Trends of solar radiation, cloudiness and atmospheric transparency during recent decades in Estonia

Abstract. This study investigated the decadal variation of the direct surface solar radiation (DiSR) and the diffuse surface solar radiation (DfSR) during 1961–2008 in the Shanghai megacity as well as their relationships to Aerosol Optical Depth (AOD) under clear-sky conditions. Three successive periods with unique features of long term variation of DiSR were identified for both clear-sky and all-sky conditions: a "dimming" period from the late 1960s to the mid 1980s, a "stabilization"/"slight brightening" period from the mid 1980s to the mid 1990s, and a "renewed dimming" period thereafter. During the two dimming periods of DiSR, DfSR brightened significantly under clear-sky conditions, indicating that change in atmospheric transparency resulting from aerosol emission has an important role on decadal variation of surface solar radiation (SSR) over this area. The analysis on the relationship between the Moderate-resolution Imaging Spectroradiometer (MODIS) retrieved AOD and the corresponding hourly measurements of DiSR and DfSR under clear-sky conditions clearly revealed that AOD is significantly correlated and anti-correlated with DfSR and DiSR, respectively, both above 99% confidence in all seasons, indicating the great impact of aerosols on SSR through absorption and/or scattering in the atmosphere. In addition, both AOD and the corresponding DiSR and DfSR measured during the satellite passage over Shanghai show obvious weekly cycles. On weekends, AOD is lower than the weekly average, corresponding to higher DiSR and lower DfSR, while the opposite pattern was true for weekdays. Less AOD on weekends due to the reduction of transportation and industrial activities results in enhancement of atmospheric transparency under cloud free conditions so as to increase DiSR and decrease DfSR simultaneously. Results show that aerosol loading from the anthropogenic emissions is an important modulator for the long term variation of SSR in Shanghai.

Download Full-text

Daily solar radiation from NASA-POWER product: assessing its accuracy considering atmospheric transparency

International Journal of Remote Sensing ◽

10.1080/01431161.2019.1650986 ◽

2019 ◽

Vol 41 (3) ◽

pp. 897-910 ◽

Cited By ~ 2

Author(s):

Silvina Sayago ◽

Gustavo Ovando ◽

Javier Almorox ◽

Mónica Bocco

Keyword(s):

Solar Radiation ◽

Atmospheric Transparency ◽

Power Product

Download Full-text

Trends of solar radiation, cloudiness and atmospheric transparency during recent decades in Estonia

Tellus B ◽

10.1034/j.1600-0889.1990.t01-1-00006.x ◽

1990 ◽

Vol 42 (2) ◽

pp. 206-210 ◽

Cited By ~ 34

Author(s):

V. RUSSAK

Keyword(s):

Solar Radiation ◽

Atmospheric Transparency

Download Full-text

Analysis on the impact of aerosol optical depth on surface solar radiation in the Shanghai megacity, China

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-11-627-2011 ◽

2011 ◽

Vol 11 (1) ◽

pp. 627-652

Author(s):

J. Xu ◽

C. Li ◽

H. Shi ◽

Q. He ◽

L. Pan

Keyword(s):

Solar Radiation ◽

Aerosol Optical Depth ◽

Optical Depth ◽

Decadal Variation ◽

Surface Solar Radiation ◽

Atmospheric Transparency ◽

Clear Sky ◽

Term Variation ◽

Sky Conditions

Abstract. This study investigated the decadal variation of the direct surface solar radiation (DiSR) and the diffuse surface solar radiation (DfSR) during 1961–2008 in the Shanghai megacity as well as their relationships to Aerosol Optical Depth (AOD) under clear-sky conditions. Three successive periods with unique features of long term variation of DiSR were identified for both clear-sky and all-sky conditions: a "dimming" period from the late 1960s to the mid 1980s, a "stabilization"/"slight brightening" period from the mid 1980s to the mid 1990s, and a "renewed dimming" period thereafter. During the two dimming periods of DiSR, DfSR brightened significantly under clear-sky conditions, indicating that change in atmospheric transparency resulting from aerosol emission has an important role on decadal variation of surface solar radiation (SSR) over this area. The analysis on the relationship between the Moderate-resolution Imaging Spectroradiometer (MODIS) retrieved AOD and the corresponding hourly measurements of DiSR and DfSR under clear-sky conditions clearly revealed that AOD is significantly correlated and anti-correlated with DfSR and DiSR, respectively, both above 99% confidence in all seasons, indicating the great impact of aerosols on SSR through absorption and/or scattering in the atmosphere. In addition, both AOD and the corresponding DiSR and DfSR measured during the satellite passage over Shanghai show obvious weekly cycles. On weekends, AOD is lower than the weekly average, corresponding to higher DiSR and lower DfSR, while the opposite pattern was true for weekdays. Less AOD on weekends due to the reduction of transportation and industrial activities results in enhancement of atmospheric transparency under cloud free conditions so as to increase DiSR and decrease DfSR simultaneously. Results show that aerosol loading from the anthropogenic emissions is an important modulator for the long term variation of SSR in Shanghai.

Download Full-text

Numerical Procedures and their Practical Application in PV Module Analyses. Part IV: Atmospheric Transparency Parameters - Application

Ecological Chemistry and Engineering S ◽

10.2478/eces-2020-0001 ◽

2020 ◽

Vol 27 (1) ◽

pp. 9-39

Author(s):

Tadeusz Rodziewicz ◽

Małgorzata Rajfur ◽

Maria Wacławek

Keyword(s):

Solar Radiation ◽

Practical Application ◽

Spectral Parameters ◽

Natural Sunlight ◽

Atmospheric Transparency ◽

Clear Sky ◽

Expensive Equipment ◽

Pv Module ◽

Component Content

AbstractThe presented article relates to aspects of PV module testing using natural sunlight in outdoor conditions. It is a continuation of the article Part III: parameters of atmospheric transparency - determining and correlations. This article discusses the practical application of the indexes: atmosphere purity - kTm, diffused component content - ks/o, beam clear sky index - Kb - in testing various modules in outdoor conditions. Their influence on the conversion of modules made from various absorbers and various technologies is demonstrated. Their practical application in module testing in outdoor conditions is described and it - has been demonstrated that the results of the analyses carried out using the indexes conform to the results obtained using spectral parameters of solar radiation (i.e. APE and UF). These are the measurements that require the use of very expensive equipment.

Download Full-text

Absence of the Impact of the Flux of Cosmic Rays and the Cloud Cover on the Energy Balance of the Earth

Journal of Atmospheric Science Research ◽

10.30564/jasr.v3i3.2129 ◽

2020 ◽

Vol 3 (3) ◽

Author(s):

H. I. Abdussamatov

Keyword(s):

Energy Balance ◽

Cosmic Rays ◽

Solar Radiation ◽

Thermal Radiation ◽

Cloud Cover ◽

Transparency Window ◽

Lower Atmosphere ◽

Atmospheric Transparency ◽

The Earth ◽

The Impact

The energy of solar radiation absorbed by the Earth, as well as the thermal radiation of the Earth’s surface, which is released to the space through the atmospheric transparency window, depends on variations of the area of the cloud cover. Svensmark et al. suggest that the increase in the area of the cloud cover in the lower atmosphere, presumably caused by an increase in the flux of galactic cosmic rays during the quasi-bicentennial minimum of solar activity, results only in an increase in the fraction of the solar radiation reflected back to the space and weakens the flux of the solar radiation that reached the Earth surface. It is suggested, without any corresponding calculations of the variations of the average annual energy balance of the Earth Е, that the consequences will include only a deficit of the solar energy absorbed by the Earth and a cooling of the climate up to the onset of the Little Ice Age. These suggestions ignore simultaneous impact of the opposite aspects of the increase in the area of the cloud cover on the climate warming. The latter will result from a decrease in the power of thermal radiation of the Earth’s surface released to the space, and also in the power of the solar radiation reflected from the Earth’s surface, due to the increase in their absorption and reflection back to the surface. A substantial strengthening in the greenhouse effect and the narrowing of the atmospheric transparency window will also occur. Here, we estimate the impact of all aspects of possible long-term 2% growth of the cloud cover area in the lower atmosphere by Е. We found that an increase in the cloud cover area in the lower atmosphere will result simultaneously both in the decrease and in the increase in the temperature, which will virtually compensate each other, while the energy balance of the Earth E before and after the increase in the cloud cover area by 2% will stay essentially the same: E1 – Eо ≈ 0.

Download Full-text