Methods based on the joint use of models and observational data in the framework of variational approach to forecasting weather and atmospheric composition quality

Presented is a new version of the methods ofvariational assimilation ofmeasurement data from various observational systems including imagery. The base of these methods is the technique of variational principles formulated with weak constraints and applied to the joint models of hydrothermodynamics and chemistry ofthe atmosphere. To implement assimilation schemes, direct algorithms are proposed which are based on splitting techniques and enable solving the four-dimensional problems of forecasting with the assimilation of available monitoring data in the operational mode.