| Contributors | Affiliation | Role |
|---|---|---|
| McCarthy, James J. | Harvard University | Principal Investigator |
| Chandler, Cynthia L. | Woods Hole Oceanographic Institution (WHOI BCO-DMO) | BCO-DMO Data Manager |
High-sensitivity euphotic zone ammonium data
See Platform deployments for cruise specific documentation
| Parameter | Description | Units |
| sta | station number from event log | |
| cast | cast number of Trace Metal Free (TM) casts | |
| event | event number, a unique assigned to each sampling operation, a concatenation of date and time (MMDDHHmm) | |
| depth | sample depth | meters |
| nh4 | ammonium concentration | micro molar |
| Dataset-specific Instrument Name | Trace Metal Bottle |
| Generic Instrument Name | Trace Metal Bottle |
| Dataset-specific Description | Trace metal (TM) clean rosette bottles were used to collect water samples. |
| Generic Instrument Description | Trace metal (TM) clean rosette bottle used for collecting trace metal clean seawater samples. |
| Website | |
| Platform | R/V Thomas G. Thompson |
| Start Date | 1992-01-30 |
| End Date | 1992-03-13 |
| Description | Purpose: Spring Survey Cruise; 12°N-12°S at 140°W
TT007 was one of five cruises conducted in 1992 in support of the U.S. Equatorial Pacific (EqPac) Process Study. The five EqPac cruises aboard R/V Thomas G. Thompson included two repeat meridional sections (12°N - 12°S), 2 equatorial surveys, and a benthic survey (all at 140° W). The scientific objectives of this study were to observe the processes in the Equatorial Pacific controlling the fluxes of carbon and related elements between the atmosphere, euphotic zone, and deep ocean. As luck would have it, the survey window coincided with an El Nino event. A bonus for the research team. Methods & Sampling PI: James McCarthy of: Harvard University dataset: Ammonium Concentrations dates: February 07, 1992 to March 09, 1992 location: N: 9.0658 S: -12.1113 W: -140.511 E: -135 project/cruise: EQPAC/TT007 - Spring Survey ship: Thomas Thompson PI-Notes: Samples were obtained with the *trace metal-clean* rosette and assayed by the method of Brzezinski (1988) Limnol. & Oceanog. 33: 1176-1182. Detection limit = 0.002 micro molar. |
| Website | |
| Platform | R/V Thomas G. Thompson |
| Start Date | 1992-08-05 |
| End Date | 1992-09-18 |
| Description | Purpose: Fall Survey; 12°N-12°S at 140°W
TT011 was one of five cruises conducted in 1992 in support of the U.S. Equatorial Pacific (EqPac) Process Study. The five EqPac cruises aboard R/V Thomas G. Thompson included two repeat meridional sections (12°N - 12°S), 2 equatorial surveys, and a benthic survey (all at 140° W). The scientific objectives of this study were to observe the processes in the Equatorial Pacific controlling the fluxes of carbon and related elements between the atmosphere, euphotic zone, and deep ocean. As luck would have it, the survey window coincided with an El Nino event. A bonus for the research team. Methods & Sampling PI: James McCarthy of: Harvard University dataset: Ammonium Concentrations dates: August 11, 1992 to September 14, 1992 location: N: 12.025 S: -11.9433 W: -140.7383 E: -134.935 project/cruise: EQPAC/TT011 - Fall Survey ship: Thomas Thompson PI-Notes: Samples were obtained with the *trace metal-clean* rosette and assayed by the method of Brzezinski (1988) Limnol. & Oceanog. 33: 1176-1182. Detection limit = 0.002 micro molar. |
The U.S. EqPac process study consisted of repeat meridional sections (12°N -12°S) across the equator in the central and eastern equatorial Pacific from 95°W to 170°W during 1992. The major scientific program was focused at 140° W consisting of two meridional surveys, two equatorial surveys, and a benthic survey aboard the R/V Thomas Thompson. Long-term deployments of current meter and sediment trap arrays augmented the survey cruises. NOAA conducted boreal spring and fall sections east and west of 140°W from the R/V Baldridge and R/V Discoverer. Meteorological and sea surface observations were obtained from NOAA's in place TOGA-TAO buoy network.
The scientific objectives of this study were to determine the fluxes of carbon and related elements, and the processes controlling these fluxes between the Equatorial Pacific euphotic zone and the atmosphere and deep ocean. A broad overview of the program at the 140°W site is given by Murray et al. (Oceanography, 5: 134-142, 1992). A full description of the Equatorial Pacific Process Study, including the international context and the scientific results, appears in a series of Deep-Sea Research Part II special volumes:
Topical Studies in Oceanography, A U.S. JGOFS Process Study in the Equatorial Pacific (1995), Deep-Sea Research Part II, Volume 42, No. 2/3.
Topical Studies in Oceanography, A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2 (1996), Deep-Sea Research Part II, Volume 43, No. 4/6.
Topical Studies in Oceanography, A U.S. JGOFS Process Study in the Equatorial Pacific (1997), Deep-Sea Research Part II, Volume 44, No. 9/10.
Topical Studies in Oceanography, The Equatorial Pacific JGOFS Synthesis (2002), Deep-Sea Research Part II, Volume 49, Nos. 13/14.
The United States Joint Global Ocean Flux Study was a national component of international JGOFS and an integral part of global climate change research.
The U.S. launched the Joint Global Ocean Flux Study (JGOFS) in the late 1980s to study the ocean carbon cycle. An ambitious goal was set to understand the controls on the concentrations and fluxes of carbon and associated nutrients in the ocean. A new field of ocean biogeochemistry emerged with an emphasis on quality measurements of carbon system parameters and interdisciplinary field studies of the biological, chemical and physical process which control the ocean carbon cycle. As we studied ocean biogeochemistry, we learned that our simple views of carbon uptake and transport were severely limited, and a new "wave" of ocean science was born. U.S. JGOFS has been supported primarily by the U.S. National Science Foundation in collaboration with the National Oceanic and Atmospheric Administration, the National Aeronautics and Space Administration, the Department of Energy and the Office of Naval Research. U.S. JGOFS, ended in 2005 with the conclusion of the Synthesis and Modeling Project (SMP).