Glagolev M.V.
Lomonosov Moscow state university
Yugra state university, Khanty-Mansiysk
In recent years, one of the objectives of the most important greenhouse gases (GreG) measurement programs is to determine quantitatively the magnitudes of the major sources and sinks of these gases, so as to arrive at an improved definition of the present-day global atmospheric budget. Better understanding of sources and sinks is required if we are to predict future trends of GreG with confidence. Such understanding should include feedback effects between slowly changing climatic variables and GreG source strength.
The emission rate from soil is measured in general by covering the surface by a box and observing the increment of GreG concentration in it; so called “chamber method”. Вecause of the heterogeneity of the emissions patterns observed, a prohibitively large and expensive number of measurements would be needed to obtain a statistically representative set of flux measurements for a large scale. The random sampling of the observation poitns followed by the chamber method measurement to obtain the averaged value is logically possible but it is extremely difficult to achieve because of logistic problems. The possible and most efficient method to evaluate the emission rate is to evaluate from the atmospheric measurement.
We present the review of Borodulin-Desyatkov-Sarmanaev inverse estimation method for the determination of the gas flux through the soil surface. Gas concentrations over the surface and some reference meteorological variables are necessary to determine the gas emission in this approach. These data are later used to solve an inverse problem of gas transfer in the atmosphere resulting in a gas flux determination (under appropriate conditions, this inversion can produce an optimized and unique solution). Cited authors derive, by what could be called an inverse calculation, the sources and sinks necessary to reproduce the concentrations that they have observed in the boundmyl ayer. In simplest case a near-ground-level concentration measurement is used to estimate a total CН4 emission rate for the wetland.
А gas concentration at any site results from a combination of two factors: local sources or sinks and transport. To separate these two effects, an atmospheric transport model is needed. To elucidate main idea and make our overview simple, we utilize a simplified atmospheric boundary layer model.
Key words: micrometeorological methods, inverse estimation method, gas flux from the soil.