Climate, considered especially in relation to man / by Robert DeCourcy Ward.

  • Robert DeCourcy Ward
Date:
[1908], [©1908]
Catalogue details

Licence: Public Domain Mark

Credit: Climate, considered especially in relation to man / by Robert DeCourcy Ward. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

    60/408 (page 36)
    Belation of Continental and Ocean Areas to Tem- perature. Land and water differ greatly in their be- haviour regarding absorption and radiation. The former warms and cools readily, and to a considerable degree; the latter, slowly and but little. (1) Of the insolation which falls upon the ocean, a good deal is at once reflected, and is therefore not available for warming the water. Land surfaces, on the other hand, are poor reflectors; but little insolation is lost in that way; hence more energy is available for raising their temperature. (2) ]Most of the insolation which enters the water is transmitted to some depth, and, therefore, is not effectively applied to warming the surface. Land is opaque and does not allow the in- cident insolation to pass beyond a comparatively thin surface stratum; hence this surface can be well warmed. (3) The evaporation of water requires a large amount of energy, which changes the state of the water without raising its temperature (latent heat). Land, although often moist, is itself non- volatile ; therefore the loss of energy in the process of evaporation is usually very slight. (4) Water is more difficult to warm than any other natural sub- stance, while land is warmed easily and quickly. If equal amounts of heat are received by equal areas of land and water, the former warms about twice as much as the latter. (5) The mobility of water keeps the warmer and the colder portions well mixed, and there- fore greatly retards the process of warming any one portion of the surface. Land cannot thus equalise