Measurements of soil heat flux were made over bare black cotton soil at Pune in the period June 1976 to February 1977, using a soil heat flux plate. Hourly values of soil heat flux from 00 to 24 LAT are presented for selected days typical of the monsoon, post-monsoon and winter seasons. The diurnal variation is generally characterised by a cross-over from negative to positive values at 07 hr, occurrence of maximum around noon and return to negative values between 16 and 18 hr. The effects of rainfall, cloudiness and soil moisture on the soil heat flux are discussed.

Results of an experiment conducted at the Central Agromet Observatory on gram crop during 1990-1991 winter crop season, to investigate relative contribution of energy balance parameters, presented in the study.   The analysis revealed that latent heat is the major source of dissipation of net r early maturity stage. After crop attains maturity, sensible heat predominates over other components.  

In part1,the effect ofatmosphe ric pollution overtime at a ai"-e n location \\'3$ discussed.The parriculate mat ter generated O"U a place is dispersed to surrounding areal> Thus II comp arative stud)'between pain ofstation s is worthwhil e. The effect of indust rial activi ty is clearly seen in the case of New Delhi when compared toJodhpur. However, the changes are not h~ly sienificanl in the case cfihe already de veloped areas like AhmedabadAnd Calcutta. Almost all statio ns show 8 decreasing trend in the net QUlgoina terrestrial radiant ent'rlf)'.

Radiation measurements are being carried out at Pune since 1957. The radiation data for the period 1986-90 are studied here with reference to general sky condition and rainfall distribution. Global irradiances show a decrease of about 5 per cent over the last four decades, The diffuse irradiation contributes about 23 per cent to the global irradiance during winter months, Its proportion increases to more than 70 per cent during the monsoon period. The specific rainfall distribution affects both global and diffuse irradiances but in opposite directions, The diffuse irradiance shows increases as the atmospheric transmission decreases, However, the changes found have not become statistically highly significant as yet.