It can be stated that the daily PAR/K↓ ratio for this location is not constant, rather it displays conservative variation. This systematic temporal variation is the net result of a number of interrelated atmospheric processes and should not be overlooked. Local climatic factors are major determinants of the temporal trend in the PAR/K↓ ratio, and the role of cloudiness, atmospheric water vapour and aerosols merit attention in PAR and PAR/K↓ regimes at this location.