Weighing the ocean with bottom-pressure sensors: robustness of the ocean mass annual cycle estimate

摘要

We use ocean bottom-pressure measurements from 17 tropical sites to determinethe annual cycle of ocean mass. We show that such a calculation is robust,and use three methods to estimate errors in the mass determination. Our finalbest estimate, using data from the best sites and two ocean models, is thatthe annual cycle has an amplitude of 0.85 mbar (equivalent to 8.4 mm of sealevel, or 3100 Gt of water), with a 95% chance of lying within the range0.61–1.17 mbar. The time of the peak in ocean mass is 10 October, with95% chance of occurring between 21 September and 25 October. Thesimultaneous fitting of annual ocean mass also improves the fitting of bottom-pressure instrument drift.