Comparative study of construction of divergence of wind field based on OLR data obtained from – polar orbiting and geostationary satellites

An assessment of Outgoing longwave radiation data obtained from polar orbiting and geostationary satellites is made to see which one, is more convenient and useful for the construction of divergence of the wind field for regional models. The availability of OLR data from TIROS-N (polar orbiting) and GOES-IO (geostationary) satellites during 1979 made it possible to assess and explore a statistical relationship among the OLR data and divergence of the wind field at 850 and 2°9 hPa. constructed from the analysls of the Global Experiment data sets. This study reveals a very strong relationship between these fields in the region of deep convective activity and this relationship has also been found to be stronger for geostationary satellite than polar orbiting satellite. The use or this relationship especially over data-sparse tropical oceanic regions for NWP models is suggested.

The Polar Code and Telemedicine

One result of a warmer global climate is increased maritime activity in the Arctic. Areas that used to be covered by ice and snow are now accessible for the scientific community and commercial users. The Norwegian government has chosen tourism as a pillar of the economy of Svalbard and facilitates the development of the tourism industry. Aase and Jabour have shown that tourist vessels sail as far north as 82° N, beyond the range of geostationary satellites. The Polar Code states that appropriate communication equipment to enable telemedical assistance in polar areas shall be provided. This paper describes a series of functional telemedicine tests carried out on board the Norwegian Coast Guard vessel NoCGV Svalbard during her transit between Svalbard and the Norwegian mainland in September 2019. Communication was established between the vessel and Haukeland University Hospital in Bergen, Norway, using the new Iridium NEXT constellation of communication satellites. Our tests show that medical services that require low bandwidths work.

Visualization of the movements of natural objects based on remote sensing data

Methods of constructing vector fields of natural objects’ movements based on a series of consecutive satellite images are considered: cloud formations in the atmosphere based on a series of consecutive images obtained from geostationary satellites; water masses and ice fields based on a series of images from low-orbit satellites; using the example of the evolution of bipolar spots, the trajectories of trial corks in the Solar photosphere are constructed based on the data of sounders installed on heliophysical satellite observatories.

Reliability Evaluation of the Joint Observation of Cloud Top Height by FY-4A and HIMAWARI-8

It is well known that the measurement of cloud top height (CTH) is important, and a geostationary satellite is an important measurement method. However, it is difficult for a single geostationary satellite to observe the global CTH, so joint observation by multiple satellites is imperative. We used both active and passive sensors to evaluate the reliability of joint observation of geostationary satellites, which includes consistency and accuracy. We analyzed the error of CTH of FY-4A and HIMAWARI-8 and the consistency between the two satellites and conducted research on the problem of missing measurement (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) has CTH data, but FY-4A/HIMAWARI-8 does not) of the two satellites. The results show that FY-4A and HIMAWARI-8 have good consistency and can be jointly observed, but the measurement of CTH of FY-4A and HIMAWARI-8 has large errors, and the error of FY-4A is greater than that of HIMAWIRI-8. The error of CTH is affected by the CTH, cloud optical thickness (COT) and cloud type, and the consistency between the two satellites is mainly affected by the cloud type. FY-4A and HIMAWARI-8 have the problem of missing measurement. The missing rate of HIMAWARI-8 is greater than that of FY-4A, and the missing rate is not affected by the CTH, COT and surface type. Therefore, although FY-4A and HIMAWARI-8 have good consistency, the error of CTH and the problem of missing measurement still limit the reliability of their joint observation.

GNSS Signal Availability Analysis in SSV for Geostationary Satellites Utilizing multi-GNSS with First Side Lobe Signal over the Korean Region

This paper verifies the applicability of multiple Global Navigation Satellite Systems (GNSSs) and side lobe signal utilization in Space Service Volume (SSV), especially for Geostationary Earth Orbit (GEO) missions over the Korean region. Unlike the ground or terrestrial systems, various constraints of space exploration in SSV cause a problem when estimating position using GNSS. This is mainly due to the limit of GNSS signal availability where its dominant variables include altitude, side lobe issues, as well as longitude because of different constellations of several GNSS. The numerical simulation shows the effectiveness of additional side lobe signals from multi-GNSS. In addition, the effect of non-MEO satellites’ signals in SSV for different longitudes is presented.

Modeling the Relationship of ≥2 MeV Electron Fluxes at Different Longitudes in Geostationary Orbit by the Machine Learning Method

The energetic electrons in the Earth’s radiation belt, known as “killer electrons”, are one of the crucial factors for the safety of geostationary satellites. Geostationary satellites at different longitudes encounter different energetic electron environments. However, organizations of space weather prediction usually only display the real-time ≥2 MeV electron fluxes and the predictions of ≥2 MeV electron fluxes or daily fluences within the next 1–3 days by models at one location in GEO orbit. In this study, the relationship of ≥2 MeV electron fluxes at different longitudes is investigated based on observations from GOES satellites, and the relevant models are developed. Based on the observations from GOES-10 and GOES-12 after calibration verification, the ratios of the ≥2 MeV electron daily fluences at 135° W to those at 75° W are mainly in the range from 1.0 to 4.0, with an average of 1.92. The models with various combinations of two or three input parameters are developed by the fully connected neural network for the relationship between ≥2 MeV electron fluxes at 135° W and 75° W in GEO orbit. According to the prediction efficiency (PE), the model only using log10 (fluxes) and MLT from GOES-10 (135° W), whose PE can reach 0.920, has the best performance to predict ≥2 MeV electron fluxes at the locations of GOES-12 (75° W). Its PE is larger than that (0.882) of the linear model using log10 (fluxes four hours ahead) from GOES-10 (135° W). We also develop models for the relationship between ≥2 MeV electron fluxes at 75° W and at variable longitudes between 95.8° W and 114.9° W in GEO orbit by the fully connected neural network. The PE values of these models are larger than 0.90. These models realize the predictions of ≥2 MeV electron fluxes at arbitrary longitude between 95.8° W and 114.9° W in GEO orbit.