HYDROXYL AND PEROXY-RADICALS IN POLLUTED TROPOSPHERIC AIR

Model calculations show that hydroxyl is a rather conservative specie with respect to abundance and diurnal variation. Calculated maximum concentrations range from about 6×10−5 to 4×10−4 ppb for winter and summer, clear and clouded sky, temperatures ranging from 0 to 25°C and pollutant emissions ranging from average values for Western industrialized countries to urban areas. Peroxy radicals show a much stronger variability in concentration partly due to their strong dependence on NO. Gas phase sulfate conversion rates up to 3% hr−1 are calculated. Sulfate and ozone are efficiently generated in moderately polluted air. Copyright 1979 by the American Geophysical Union.