Cosmogenic 32P and 33P in the Atmosphere and Oligotrophic Ocean and Applications to the Study of Phosphorus Cycling
Abstract
Cosmogenic 32P (14.28 days) and 33P (25.3 days) are powerful tracers of upper ocean P cycling, when coupled with time-series of the atmospheric sources. A method was developed to determine the low-level beta activities in rainwater and plankton. The wet deposition rates of 32P and 33P were determined during 12 months at a marine site, at Bermuda, coinciding with measurements of the activities and activity ratio 33P/32P in suspended particles and plankton tows at BATS station. The in situ production rates of radiophosphorus in the upper ocean were estimated by measuring the activities induced in Cl, K and S targets by cosmic rays. Knowledge of all the sources of radiophosphorus to the Sargasso Sea allowed the cycling of 32P and 33P in suspended particles and macro-zooplankton to be studies. The study was based on the determination of the activity ratio 33P/32P in different particulate pools. The activity ratio was higher in particle collections dominated by higher levels in the food web. The increase in the ratio in plankton relative to rain allowed the determination of the turnover times of P in plankton and in situ grazing rates. Cosmogenic, Phosphorus, Nutrient cycling
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1993
- Accession Number
- ADA279438
Entities
People
- Nathalie A. Waser
Organizations
- Woods Hole Oceanographic Institution