An overview of the work on the development and use of global numerical models of the atmosphere, that has been carried out in the Laboratory for Atmospheric Chemistry and Dynamics (Central Aerological Observatory), is presented. The models were created in the framework of the Roshydromet plans.

A review of the results of Russian studies of the middle atmosphere in 2015–2018 prepared by the Commission on the Middle Atmosphere of the Association of Meteorology and Atmospheric Sciences National Geophysical Committee for the National Report on Meteorology and Atmospheric Sciences to the 27th General Assembly of the International Union of Geodesy and Geophysics (Canada, 2019) is presented.

Представлен обзор результатов российских исследований средней атмосферы в 2007–2010 гг., подготовленный Комиссией по средней атмосфере Секции метеорологии и атмосферных наук Национального геофизического комитета для Национального отчета по метеорологии и атмосферным наукам к XXV Генеральной ассамблее Международного союза геодезии и геофизики (г. Мельбурн (Австралия), 28 июня–7 июля 2011 г.)

Представлено описание численной глобальной фотохимической модели CHARM (CHemical Atmospheric Researh Model) и результаты трехмерного численного моделирования климатологических распределений озона и других малых газовых составляющих атмосферы Земли в диапазоне высот 0–90 км. Представлены также результаты реализации численных сценариев воздействия, вызванного изменением потоков УФ радиации Солнца в цикле его активности, а также обусловленного разрушением озона в полярных областях частицами высоких энергий космического происхождения. Для описания пространственного переноса химически активной примеси в модели (схема Пратера) были использованы расчеты глобальных полей компонент ветра и полей температуры с помощью модели общей циркуляции ARM (Atmospheric Research Model).

We describe the numerical global photochemical model CHARM (CHemical Atmospheric Research Model) and the results of a numerical simulation of climatological distributions of ozone and other atmospheric trace gases in a height range of up to 90 km. We also present the results of numerical scenarios of an impact induced by a change in UV radiation fluxes in the solar activity cycle and conditioned by ozone depletion in polar regions by high-energy particles of cosmic origin. The spatial transport of chemically active species is described in the model (the Prather scheme) on the basis of global fields of wind components and temperature calculated by the ARM (Atmospheric Research Model) general circulation model.

We describe the three-dimensional numerical global photochemical model CHARM-I (CHemical Atmospheric Research Model with Ions) and the results of numerical calculations of global distributions of neutral and charged atmospheric trace gases (in the height range of up to 90 km), such as ozone, nitrogen oxides, electrons, and positive and negative ions. This model is an improved version of the CHARM three-dimensional photochemical model of neutral components with additional reactions with the involvement of ions (a total of 200 photochemical reactions). The model incorporates UV-radiation fluxes on the Lyman-α line and galactic cosmic rays as ionizing factors. The neutral components are calculated with the method of “chemical families” and the concentrations of charged components are calculated by the electroneutrality condition at each time step. The spatial transport of chemically active species is described in the model by the Prather scheme. The developed model makes it also possible to take into account solar flares and particle precipitations in the ionospheric D-region.

The results of simulations of the global circulation and temperature regime in the altitude range from the lower tropospheric layers to 135 km are presented. They were obtained with the Atmospheric Research Model (ARM), an advanced modification of a version of the Cologne Middle Atmosphere Model (COMMA). The ARM is characterized by higher spatial resolution and better parameterizations of the radiation sources and heat sinks. At the lower boundary of the model, wavy sources of perturbations, which are caused by internal gravity waves and planetary waves, are specified. The results of the modeling of the global temperature and wind fields for the mean solar activity level are presented, and their changes, which are caused by variations of the UV-radiation fluxes in the solar activity cycle and by solar proton flares, are also considered.

This paper presents a review of the results from Russian studies of the middle atmosphere in 2007–2010 drawn up by the Commission on the Middle Atmosphere of the Section of Meteorology and Atmospheric Sciences of the National Geophysical Committee, Russian Academy of Sciences, for the National Report on Meteorology and Atmospheric Sciences submitted to the XXIV General Assembly of the International Union of Geodesy and Geophysics (Melbourne, Australia, June 28–July 7, 2011).

The state of the Earth's upper atmosphere is formed with the participation of impacts by energetic particles, such as galactic cosmic rays, protons of solar proton events, and precipitation of relativistic electrons. Changes in the neutral composition and the thermal and dynamical regime of the upper atmosphere during periods of disturbances caused by the influence of energetic particles are considered.

New information about the chemical composition of the stratosphere and mesosphere is reviewed. This information was obtained in different seasons in both hemispheres with the use of the MIPAS (IR limb sounder), Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY; UV-visible and near-IR nadir and limb viewer), and Global Ozone Mapping Spectrometer (GOMOS) instruments installed on the European Envisat satellite launched in 2002. Measurements with the MIPAS instrument make it possible to retrieve information about the composition of the nighttime atmosphere. It should be noted that several powerful solar proton events (SPEs) occurred on the Sun in the period of satellite measurements. As is well known, the ionization of the polar atmosphere by SPEs is responsible for the intense interaction between ionic and neutral constituents below 100 km, which leads to the additional formation of nitrogen oxides and OH radicals destroying the ozone. Therefore, observations of the composition of the middle atmosphere in these periods are of great interest, because such situations serve as a unique test which makes it possible to check our knowledge not only about photochemical processes in the atmosphere but also about its interaction with cosmic plasma. The results of a comparison of model calculations with newly obtained data on the chemical composition, including those for SPE periods, are presented.

Using the solar proton fluxes data in different energetic channels, as measured by GOES-10 satellites, the strongest solar proton events (SPE) of the 23-rd cycle of the Sun activity have been selected. The atmosphere ionization rates caused by the strongest SPEs were calculated using energetic solar protons spectrum. This data have been used for calculations of middle north polar atmosphere ionization rates during appropriate periods. The response of the middle atmosphere composition was simulated. The computation results showed that the atmosphere ionization and ozone content depletion was strongest after SPE 14.07.2000, 08.11.2000, 04.11.2001, 28.10.2003. The special season features of atmospherical response were found.

Using the data on solar proton fluxes measured on board the GOES satellites, the most powerful solar proton events (SPEs) of solar cycle 23 are selected, and ionization rates in the atmosphere in these periods at high latitudes of the Northern Hemisphere are calculated. Assuming that each ion pair formed at the retardation of solar protons in the atmosphere leads to the formation of 1.25 molecules of nitric oxide, 2.0 molecules of the OH radical, and one oxygen atom, changes in the content of ozone, nitrogen and other compounds were calculated using a photochemical model. The calculations showed that the strongest ionization and destruction of ozone was caused by SPEs that occurred on July 14, 2000; November 8, 2000; November 4, 2001; and October 28, 2003. The results can form the basis for compiling the catalog of changes in ionization and ozone in the atmosphere caused by solar proton activity.