Polar meteorology: The results of Russian research in 2003–2006

This publication is a review of the results of Russian polar studies performed in 2003–2006. It is based on material prepared by the Commission on Polar Meteorology of the National Geophysical Committee, Russian Academy of Sciences, and included in the National Report on Meteorology and Atmospheric Sciences to the XXIV General Assembly of the International Union of Geodesy and Geophysics, Perugia, Italy, July 2–13, 2007.     

Environmental research and provision of hydrometeorological safety in high-latitude and polar regions

The information is presented on the activity of Roshydromet in high-latitude and polar regions for providing the hydrometeorological safety of population and economy in the Arctic and presence in Antarctica as well as on its development and modernization since the 2000s and on the contribution of Roshydromet to Russian studi es and works in the framework of the International Polar Year 2007–2008.     

The structure of the Lomonosov volcanic pipe in the Arkhangel’sk diamond province from anomalies of the microseismic field

This paper presents results from a study of the Lomonosov volcanic pipe as derived from anomalies of the microseismic field. Microseismic sounding revealed that this volcanic pipe is a cone-shaped body with a small gradient of microseismic intensity motion (2 to 5 dB). Discontinuities generally show greater contrasts compared with the variations of microseismic motion in the pipe body. Comparison of the results of this microseismic sounding with other geological and geophysical data showed that the intensities of the microseismic field along lines that traversed the pipe reflect realistic structures of a kimberlite pipe and the host rocks. The method of microseismic sounding was used to reconstruct the deeper structure of the volcanic pipe and the host rocks down to depths greater than 2 km. We estimated the velocity contrast and the errors involved in the identification of vertical boundaries of the pipe. The volcanic pipe has a shape that is consistent with a nearly vertical source situated at a depth of a few hundred meters. This is hypothesized to be a typical occurrence for other diamond-bearing pipes as well.     

On the impact of atmospheric vs oceanic resolutions on the representation of the sea surface temperature in the South Eastern Tropical Atlantic

Climate Dynamics - Despite the efforts of the modelling community to improve the representation of the sea surface temperature (SST) over the South Eastern Tropical Atlantic, warm biases still...     

Evaluation of a Finite-Element Sea-Ice Ocean Model (FESOM) set-up to study the interannual to decadal variability in the deep-water formation rates

The characteristics of a global set-up of the Finite-Element Sea-Ice Ocean Model under forcing of the period 1958–2004 are presented. The model set-up is designed to study the variability in the deep-water mass formation areas and was therefore regionally better resolved in the deep-water formation areas in the Labrador Sea, Greenland Sea, Weddell Sea and Ross Sea. The sea-ice model reproduces realistic sea-ice distributions and variabilities in the sea-ice extent of both hemispheres as well as sea-ice transport that compares well with observational data. Based on a comparison between model and ocean weather ship data in the North Atlantic, we observe that the vertical structure is well captured in areas with a high resolution. In our model set-up, we are able to simulate decadal ocean variability including several salinity anomaly events and corresponding fingerprint in the vertical hydrography. The ocean state of the model set-up features pronounced variability in the Atlantic Meridional Overturning Circulation as well as the associated mixed layer depth pattern in the North Atlantic deep-water formation areas.     

Discussion of the Problem of Ionospheric Precursors of Magnetic Storms

Geomagnetism and Aeronomy - The problem of disturbances of the parameters of the F2 layer and the upper ionosphere during the days preceding the beginning of a magnetic storm has already been known...     

Energy parameters of deep fluid systems

Doklady Earth Sciences -     

Stellar fluxes in numerical dynamical models of open clusters

Fluxes of stars in models of open clusters that are nonstationary in the regular field of the cluster are analyzed. An equilibrium distribution function describes the state of these models from the beginning of their dynamical evolution. Violent relaxation in the open-cluster models proceeds under equilibrium conditions in phase space and does not result in virial equilibrium. The cluster relaxation times in the one-dimensional spaces of a number of stellar-motion parameters are estimated. The stellar fluxes are anisotropic in some two-dimensional parameter spaces. Such open-cluster models exhibit a number of manifestations of self-organization (an energy flux toward the center of the cluster and a transfer of energy from large-scale to small-scale motions, periodic decreases in the entropies of the cluster models with a period equal to that of oscillations of the regular field of the cluster, etc.). It is concluded that violent relaxation represents one form of self-organization in such systems.     

Equilibrium phase-space density distribution in numerical dynamical models of open clusters

In dynamical models for open clusters, virial equilibrium is not achieved over the violent relaxation time scale τ_vr. The stars form an equilibrium distribution in (?, ?_ζ, l) space, where ? and l are the energy and angular momentum per unit stellar mass in the combined field of the Galaxy and cluster and ?_ζ is the energy of motion perpendicular to the Galactic plane per unit mass of cluster stars in the gravitational field of the Galaxy. This distribution of stars changes little when t>τ_vr. The stellar phase-space distribution corresponding to this type of equilibrium and the regular cluster potential vary periodically (or quasi-periodically) with time. This phase-space equilibrium is probably possible due to an approximate balance in the stellar transitions between phase-space cells over times equal to the oscillation period for the regular cluster field.