Frequently asked questions bout ocean observations
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Figure legend: Example of occupations of a High-Density XBT line by the Physical Oceanography Division of NOAA’s Atlantic Oceanographic and Meteorological Laboratory. 3.3) What is an Argo float? Argo floats are autonomous instruments designed to provide profiles of ocean temperature and salinity within the upper half of the ocean, with newer floats measuring oxygen and plans to increase the sensor suite even further in the future. The floats also provide an estimate of the velocity field at the surface and at the ‘parking’ depth of the float, which is typically 1000 dbar (i.e., approximately 1000 m). The original float was developed to sink after launch to a prescribed pressure level (i.e., the parking depth). After a preprogrammed time (typically 10 days) at this pressure, the float returned to the surface, collecting temperature and salinity profiles as it rises. On the surface, the float transmits the data it has collected to satellites. The float then sinks once again to it’s parking depth and the cycle repeats. Newer floats can be programmed to drift at and profile to a range of different pressure levels. For instance, if a scientist’s interest is in the current field at 400 m, the float is programmed to drift at this pressure for a prescribed time. Before surfacing, floats have the ability to sink to a greater pressure (e.g., 2000 dbar) so that they provide profiles of temperature and salinity over a larger range in the ocean. As before, these newer floats then return to the surface collecting temperature and salinity data and the mission then repeats. Argo floats are designed to have an average lifespan of 4 years. The international Argo program has been designed to use Argo floats to provide for the first time global data on the temperature and salinity structure of the ocean. Numerous countries deploy floats as part of this program, with each float set with a ‘parking depth’ of 1000 dbar and with most programmed to sink down to 2000 dbar before collecting their upward profiles of temperature and salinity. The program seeks to have 3000 Argo floats in the water at all times, with a goal of spanning nearly the entire world ocean with an Argo float on a quasi-regular grid of 3 degrees of longitude by 3 degrees of latitude. These floats are used to characterize the temperature and salinity structures in the ocean and to increase understanding of the dynamics of ocean variability, which is a crucial step in developing climate forecast capabilities. They are also beginning to be used to initialize seasonal-to-interannual climate forecasts in predictions of phenomena such as El Niño. For more information on the Argo activities of the Physical Oceanography Division of NOAA’s Atlantic Oceanographic and Meteorological Laboratory go to: http://www.aoml.noaa.gov/phod/argo/index.php 
Figure legend: Schematic diagram of an Argo float. 
Figure legend: Schematic diagram showing one type of float mission. Argo.avi is a float animation that explains the purpose and method of Argo 
Directory: phod -> pub -> lusic lusic -> Physical Oceanography Division cy-2010 Publications pub -> North Atlantic Gyre Circulation Variability Associated with the Atlantic Multidecadal Oscillation phod -> Chunzai Wang phod -> March 2018 Cruise Plan – ax18 Download 16.64 Mb. Share with your friends:
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