Western North Atlantic Hydrography Expedition

US GO-SHIP A20 and A22 lines repeat hydrography: western North Atlantic

As part of the NSF and NOAA-funded U.S. Global Ocean Carbon and Repeat Hydrography Program (US GO-SHIP)scientists from many institutions will embark on an expedition on board the R/V Thomas G Thompson, in the western North Atlantic Ocean. The 2-leg cruise (A20 and A22 lines) is part of an international program (GO-SHIP) to carry out a systematic and global re-occupation of selected hydrographic sections to quantify changes in storage and transport of heat, fresh water, carbon dioxide (CO2), and related parameters, integrating the scientific needs of the carbon and hydrography/tracer communities.

The 2-leg cruise (60 days-at-sea in total) will depart from Woods Hole in March 2021, following the A20 track of the previous CLIVAR 2012 occupation (nominally at ~52.5°W). Crossing the Gulf Stream, the Sargasso Sea, and towards the South American continental shelf close to French Guiana, the cruise will then head to the Virgin Islands for a brief stop, before proceeding with the A22 line (nominally ~66°W). From the Carribean Sea, the cruise will then head north, ending in Woods Hole in mid-May 2021. Approximately 200 full depth Rosette/CTD/LADCP/Fluorescence/Transmissometer casts will be occupied along the cruise track, and water samples for measurement of various water properties, such as CO2-related parameters, dissolved CFCs, oxygen, salinity, nutrients, etc., will be collected. A series of profiling floats and drifters will also be deployed: RAFOS, core and deep Argo, and the first biogeochemical (BGC) Argo floats from the GO-BGC program! You can also view the expedition blog from the US GO-SHIP program. 

Cover photo photo by Rachel Kahn

Chief scientists: Ryan Woosley and Viviane Menezes

Find out where the R/V Thomas G Thompson is on this interactive map from the University of Washington School of Oceanography. Click the pulsing dot for detailed information.


You can also follow this expedition on the US GO-SHIP blog, and on social media with #goship_a20_a22

North Atlantic Expedition Logs

April 8, 2021—Day 24

April 8, 2021—Day 24

The artwork by Elena Perez is amazing! The Flysch was launched todayApril 8, 2021 The Flysch is launched and we hope it will never find its namesake!At 1425 UTC (coordinated Universal Time) on April 8th, 2021, the eighth float of the newly NSF funded GO-BGC Array...

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Weekly Cruise Update #3

Weekly Cruise Update #3

Efficiency at sea - practice makes perfectApril 7, 2021 A20 Weekly Cruise update #3This last week has been one of pleasant routine. We’ve become a well-oiled machine of preppingthe CTD rosette, deploying, recovering and sampling the rosette, and steaming to the...

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April 6, 2021—Day 22

April 6, 2021—Day 22

The artwork by Elena Perez is amazing! Weddell was launched todayApril 6, 2021 Weddell enters the North Atlantic watersAt 1400 UTC (coordinated Universal Time) on April 6th, 2021, the seventh float of the newly NSF funded GO-BGC Array program was launched over the...

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April 4, 2021—Day 20

April 4, 2021—Day 20

WMO #5906339 is on the way; the tag line will be removed next allowing the float to drift free before sinkingApril 4, 2021 Science doesn't take any holidays at seaAt 1340 UTC (coordinated Universal Time) on April 4th, 2021, the sixth float of the newly NSF funded...

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April 2, 2021—Day 18

April 2, 2021—Day 18

WMO #5906340 carefully carried from the crate to the railApril 2, 2021 No fooling around here as the fifth GO-BGC float is launchedAt 1215 UTC (coordinated Universal Time) on April 2nd, 2021, the fifth float of the newly NSF funded GO-BGC Array program was launched...

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March 31, 2021—Day 16

March 31, 2021—Day 16

WMO #5906435 (Windston 7) from Anoka, MNMarch 31, 2021 No cyclones on the horizon for the launch today!At 1515 UTC (coordinated Universal Time) on March 31st, 2021, the fourth float of the newly NSF funded GO-BGC Array program was launched over the side after CTD...

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Weekly Cruise Update #2

Weekly Cruise Update #2

A busy week at seaMarch 30, 2021 A20 Weekly Cruise update #2The last week has been a busy one. We completed the closely spaced shelf and slope boundary stations around 1:30 am on March 24 (ship time) and turned due south. With wider spacing of approximately 30 nm the...

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March 29, 2021—Day 14

March 29, 2021—Day 14

WMO #5906440 (VIS) is getting a final check before launchMarch 29, 2021 A beautiful daytime launch for Vanadium Iodine Sulfur (VIS) At 1240 UTC (coordinated Universal Time) on March 29th, 2021, the third float of the newly NSF funded GO-BGC Array program was launched...

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March 27, 2021—Day 12

March 27, 2021—Day 12

Lewisburg Eel Express heading to the rail for launchMarch 27, 2021 Second float away as A20 keeps heading southAt 0800 UTC (coordinated Universal Time) on March 27th, 2021, the second float of the newly NSF funded GO-BGC Array program was launched over the side after...

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March 25, 2021—Day 10

March 25, 2021—Day 10

Europa is launched marking the start of a new NSF funded programMarch 25, 2021 The start of a new NSF funded program - the GO-BGC ArrayAt 2347 UTC (coordinated Universal Time) on March 24th, 2021, the first float of the newly NSF funded GO-BGC Array program was...

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Weekly Cruise Update #1

Weekly Cruise Update #1

The first CTD rosette deployment of Expedition A20March 23, 2021 A20 Weekly Cruise update #1In 2021 embarking on an oceanographic voyage has unique challenges. Before joining the ship, everyone underwent a 14-day pre-boarding isolation and received two negative...

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March 22, 2021—Day 7

March 22, 2021—Day 7

The GO-BGC floats are being decorated with their adopted namesMarch 22, 2021 One day to first GO-BGC deploymentThe R/V Thomas G Thompson has started the A20 Expedition and the first GO-BGC float is scheduled to be launched tomorrow (March 23rd, 2021). As time permits,...

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