| Summary: | High uncertainties in aerosol radiative forcing (ARF) arise from inaccurate estimation for aerosol optical depth (AOD) as an input parameter into Santa Barbara Discrete Ordinate Radiative Transfer (SBDART) model. Influence of AOD in ARF at the top of atmosphere (TOA) and surface over Kuching from 2011 until 2015 was investigated using Moderate Resolution Imaging Spectroradiometer (MODIS). Multi plane regression technique was used to retrieve AOD from MODIS (AODMODIS) by using different statistics (mean and standard deviation (MODISµ±σ) and relative absolute error (MODISRAE) for accuracy assessment in spatial averaging and compared with Aerosol Robotic Network (AERONET). The relationship between AODMODIS and AOD from AERONET (AODAERONET) showed R2 value for MODISµ±σ and MODISRAE is 0.906 and 0.932, respectively. AODMODIS over Kuching tends to underestimate AOD during low variations and overestimate AOD when aerosol loading is higher. The retrieval of AODMODIS was used as an input parameter into SBDART for ARF estimation and compared with ARF from AERONET. When using AODMODIS from MODISµ±σ, the ARF at TOA was between-5.95 Wm-2 and 0.89 Wm-2 and at the surface was from-389.7 Wm-2 and-31.4 Wm-2 while for MODISRAE, ARF value at the surface was from-392.3 Wm-2 and-27.3 Wm-2 while at TOA was between-5.89 Wm-2 and 0.98 Wm-2. Average ARF value within the atmosphere for both MODISµ±σ and MODISRAE were 151.6 Wm-2 and 130.4 Wm-2, respectively. There is a poor relationship between the SBDART and AERONET for MODISµ±σ where R2 is 0.33, while strong relationship is observed for MODISRAE with R2 value at 0.724. © 2017 Universiti Putra Malaysia Press.
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