Murray¹, James W., Wendy Gentleman² and Anthony Aufdenkampe³

¹School of Oceanography, University of Washington, Seattle WA 98195-5351, Tel: (206) 543-4730, E-mail: jmurray@u.washington.edu, ²Dept. of Engineering Mathematics, Dalhousie University, Halifax, NS B3J 2X4 Canada and ³ Stroud Water Research Center, 970 Spencer Road, Avondale, PA 19311

Estimation of new production in high nitrate-low chlorophyll (HNLC) ocean regimes

What factors control variability in new production (NP) within and between HNLC ocean regions? There are three major ocean areas that are iron limited but have a major impact on global new production. These regions are the equatorial Pacific, subarctic North Pacific and Southern Ocean. All three were studied during the JGOFS era. Even though all three are HNLC regions, there are significant differences between them. Their similarities, given these differences, are intriguing. Our approach is to utilize multiple linear regression (MLR) analysis of JGOFS synthesis data sets from the subarctic North Pacific and equatorial Pacific. None of the historical regressions can explain the observed variability, either within or between regions. Simple MLR regressions using primary production, nitrate, ammonium and temperature can be derived to explain NP variability in each region but the best MLR for each region cannot explain the variability between regions. New MLR can be derived to explain f-ratios for both regions together.