PRELIMINARY COMPUTATIONS ON THE MAINTENANCE AND PREDICTION OF SEASONAL TEMPERATURES IN THE TROPOSPHERE

JULIAN ADEM Extended Forecast Branch, NMC, U.S. Weather Bureau, Washington, D.C.

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Abstract

By considering the conservation of energy and the balance of radiation in the troposphere, in the cloud layer, and in the surface of the earth, we obtain a system of six equations containing six unknowns. The variables are the temperatures and the excesses of radiation in the troposphere, in the cloud layer, and in the surface of the earth. The equations contain as parameters the insolation, the cloudiness, the heat given off by the oceans and the continents to the atmosphere, and the initial temperature distributions. The model contains only meridional turbulent transport in the troposphere. Computations for both hemispheres and for the four seasons, as well as for the annual case, are carried out, obtaining a remarkable agreement with observations.

The meridional transport is accomplished by the cyclones and anticyclones of the middle latitudes with an austausch coefficient of the order of magnitude of 5×1010 cm.2 sec.−1.

The energy received from the surface of the earth by the atmosphere is very important for the maintenance and prediction of temperatures.

In the seasonal and in the annual cases there is no substantial storage of energy in the troposphere and a balance almost exists among the excess of radiation, the energy transported meridionally by turbulence, and the heat given off by the oceans and the continents. Therefore the prediction of the seasonal temperatures does not depend strongly on the initial temperatures in the troposphere itself.

In the annual case there also exists a balance in the upper layer of continents and oceans between the excess of radiation and the heat given off to the atmosphere. However in the seasonal case there exists a large storage of energy in the oceans and no such balance exists. Therefore, the mean seasonal temperature in the troposphere depends very strongly on the temperature in the oceans and we need to prescribe the temperature in the oceans at the early part of the season to predict the mean tropospheric temperature for the whole season.

Abstract

By considering the conservation of energy and the balance of radiation in the troposphere, in the cloud layer, and in the surface of the earth, we obtain a system of six equations containing six unknowns. The variables are the temperatures and the excesses of radiation in the troposphere, in the cloud layer, and in the surface of the earth. The equations contain as parameters the insolation, the cloudiness, the heat given off by the oceans and the continents to the atmosphere, and the initial temperature distributions. The model contains only meridional turbulent transport in the troposphere. Computations for both hemispheres and for the four seasons, as well as for the annual case, are carried out, obtaining a remarkable agreement with observations.

The meridional transport is accomplished by the cyclones and anticyclones of the middle latitudes with an austausch coefficient of the order of magnitude of 5×1010 cm.2 sec.−1.

The energy received from the surface of the earth by the atmosphere is very important for the maintenance and prediction of temperatures.

In the seasonal and in the annual cases there is no substantial storage of energy in the troposphere and a balance almost exists among the excess of radiation, the energy transported meridionally by turbulence, and the heat given off by the oceans and the continents. Therefore the prediction of the seasonal temperatures does not depend strongly on the initial temperatures in the troposphere itself.

In the annual case there also exists a balance in the upper layer of continents and oceans between the excess of radiation and the heat given off to the atmosphere. However in the seasonal case there exists a large storage of energy in the oceans and no such balance exists. Therefore, the mean seasonal temperature in the troposphere depends very strongly on the temperature in the oceans and we need to prescribe the temperature in the oceans at the early part of the season to predict the mean tropospheric temperature for the whole season.

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