2021 |
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1. | B. Barja; J. Rosas; V.E. Cachorro; C. Toledano; J.C. Antuña-Marrero; R. Estevan; A.M. de Frutos In: Atmósfera, vol. 36 (1), pp. 41-56, 2021. Abstract | Links | BibTeX | Tags: AERONET, cloud effects on solar radiation (CRE) at surface, cloud radiative effect, radiative transfer simulations @article{Barja2021, The effects of cumulus (Cu) clouds and the combination of stratocumulus-cumulus (Sc-Cu) clouds on solar radiation at the Earth’s surface were evaluated at Camagüey, Cuba, during a 6-yr period (from June 2010 to May 2016). Two methods to calculate the cloud radiative effect (CRE) were employed. The first method (CREm) uses solar irradiances in cloudy conditions from actinometric observations, where cloud informa-tion was also reported by visual observation. In the second method (CRE0) surface solar irradiances were estimated for both cloudy and clear sky conditions using a 1-D radiative transfer model, and cloud optical depth (COD) retrieved from an AERONET sun-photometer as the main input. A temporal correspondence criterion between COD retrievals and actinometric observations was performed in order to classify the COD of each cloud type. After the application of this criterion, the COD belonging to the optically thin clouds was removed. Finally, 255 and 732 COD observations for Cu and Sc-Cu, respectively, were found. Results show a statistically significant difference at the 95% confidence level between CRE calculated for Sc-Cu and Cu, using both methods. Mean values of CREm and CRE0 for Cu (Sc-Cu) were ?442 (?390) and ?460(?417) Wm–2, respectively. CRE0 shows a linear relation with ln(COD), with stronger correlation at a lower solar zenith angle. The shortwave cloud effect efficiency (CEE) for the two cloud types sharply decreases with the increase of the COD value up to 20. For larger COD, the CEE is less sensitive to the increase of COD. |
2020 |
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2. | David Mateos; Manuel Antón Worldwide Evaluation of Ozone Radiative Forcing in the UV-B Range between 1979 and 2014 Journal Article In: Remote Sensing, vol. 12, no. 3, 2020, ISSN: 2072-4292. Abstract | Links | BibTeX | Tags: global analysis, long-term trends, ozone radiative forcing, radiative transfer simulations, reanalysis data, ultraviolet radiation @article{rs12030436, Ultraviolet (UV) radiation plays a key role in different planetary mechanisms, thus necessitating a worldwide analysis of this solar spectrum interval. This study offers a worldwide and long-term analysis of ozone radiative forcing (ORF) in the UV-B range between 1979 and 2014. The method uses monthly total ozone column (TOC) values obtained from the ERA-Interim reanalysis data collection and radiative transfer simulations. A global mean ORF of 0.011 Wm−2 is obtained, with marked differences between mid-latitude and tropical areas. The mid-latitude belts in the Northern and Southern Hemispheres exhibit the following statistically significant ORF trends between 1982 and 2014 with respect to pre-1980 values: 0.007 Wm−2 per decade in the 60–45°S belt and around 0.004 Wm−2 per decade in the 45–30°S and 45–60°N belts. The increase observed in the net UV-B radiation levels at the troposphere might have relevant photochemical effects that impact climate change. |
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2021 |
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1. | In: Atmósfera, vol. 36 (1), pp. 41-56, 2021. |
2020 |
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2. | Worldwide Evaluation of Ozone Radiative Forcing in the UV-B Range between 1979 and 2014 Journal Article In: Remote Sensing, vol. 12, no. 3, 2020, ISSN: 2072-4292. |