# Presentation: 492221

## The Atlantic Ocean:  from Meteor through WOCE 

- The Atlantic Ocean:  from Meteor through WOCE

- R Allyn Clarke
- Bedford Institute of Oceanography

## Challenger Expedition 1873-1875

**Notes:**
Sir Charles Wyville Thomson, Sir John Murray and John Buchanan:Chief naturalist, assistant naturalist and chemist aboard the HMS Challenger
The Challenger Expedition claims the title of the world's first totally scientific oceanographic expedition By the time the HMS Challenger left the dock on December 21, 1872 (why do these British voyages always start around Christmas time?), the world was experiencing an intellectual and technological revolution of sorts. Except for the poles, few places remained to be conquered by man. And in a time when knowledge began to be equated with power, the British government was amenable to schemes for acquiring knowledge.
With a rising tide of intellectual fervor behind him, Sir Charles Wyville Thomson, a natural history professor at the University of Edinburgh in Scotland, and his Canadian-born student, John Murray (later, Sir John Murray) hatched a scheme to explore the oceans in the grandest oceanographic mission ever conceived. They called their proposal "oceanography" and pleaded their case before the Royal Navy and the Royal Society to send a ship around the world for one purpose: to study the oceans.

## Meteor Expedition

**Meteor Expedition**
**1925-1927**

**1927**

**1926**

**1925**

## Meridional Sections

**Meridional Sections**
**Georg Wüst (1935)**
** ****Meteor plus other data**
** ****other data spans decades**

## Western Section

**Western Section**

**1000 m**

**2000 m**

**3000 m**

**4000 m**

**5000 m**

**Equator**

- Labrador Sea

**Antarctica**

**Salinity**

**Oxygen**

## Central Section

**Central Section**

**1000 m**

**2000 m**

**3000 m**

**4000 m**

**5000 m**

**Equator**

- Irminger Sea

**Antarctica**

**Temperature**

**Sigma T**

## Eastern Section

**Eastern Section**

**1000 m**

**2000 m**

**3000 m**

**4000 m**

**5000 m**

**Equator**

- Rockall Trough

**Antarctica**

**Salinity**

**Oxygen**

## Wüst (1935)

**Wüst (1935)**

**Subantarctic Intermediate Water**
**SAAIW**
- defined by the intermediate salinity minimum
- also seen in temperature and oxygen
- figure shows % subantarctic component

**% SAAIW**

- 70

- 50

- 30

## Wüst (1935)

**Wüst (1935)**

**SAAIW**

**Upper North Atlantic Deep Water**
**uNADW**
** ****intermediate salinity Maximum**
** ****also in temperature **
** ****% Mediterranean **

**uNADW**

- 30

- 15

- 20

## Wüst (1935)

**Wüst (1935)**

**SAAIW**

**uNADW**

**Middle North Atlantic Deep Water**
**mNADW**
-  intermediate oxygen maximum
-  salinity maximum
-  % North Atlantic component

**mNADW**

- 90

- 60

- 40

## Wüst (1935)

**Wüst (1935)**

**SAAIW**

**uNADW**

**mNADW**

**Antarctic Bottom Water**
**AABW**

**AABW**

- 90

- 10

- 30

## International Geophysical Year

**International Geophysical Year**

**1957**

**1958**

- 12 zonal IGY trans Atlantic sections
- winter and summer surveys of the northern sub polar gyre ICES Polar Front Survey

## The 70s and the 80s

- Fukumori, Martel & Wunsch, 1991

**The 70s and the 80s**

- GEOSECS Atlantic 1972-73

**TTO, Long Lines & SAVE**

## We believed we knew a lot about the North Atlantic when planning WOCE

**We believed we knew a lot about the North Atlantic when planning WOCE**

## WOCE planning for the Atlantic

**One time hydrography**

**Repeat hydrography**

**Moorings**

## How did we do?

**How did we do?**

**Moorings**

**One time Hydrography**

## Surface Drifters

**Surface Drifters**
**Annual Trajectories 1990 to 1999**
**(Fratantoni, JGR 106 (C10), 2001)**

## Surface Drifters

**Surface Drifters**
**No of Observations per degree square**
**(Fratantoni, JGR 106 (C10), 2001)**

## Surface Drifters

**Fastest and Slowest surface currents**** (Fratantoni, JGR 106 (C10), 2001)**

## Surface Drifters

**Eddy Kinetic Energy**
**(Fratantoni, JGR 106 (C10), 2001)**

## Surface Drifters

**Sub Tropical Sub Polar Exchange**
**(Cuny, Rhines, Niiler & Bacon, JPO 32(2), 2002)**

## Western Atlantic WOCE  Section

**Western Atlantic WOCE  Section**
**Salinity**

## Western Atlantic WOCE  Section

**Silicate**

## Atlantic WOCE  A16 Section

**Salinity & Oxygen**

## New Climatology North Atlantic

**Mean Properties on ************= 26.50**
**Lozier, Owens & Curry Prog. Ocean. 36(1), 1995**

- Pressure

- Theta

- Salinity

- Oxygen

**Std Dev ******

## Properties on the AAIW (Oxygen Maximum)

**Talley, 1996**

- Salinity

- Oxygen

## CFCs in the Atlantic Overturning Circulation

**Rhein, Fischer, Smethie, Smythe-Wright, Weiss, Mertens, Min, Fleischmann & Putzka, JPO, 2002**
**Andrie, Rhein, Freudfenthal & Plahn,  DSR I, 49(2), 2002**
**Andrie, The South Atlantic, 1996**

- CFC-11 inventory in the subpolar gyre

- CFC-11 in DWBC at the Equator

- Increase over the 90s of

- 1983    1993

## Intermediate Circulation Labrador & Irminger Seas

-  < 400 m  **400 < ******** < 800**** ** > 800 m

**Intermediate Circulation Labrador & Irminger Seas**
- Lavender, Davis, & Owens,   Nature 407(6800), 2000

**V < .05 m/s displacements over 30 days**
- V > .05 m/s displacements over 8 days

**750 m streamfunction**

## Intermediate Circulation subpolar North Atlantic

**LSW layer**

**Intermediate Circulation subpolar North Atlantic**
- Bower, Le Cann, Rossby, Zenk, Gould, Speer, Richardson, Prater & Zhang, Nature 419(6907), 2002

- Upper level
********** ****= 27.5**

- LSW layer

## Intermediate Circulation Equatorial Atlantic

**Molinari, Garzolli & Schmidt, GRL 26(3), 1999**
**Stramma & Schott,        DSR II 46, 2000**

## Intermediate Circulation Subtropical South Atlantic

**(750 m.)**
**Schmid, Siedler & Zenk, JMR 30(12), 2000**

- Float Trajectories
- Black - RAFOS
- Gray - ALACE

- Potential Vorticity

- AAIW Circulation

## Western Boundary Transports at 42 N

**Hendry, Clarke & Yashayaev**

## Western Boundary Transports at 26.5 N

**Fillenbaum, Lee, Johns & Zantopp, JPO 27(1), 1997**

- Volume Transport

- Heat Transport

## Deep Western Boundary Current in the Equatorial Atlantic

**Fischer & Schott,           JGR 102(C13), 1997**

## Deep Western Boundary Current at 18oS

**Deep Western Boundary Current at 18oS**
**18 month record mean currents**
**Weatherly, Kim & Kontar JPO 30(5) 2000**

**AAIW**

**uNADW**

**LNADW**

**AABW**

## AABW Transport at 30oS

**Hogg, Seidler & Zenk,           JPO 29(2), 1999**
**Zenk, Seidler, Lenz & Hogg JPO 29(11), 1999**

- Hunter Channel

## Brazil Malvinas Current Confluence at 38oS

**Maamaatuaiahutapu, Garçon, Provost & Mercier, JMR 56(2), 1998**

**Rel. 1500 m**

**Rel. 3000 m**

- 41

- 12.6

-  3

- 1.2

- 56

- 44

- 30

- 23

- 6.8

- 2.2

- 1.8

- 35

- 7.6

- 2.1

- 0.4

- 30

- 20

- 46

- 29

-  3.4

-  3.4

-  3

- 19.8

-   3.8

-   1.4

- 1.7

- 37

- 6

- 1.5

- 1.4

## Volume Transport of the Malvinas Current at 41oS

**Vivier & Provost, **
**JGR 104(C9), 1999**

**Mean Velocity**

****** ****T/P **
**- mooring**

- Transports

- T/P
- Moorings
- CTDs

## Circulation of the South Atlantic

**Stramma & England,           JGR 104, 1999**

- 100 m.

- SACW

- AAIW

- NADW solid
- AABW dash

## Changes in the Water Masses of the North Atlantic

**Yashayaev, Clarke & Lazier**

- Salinity above
- Theta to the left
- dashed contours are potential density

## Changes in the Labrador Sea Water

**Yashayaev**

## Changes in the Water Masses of the North Atlantic

**Changes in the Water Masses of the North Atlantic**
**Yashayaev**

## Changes in the Water Masses of the Atlantic

**Joyce**
**Zenk & Hogg, 1996**

- Temperature Anomaly 500 to 2500 dbars Bermuda Station S

- 1920                   1960             1990

- 0.0

- 0.2

- -0.2

## WOCE has provided

**WOCE has provided**
** ****new data and data tools**
** ****New models**
** ****New insights**
** ****New instruments**

## Future Atlantic Work

**Need strategy to improve estimates of air-sea fluxes; particularly fresh water**
**Integration with the Nordic Seas and Arctic**
**Continuation of repeat sections associated with MOC (augment in the South Atlantic)**
**Resurvey for tracers on 5-10 year time scale**
**Integration with carbon and biological observations and modelling.**

## Slide 46