Use of Clear Day Solar Radiation for Estimation of Anthropogenic Aerosols in Atmosphere of Tirana (original) (raw)

Modification of Solar Energy Potential Due to Anthropogenic Aerosols in Atmosphere of Tirana

2017

Change of irradiative properties of the atmosphere during clear days is an indicator, among others, of existence of atmospheric aerosols and can be used as an indicator for assessment both air pollution and local modifications of solar energy potentials. The main objective of this study is estimation of influence of anthropogenic aerosols on solar energy falling in a horizontal surface during a clear day in the city of Tirana. We have analyzed and quantified the effect of aerosols on reducing the amount of solar energy that falls on the horizontal ground surface in cloudless sky conditions, estimating temporal evolution, both in daily and hour scale, considering also, side effects caused by relative humidity of the air wind speed and geometric factor.In order to determine the presence of aerosols in atmosphere, we agreed to use the attenuation of solar radiation after the last rainy day. Solar radiation received on a horizontal surface affected by some parameters: relative humidity,...

An estimation of impact of anthropogenic aerosols in atmosphere of Tirana on solar insolation. Part I: Clear day variation of ground insolation

AIP Conference Proceedings 1722(1):270001, 2016

Solar energy is a freely available renewable energy source, abundant in almost every part of the world. However, in many cases, the presence of aerosols in the atmosphere has an essential effect on modifying the ground energy budget, an effect that is known as irradiative forcing. The impact on anthropogenic aerosols' climate has recently attracted wide attention, especially in big cities. In this case, improving our knowledge about the processes driving these changes is essential. This study aims to estimate the impact of anthropogenic aerosols in the atmosphere of Tirana on solar insolation received on a horizontal surface. Measurements were carried at a height of 20 m over the ground using meteorological station Davison. Estimation of the influence of concentration of aerosols in the atmosphere was made by measurement of the time evolution of insolation during consecutive clear sky days after the last heavy rainy day. Careful measures were taken to estimate the influence of air humidity and wind speed on modifying solar insolation data. We have found that in all cases, solar insolation decreases with an increasing number of days from the last rainy day. The best fitting function describing the day-to-day decrease is a power function. Correlation coefficients and power indexes vary for data sets taken in different periods of the year. Also, daily periodical variation of solar insolation, a decrease in evening hours followed by an increase in morning hours, strongly indicates aerosols' anthropogenic origin.

Construction of an inexpensive sun photometer to measure aerosol optical depth and comparisons between the measured data and satellite observations

Abstract: At present the absorption and scattering of solar radiation by aerosols have been recognized as important parameters for climate change. A way of probing the atmosphere from the ground is to measure the effects of the atmosphere on sunlight transmitted to Earth's surface. This indirect technique provides information about the entire atmosphere above the observer. This paper describes a new kind of inexpensive two channels LED sun photometer for monitoring aerosols that provide long-term stability. In this study, we have constructed a handheld sun photometer and used it to measure and monitor the aerosol optical depth (AOD) and compared the measured values with the satellite data. The ground based measurements of AOD at 550nm from a handheld sun photometer is compared with the Terra and Aqua MODerate Resolution Imaging Spectroradiometers (MODIS) AOD retrievals over the region of Rajshahi division, Bangladesh for the 15 days duration of June 2012. The results indicate that the constructed handheld sun photometer measurements have good correlations with Terra and Aqua MODIS retrievals with correlation coefficients r = 0.88 for Terra and r = 0.55 for Aqua whereas correlation coefficients between Terra and Aqua is 0.65. AOD at 625nm is also documented to find out the relation of AOD at different wavelengths.

A study of aerosol particle sizes in the atmosphere of Athens, Greece, retrieved from solar spectral measurements

This work aims at determining the aerosol particle radii in the atmosphere of Athens. Such a work is carried out in Athens for the first time. For this purpose, solar spectral direct-beam irradiance measurements were used in the spectral range 310–575 nm. To estimate the particle radius from aerosol optical depth retrieval, a minimization technique was employed based on the golden-section search of the difference between experimental and theoretical values of the aerosol optical depth. The necessary Mie computations were performed based on the algorithm LVEC. In this study, the mean particle radius of a given distribution was calculated every 30 min during cloudless days in the period November 1996 to September 1997. The largest particles were observed in the summer and the smallest during winter. The result was verified by the increased values of the aerosol optical depth and the turbidity factors calculated in the summer. The differences in the diurnal variation from season to season are attributed to the prevailing wind regime, pollutant emission and sink rates in the atmosphere of Athens.