Greenhouse effect temperature profile

The greenhouse effect takes place in the lower part of the atmosphere, called the troposphere. This phenomenon is an enhancement of natural processes which manages the radiation balance at the Earth s surface owing to a permanent increase of the GHG concentrations. For a better understanding of this problem we should consider the chemical composition of the troposphere and residence times of some species of interest, the temperature profile in the whole atmosphere and the increasing concentrations of greenhouse gases. 

Figure 23.11 shows a way to view the greenhouse effect. The mean atmospheric temperature profile is shown starting from the current mean surface temperature of 288 K. If we assume a global average rate of decrease of temperature with height of 5.5 K km-1, the temperature of 255 K, the blackbody temperature corresponding to the mean emitted... 

Atmospheres modify the amount of heat that enters and leaves the planets over the entire electromagnetic spectrum. Strong greenhouse effects can raise the temperatures considerably over that calculated from the ideal models. The presence of internal sources of energy within a planet can modify its effective temperature and affect the thermal profile of the atmosphere. Surface emissiv-ity effects modify the apparent temperature of the planets. Nonuniform heating of the planets by the Sun due to orbit eccentricity and rotational effects also produces departures from the ideal model. Nonthermal emission from planetary magnetospheres produces the largest departures from the blackbody model. The role of the planetary astronomer is to sort out the various effects that take place and to measure and infer the actual physical characteristics of the planets. 

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