Chemical composition of precipitation at coastal and marine sampling sites in Mexico

Abstract

In the other hand, in Puerto Morelos, during sampling campaign performed at the end of the mid-summer drought, NO 3 -levels were the highest and also higher than SO 4 2-concentrations, exceeding background level; and pH values observed were low. Excluding, Puerto Morelos, where other sources influenced the rain chemistry composition; all remaining sampling sites were clearly influenced by marine aerosol, showing ionic concentrations typical of sites with a minimal anthropogenic influence, and therefore, their ionic concentrations can be considered as representative of background values for this region. KEY WORDS:Tropical oceanic rain; coastal rainwater chemistry; Mexico. INTRODUCTIONTemporal and spatial trends in precipitation chemistry are affected by seasonal variations in biogenic emissions, local agricultural practices, long-range transport, local meteorology, marine salt, and episodes like hurricanes and volcanic activity. In coastal sites, sea-salt aerosol dominates precipitation chemistry, accounting for 95-100% of Na