Estimation of Atmospheric Turbidity Parameters in Ile-Ife, Nigeria

This study estimated the levels of atmospheric turbidity in Ile-Ife, a tropical location in the Southwest of Nigeria, from November, 2017 to March, 2019. This was with the aim to quantify the degree of atmospheric cleanliness of the study location. The methods of estimation used are: the Angstrom turbidity parameters (α and β), Linke turbidity factor (TL) and horizontal visibility (VH). The values of α and β range between 0.6 and 1.4; 0.10 and 0.91 respectively. The values obtained for TL varied between 1 and 7 while visibility values ranged between 2 and 14 km. Maximum values of β and TL (corresponding to low values of VH) were obtained in the dry season (particularly in the months of January and February) while the lowest values of the same methods of estimation (corresponding to high values of VH) were recorded in the wet season (specifically in August and September). The elevated turbidity observed in the dry season was linked to episodes of Harmattan dust storms usually experienced at the study location. The study concluded that a polluted atmosphere dominates the study location especially in the dry season as indicated by the different atmospheric turbidity parameters.

Study of Linke Turbidity Factor over Bode, Bhaktapur

The daily aerosol optical depth (AOD) data are derived from AERONET over Bode, Bhaktapur (27.68° N, 85.39° E, 1297 m above sea level) for a period of one year 2013. Annual mean of Atmospheric turbidity factors are calculated. The effect of different physical as well as meteorological parameters on the Linke turbidity factor was analyzed. The yearly mean of solar insolation, Angstrom exponential (α),Angstrom coefficient of turbidity (β) and Linke turbidity (LT) were found 4.70 ± 1.10kWh/m2/day, 1.13 ± 0.21 ,0.18 ± 0.14 and 5.70 ± 2.46 respectively. Annual average of visibility is 2.98 ± 2.13 km. Result of this research work is beneficial for the further identification, impact and analysis of atmospheric turbidity at different places.

Study of Impact of Linke Turbidity on Solar Radiation over Kathmandu Valley

Population growth, mechanization, and industrialization have now made humanity the equivalent of other natural processes in its effect on air-pollution levels and associated climatic change. Link turbidity is an important parameter for assessing the air pollution of Kathmandu (Lat.:27.72oN, Long.: 85.32oE and Alt.: 1350 m. above sea level). The Because of the unavailability of spectral measurements, a model has been used to estimate the Linke turbidity factor (TL) from broadband measurements of Global Solar radiation on 2012 by using CMP6 paranometer. The average value of extinction coefficient (K) and Linke turbidity are 0.69 ± 0.03 and 5.53±0.23$ respectively, which can be compared with other sites around the world. Relationship between turbidity co-efficient with meterological parameters (humidity, temperature and water contained) have been investigated further.

Climatology of the Linke and Unsworth–Monteith Turbidity Parameters for Greece: Introduction to the Notion of a Typical Atmospheric Turbidity Year

Solar rays are attenuated by the Earth’s atmosphere. This attenuation can be expressed by the turbidity parameters; two of them are the Linke turbidity factor (TL) and the Unsworth–Monteith turbidity coefficient (TUM). In this sudy, both parameters are estimated for 33 sites across Greece, and the notion of a Typical Atmospheric Turbidity Year (TATY) is also introduced. Use of the modified clearness index (k’t) is made, while a suggestion for a modified diffuse fraction (k’d) is given. The adoption of the four climatic zones in Greece for energy purposes is made, where the variation of TL and TUM is studied during a TATY under all and clear-sky conditions. The analysis shows maximum levels in both parameters in late winter–early spring in morning and evening hours, with minimum values at midday. The intra-annual variation of the parameters shows maximum values around March and August and minimum values in summertime and late winter. Maps of annual mean TL and TUM values over Greece show persistent minimum values over Peloponnese and maximum values over South Ionian Sea. Linear expressions of TUM vs. TL are derived for all sites under all and clear-sky conditions. Finally, linear expressions for k’d vs. k’t are given for all sites and sky conditions.

Study of Linke Turbidity Factor on Solar Radiation over Jumla

Population growth, mechanization, and industrialization are the by product of human civilization and its resultant impacts goes to degrade the natural environment by the affecting of air-pollution and also associated with climatic change. Linke turbidity factor (LT) is an important parameter for assessing the air pollution at Jumla (Lat.:29.28o N, Long.: 82.16o E and Alt. 2300 masl). Because of the unavailability of spectral measurements data , a model has been used to estimate the Linke turbidity factor (TL) from broadband measurement of Global Solar radiation in 2012 .The annual average solar insolation, clearness index (KT) and extinction coefficient (K) are 5.11 ±2.34kWh/m2/day ,0.71 ± 0.12 and 0.25 ± 0.13 respectively. Similarly, the annual average value of Linke turbidity factor (LT) and visibility 1.97± 0.47 and 28.09 ± 21.08 km are found. Finally it is found that there is strong relation between Linke turbidity factor and meteorological parameters i.e. relative humidity, temperature, water content, ozone and rain fall.

Modelling of real solar radiation spatial distribution as a tool for solar energy cadastre in the cities

The increasing needs of energy and decreasing traditional energy sources are becoming one of the biggest issues of our civilization. The provision of stable energy supply is a matter of state security. The energy consumption keeps growing especially in big cities. Therefore, it became reasonable to produce energy directly in cities. To optimize the use of the solar energy in the city areas, a fundamental issue is to find and estimate the amount of solar radiations at a specified location by using available tools and data. The main goal of this work is to demonstrate the potential of the r.sun model, a component of GRASS software, in calculating real solar radiation for the selected location. The work starts with demonstrating the effect of cloud cover for the amount of solar radiation reaching the Earth’s surface and the usage of GIS software and Ogimet website in the spatial analysis of real solar radiation distribution. For this purpose, data concerning cloud cover for selected locations were analysed. The study is based on the synoptic data obtained from Ogimet. Average daily cloud cover totals and long-term values were calculated. Apart from the cloud cover data, a significant variable, the Linke turbidity factor, describing the weakening of solar radiation due to the presence of aerosols and water vapour in the atmosphere, was taken into consideration. The obtained results were used to develop a map of real solar radiation distribution for a part of Wrocław. The results obtained by that model with the acquired data by the local meteorological station show compatibility.

Comparison of the Linke turbidity factor in Warsaw and in Belsk

The paper describes the relationship between direct solar radiation in a city (Warsaw) and in its broadly-defined suburban area (Belsk). The analysis covers the days of 1969-2003 when observations were carried out at both sites. The degree of extinction of solar radiation was expressed by means of Linke’s turbidity factor. Its mean annual value on the selected days of the period under consideration was 3.00± 0.10 in Warsaw and 2.87±0.11 in Belsk. Average atmospheric turbidity for individual seasons of the year as well as for the whole year was higher in Warsaw than in Belsk. In all cases, except for the summer, these differences were statistically significant. The period considered was divided into two sub-periods (1969-1993 and 1994-2003), in which atmospheric turbidity in Warsaw and in Belsk was compared by individual seasons and whole years. At both analysed sites Linke’s atmospheric turbidity factor decreased in 1994-2003, compared to the values for the earlier sub-period (1969-1993). However, the average annual atmospheric turbidity in Warsaw in comparison to Belsk remained the same, i.e. greater turbidity occurred in the city in both sub-periods.