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

1999; American Geophysical Union; Volume: 104; Issue: D9 Linguagem: Inglês

10.1029/1998jd100101

2156-2202

Claudia R. Benitez‐Nelson, Ken O. Buesseler,

Radioactive element chemistry and processing

The deposition of 32 P, 33 P, 7 Be, and 210 Pb 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 32 P and 33 P 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 210 Pb 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 Portsmouth. High ratios of 33 P/ 32 P were observed in rain during severe storm events, suggesting that these isotopes trace stratosphere/troposphere exchange processes. Similar occurrences, however, were not observed in 7 Be/ 32 P, 7 Be/ 33 P, and 7 Be/ 210 Pb ratios. This indicates that there is substantial fractionation occurring among phosphorus, beryllium, and lead between time of production and atmospheric removal via precipitation.