Phosphorus 32, phosphorus 37, beryllium 7, and lead 210: Atmospheric fluxes and utility in tracing stratosphere troposphere exchange

The deposition of P-32, P-33, Be-7, and Pb-210 was measured in individual rain events at Woods Hole, Massachusetts, from March 1996 to February 1998 and in bimonthly integrated samples from Portsmouth, New Hampshire, from March to November 1997. Annual depositional fluxes of P-32 and P-33 were 0.178 and 0.165 disintegrations per minute (dpm) cm(-2) yr(-1) respectively, at Woods Hole and 0.212 and 0.175 dpm cm(-2) yr(-1) at Portsmouth. Beryllium 7 and Pb-210 fluxes averaged 12.8 and 1.43 dpm cm(-2) yr(-1), respectively, at Woods Hole and 16.6 and 0.95 dpm cm(-2) yr(-1), at Portmouth. High ratios of P-33/P-32 were observed in rain during severe storm events, suggesting that these isotopes trace stratosphere/troposphere exchange processes. Similar occurrences, however, were not observed in Be-7/P-32, Be-7/P-33, and Be-7/Pb-210 ratios. This indicates that there is substantial fractionation occurring among phosphorus, beryllium, and lead between time of production and atmospheric removal via precipitation.