Exchange time atmosphere ocean

The direction of the NH3 flux cross the ocean/atmosphere interface depends on the concentration difference between NH3 in the surface ocean (NH3)got.ej j and (NH3)g j,tmos in the marine boundary layer. In the case of an ocean/atmosphere equihbrium the concentration difference is 0 and no gas exchange is possible. Ideally, both parameters should be measured simultaneously to allow a reasonable flux estimate. Disequfribria, (NH3)g ocean (NH3)g nnos, can develop because the gas exchange across the ocean/atmosphere interface is slow compared to the Hfe times of NH3 in the marine boundary layer and in the surface ocean (Quinn et al., 1992). 

Fig. 11-4. Exchange of C02 between atmosphere and ocean in a two-box ocean model. Reservoir contents are shown in units of Pg C ( = 1012 kg C), exchange coefficients in yr l, and residence times in years. For comparison, the exchange of atmospheric carbon with the biosphere is shown in parallel. For simplicity the biosphere is represented by the two reservoirs of short-lived photosynthetic active components and the long-lived structural material. A more detailed breakdown of the biospheric reservoir is shown in Fig. 11-6.

Fluctuations that have been measured in the 5 G values of sedimentary organic matter over the Earth s history (e g. Schidlowski 1988) can thus be interpreted in terms of the productivity in the water coltrrrm and the availability of DIG in a particular geological time period. In a study of sediments from the central equatorial Pacific Ocean spanning the last 255,000 years it has been demonstrated that the carbon isotopic composition of fossil organic matter depends on the exchange between atmospheric and oceanic GO. Ghanges with time can then be used to estimate past atmospheric carbon dioxide concentratiorrs (Jasper et al. 1994). 

Fig. 4-17 Rough estimates of characteristic time for exchange of air and water respectively, between Afferent parts of the atmosphere and oceans.

The content of the material in a carbon reservoir is a measure of that reservoir s direct or indirect exchange rate with the atmosphere, although variations in solar also create variations in atmospheric content activity (Stuiver and Quay, 1980, 1981). Geologically important reservoirs (i.e., carbonate rocks and fossil carbon) contain no radiocarbon because the turnover times of these reservoirs are much longer than the isotope s half-life. The distribution of is used in studies of ocean circulation, soil sciences, and studies of the terrestrial biosphere. 

While the natural exchange of mercury between the land and atmosphere and the atmosphere and oceans is balanced, human activity has tipped this balance. There is now about three times more mercury in the atmosphere and fluxes of more than four times to and from the atmosphere. 

The previous model setup included an identical horizontal resolution for ocean and atmosphere, and online coupling was implemented in the ECHAM submodel with an exchange rate of 3 hours. In the current model setup atmosphere and ocean are coupled online using the Ocean-Atmosphere-Sea Ice-Soil (OASIS) coupler [Valcke et al (2004)] with a coupling time step of one day. OASIS passes boundary condi-... 

The exchange of carbon between atmosphere and surface ocean is characterized by a transfer time distime... 

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