Abstract
Abstract Knowledge of solar radiation is required for many applications. However, this atmospheric variable is not measured with an adequate space resolution. In this sense, to sites where solar radiation data are not directly measure, estimative using Ångström-Prescott equation can be used in order to provide solar radiation data, with input of sunshine duration. Thus, the objective of present study was to calibrate the Ångström-Prescott equation for different sites in Rio Grande do Norte state, Brazil. The performance of the calibrated Ångström-Prescott equation was evaluated by comparing of daily global solar radiation observed in situ. The MBE (Mean Bias Error) was lower than 1.50 MJ m-2 day-1, the Pearson's correlation coefficient about 0.90 and Willmott's index of agreement higher than 0.90, which are considered satisfactory.
Highlights
Knowledge of solar radiation on the Earth’s surface is required for many applications including architecture, active and passive solar energy systems, agriculture, meteorology and climatology
The Rio Grande do Norte (RN) state is located on Northeastern region of Brazil (Fig. 1)
It is possible noted different values of coefficients to the four weather stations studied on RN relatively to proposed by Allen et al (1998), i.e., a higher than 0.25 and b lower than 0.50 (Table 2)
Summary
Knowledge of solar radiation on the Earth’s surface is required for many applications including architecture, active and passive solar energy systems, agriculture, meteorology and climatology This variable is a proxy evaluating the availability of solar resources, being a prerequisite at any desired site (Sen et al, 2001; Morandi, 2009). Solar radiation is not directly measured with adequate space resolution and time sampling due to cost of maintenance and the frequent calibration procedures (Santos et al, 2014) These data are usually scarce, but to the places where solar radiation data are not available, this meteorological variable can be estimated from measurements of daily sunshine duration, which has locations with long-term records, applied to equation proposed by Ångström-Prescott (Ångström, 1924; Prescott, 1940).
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
