Analysis and correlation of ultraviolet solar radiation from routine meteorological measurements over Egypt

For three years (1990-92) measurements of the monthly average daily global, G, and ultraviolet, UV, solar radiation incident on a horizontal surface at Cairo (30°15'N, 31°17'E) and Aswan (23°58'N, 32°47'E) are presented. processed and analysed. It was found that the computed monthly average daily values for the obtained solar radiation components, G and UV, were (18.1 MJ/m2, 0.55 MJ/m2, for Cairo and (22.1 MJ/m2, 0.71 MJ/m2, for Aswan. The effect of atmospheric dust on the measured solar radiation components is also investigated and discussed. The ratio of the ultraviolet to global radiation (UV/G) are calculated and compared with other sites in the Arabian Peninsula. A regression analysis has been done to find a correlation between G and UV at the selected sites during the three year period and the recommended correlation equations have also been stated. Since the meteorological measurements of UV solar radiation are not available over Egypt. except at Cairo (Lower Egypt) and Aswan (Upper Egypt) stations, our correlation equations can be used to calculate this component from the available global solar radiation measurements at any site in the two zones of Upper and Lower Egypt.

Comparison of the optical depth of total ozone and atmospheric aerosols in Poprad-Gánovce, Slovakia

The amount of ultraviolet solar radiation reaching the Earth's surface is significantly affected by atmospheric ozone along with aerosols. The present paper is focused on a comparison of the total ozone and atmospheric aerosol optical depth in the area of Poprad-Gánovce, which is situated at the altitude of 706 m a. s. l. in the vicinity of the highest mountain in the Carpathian mountains. The direct solar ultraviolet radiation has been measured here continuously since August 1993 using a Brewer MKIV ozone spectrophotometer. These measurements have been used to calculate the total amount of atmospheric ozone and, subsequently, its optical depth. They have also been used to determine the atmospheric aerosol optical depth (AOD) using the Langley plot method. Results obtained by this method were verified by means of comparison with a method that is part of the Brewer operating software, as well as with measurements made by a Cimel sun photometer. Diffuse radiation, the stray-light effect and polarization corrections were applied to calculate the AOD using the Langley plot method. In this paper, two factors that substantially attenuate the flow of direct ultraviolet solar radiation to the Earth's surface are compared. The paper presents results for 23 years of measurements, namely from 1994 to 2016. Values of optical depth were determined for the wavelengths of 306.3, 310, 313.5, 316.8 and 320 nm. A statistically significant decrease in the total optical depth of the atmosphere was observed with all examined wavelengths. Its root cause is the statistically significant decline in the optical depth of aerosols.

Design of a monitoring system for the cultivation of garden tomato in greenhouse

This paper briefly discusses the design and implementation of a prototype that monitors temperature, humidity and ultraviolet solar radiation levels in a greenhouse set for the cultivation of garden tomato. The Scrum agile methodology was applied through the deployment of the prototype. The monitoring system is composed by low cost, commercially available sensors, a database and a computer program developed in JAVA. It provides charts, audible and visual alerts, as well as daily, monthly and yearly statistical reports of sensed data. Implementation in the greenhouse aids farmers in the decision- making process regarding crop exposure to the sun, water and ambient temperature, thus enhancing quality of the cultivation process.