Levels of formate and acetate in dew were measured at Dayalbagh, India, usi
ng surrogate surfaces. The dew formed per night ranged between 0.06 l m(-2)
and 1.38 l m(-2), with an average of 0.59 l m(-2). pH ranged between 6.7 a
nd 7.4. Mean concentrations of formate and acetate in dew were 10.2 +/- 10.
2 mu eq l(-1) and 7.5 +/- 4.5 mu eq l(-1), respectively. The correlation co
efficient between the two ions was 0.80 (p = 0.001), which suggested that c
oncentrations of these species in dew are linked together. They have either
common or different sources with fairly constant strengths or products of
same reaction. Good correlation of formate and acetate with Ca (r = 0.82 an
d r = 0.70, respectively) and Mg (r = 0.74 and r = 0.71, respectively) sugg
ested that these ions may be associated with Ca and Mg after the neutraliza
tion process. Deposition rates for formate and acetate in dew per night wer
e 10.2 +/- 7.22 mu mol m(-2) per night and 4.6 +/- 2.2 mu mol m(-2) per nig
ht, respectively. The theoretical Henry's law constant (K-H*) and the field
-observed Henry's law coefficient (K-H*) as calculated from concurrent meas
urements of gas phase and dew for both acids showed large discrepancies of
three orders of magnitude.