| dc.description.abstract | Solar radiation at Erath surface has notable impacts on the sustainability of ecology, management of agriculture, and even changes of regional climate. In order to monitor the variation of surface solar irradiance, scientists have built many networks measuring atmospheric radiation with high accuracy since 1990s. However, while looking for a location for new photovoltaic (PV) plant, it is not reliable to use the nearest surface measurement of irradiances representing solar energy of the site since the surface solar measurements vary significantly over space. Therefore, this thesis provides a method to derive daily regional 2-D surface solar irradiance based on satellite measurements and one-layer radiative transfer model. Data from MTSAT-2 visible band are used as a sum of out-going visible radiation. The absorption of ozone is calculated with total column ozone from OMI sensor onboard AURA satellite. Precipitable water from MERRA2 reanalysis data are used to calculate the absorption of water vapor. Attenuation of aerosol is calculated from MODIS 8-day averaged aerosol dataset. Surface measurement of solar irradiance from some locations are also needed to adjust the model. Finally, the datasets in 2013 and 2014 are used to construct the model, and data in 2015 were used to validate the accuracy of the derived daily surface solar irradiance.
As a result, this model has the ability to represent the distribution of surface solar irradiance over Taiwan with effects of annual variation of solar position, cloud formation along terrain, and aerosol loading by human abilities. The model calculation indicates a high consistency of daily irradiance with a relative mean bias error of +1.91% and relative root mean square error of 15.37% while comparing with 16 surface solar measurement sites in Taiwan. The solar radiation reduction due to the existing of ozone, water vapor and aerosols are calculated by subtracting the derived surface solar irradiance from the one without ozone, water vapor, or aerosols. Our results show a 25 % reduction of surface radiation caused by water vapor, and 2 % reduction by ozone. Aerosols also reduce solar radiation by up to 12 % in Taiwan. The maximum reduction of radiation by aerosols are located at south western Taiwan from Chunghua to Pintung County where many factories and companies are built. This result suggests that southern Taiwan has higher availability of solar energy resource but it is also hampered by higher aerosol loading. Although the precision of the method is not as good as surface measurements, this work provides a reliable and efficient database for the site survey of PV plants over Taiwan. | en_US |