JGOFS Study

Table 6.2 Seasonally averaged/-ratios for various sub-regions of the US JGOFS study area (coastal upwelling Stas. N1-N2, S1-S4 Somali Jet axis S5-S10 southeast S12-S15 off Indian coast N4-N10) - after Sambrotto (2001)...

Garrison, D.L., Gowing, M.M. and Hughes, M.P. (1998) Nano- and microplankton in the northern Arabian Sea during the southwest monsoon, August-September 1995 a US JGOFS study. Deep-Sea Research II, 45, 2269-2299. 

Murray, J. W., LeBorgne, R. and Dandonneau, Y. (eds) (1997). A JGOFS Process Study in the Equatorial Pacific. Deep-Sea Res. II44,1759-2317. 

Smith, S. (ed.) (1998). U.S. JGOFS Arabian Sea Process Study. Deep-Sea Res. II45. 

Southern Ocean JGOFS The UK "Sterna" Study in the Bellingshausen Sea. Deep-Sea Res. II 42, 907-1335. 

Results of the past decade JGOFS and other studies... 

A major opportunity to test the use of " Th as a proxy for POC flux arose with the Joint Global Ocean Flux Study (JGOFS). JGOFS had as a central goal a better understanding of the ocean carbon cycle, including the flux of POC leaving the euphotic zone. Process studies were carried out in the Atlantic Ocean, Pacific Ocean, Arabian Sea and Southern Ocean. " Th profiles were obtained as a part of each process study. 

Sampling artifacts. The use of in situ pumps to collect water samples for " Th analysis permits simultaneous collection (and separation) of different particle fractions as well as dissolved Th. As pumping systems have been modified to permit determination of POC on the pump filters, it became possible to compare POC determined from the pump samples with conventional POC determinations made on small volume samples (0.5 - 2 L) taken from hydrocasts. The JGOFS data from multiple studies show large discrepancies between these two sample collection methods, with pump POC values 3 to 100 times lower than bottle POC values. Possible artifacts with each approach have been identified. For example Moran et al. (1999) have suggested that DOC is adsorbed onto... 

An early attempt to resolve the discrepancy between the high values of Sugimura and Suzuki (1988) and more traditional analyses failed to reach a definitive conclusion (Williams, 1992). The start of the Joint Global Ocean Flux Study (JGOFS) field program with the North Atlantic Bloom Experiment in 1989 put additional pressure on the various groups to resolve this issue quickly. The National Science Foundation (NSF) and the National Oceanic and Atmospheric Administration (NOAA) funded a workshop held in Seattle in July 1991 to resolve the issue. 

The urgent need for nutrient standards was demonstrated during the recently completed World Ocean Circulation Experiment (WOCE) and Joint Global Ocean Flux Study (JGOFS) measurements which were made by different laboratories. The internal consistency of the nutrient data was evaluated by comparing measurements made in deep water (depth over 3500 m) at nearby stations on different cruises. If one assumes that nutrient concentrations in deep water at the same location should not... 

JGOFS Joint Global Ocean Flux Study... 

Uher G, Schebeske G, Barlow RG, Cummings DG, Mantoura RFC, Rapsomanikis SR, Andreae MO (2000) Distribution and air-sea gas exchange of dimethyl sulphide at the European western continental margin. Mar Chem 69 277-300 UNESCO (1994) Protocols for the Joint Global Ocean Flux Study (JGOFS). Core Measurements, Scientific committee on Oceanic Research Manual and Guides 29 170... 

---