E. A. Sharkov

Revealing the energy sources of alternating intensity regimes of the evolving Alberto tropical cyclone using microwave satellite sensing data

The trajectory characteristics and the intensity evolution of the Alberto tropical cyclone (TC) in the integral water-vapor field are analyzed in detail using a software-algorithmic complex designed for constructing highly detailed global radio-thermal fields of the ocean-atmosphere system based on microwave satellite measurements. This complex was developed by the authors earlier and allows one to obtain global animated radio-thermal fields with a time step of 1.5 h and a spatial resolution of 0.2°. Special attention is paid to the problem of revealing the energy sources of three consecutive intensifications of this TC. The analysis of satellite data with the use of the animation method developed by the authors shows for the first time that these sources are regions with an increased (exceeding the critical level) integral water-vapor content located in different geographical areas lying along the complex trajectory of the TC with a variable intensity. The first region was located in the equatorial intertropical convergence zone, the second was located above the Gulf Stream water area, and the third resided in the area affected by the Azores High.

Increased water-vapor content in the atmosphere of tropical latitudes as a necessary condition for the genesis of tropical cyclones

The hypothesis about the interrelation of the integral water-vapor concentration (from data of microwave satellite systems) and plural tropical cyclogenesis in cyclonogenerating water areas of the World Ocean in 2001 is verified with the aid of the EVA-01 (IKI RAN) database (DB) with elements of the objectrelation type formed by the authors. It is experimentally proved in the work that there is a critical value of the integral water-vapor concentration (a peculiar necessary condition) at which the mature form of a tropical cyclone (TC) is formed with a lifetime exceeding 24 h. It is also experimentally proved that, in the same time interval, there is another group of TCs with a short lifetime (less than than 24 h) which do not possess a clearly pronounced boundary value of the water-vapor intensity and can be formed in a wide range of its values. The relations between the regions with an increased concentration of water vapor and genesis of TCs have become obvious only with the use of object-relation computer technologies.

Main results of recent investigations into the physical mechanisms of the interaction of tropical cyclones and the ionosphere

International investigations into the correlation between tropical cyclones (TCs) and the ionosphere are associated with great difficulties in proving the influence of possible TC mechanisms on the ionosphere. In this paper, the ionospheric parameters obtained by ground-based and satellite sensing over the TC and at a certain distance from it are analyzed. This paper is a brief presentation of the main areas of research on the TC–ionosphere interaction problem by different international teams of scientists from the formulation of the problem to the present. The main conclusion of the paper is that internal gravity waves are the main factors that influence the ionosphere from the active cyclones.

Searching for an energy source of the intensification of tropical cyclone Katrina using microwave satellite sensing data

The possibility of utilizing a specialized approach to the space-time interpolation of satellite data that takes the kinematics of multiscale processes into account in solving the problems of remote sensing of fast processes in the Earth’s atmosphere is considered. The approach is borrowed from the rapidly progressing disciplines of machine vision and video data compression. The main advantages of this method are its completeness with respect to the input (interpolated) satellite data, its capacity to estimate the kinematics of multiscale processes and take it into account, a relatively low computational cost, and the ease of its software-algorithmic implementation. The problem of an “instantaneous” source of hidden energy for the intensification of Tropical Cyclone (TC) Katrina is solved based on the developed software-algorithmic approach using data from the SSM/I satellite radiometers of the DMSP mission.

Satellite microwave radiometry of sea ice of polar regions: a review

This is a review of methods of passive microwave satellite monitoring of the sea-ice cover in polar regions. We briefly describe the microwave radiometers launched into the Earth’s orbit and provide data used in studies of Arctic and Antarctic sea ice. We give a detailed description of currently used algorithms for determining the sea-ice concentration and cover in polar regions according to satellite microwave radiometry. The methods for constructing these algorithms and their related drawbacks are considered. The final section of this paper briefly analyzes the studies that compare current algorithms with each other, with radar data, infrared data, and data of visual ship observations.

Integrative algorithm of determining ice conditions in Polar Regions by data of satellite microwave radiometry (VASIA2)

In this paper, a new algorithm for determining the concentration of the ice cover in Polar Regions by data of satellite microwave radiometry is considered. The technique of its construction is described in detail; it cardinally differs from the technique of creating present-day algorithms. The new algorithm demonstrates good results in determining the concentration of the ice cover in Polar Regions. The algorithm permits one not only to obtain maps of ice concentration, but also to determine areas of puddles covering the ice-cover surface in summer months. The algorithm is easy-to-use and requires no additional or fitting parameters. At the end of the work, advantages and disadvantages of the new algorithm are discussed.

Energy Features of Plural Tropical Cyclogenesis from Multispectral Satellite Observations

Energy features of the succession of interrelated tropical cyclones (plural cyclogenesis) in the oceans of the Southern Hemisphere (the southern part of the Indian Ocean and the southwestern part of the Pacific Ocean) over February 2008 are comprehensively analyzed on the basis of the method of combining different-scale data of the infrared and radio thermal satellite sounding. The data of infrared thermal channels of the geostationary Meteosat-7 satellite and the results of reconstruction of integral water vapor from data of the AMSR-E microwave complex of the Aqua satellite were used. The analysis showed that the region where water vapor has an increased integral concentration is the most effective channel for pumping the latent heat energy from the tropics into midlatitudes. Each cyclone captures this region from the tropical zone and retains it throughout the entire stage of its own evolution with the aid of the jet spiral bridge. The quantitative estimates of the latent energy of the central equatorial region of water vapor in the intratropical convergence zone (ITCZ) of the Indian and Pacific oceans were a basically new result, as well as the detection of considerable time variations in the latent heat associated with the ejection of coherent water-vapor regions into high latitudes by plural cyclogenesis.

Satellite Radiothermovision on Synoptic and Climatically Significant Scales

This paper is focused on the development of a methodological basis for the authors’ approach to the processing of large volumes of satellite radiothermal data, which is known as satellite radiothermovision. A closed scheme for calculating the latent heat flux (and other integral characteristics of the dynamics of geophysical fields) through arbitrary contours (boundaries) has been constructed and mathematically described. The opportunity for working with static, as well as movable and deformable boundaries of arbitrary shape, has been provided. The computational scheme was tested using the example of calculations of the atmospheric advection of the latent heat from the North Atlantics to the Arctic in 2014. Preliminary analysis of the results showed a high potential of the approach when applying it to the study of a wide range of synoptic and climatically significant atmospheric processes of the Earth. Some areas for the further development of the satellite radiothermovision approach are briefly discussed. It is noted that expanding the analysis of the available satellite data to as much data as possible is of considerable importance. Among the immediate prospects is the analysis of large arrays of data already accumulated and processed in terms of the satellite radiothermovision ideology, which are partially presented and continuously updated on a specialized geoportal.

Satellite Radiothermovision Analysis of the Evolution of a System of Interacting Typhoons

In this paper we develop further the satellite radiothermovision methods for analyzing the evolution of tropical cyclones. The complicated case of Goni and Atsani interacting typhoons is considered. It has been shown that, although their interaction does not explicitly influence the features of the typhoon trajectories, indications of the formation of complex advective fluxes in the lower troposphere can be revealed from both a qualitative analysis of miscellaneous satellite data and a quantitative estimation of latent heat advection. At the same time, in contrast to the previous works, we had to introduce the integration contours of a complex form (differing from a circular one) into the analysis, so that the energy balance of the typhoon system is correctly described. In a general way, defining such contours is a separate problem whose solution is probably related to the invocation of a large volume of additional satellite information. Due to the peculiarity of the considered case of Goni and Atsani twin typhoons, we demonstrated the effectiveness of a simplified approach that uses a composite contour formed by overlapping two circular ones. Generally, as in the cases previously considered, we found the interrelation between the intensification and dissipation of typhoons (tropical cyclones) and the modes of convergent and divergent advection of latent heat with amplitudes sufficient to support the total power of the system.

A multisensory algorithm of satellite radiothermovision

A multisensory algorithm of satellite radiothermovision has been proposed that makes it possible to combine the data of satellite radiothermal monitoring of the Earth from different sources within a single method of spatiotemporal interpolation taking into account the differences in time of measurements and in the spatial resolution of different instruments. The new algorithm was tested in a series of measurements with SSMIS instruments onboard F16, F17 satellites of DMSP and AMSR-2 instruments onboard the GCOMW1 satellite in November 2013, as well as a series of measurements with the same instruments in August 2012 supplemented with data from WindSat. The parameters of the spatiotemporal interpolation of total precipitable water fields are improved nearly twofold (with a time step of 1.5 h on a regular grid with 0.125° sampling) compared with the method that previously used only SSM/I data. The achieved spatial sampling exceeds known world analogues while maintaining a high accuracy of interpolation. In addition, the problem of the transition from the fields at a fixed local time to the fields at a fixed universal time is briefly considered. It has been shown that this transition is mainly relevant in the study of the fast atmospheric processes on a global scale with high temporal resolution.