea water is important is that the equilibrium vapor pressure of water in the air is higher as the sea water gets warmer, so the absolute humidity increases. This means each parcel of air carries more energy in terms of latent heat which can feed the engine. This is why the west coast has such a pleasant climate compared to the gulf coast; the cold pacific water lowers the humidity.

Hurricanes like to have the top few hundred feet of water warm, since they churn the water so much. If the warm layer is too shallow, the churning brings cooler water to the surface, reducing the absolute humidity of the air. Passage of a hurricane takes the punch out of the churned water for a time, but not sure how long. Probably a few weeks during the peak season, but that's just my guess.

Answer 3

It's not an easy question to answer. Usually warmer water is near the surface and cooler water below, so a hurricane often stirs up the water brings some of the cool water to the surface and pushes some of the warm water down, that leaves a cool trail behind it which can impede closely following storms. However, after a fairly short period (maybe a few weeks) the surface waters re-warm and now there is warm water at the surface AND warm water below that got pushed down in the last storm, so then a new storm may be STRONGER when going over the previously stirred up water. This is brand new research, just published over the last few months.

Answer 4

inanimate objects don't suffer wind chill,.....if that is what you are asking,.....