Diffuse solar radiation estimates from sunshine hours and clearness index for Karachi, Pakistan

1990 ◽  
Vol 30 (4) ◽  
pp. 439-447 ◽  
Author(s):  
Firoz Ahmad ◽  
S.M. Aqil Burney ◽  
S.A. Husain
Keyword(s):  
Solar Radiation ◽  
Clearness Index ◽  
Diffuse Solar Radiation ◽  
Sunshine Hours

Estimation of Diffuse Solar Radiation from Clearness Index for Multan, Southern Punjab, Pakistan

2016 ◽  
Vol 12 ◽  
pp. 441-444
Author(s):  
M. Tanweer ◽  
◽  
Firoz Ahmad ◽  
Zaheer Uddin ◽  
Saif Rehman ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Clearness Index ◽  
Diffuse Solar Radiation

scholarly journals China's dimming and brightening: evidence, causes and hydrological implications

2014 ◽  
Vol 32 (1) ◽  
pp. 41-55 ◽  
Author(s):  
Y. W. Wang ◽  
Y. H. Yang
Keyword(s):  
Solar Radiation ◽  
Systematic Investigation ◽  
Pan Evaporation ◽  
Anthropogenic Aerosol ◽  
Surface Solar Radiation ◽  
Diffuse Solar Radiation ◽  
Sunshine Hours ◽  
Changing Trend ◽  
Global Dimming ◽  
The 1960S

Abstract. There is growing evidence that, corresponding to global dimming and brightening, surface solar radiation and sunshine hours over China have undergone decadal fluctuations during the 1960s–2000s. The results of a number of these analyses are, however, very different. In this study, we synthesize reliable results and conclusively address recent advances and insufficiencies in studies on dimming and brightening in China. A temporally and spatially prevalent dimming trend is noted in surface solar radiation, direct solar radiation and sunshine hours since the 1960s. Meanwhile, the changing trend in diffuse solar radiation is less pronounced. Increasing anthropogenic aerosol loading is regarded as the most plausible explanation for China's dimming. The brightening trend since 1990, which mainly occurs in southeastern China and in the spring season, is weak and insignificant. The reverse in the solar radiation trend is associated with climate change by cloud suppression and slowdown in anthropogenic emissions. The future solar radiation trend in China could largely depend on the development of air quality control. Other potential driving factors such as wind speed, water vapor and surface albedo are also non-negligible in specific regions of China. Hydrological implications of dimming and brightening in China lack systematic investigation. However, the fact that solar radiation and pan evaporation trends in China track a similar curve in 1990 further suggests that the pan evaporation paradox could be partly resolved by changes in solar radiation.

scholarly journals Analysis of ratio of global to extra-terrestrial radiation (clearness index) at some tropical locations in India

2017 ◽  
Vol 21 (3) ◽  
pp. 1379-1387
Author(s):  
Shanmugham Ravichandran ◽  
Jebamani Rathnaraj
Keyword(s):  
Solar Radiation ◽  
South India ◽  
Correlation Equations ◽  
Clearness Index ◽  
Diffuse Solar Radiation ◽  
Daily Average ◽  
Proposed Model ◽  
Performance Statistics ◽  
Term Data

An attempt has been made to analyze and evaluate the daily average clearness index (Hg/H0) in terms of daily average cloudiness index (Hd/H0) for three tropical locations in South India (Chennai, Trivandrum, and Visakapatnam). Long term data (15 years, 1993-2007) of measured daily average global and diffuse solar radiation for the locations have been used for this study. Two correlation equations (linear and polynomial) for each location have been developed for clearness index in terms of cloudiness index and found its validity. Performance statistics of the model has been done and applicability of the model is done by comparing the performance statistics with the existing models. It has been found that the proposed model has least error compared with the existing models.

scholarly journals Estimation of Global Solar Radiation on Horizontal Surfaces using Temperature-Based Model in Ilorin, Nigeria

2021 ◽  
Author(s):  
YAQUB BABATUNDE ADEDIJI ◽  
Ayobami Bamigboye ◽  
Joel Oluwaremilekun Aboderin ◽  
Onyeije Allison Lekwa ◽  
Emmanuel Onyedikachi Uzim
Keyword(s):  
Solar Radiation ◽  
Global Solar Radiation ◽  
Measuring System ◽  
Solar Irradiation ◽  
Clearness Index ◽  
Power Parameter ◽  
Diffuse Solar Radiation ◽  
Global Solar Irradiation ◽  
The Mean ◽  
Parameter Measuring

In this study, the Solar Irradiation received was estimated in Illorin, Kwara, Nigeria, using the maximum and minimum temperature measured by an Arduino-based solar power parameter measuring system. The Extraterrestrial, Global and Diffuse Solar Radiation were estimated monthly using the Hargreaves and Samani model. This model also required the daily temperature, clearness index, and extraterrestrial solar irradiation in its use alongside the maximum and minimum temperatures. In using this model, we resolved the graphs of the three types of Solar Irradiation over ten days. For the selected days, the estimated extraterrestrial solar irradiation varies from 10.41kWh/m2 to 10.47 kWh/m2, while the mean extraterrestrial solar irradiation is 10.44 kWh/m2. The estimated global solar irradiation varies from 4.42 kWh/m2 to 5.677kWh/m2, while the estimated mean global solar irradiation is 5.19kWh/m2 per day. The estimated diffuse solar irradiation varies from 3.46kWh/m2 to 5.48kWh/m2, while the mean diffuse solar irradiation is per day is 4.61kWh/m2.

Sign in / Sign up

Export Citation Format

Share Document