The monthly average daily global irradiation exhibits a maximum value of 7932.2 Wh/m2 in June and a minimum value of 2950.6 Wh/m2 in December, cf., Table 1. The corresponding monthly average and median values are very similar throughout the year, i.e., on the average differ by 0.50%; maximum and minimum deviations 1.10 and 0.06%, respectively. This is indicative of an even distribution of daily values around the average. The magnitude of the coefficient of variation (Cv%) is a measure of the width of the spread of the individual values around the average monthly value and it is relatively low throughout the year; having a maximum value of 7.33% in January, viz., the variation of individual values during a particular month is inversely proportional to the magnitude of the Cv%.
It is apparent from the monthly p-values that there is no apparent trend regarding the global irradiation during the time period under investigation (26 years).
The monthly average daily UVB irradiation has a maximum value of 1.571 Wh/m2 in June and a minimum value in December of 0.341Wh/m2, cf., Table 2. The deviation between monthly average and median values for the individual months are in the range of 0.62% (January) to 3.74% (March); the average deviation is 1.93%. The Cv% exceeds 10% throughout the year; an indication of a greater monthly variation of the magnitude of the daily UVB irradiation for individual months relative to that for global irradiation.
Once again, based upon the monthly p-values there is no apparent trend regarding UVB irradiation during the time period being studied (24 years).
The UVA irradiation exhibits a monthly maximum of 400.58 Wh/m2 in June and monthly minimum of 133.90 Wh/m2 in December, cf., Table 3. The individual monthly average and median values differ between 0.10% (January) and 2.41% (March); the average deviation being 0.61%. The Cv% exceeds 10% only during February (11.11%) and is in the range of 1.82% (August) to 9.58% (May).
There is no indication of an apparent trend regarding UVA irradiation, based upon the individual monthly p-value analysis for the time period studied (24 years).
The statistical analysis of the dry bulb temperature was performed for the abovementioned three different time intervals:
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Diurnal- between 06:00 to 18:00
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Nocturnal- between 18:00 to 06:00
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Daily- between 00:00 to 24:00
The results of the individual statistical analysis can be summarized as follows, cf., Table 4:
Diurnal dry bulb temperature-
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maximum temperature 35.8°C in August; minimum temperature 18.4°C in January;
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deviation between monthly average and median temperatures is between 0.12% (November) and 2.97% (July); average monthly deviation 0.93%;
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average monthly Cv% is 6.53% and it exceeds 10% only during July (11.10%).
Nocturnal dry bulb temperature-
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maximum temperature 32.3°C in July; minimum temperature 16.4°C in January;
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deviation between monthly average and median temperatures is between 0.08% (March) and 1.57% (August); average monthly deviation 0.78%;
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average monthly Cv% is 5.71% and does not exceed 10% throughout the year.
Daily dry bulb temperature-
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maximum temperature 34.2°C in July; minimum temperature 17.4°C in January;
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deviation between monthly average and median temperatures is between 0.07% (May) and 1.51% (August); average monthly deviation 0.76%;
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average monthly Cv% is 5.75% and does not exceed 10% throughout the year.
It is observed from the p-value analysis, applied to the three different time intervals studied, that there is no apparent trend regarding the dry bulb temperature during the time interval under investigation (26 years) with the exception of the nocturnal dry bulb temperature during the month of October, viz., p-value = 0.005. The month of October exhibits a positive nocturnal trend of 0.78°C/decade.