We analyzed 21‐year long records of precipitation chemistry from central Scandinavia and the north‐eastern US to compare seasonal variations of three major pollutant ions, SO42−, NO3− and NH4+. Seasonal variations in concentrations of the individual ions were distinctly different between the two regions. However, despite these differences, we found strong and unexpected similarities between the two regions in seasonal variations of the concentration ratios NO3−/SO42−, NH4+/NO3– and NH4+/SO42−. A preliminary analysis suggests that these similarities are due to similarities between the two regions in chemical transformation and removal processes affecting SO42− and NO3− in the atmosphere, and to a coupling between NH4+ and SO42− aerosol in long‐range transport. Ion ratios appear to be less sensitive to seasonal variations in SO2 and NOx emissions compared to individual ion concentrations.
|Original language||English (US)|
|Number of pages||9|
|State||Published - Jan 1 1990|
All Science Journal Classification (ASJC) codes
- Atmospheric Science