Use of data from meteorological satellites in long-range weather forecasting

In the Soviet Union experiments on obtaining meteorological information by means of man-made Earth's satellites were initiated in 1966 (the “Meteor” meteorological system).Starting with 1975 the launches of the “Meteor-2” updated meteorological satellites of the second generation were carried out. The detailed information about the Soviet meteorological satellite system can be found in [9].Below, the problems concerning the use of satellite data in schemes of long-range weather forecasts are considered. Particular attention is paid to the role of external sources of energy. The role of cloud cover over the oceans is emphasized as a heat influx regulator in the process of absorption radiant solar heat by the ocean. The dynamic and statistical method of ocean heat memory parameterization is stated.     

Climatological characteristics of cloud cover over Europe from meteorological satellites

Climatological characteristics of cloud cover - means, variances, structure functions - previously computed for five years are compared with the results of a new test cloud cover data set of one year period. The effects on the cloud field of the Alps, the Carpathian basin and the land-ocean interface, further the seasonal changes of the general circulation are well reflected. The new test data set is based upon digitized data of one morning as well as one afternoon picture per day. Therefore some results are also obtained of the cloud cover variations during the day.     

Statistical studies of cloud cover based on pictures from meteorological satellites

Cloud amounts data of a five year period manually digitized from meteorological satellite imagery are used for cloud statistics over the European region. Spatial and temporal structure functions of the cloud field are computed and analysed for the seasons. The results give a numerical representation of the effects of the general circulation and the geographical-physical conditions on cloudiness.     

The compatability of cloud tracked winds from the United States,European, and Japanese geostationary satellites

Overlap of coverage of the five geostationary satellites has allowed an intercomparison of the FGGE cloud tracked winds. No attempt was made during FGGE to standardize the cloud tracking techniques. In spite of this potential for differences between data sets, the compatability of the various cloud wind data sets was generally quite good. The vector magnitude differences between nearly co-located vectors showed similar cumulative frequency statistics for all data producers. A study of systematic biases which could affect a global wind analysis of any given synoptic period showed that image alignment errors caused less than 2 m s^?1 bias for all data producers except the NESS high level winds which had an average bias of slightly greater than 3 m s^?1. This appears to be caused by the manual alignment of images in the movie loops. Height bias studies showed the Japanese winds to be higher than other data producers by as much as 100 mb for both the high and low levels winds. Height biases appear to be caused by the differences in cloud wind height assignment procedures.     

The connection between space weather and Single Event Upsets in polar low earth orbit satellites

Space weather is driven and modulated by the activity in the Sun. Space weather events have the potential to inflict critical damage to space systems. Nowadays, space assets are essential in our basic needs, such as communications, cell phone networks, navigation systems, television and internet. Hence, understanding space weather dynamics and its effects on spacecraft is crucial for satellites engineers and satellite operators, in order to prevent and mitigate its impacts.In the last decade our Sun has erupted several times causing dozens of space weather events. Some of these led to satellite malfunctions and outages lasting from mere hours, up to days and weeks. This research is focused on two different space weather events, March 7–8, 2012, and September 6–10, 2017, that occurred during the last ten years and caused satellite anomalies that are related to an increase in the single event upsets rate. Single event upset is a bit flip in a memory device due to high energy particle interaction with the device sensitive volume. During these two periods, Eros B, a low Earth orbiting polar satellite detected an increased rate of single event upsets on two of its processing computers when the high energy proton flux was elevated. On both occasions X-class flares were detected, and the increased single event upsets count rate in Eros B took place only after the 100 MeV protons flux was three orders of magnitude above the background levels. In this research, Israeli satellite anomalies that were detected are first demonstrated.     

Different space weather effects in anomalies of the high and low orbital satellites

Preliminary results of the EU INTAS Project 00810, which aims to improve the methods of safeguarding satellites in the Earth’s magnetosphere from the negative effects of the space environment, are presented. Anomaly data from the “Kosmos” series satellites in the period 1971–1999 are combined in one database, together with similar information on other spacecraft. This database contains, beyond the anomaly information, various characteristics of the space weather: geomagnetic activity indices (Ap, AE and Dst), fluxes and fluences of electrons and protons at different energies, high energy cosmic ray variations and other solar, interplanetary and solar wind data. A comparative analysis of the distribution of each of these parameters relative to satellite anomalies was carried out for the total number of anomalies (about 6000 events), and separately for high (5000 events) and low (about 800 events) altitude orbit satellites. No relation was found between low and high altitude satellite anomalies. Daily numbers of satellite anomalies, averaged by a superposed epoch method around sudden storm commencements and proton event onsets for high (>1500 km) and low (<1500 km) altitude orbits revealed a big difference in a behavior. Satellites were divided on several groups according to the orbital characteristics (altitude and inclination). The relation of satellite anomalies to the environmental parameters was found to be different for various orbits that should be taken into account under developing of the anomaly frequency models.     

地基北斗GEO卫星直反信号功率测量偏差分析

针对接收天线方向性造成的北斗地球同步轨道（GEO）卫星直反信号功率测量偏差进行研究。给出地基场景下实际天线接收的直反信号及其功率表达式,讨论天线方向性造成的北斗GEO卫星直反信号功率测量相对偏差,设置具体观测场景进行仿真分析。理论与仿真结果表明：具体场景和时刻下的北斗GEO卫星直反信号功率测量偏差为固定偏差,由天线对干扰信号的抑制性能、天线架设高度和反射面介电常数共同决定;相对偏差的大小随着天线对干扰信号抑制性能的增强而减小,随着天线架设高度的变化在某一范围内波动,也会随着反射面介电常数的变化而变化。     

The possibilities of polar meteorology,environmental remote sensing,communications and space weather applications from Artificial Lagrange Orbit

The ability to observe meteorological events in the polar regions of the Earth from satellite celebrated an anniversary, with the launch of TIROS-I in a pseudo-polar orbit on 1 April 1960. Yet, after 50 years, polar orbiting satellites are still the best view of the polar regions of the Earth. The luxuries of geostationary satellite orbit including rapid scan operations, feature tracking, and atmospheric motion vectors (or cloud drift winds), are enjoyed only by the middle and tropical latitudes or perhaps only cover the deep polar regions in the case of satellite derived winds from polar orbit. The prospect of a solar sailing satellite system in an Artificial Lagrange Orbit (ALO, also known as “pole sitters”) offers the opportunity for polar environmental remote sensing, communications, forecasting and space weather monitoring. While there are other orbital possibilities to achieve this goal, an ALO satellite system offers one of the best analogs to the geostationary satellite system for routine polar latitude observations.     

基于对抗和迁移学习的灾害天气卫星云图分类

针对卫星云图中的灾害天气数据存在严重不平衡问题,提出一个结合生成对抗学习（GAN）和迁移学习（TL）的卷积神经网络（CNN）框架以解决上述问题进而提高基于卫星云图的灾害天气分类精度。该框架主要包含基于GAN的数据均衡化模块和基于迁移学习的CNN分类模块。上述2个模块分别从数据和算法层面解决数据的类间不平衡问题,分别得到一个相对均衡的数据集和一个可在不同类别数据上提取相对均衡特征的分类模型,最终实现对卫星云图的分类,提高其中灾害天气的卫星云图类别分类准确率。与此同时所提方法在自建的大规模卫星云图数据上进行了测试,消融性和综合实验结果证明了所提数据均衡方法和迁移学习方法是有效的,且所提框架模型对各个灾害天气类别的分类精度都有显著提升。      

A study of positrons from Soviet nuclear powered satellites as tracers for magnetospheric research

Two Soviet satellites carrying nuclear reactors operated in circular 790 km orbits (65° inclination) in 1987 and 1988. Positrons generated in the satellites' surfaces by the intense reactor gamma radiation escaped and were trapped for periods of minutes to hours in the geomagnetic field. These positrons have been observed on many occasions by gamma ray sensors on the SMM satellite (in 500 km orbit) which identify the positrons by the 511 keV gamma rays created when they annihilate in the satellite surface. The SMM detector provides a time resolution of 64 milliseconds. It has recorded positron rise-times of less than 0.5 second (corresponding to a satellite travel distance of about 1 positron gyroradius) on many occasions as it encounters the low-L edge of positrons injected by the Soviet satellites as far as half-way around the earth. We are studying the potential of these sharply defined positron shells as magnetospheric tracers and as a means for examining particle diffusion and loss processes.     

Remote sensing of aerosol and radiation from geostationary satellites

The paper presents a high-level overview of current and future remote sensing of aerosol and shortwave radiation budget carried out at the US National Oceanic and Atmospheric Administration (NOAA) from the US Geostationary Operational Environmental Satellite (GOES) series. The retrievals from the current GOES imagers are based on physical principles. Aerosol and radiation are estimated in separate processing from the comparison of satellite-observed reflectances derived from a single visible channel with those calculated from detailed radiative transfer. The radiative transfer calculation accounts for multiple scattering by molecules, aerosol and cloud and absorption by the major atmospheric gases. The retrievals are performed operationally every 30 min for aerosol and every hour for radiation for pixel sizes of 4-km (aerosol) and 15- to 50-km (radiation). Both retrievals estimate the surface reflectance as a byproduct from the time composite of clear visible reflectances assuming fixed values of the aerosol optical depth. With the launch of GOES-R NOAA will begin a new era of geostationary remote sensing. The Advanced Baseline Imager (ABI) onboard GOES-R will offer capabilities for aerosol remote sensing similar to those currently provided by the Moderate Resolution Imaging Spectroradiometer (MODIS) flown on the NASA Earth Observing System (EOS) satellites. The ABI aerosol algorithm currently under development uses a multi-channel approach to estimate the aerosol optical depth and aerosol model simultaneously, both over water and land. Its design is strongly inspired by the MODIS aerosol algorithm. The ABI shortwave radiation budget algorithm is based on the successful GOES Surface and Insolation Product system of NOAA and the NASA Clouds and the Earth’s Radiant Energy System (CERES), Surface and Atmospheric Radiation Budget (SARB) algorithm. In all phases of the development, the algorithms are tested with proxy data generated from existing satellite observations and forward simulations. Final assessment of the performance will be made after the launch of GOES-R scheduled in 2012.     

Stereoscopic observations of hurricanes and tornadic thunderstorms from geosynchronous satellites

Results are presented to show the application of GOES stereoscopy to the study of hurricanes and tornadic thunderstorms. Stereoscopic cloud top height contour maps were constructed to observe the structural evolution of two hurricanes: Frederic, 12 September 1979 and Allen, 8 August 1980 and a tornadic thunderstorm complex over Oklahoma on 2–3 May 1979. Stereoscopic height contours of Hurricane Allen show a very intense and symmetric storm with a circular shaped Central Dense Overcast (CDO) with an average height of 16.5 km. Height contours of Hurricane Frederic show a preferred region for convection with an explosive exhaust tower reaching a maximum height of 17.8 km. A technique for estimating tropical cyclone intensity using GOES stereoscopic height and infrared temperature information is also presented. Utilizing short interval (3-min) GOES stereoscopic data from 2 May 1979 and 9 May 1979 (SESAME days), cloud top ascent rates were measured and used in determining the intensity of growing convective cells. Results show vertical motions ranging from 4.4 m s^?1 for a moderate storm to 7.7 m s^?1 for an intense storm. These results compare well in magnitude with growth rates determined from simultaneous GOES infrared observations and previous estimates of visual and radar echo top growth rates of other thunderstorms.     

Estimation of cloud top height and effective cloud cover from infrared satellite soundings

The paper deals with a new method for simultaneous determination of cloud top height and effective cloud cover, using infrared radiance data of satellite-borne instruments. These cloud properties derived from the Selective Chopper Radiometer on the Nimbus 5 satellite are compared with nearly simultaneous observations by radiosondes and with satellite images. Encouraging results for Central-Europe during January, April, July, August and October 1974, as well as numerical simulations indicate that the method proposed here, would be useful also for global application. Another advantage of the described procedure are the small amount of computing time, and that no other data are required than 3 of infrared channel values, for each sounded spot.     

ACE和STEREO-B太阳风速度的统计分析

采用小波分析方法讨论了2008—2011年ACE和STEREO-B卫星太阳风速度的27天周期特性,运用一元线性回归分析方法计算了两颗卫星太阳风速度的线性表达式,分析和计算结果表明,ACE和STEREO-B卫星探测到的太阳风速均在8～16d,16～32d的频域尺度上较为显著,在局部相同时域上,二者太阳风速的27天周期均较为显著;当太阳活动为低年时,相关性好. 作为应用实例,使用STEREO-B卫星太阳风探测数据,预测2012年10月1—17日的ACE太阳风速度,结果表明,预测值与实测值趋势一致,CME过程对预测值有一定影响. 通过本项研究,初步统计出了ACE与STEREO-B太阳风速度的关系,利用STEREO-B能够提前数天监测到即将由太阳吹向地球的太阳风特性,为建立直观的重现型地磁暴中期预报模型奠定了基础.     

Polarization imaging of dust cloud particles: Improvements and applications of the PROGRA2 instrument

The imaging system of the -PROGRA2 instrument allows to obtain maps of polarization and brightness of levitating dust clouds with a theoretical resolution of 10 μm per pixel. The measurements are conducted in microgravity during parabolic flights and on the ground by air-draught. It is then possible to measure the contribution of individual particles (grains, aggregates and agglomerates.) The size distribution can be retrieved, as well as the variation of polarization for a given phase angle with size for particles larger than 10 microns. Two different kinds of particles are considered: compact grains and (aggregates and agglomerates of) fluffy particles. Opposite results are obtained for these two kinds of particles, concerning the dependence of polarization with size and color in the visible domain for gray materials. These results, coupled with such remote sensing observations in the solar system, can then help to better understand the physical properties of solid particles and their variation in cometary comae, as well as in the Earth's atmosphere.     

Climatic variations in the outgoing longwave radiation of the past decade as observed from NOAA polar orbiting satellites

Components of the earth radiation budget have been calculated on a regular basis since June 1974 (except for a 10 month gap in data in 1978) based on measurements by the scanning radiometers and the advanced very high resolution radiometers on the operational NOAA polar orbiting satellites. A new base set of monthly and seasonal averages of outgoing longwave radiation has been prepared by NOAA's Climate Analysis Center (CAC) for the entire period of record through November 1983. Anomalies relative to these new normals have now been constructed for each month and season in the entire record.In this presentation, some of the more prominent anomalies of outgoing longwave radiation over the past decade are discussed. A major concentration is on the tropics and subtropics where there have been very substantial radiation variations associated with major shifts in convective cloudiness accompanying El Niño/Southern Oscillation events.     

Comparison of time-periodic variations in temperature and wind from meteorological rockets and satellites

Although the Meteorological Rocket Network operated by or in cooperation with the United States has decreased from fourteen to nine stations in the past five years, there have been many observations accumulated in the ten years since CIRA 1972 was prepared with data up to 1969. The mean, annual and semiannual variations of temperature and wind are presented and special attention is directed to the polar semiannual wave. The results are compared with the Oxford SCR-PMR five-year data set, the CDC-SCR seven-year data, and CIRA 1972 with respect to both temperature and zonal winds, as far as presently available. The agreement among the data sets is very good.     

Time-cumulated visible and infrared histograms used as descriptor of cloud cover

To study the statistical behavior of clouds for different climate regimes, the spatial and temporal stability of VIS-IR bi-dimensional histograms is tested. Also, the effect of data sampling and averaging on the histogram shapes is considered; in particular the sampling strategy used by the International Satellite Cloud Climatology Project is tested.     

Gravity field models from kinematic orbits of CHAMP,GRACE and GOCE satellites

The aim of our work is to generate Earth’s gravity field models from GPS positions of low Earth orbiters. Our inversion method is based on Newton’s second law, which relates the observed acceleration of the satellite with forces acting on it. The observed acceleration is obtained as numerical second derivative of kinematic positions. Observation equations are formulated using the gradient of the spherical harmonic expansion of the geopotential. Other forces are either modelled (lunisolar perturbations, tides) or provided by onboard measurements (nongravitational perturbations). From this linear regression model the geopotential harmonic coefficients are obtained.     

Synergetic retrieval of terrestrial AOD from MODIS images of twin satellites Terra and Aqua

Aerosol optical depth (AOD) is one of the most important indicators of atmospheric pollution. It can be retrieved from satellite imagery using several established methods, such as the dark dense vegetation method and the deep blue algorithm. All of these methods require estimation of surface reflectance prior to retrieval, and are applicable to a certain pre-designated type of surface cover. Such limitations can be overcome by using a synergetic method of retrieval proposed in this study. This innovative method is based on the fact that the ratio K of surface reflectance at different angles/geometries is independent of wavelength as reported by Flowerdew and Haigh (1995). An atmospheric radiative transfer model was then established and resolved with the assistance of the ratio K obtained from two Moderate Resolution Imaging Spectroradiometer (MODIS) spectral bands acquired from the twin satellites of Terra and Aqua whose overpass is separated by three hours. This synergetic method of retrieval was tested with 20 pairs of MODIS images. The retrieved AOD was validated against the ground observed AOD at the Taihu station of the AErosol RObotic NETwork (AERONET). It is found that they are correlated with the observations at a coefficient of 0.828 at 0.47 μm and 0.921 at 0.66 μm wavelengths. The retrieved AOD has a mean relative error of 25.47% at 0.47 μm and 24.3% at 0.66 μm. Of the 20 samples, 15 and 17 fall within two standard error of the line based observed AOD data on the ground at the 0.47 μm and 0.66 μm, respectively. These results indicate that this synergetic method can be used to reliably retrieve AOD from the twin satellites MODIS images, namely Terra and Aqua. It is not necessary to determine surface reflectance first.