Lomas, M.W., A.H. Knap, N.R. Bates and R.J. Johnson

Bermuda Biological Station for Research, Inc., 17 Biological Lane, St. George’s GE01, Bermuda, Tel: 441-297-1880 x303, Fax: 441-297-8143, E-mail: mlomas@bbsr.edu

The Bermuda Atlantic Time-series Study (BATS): A time-series window on climate forcing of ocean variability

The Bermuda Atlantic Time-series Study (BATS) was started over 14 years ago as part of the Joint Global Ocean Flux Study. The BATS sampling region lies ~82km southeast of Bermuda in about 4600m of water near the Ocean Flux Program site and the Bermuda Testbed Mooring. Over this 14-year period, a suite of core measurements has been made monthly or bi-weekly during the winter/spring bloom period (January to April). These measurements cover a wide range of physical, chemical and biological stock measurements. In conjunction with these stock measurements, a number of BATS core rate process measurements are made such as primary and bacterial production, and particle mass flux. Over the record of this program, numerous ancillary projects have greatly enhanced the context of these core measurements.

This 14-year time-series data set affords us the opportunity to re-examine some of the dominant paradigms in biological oceanography. The past decade has seen a shift in fate of the carbon fixed during primary production that is correlated with variability in phytoplankton community structure and climatic forcing. The interannual anomalies of hydrography and ocean biology and biogeochemistry are partially linked to large-scale climate variability such as North Atlantic Oscillation (NAO) and El Niño Southern Oscillation (ENSO). Temperature, mixed layer depth, primary production, phytoplankton community structure and TCO₂ anomalies are correlated with NAO variability, with cold anomalies at BATS coinciding with NAO positive states. Salinity, alkalinity and nTCO₂ anomalies were correlated with the Southern Oscillation Index (SOI), lagging ENSO events by 6-12 months.