Free Nautical Charts

Why do maritime areas have such moderate temperatures?

Public Comments

1. large body of water at a constant temp modulate the surrounding land areas
2. water moderates the temperature.
3. have you ever stood next to a pot of boiling water, do you feel the heat coming from it? I live on the Texas Gulf Coast and the Gulf of Mexico gets pretty warm in the summer time, at least 80 degrees in the water, thus the humidity gets really bad. In the winter, we very rarely get below freezing because the water in the ocean doesn't cool off below 50, so it's like a blanket of protection for us. In the Spring, tourists get surprised when they come to the beach down here the day after a cool front, when the wind has shifted back from the south. It's warmer in Houston, the breeze is warm, the air is warm and it feels like you could go for a nice warm swim in the ocean. They drive down here to Galveston and are shocked because the winds are chilly because the ocean temp is in the 60's. In the fall, it takes several cool fronts to cool off the ocean and make it feel nice again. Overall, it's usually 6 months hot and 6 months cool or cold here.
4. Water requires more heat for raising its temperature than soil,- the specific heat of the water being more than that of a soil.Therefore a sea surface gets less heated than a land surface. Soil is a poor conductor of heat-the solar insolation therefore heating a thin layer of air immediately above the ground by conduction.In case of sea water, being fairly tranparent to solar radiation,- the heating effect penetrates to a considerable depth.Therefore, the air above the sea surface does not get that much opportunity to be heated by solar radiation.Further,the incident solar radiation mainly is utilised in evaporating water from the surface only,not therefore appreciably raising the temperature of the air above the water surface. Because of the above reasons,the air over the water surface is less heated than that over the land.This tries to bring down the temperature over land during day time. Land being a good absorber of heat,is also a good radiator of heat.So during night it gives out more heat.But the nearby water surface gives out the heat slowly.So the air over water is warmer than that over the land.This will try to warm the air overthe adjacent land during night. So , in the coastal stations ,the water surface tries to lower the temperature during day time and tries to increase the tremperature during night. Hence maritime areas have moderate temperatures always.