Surface-troposphere system

The surface-troposphere system will continue to warm until the entire system reaches a new equilibrium. This may take a considerable time due to the very high heat capacity of the ocean and it will certainly last several decades before an equilibrium is reached, if at all. 

RADIATIVE FORCING OF THE TROPOSPHERE-SURFACE CLIMATE SYSTEM... 

Three regions of the atmosphere are seen to have significant zonal components of flow and thus of advection. The mid-latitude troposphere at the surface tends to exhibit westerly flow (i.e., flow from west to east) on the average. This region contains the familiar high- and low-pressure systems that cause periodicity in mid-latitude weather. Depending on the lifetime of the substances of concern, the motion in these weather systems may be important. 

In short, mass spectrometry is a powerful analytical tool that has been used successfully for a number of years at high altitudes and is now seeing increasing use in the troposphere, including at the earth s surface. A number of different approaches have been developed, including systems that are designed to measure species such as OH, NO, and HNO. They are described in more detail in the sections on measurement techniques for the individual species. 

Despite the difficulty of interpreting 14C measurements on surface ocean water such measurements are of great interest. The net transport of excess 14C from the atmosphere to the sea depends on the difference between the 14C concentration in atmospheric C02 and that in the carbonate system at the sea surface. The decline in the atmospheric reservoir of excess 14C is therefore controlled by the 14C concentration at the sea surface. This in turn depends upon diffusion and advection into the deep sea. As the levels of excess 14C in the troposphere and the mixed layer of the sea begin to approach each other, mixing from the mixed layer of the sea into the deep sea will be the factor controlling the levels of excess 14C in the atmosphere. 

Photoreactions are often complex reactions that not only control the fate of many chemicals in air and water, but often produce products with chemical, physical, and biological properties quite different from those of their parent compounds more water soluble, less volatile, and less likely to be taken up by biota. Photooxidation removes many potentially harmful chemicals from the environment, although occasionally more toxic products form in oil slicks and from pesticides (Larson et al., 1977). Biogeochemical cycling of organic sulfur compounds in marine systems involves photooxidation on a grand scale in surface waters, as well as in the troposphere (Brimblecombe and Shooter, 1986). 

The tropospheric photochemical system consists of a highly complex chemical scheme in which free radical species and especially OH produced in the presence of solar radiation play a central role. The overall trend of this radical system is to oxidize reduced species emitted from earth s surface and cause their eventual return to the biosphere-lithosphere-hydrosphere in an oxidized valence state. This atmospheric chemical cycle is actually one component of a larger set of cycles. In these larger cycles... 

DMS reactions in the troposphere are believed to lead to enhanced reflectivity of marine clouds [171] and thus DMS emissions may have a cooling influence on the atmosphere. One of the best demonstrations of the link between the natural atmospheric sulfur cycle and the physical climate system are the observations that link the satellite derived stratus cloud optical depth and observed DMS derived cloud condensation nuclei (CCN) concentrations at Cape Grim, Australia [175]. Statistical evidence indicates that the optical depth of the clouds is correlated with the number of CCN in the atmosphere. Thus, any UV-related changes at the surface of the ocean that result in the alteration in DMS flux to the atmosphere and the subsequent formation of CCN would also alter the atmospheric radiation budget for the affected region. 

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