Trends in Global Solar Radiation and Sunshine Duration in Past Two Decades in Japan

Global solar radiation (GSR) is an essential physical quantity for agricultural management and designing infrastructures. Because GSR has often been modeled as a function of sunshine duration (SD) and day length for a given set of locations and calendar days, analyzing interannual trends in GSR and SD is important to evaluate, predict or regulate the cycles of energy and water between geosphere and atmosphere. This study aimed to exemplify interannual trends in GSR and SD, which had been recorded from 2001 to 2022 in 40 meteorological stations in Japan, and validate the applicability of an SD-based model to the evaluation of GSR. Both the measured GSR and SD had increased in many of the stations in the study period with averaged rates of 0.252 [W·m−2·y−1] and 0.015 [h·d−1·y−1], respectively. The offset and the slope of the SD-based model were estimated by fitting the model to the measured data sets and were found to have been almost constant with the averages of 0.201[-] and 0.566[-], respectively, indicating that characteristics of the SD-GSR relation had not varied for the 22-year period and that the model and its parameter set can be stationarily applicable to the analyses and predictions of GSR in recent years. The stable trends in both parameters also implied that the upward trend in SD can be a main explanatory factor for that in the measured GSR. The upward trend in SD had coincided with the increase in the frequency of heavy-shortened rains, suggesting that the time period of each rainfall event had gradually decreased, which may be attributable to the obtained upward trend in SD. Further studies are required to clarify if there is some cause-effect relation between the changes in rainfall patterns and the standard level of solar radiation reaching the land surface.

Effect of atmospheric aerosols on UV-B radiation reaching the ground

Solar ultraviolet radiation reaching the ground can be reduced due to light scattering of atmospheric aerosols. Aerosol pollution has led to the decrease in biological active UV-B radiation by about 45% and 10% in city and rural areas, respectively. In populated areas, effect of aerosol scattering on UV-B radiation may offset the increased amount of UV-B caused by ozone depletion, but in clean areas such as two poles, ozone depletion may have great damage effects on ecosystems.

Research on the Changes of Celestial Tide-generating Force and the Outgoing Long-wave Radiation before the Lushan (China) M_S7.0 Earthquake

Calculation of tidal changes reveals that the MS 7. 0 Lushan County,Sichuan,China,earthquake of April 20,2013 occurred at the minimum phase point of tidal force. It indicates that the seismogenic fault on which the tidal force acts on is of thrust type. The outgoing long-wave radiation( OLR) is the energy radiating from the Earth as infrared radiation at low energy to space. According to the tidal cycle,abnormal OLR change is analyzed based on NOAA satellite data around the whole of China before and after the earthquake. The result shows that the OLR changed evidently with the tide force change.Temporally,the change went through the course: initial OLR rise → s trengthening →reaching abnormal peak → a ttenuation → r eturning to normal; in space,the abnormal area was distributed along the Longmenshan fault and evolved as: scattering→ c onvergent→ s cattering. The process is similar to the change process of rock breaking under stress loading. It indicates that the celestial tidal force can trigger earthquakes when the tectonic stress reaches the critical break point of an active fault and the OLR anomaly is proportional to the seismic tectonic stress change. It is of practical value to combine OLR and tidal force anomaly with earthquake precursor studies.

Numerical Experiment of Combined Infrared and Ultraviolet Radiation Remote Sensing to Determine the Profile and Total Content of Atmospheric Ozone

A new remote sensing method is described to determine the vertical distribution and total content of atmospheric ozone. The method combines surface infrared, satellite infrared and ultraviolet channels. The width of the infrared channels is 0.01 cm-1, less than Lorentz half-width at the earth's surface, rather than the present width, because these channels can obtain information about variations in the ozone profile below the profile main-peak. The numerical experiments show that the method has a satisfactory precision in determining total ozone content, just about I percent error, and vertical distribution from the earth to 65 km space. In addition, some semi-analysis functions lor calculating backscattered ultraviolet and a relaxation equation are described in this paper.

OBSERVATIONAL STUDY ON THE CHARACTERISTICS OF THE RADIATION AND SURFACE ATMOSPHERIC BOUNDARY LAYER OVER ANTARCTICA

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Advances in Atmospheric Radiation:Theories,Models,and Their Applications.PartⅠ:Atmospheric Gas Absorption and Particle Scattering

Atmospheric radiation is a major branch of atmospheric physics that encompasses the fundamental theories of atmospheric absorption,particle scattering(aerosols and clouds),and radiative transfer.Specifically,the simulations of atmospheric gaseous absorption and scattering properties of particles are the essential components of atmospheric radiative transfer models.Atmospheric radiation has important applications in weather,climate,data assimilation,remote sensing,and atmospheric detection studies.In PartⅠ,a comprehensive review of the progress in the field of gas absorption and particle scattering research over the past 30 years with a particular emphasis on the contributions from Chinese scientists is presented.The review of gas absorption includes the construction of absorption databases,the impact of different atmospheric absorption algorithms on radiative calculations,and their applications in weather and climate models and remote sensing.The review on particle scattering starts with the theoretical and computational methods and subsequently explores the optical modeling of aerosols and clouds in remote sensing and atmospheric models.Additionally,the paper discusses potential future research directions in this field.

Advances in Atmospheric Radiation:Theories,Models,and Their Applications.PartⅡ:Radiative Transfer Models and Related Applications

The subject of“atmospheric radiation”includes not only fundamental theories on atmospheric gaseous absorption and the scattering and radiative transfer of particles(molecules,cloud,and aerosols),but also their applications in weather,climate,and atmospheric remote sensing,and is an essential part of the atmospheric sciences.This review includes two parts(Part I and PartⅡ);following the first part on gaseous absorption and particle scattering,this part(PartⅡ)reports the progress that has been made in radiative transfer theories,models,and their common applications,focusing particularly on the contributions from Chinese researchers.The recent achievements on radiative transfer models and methods developed for weather and climate studies and for atmospheric remote sensing are firstly reviewed.Then,the associated applications,such as surface radiation estimation,satellite remote sensing algorithms,radiative parameterization for climate models,and radiative-forcing related climate change studies are summarized,which further reveals the importance of radiative transfer theories and models.

Atmosphere Transmission Performance for 0.4 μm～0.8 μm Ray Radiation in Middle Latitude of China

This paper researched on the atmospheric transmission performance of 0.4 μm～0.8 μm ray radiation based on the characteristic of the middle latitude atmosphere in China.By analysis of the characteristic of the actual atmosphere,the absorption of molecular and the scattering of the steam and ozone,as well as the aerosol scattering(big granule scattering) are play a leading role to the 0.4 μm～0.8 μm ray radiation.Then a better atmospheric transmission formula in horizontal path has been deducted.The result of computer simulation indicates that this equation can best calculate the transmission performance of 0.4 μm～0.8 μm visible radiation in the middle latitude area of China.This computing result was applied to the nuclear explosion parameter detection system based on 0.4 μm～0.8 μm visible radiation.Through nuclear explosion simulator to produce ray radiation,the tested result indicates that this method has the better measuring precision than the traditional method with the software of LOWTRAN.The calculation result of this formula not only can apply directly to each kind of optoelectronics detecting system,but also to the optical wireless communication system based on the 0.4 μm～0.8 μm ray radiation.

The Thermal Radiation of the Atmosphere and Its Role in the So-Called Greenhouse Effect

Knowledge about thermal radiation of the atmosphere is rich in hypotheses and theories but poor in empiric evidence. Thereby, the Stefan-Boltzmann relation is of central importance in atmosphere physics, and holds the status of a natural law. However, its empirical foundation is little, tracing back to experiments made by Dulong and Petit two hundred years ago. Originated by Stefan at the end of the 19th century, and theoretically founded afterwards by Boltzmann, it delivers the absolute temperature of a blackbody—or rather of a solid opaque body (SOB)—as a result of the incident solar radiation intensity, the emitted thermal radiation of this body, and the counter-radiation of the atmosphere. Thereby, a similar character of the blackbody radiation—describable by the expression σ·T4—and the atmospheric counter-radiation was assumed. But this appears quite abstruse and must be questioned, not least since no pressure-dependency is provided. Thanks to the author’s recently published work—proposing novel measuring methods—, the possibility was opened-up not only to find an alternative approach for the counter-radiation of the atmosphere, but also to verify it by measurements. This approach was ensued from the observation that the IR-radiative emission of gases is proportional to the pressure and to the square root of the absolute temperature, which could be bolstered by applying the kinetic gas theory. The here presented verification of the modified counter-radiation term A·p·T0.5 in the Stefan-Boltzmann relation was feasible using a direct caloric method for determining the solar absorption coefficients of coloured aluminium-plates and the respective limiting temperatures under direct solar irradiation. For studying the pressure dependency, the experiments were carried out at locations with different altitudes. For the so-called atmospheric emission constant A an approximate value of 22 Wm-2 bar-1 K-0.5 was found. In the non-steady-state, the total thermal emission power of the soil is given by the difference between its blackbody radiation and the counter-radiation of the atmosphere. This relation explains to a considerable part the fact that on mountains the atmospheric temperature is lower than on lowlands, in spite of the enhanced sunlight intensity. Thereto, the so-called greenhouse gases such as carbon-dioxide do not have any influence.

Sources of IR Radiation in the Earth’s Atmosphere in Connection with the PeTa Effect

The PeTa (Perelman-Tatartchenko) effect is the radiation of the energy of a first-order phase transition during the transition from a less condensed phase to a more condensed one. The effect was independently discovered by M. Perelman and the author of this paper. Six papers on the PeTa effect have been published in this journal over the past nine years. They are devoted to the development of PeTa models to explain the following phenomena: IR radiation from cold surfaces, cavitation luminescence/sonoluminescence (CL/SL), laser-induced bubble luminescence (LIBL), and vapor bubble luminescence (VBL) in underwater geysers. This paper describes the sources of PeTa radiation in the Earth’s atmosphere. These sources of infrared radiation have been investigated by numerous research groups, but their interpretation either does not exist at all, or it is erroneous. The following phenomena are specifically considered: PeTa radiation during the formation of clouds and fog;a pulse laser based on the PeTa radiation;condensation explosions as sources of PaTa radiation;measurement of the concentration of water vapor in the atmosphere using PeTa radiation;atmospheric scintillation of infrared radiation in the atmosphere due to the PeTa effect;PeTa radiation as a source of comfort for the igloo;the influence of PeTa radiation on living organisms;PeTa radiation due to characteristics of tropical storms;PeTa radiation as a possible precursor to earthquakes. The problem of global warming, which worries everyone, as it turns out, is also associated with the PeTa effect.

Radiation of Ultra Low Frequency Electromagnetic Waves from Atmosphere under the Influence of Strong Shock Waves

We present preliminary results from the experimental investigation of the response of the atmosphere due to the impact of powerful shock waves. The response is evidenced as ultra low frequency electromagnetic wave radiation at frequency of 2-5 kHz and in duration of 3 7s. We hypothesize that this radiation appears due to the following process： the shock wave ionizes the neutral particles in the air and these charged and neutral particles continue their vertical motion, which forms in the trail of the shock wave. Such motion can cause the cyclotron-like radiation measured.

SEASONAL VARIATIONS OF NET RADIATIVE HEATING IN THE EARTH-ATMOSPHERIC SYSTEM AND ITS RELATIONS TOASIAN SUMMER MONSOON

Satellite-derived data of the outgoing longwave radiation (OLR), net shortwave radiation at thetropopause (SRT) and circulation information as predicted by NCEP are used in the work to study seasonal variations of net radiative heating in the earth-atmospheric system and its relationship with the Asian summer monsoon. As is shown in the result, the zonal deviations of the zonal deviations of the heating, manifested as mutations in direction between land and sea with seasons, is an indication of the thermal difference between them.Being a month earlier than that in the general circulation from spring to summer, the seasonal reversal of directionmay be playing an essential role in triggering the onset and withdrawal of summer monsoon in Asia.

Role of atmospheric factors in forcing Arctic sea ice variability

The spatial structure of the Arctic sea ice concentration(SIC)variability and the connection to atmospheric as well as radiative forcing during winter and summer for the 1979–2017 period are investigated.The interannual variability with different spatial characteristics of SIC in summer and winter is extracted using the empirical orthogonal function(EOF)analysis.The present study confirms that the atmospheric circulation has a strong influence on the SIC through both dynamic and thermodynamic processes,as the heat flux anomalies in summer are radiatively forced while those in winter contain both radiative and“circulation-induced”components.Thus,atmospheric fluctuations have an explicit and extensive influence to the SIC through complex mechanisms during both seasons.Moreover,analysis of a variety of atmospheric variables indicates that the primary mechanism about specific regional SIC patterns in Arctic marginal seas are different with special characteristics.

Mid-infrared atmospheric transmittance at 5100 m-altitude Ali Observatory

Ali in Tibet,5100 m above sea level,is one of the most suitable locations in the world for infrared spectral observations.The atmospheric transmittances at Ali Observatory and Mauna Kea Observatory were calculated by MODTRAN using radiosonde data.The results were 0.848 and 0.789 respectively which indicated better conditions at Ali Observatory.A self-made instrument with a 320×256-pixel HgCdTe infrared focal plane array and a 7.5-cm diameter telescope was utilized for the actual measurements.Without the help of standard stars,the on-site and real-time atmospheric transmittance can be obtained as 0.831 by fitting the relation between the measured atmospheric radiation intensity and the zenith angle based on radiation transfer equations.This paper firstly reports the atmospheric transmittance in the M'band(4.605–4.755μm)at the 5100 m-altitude Ali observatory by actual measurement.It shows that the high-altitude Ali observatory with sufficiently low water vapor content is suitable for observation in the mid-infrared bands.

Synthesising solar radio images from Atmospheric Imaging Assembly extreme-ultraviolet data

During non-flaring times,the radio flux of the Sun at wavelengths of a few centimeters to several tens of centimeters mostly originates from thermal bremsstrahlung emission,very similar to extremeultraviolet(EUV) radiation.Owing to such a proximity,it is feasible to investigate the relationship between the EUV emission and radio emission in a quantitative way.In this paper,we reconstruct the radio images of the Sun through the differential emission measure obtained from multi-wavelength EUV images of the Atmospheric Imaging Assembly on board Solar Dynamics Observatory(SDO).Through comparing the synthetic radio images at 6 GHz with those observed by the Siberian Radioheliograph,we find that the predicted radio flux is qualitatively consistent with the observed value,confirming thermal origin of the coronal radio emission during non-flaring times.The results further show that the predicted radio flux is closer to the observations in the case that includes the contribution of plasma with temperatures above 3 MK than in the case of only involving low temperature plasma,as was usually done in the pre-SDO era.We also discuss applications of the method and uncertainties of the results.

A new model describing Forbush Decreases at Mars: combining the heliospheric modulation and the atmospheric influence

Forbush decreases are depressions in the galactic cosmic rays (GCRs) that are caused primarily by modulations of interplanetary coronal mass ejections (ICMEs) but also occasionally by stream/corotating interaction regions (SIRs/CIRs). Forbush decreases have been studied extensively using neutron monitors at Earth;recently, for the first time, they have been measured on the surface of another planet, Mars, by the Radiation Assessment Detector (RAD) on board the Mars Science Laboratory’s (MSL) rover Curiosity. The modulation of GCR particles by heliospheric transients in space is energy-dependent;afterwards, these particles interact with the Martian atmosphere, the interaction process depending on particle type and energy. In order to use ground-measured Forbush decreases to study the space weather environment near Mars, it is important to understand and quantify the energy-dependent modulation of the GCR particles by not only the pass-by heliospheric disturbances but also by the Martian atmosphere. Accordingly, this study presents a model that quantifies both at the Martian surface and in the interplanetary space near Mars the amplitudes of Forbush decreases at Mars during the pass-by of an ICME/SIR by combining the heliospheric modulation of GCRs with the atmospheric modification of such modulated GCR spectra. The modeled results are in good agreement with measurements of Forbush decreases caused by ICMEs/SIRs based on data collected by MSL on the surface of Mars and by the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft in orbit. Our model and these findings support the validity of both the Forbush decrease description and Martian atmospheric transport models.

Estimation of Thermal Imaging System Operating Range Based on Background Radiation

Traditional operating range prediction methods assume that the atmospheric radiances in a target path and a background path are equal. But they are different in a real-world environment. To solve this problem,the influence of atmospheric radiance on operating range prediction is analyzed in this paper. Range estimation model in thermal imaging based on background radiation（ REBR） is proposed. Infrared image radiometric calibration is used to calculate the background radiation of a system entrance pupil. The result shows that,compared with traditional operating range prediction methods,the REBR method is more suitable for the actual atmospheric transmission process and the physical process of infrared imaging.

First Order Phase Transitions as Radiation Processes

This paper presents new experimental evidence of the PeTa effect—infrared characteristic radiation under first order phase transitions, especially the crystallization of melts and the deposition and condensation of vapours/gases. The PeTa effect describes the transient radiation that a particle (i.e., atom, molecule or/and cluster) emits transient radiation during a transition from a meta-stable higher energetic level (in a super-cooled melt or a super-saturated vapour) to the stable condensed lower level (in a crystal or a liquid). The radiation removes latent heat with photons of characteristic frequencies that are generated under this transition. The abbreviation “PeTa effect” means Perel’man-Tatartchenko’s effect.

First Order Phase Transitions as Radiation Processes, Part Two

This paper presents new experimental results concerning the PeTa effect—infrared characteristic radiation under first order phase transitions, especially during deposition and condensation of vapours/gases and the crystallisation of melts. The abbreviation “PeTa effect” means Perel’man-Tatartchenko’s effect. The nature of the PeTa effect is transient radiation that a particle (i.e., atom, molecule or/and cluster) emits during a transition from a meta-stable higher energetic level (in a super-cooled melt or super-saturated vapour) to the stable condensed lower level (in a crystal or liquid). The radiation removes latent heat with photons of characteristic frequencies that are generated under this transition. This paper is the second in a set describing the appearance of PeTa radiation under air cooling with deposition and condensation of air components. The radiation was recorded using an IR Fourier Spectrometer with a highly sensitive MCT detector. Certain peculiarities of the recorded radiation as well as its applications in the physics of the atmospheres of Earth and Jupiter are analysed.

RADIATION OF ALL WAVELENGTHS ON FINE WINTER DAYS INSIDE AND OUTSIDE LOW-LATITUDE CITIES OVER PLATEAU

The observation of radiation of different wavelengths was conducted in the urban and rural areas of Kunming City. The main results for clear days obtained in this paper are summarized as follows. (1) In the urban area.the fluctuation of radiation of different wave length are larger in the urban area due to strong effect of pollution.The radiation (difference and ratio between urban and rural areas) is lesser in the urban than in the rural areas.The difference is outstanding in the morning when the pollution is strong. (2) In the urban area of cities on low.latitude plateau, percentage of radiation of different wavelengths in total radiation differ between the morning and afternoon on fine winter days, so do that between the urban and rural areas and relevant variations, and the difference is most substantial at the time before midday when the air pollution is serious. (3) The difference between the urban and rural areas also exists for the diurnal total, totals for the time before and after midday in radiation of all wavelengths under the same sky conditions.