ii. Figure above shows the mean annual pattern of energy transfer by the three mechanisms. The latitudinal zone of maximum total transfer rate is found between latitudes 35o and 45oin both hemispheres, although the patterns for the individual components are quite different from one another. The latent heat transport, which occurs almost wholly in the lowest 2 or 3 km, reflects the global wind belts on either side of the subtropical high-pressure zones. The more important meridional transfer of sensible heat has a double maximum not only latitudinally but also in the vertical plane, where there are maxima near the surface and at about 200 hPa. The high-level transport is particularly significant over the subtropics, whereas the primary latitudinal maximum about 50o to 60oN is related to the travelling low-pressure systems of the westerlies.
b. Absorption of Water:
i. Comparing with other materials, water has a larger specific heat, and it is difficult to increase the temperature of the water relatively.
ii. Water has a large transparency. Some energy of insolation which is absorbed by the water penetrates to a great depth.
iii. There is a circulation in the ocean. The surface warm water can be brought to deep sea and the cold water also can be transported to the sea surface.
Some solar energy doesn't use for the water heating, but use for evaporation. In general, 1/3 energy are used for evaporation.
c. The Effect of the Ocean Currents:
i. As shown in the figure on previous page, the ocean currents account for significant proportion of the poleward heat transfer in low latitudes.
ii. The so-called "Warm Currents" refer to those sea water which travels from low to high latitudes while the "Cold Currents" refer to those moving from high to low latitudes. The essential features of the ocean currents are shown in the figure below.
iii. Among the warm currents, the most influential ones should be the Gulf Stream and its extension towards the Norwegian Sea in Northern Atlantic Ocean and the Kuro Siwo Currents in Northern Pacific Ocean. In the North Atlantic, vast masses of warm water are transported by Gulf Stream from low to high latitudes. Three important features make the Gulf Stream the dominating factor influencing the climate of Europe: