The Meteor-M No. 2-2 meteorological satellite with the microwave radiometer MTVZA-GY on board was launched into a circular sun-synchronous orbit on July 5, 2019. The radiometer conducts a conical scanning at 65-degree incidence angle and receives the Earth's outgoing radiation in the frequency range ν ≈ 6–190 GHz. The swath width is 2500 km on ascending orbits and 1500 km on descending orbits. The parameters of the ocean, land surface, and troposphere are extracted from brightness temperatures TB(ν) measured at imager frequencies of 6.9, 10.65, 18.7, 23.8, 31.5, 36.5, 42, 48, and 91.65 GHz in vertical and horizontal polarizations. Measurements at the sounder frequencies (ten channels in the 52–58 GHz oxygen absorption band and three channels in the strong water vapor resonance line region centered at 183.31 GHz) provide information on air temperature and humidity in the troposphere and stratosphere. The structure and development of dynamic atmospheric phenomena of synoptic scale are imprinted on the global TB(ν) maps at imager frequencies. The TB(ν) time series at the sounder frequencies allowed us to detect and trace the evolution of a rare phenomenon — a sudden stratospheric warming over Antarctica in August–September 2019.

Probing of the typhoon Hagibis in stage of maximum intensification with satellite active and passive microwave sensors onboard GPM (Global Precipitation Measurements), GCOM-W1, Meteor-M No. 2-2 and Sentinel-1 satellites permitted retrieving the ocean surface and atmospheric parameters and investigate evolution of their spatial structure. Wind speed W, cloud liquid water content Q and total atmospheric water vapor content V were estimated from GMI and AMSR2 data with original algorithm based on total atmospheric absorption at frequency of 10.65 GHz τ(10). Mean square slope (mss) was retrieved from Ku-band channel of DPR radar. The location of typhoon center was traced due to the difference of retrieved parameters between the eye and surrounding area. Hagibis warm core was found by MTVZA-GY radiometer at several frequencies at oxygen absorption band. The position of the sharp gradient zones in V, Q and τ(10) fields served as an indicator of the change of typhoon area and structure. The calm cloudless region in the western Japan Sea was used as the reference area for matching to zero level of the retrieved wind speed and mss.

Taklamakan is the second largest shifting sand desert in the world and a major source of dust aerosols in East Asia. The time series of GCOM-W1 AMSR2 brightness temperatures T B s were constructed over the Tazhong weather station (39.00° N, 83.40° E, elevation H =1100 m) in Taklamakan desert for the period 1 January 2015 - 31 December, 2016. T B s were analyzed together with the time series of meteorological variables: air pressure, temperature and humidity, measured 8 times per a day. The AMSR2 sensing was performed on the ascending (A) and descending (D) orbits at approximately 1:30 PM and 1:30 AM (local time), which is close to the daily maximum and minimum air surface temperature T air , respectively. Land surface temperature was not measured. The T B s were averaged each day separately for ascending and descending orbits. The seasonal, synoptic, and diurnal T B variations differ significantly with frequency and polarization. The influence of the variations of atmosphere parameters and the surface emissivity on T B s was estimated by numerical integrating of the microwave radiation transfer equation in the atmosphere-underlying surface system The linear regression equations T air = F[T B (ν)] were derived and the T air retrieval errors were estimated. The proposed method of T air estimating can be applied in areas with different physical-geographic conditions, including Greenland and Antarctica, as well as for external calibration of satellite microwave radiometers.

Dual-frequency precipitation radar (DPR) is a powerful instrument for remote sensing of sea waves but its application is yet limited. Measurements of a radar backscattered signal are made at small incidence angles and retrieval algorithms permit to retrieve mean square slopes (mss) of the sea surface. The combination of the DPR product and the sea surface wind speed (SSW) field retrieved from microwave radiometer and scatterometer data with a resolution of 5 10 km can be used to estimate the relationships between wind and waves, reveal the spatial features of the air sea interaction in cyclones, atmospheric fronts, cold air outbreaks, and other meso- and synopticscale weather systems. For the first time, the DPR and microwave radiometer data were processed for extratropical cyclones. Changes of mss and wind in the areas of cyclonic activity were analyzed. A strong correlation of mss and near-surface wind characteristic was shown. Short wind-generated waves strongly affect mss and they rapidly respond to changes in the wind speed.

Monitoring the formation, development, melting, concentration, thickness, movement and other parameters of ice in the Okhotsk and Japan Seas is vital importance to physical oceanographers to study regional climate changes, air/sea/ice interaction, and formation of ocean water properties. Information about sea ice is used in activities associated with transportation, fishing, disaster mitigation, oil deposit and other commercial development. Satellite SAR is a powerful tool for the detailed ice mapping, detection of the ice type, concentration, roughness, floe size and velocity through its high resolution and independence on cloudiness. Joint analysis of C- and L-band SAR data with the visible and/or infrared images with resolution of several tens-hundred meters improves interpretation of sea ice signatures and allows estimation of ice parameters.

The Meteor-M N 2 spacecraft with microwave radiometer MTVZA-GY has been launched on July 8, 2014 on sunsynchronous orbit at an altitude of 830 km. MTVZA-GY is a 29 channel microwave imager/sounder for remote sensing of the ocean and land surface parameters as well as for measuring total atmospheric water vapor content, total cloud liquid water content, air temperature and humidity profiles. MTVZA GY operates at frequencies10-190 GHz. The total power radiometer configuration is employed. The antenna system of MTVZA-GY consists of an offset parabolic reflector of dimension 65 cm, illuminated by four feed-horns antenna. Results of vicarious calibration and longtime stability study are discussed. Globe MTVZA-GY data are presented. The examples of joint analysis of MTVZA-GY and other remote and ground-based observations of severe marine weather systems and Antarctica are discussed.

A new approach to retrieve sea surface wind speed (SWS) in tropical cyclones (TCs) from the Advanced Microwave Scanning Radiometer 2 (AMSR2) data is presented. Analysis of all six AMSR2 C-and X-band channel measurements over TCs is shown to efficiently help to separate the rain contribution. Corrected measurements at 6.9 and 10.65 GHz are then used to retrieve the SWS. Spatial and temporal collocation of AMSR2 and tropical rain measurement mission (TRMM) microwave instrument (TMI) data is then further used to empirically relate TMI rain rate (RR) product to RR estimates from AMSR2 in hurricanes. SWS estimates are validated with measurements from the stepped frequency microwave radiometer (SFMR). As further tested, more than 100 North Atlantic and North Pacific TCs are analyzed for the 2012-2014 period. Despite few particular cases, most SWS fields are in a very good agreement with TC center data on maximum wind speeds, radii of storm, and hurricane winds. As also compared, very high consistency between AMSR2 and L-band SMOS wind speed estimates are obtained, especially for the super typhoon Haiyan, to prove the high potential of AMSR2 measurements in TCs.

Development of microwave technologies and our ability to penetrate into Tropical Cyclones (TCs) by instrumented aircraft and observe from satellites have contributed much of the knowledge and understanding that exist today. We can now follow the structure and development of a storm from inception through the many stages towards a dangerous typhoon, hurricane or cyclone, as they are variously called around the globe. The data from satellite microwave radiometers, scatterometers, altimeters, Synthetic Aperture Radars (SARs), microwave sounders, a rain radar and a cloud profiling radar as well as coastal radars, airborne radars and microwave radiometers have all contributed to changing the fields of both TC research and TC operational forecasting.

In this study, we considered the geophysical model for microwave brightness temperature (BT) simulation for the Atmosphere-Ocean System under non-precipitating conditions. The model is presented as a combination of atmospheric absorption and ocean emission models. We validated this model for two satellite instruments-for Advanced Microwave Sounding Radiometer-Earth Observing System (AMSR-E) onboard Aqua satellite and for Special Sensor Microwave Imager/Sounder (SSMIS) onboard F16 satellite of Defense Meteorological Satellite Program (DMSP) series. We compared simulated BT values with satellite BT measurements for different combinations of various water vapor and oxygen absorption models and wind induced ocean emission models. A dataset of clear sky atmospheric and oceanic parameters, collocated in time and space with satellite measurements, was used for the comparison. We found the best model combination, providing the least root mean square error between calculations and measurements. A single combination of models ensured the best results for all considered radiometric channels. We also obtained the adjustments to simulated BT values, as averaged differences between the model simulations and satellite measurements. These adjustments can be used in any research based on modeling data for removing model/calibration inconsistencies. We demonstrated the application of the model by means of the development of the new algorithm for sea surface wind speed retrieval from AMSR-E data.

This study presents the results of the comparison between sea surface wind speed (SWS) estimates made by MetOp-A scatterometer ASCAT and GCOM-W1 Advanced Microwave Sounding Radiometer 2 (AMSR2) relating to winds developing in the extratropical cyclones (ECs) over the North Atlantic. One season of winter ECs of 2012–2013 is considered in which 33 most intensive ECs are selected for the study. ASCAT Level 2 operational coastal wind vector product is used for the comparison, whereas AMSR2 SWS values are calculated with newly developed algorithms. Two algorithms for SWS retrieval from AMSR2 are based on numerical simulation of AMSR2 brightness temperatures (TB) over the oceans and their following inversion with Neural Networks. The first algorithm uses TB measurements at higher frequency AMSR2 channels (HF algorithm), the second one uses TB measurements at lower frequency channels (LF algorithm). It is demonstrated that both AMSR2 SWS estimates are highly correlated with ASCAT SWS for the range of low and moderate wind speeds which opens new potential for possible merging of active and passive microwave SWS products. It is shown also that LF AMSR2 algorithm overestimates ASCAT winds greater than 15m/s. To support the comparison results SWS estimates by AMSR2 are validated against in-situ wind speed measurements from platform weather stations in the North Sea and Norwegian Sea, including high wind events.

Monomolecular surface films (sea slicks) are well known to dampen small-scale waves at the water surface, thereby influencing transport processes at the air-sea interface. Because of their strong wave-damping capacity, they can often be observed, not just on synthetic aperture radar imagery, but also on imagery acquired in the visible and infrared spectral ranges. Because sea slicks tend to accumulate at the water surface along lines of, for example, current shear in fronts and eddies, they can be used as proxies for observing such marine processes from space. We demonstrate how well sea slicks are suited to indicate marine processes in the coastal zone. A slick's damping capability depends on the surfactant concentration on the sea surface and, thus, on the compression status of the slick-forming material. Furthermore, we show that slick signatures can be used to derive surface current vectors at higher spatial resolution than that of numerical models.

Biogenic surface films, which are often present in coastal areas, may enhance the signatures of hydrodynamic processes in microwave, optical, and infrared imagery. We analyzed ERS-1/2 Synthetic Aperture Radar (SAR) and Envisat Advanced Synthetic Aperture Radar (ASAR) images taken over the Japan/East Sea (JES). We focused on the appearance of the contrast SAR signatures, particularly the dark features of different scales caused by various oceanic and atmospheric phenomena. Spiral eddies of different scales were detected through surface film patterns both near the coast and in the open regions of the JES in warm and cold seasons. During field experiments carried out at the Pacific Oceanological Institute (POI) Marine Station 'Cape Shults' in Peter the Great Bay, the sea surface roughness characteristics were measured during the day and night using a developed polarization spectrophotometer and various digital cameras and systems of floats. The velocity of natural and artificial slicks was estimated using video and ADCP time series of tracers deployed on the sea surface. The slopes of gravity-capillary wave power spectra varied between .4 and .5. Surface currents in the natural and artificial slicks increased with the distance from the coast, varying between 4 and 40 cm/s. The contrast of biogenic and anthropogenic slicks detected on vertical and horizontal polarization images against the background varied over a wide range. SAR images and ancillary satellite and field data were processed and analyzed using specialized GIS for marine coastal areas.

Satellite and in situ data were examined for insights into the behavior of water vapor, cloud liquid water and wind speed during formation and evolution of synoptic-scale and mesoscale cyclones and cold air outbreaks — weather systems, which are usually accompanied by gale winds and intensive air-sea interaction. Satellite measurements carried out at visible, infrared and microwave ranges were collected over the Northern Pacific and Northern Atlantic Oceans in winter allowed investigating both the large-scale structural features (the main and the secondary fronts, etc.) and the small- and fine- scale details of the frontal boundaries, organized convection in the marine boundary layer of the atmosphere, etc. Multisatellite approach improved temporal resolution and the possibility to trace the location and characteristics of weather systems including fast moving and fast evolving systems.

Monomolecular surface films ("sea slicks") and mineral oil spills are both well known to dampen small-scale waves at the water surface, and thereby to influence transport processes at the air-sea interface. Because of their strong wave-damping capabilities they can often be delineated on synthetic aperture radar (SAR) imagery, but also on satellite imagery acquired in the visible and infrared spectral ranges. Since sea slicks tend to accumulate at the water surface along shear current lines, fronts, eddies, etc., they can be used as a proxy for observing such marine processes from space. In order to document the dynamics of marine surface films under different environmental conditions we present the main results of our experimental efforts, as well as a selection of ERS and ENVISAT SAR images that demonstrate how well sea slicks are suited to indicate marine processes in the coastal zones. Furthermore, we demonstrate how remote sensing data can be used to detect marine oil pollution in coastal waters, and how pollution signatures can be discriminated from those of sea slicks.

Monomolecular surface films (“sea slicks”) are well known to dampen small-scale waves at the water surface, and thereby to influence transport processes at the air-sea interface. Because of their strong wave-damping capabilities they can often be delineated on synthetic aperture radar (SAR) imagery, but also on satellite imagery acquired in the visible and infrared spectral ranges. Since sea slicks tend to accumulate at the water surface along shear current lines, fronts, eddies, etc., they can be used as a proxy for observing such marine processes from space. In order to document the dynamics of marine surface films under different environmental conditions we present the main results of our experimental efforts, as well as a selection of ERS and ENVISAT SAR images that demonstrate how well sea slicks are suited to indicate marine processes in the coastal zones.

The distributions of total water vapor content, total cloud liquid water content, precipitation and surface wind were derived for tropical cyclone Herb during the period of 29 July-1 August 1996 from the F10, and F11 Defense Meteorological Satellite Special Sensor Microwave Imager (SSM/I) and Russian Okean-7 satellite X band Real Aperture Radar (RAR) observations. The observations on 29 July when the RAR image was taken were investigated in detail. Using a satellite RAR enables us to estimate both the surface wind field under heavy clouds and the location of individual rain cells with rainfall rate > 10-15 mm/h which are undistinguishable on SSM/I-retrievals due to antenna smoothing. Precipitating clouds were localized mainly within a broad spiral band adjoining to the typhoon from the south. Nonprecipitating clouds prevailed north of the center. Comparison of radar and passive microwave images demonstrates the need for better spatial resolution to distinguish precipitation falling from convective and strati-form clouds. The set of total water vapor content distributions revealed cyclonic movement of dry airflow around the typhoon center confirmed by radiosonde reports.

More than a hundred ERS SAR images were analyzed to investigate the features of wind regime and surface circulation in the Japan Sea during the winter monsoon season. Most of the images cover the northwestern portion of the sea. 35 of them were eliminated from the analysis due to strong winds. Background radar characteristics on the rest images varied from practically uniform when the marine boundary layer of the atmosphere was stable or neutral to highly variable when the boundary layer was unstable. Dynamics and thermal factors were responsible for formation of radar signatures of oceanic phenomena such as eddies and fronts. Sometimes the location of radar signatures were correlated with the thermal boundaries of eddies. These signatures had both positive and negative contrast against the background, probably, due to the change of angle between sensing direction and current direction. In December-March sea surface temperature derived from NOAA AVHRR and in situ data varied here from –1.8 to + 3-5 °C. Thermal contrasts were associated with eddies and streamers in the subarctic frontal zone and also near coast where sea ice formation took place. The oceanic radar signatures were also detected in the areas without clear thermal features. Probable detection of SAR signatures of deep ocean convection is discussed. The differences in radar signatures allowed us to distinguish the imprints of oceanic phenomena against variable background.