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

A22 Weekly Update #4

A22 ends as we get home a little early!May 16, 2021 A22 Weekly Cruise update #4We could have done new stations with the time left — a plan B was indeed traced, zig-zagging the Deep Western Boundary Current at the end of the transect— but our final decision was to...

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A22 Weekly Update #3

A22 Weekly Update #3

A22 Expedition in the home stretchMay 11, 2021 A22 Weekly Cruise update #3We have just finished our third week at sea. Four days ago, we crossed the eastern side of Bermuda, and now we are occupying the famous line-W, from Bermuda to Woods Hole. In these three weeks,...

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May 10, 2021—Day 20

May 10, 2021—Day 20

The last GO-BGC float of this expedition - Integrity (illustrated by Caitlyn Webster)May 10, 2021 Fourth and final GO-BGC float Integrity is launchedAt 2250 UTC (coordinated Universal Time) on May 9th, 2021, the twelfth float of the newly NSF funded GO-BGC Array...

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May 6, 2021—Day 16

May 6, 2021—Day 16

Three floats launched now, with one to goMay 6, 2021 AHEA is launched during calm conditionsAt 1015 UTC (coordinated Universal Time) on May 6rd, 2021, the eleventh float of the newly NSF funded GO-BGC Array program was launched over the side after CTD Station #58....

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A22 Weekly Update #2

A22 Weekly Update #2

A22 Expedition leg hits the halfway pointMay 3, 2021 A22 Weekly Cruise update #2We are completing our second week at sea and are halfway through A22. Right now, we are on station 50! Time has passed in the blink of an eye, but it also feels like living forever on the...

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May 3, 2021—Day 13

May 3, 2021—Day 13

Dogie Diver got wet today but not before being illustrated by Caitlyn WebsterMay 3, 2021 Dogie Diver gets wet in the North AtlanticAt 1305 UTC (coordinated Universal Time) on May 3rd, 2021, the tenth float of the newly NSF funded GO-BGC Array program was launched over...

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April 26 2021—Day 6

April 26 2021—Day 6

First two GO-BGC floats of A22 ready for launch! Comets decorated by Caitlyn Webster and Jesse Anderson; Dogie Diver decorated by Caitlyn WebsterApril 26, 2021 A22 starts heading northAt 0316 UTC (coordinated Universal Time) on April 25th, 2021, the ninth float of the...

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A22 Weekly Update #1

A22 Weekly Update #1

A22 Expedition leg is underwayApril 26, 2021 A22 Weekly Cruise update #1Although this is our first week at sea, for many of us (12 scientists and 8 crew members), A22 started well before. On the weekend of April 3-4, we traveled to beautiful and sunny St. Thomas, U.S....

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April 22, 2021—Day 2

April 22, 2021—Day 2

April 22, 2021 As the A20 was underway in the North Atlantic, simultaneously, there was a bunch of people from all over the country scrambling to get to the end point of the 1st leg, which was St. Thomas island. The second leg (A22) of this expedition left dock on...

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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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A20 Weekly Update #3

A20 Weekly 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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