Embed Size (px)
DESCRIPTION
Antarctic Intermediate Water (AAIW) Stramma & England 1999
Citation preview
South Atlantic deep water circulation
Stramma & England 1999
South Atlantic Central Water (SACW)
Stramma & England 1999
Antarctic Intermediate Water (AAIW)
Stramma & England 1999
The compensating meridional flows
Stramma & England 1999
The light blue shading indicates the high eddy kinetic energy regions in the Brazil/Malvinas Confluence and the Agulhas Retroflection. Light orange shading indicate the regions of convection and subduction. Light green shading areas of upwelling associated to the shallow tropical cells. Red lines depict areas of interest for monitoring the inter-ocean exchanges and the bifurcation of the South Equatorial Current. Purple line near 30°S region for monitoring the meridional mass and heat flux
South Atlantic observations
PIRATA backbone + extensions
GOOD HOPE + BONUS
AX18
AX98ATLAS buoy
GEF
IfM – SIO (Russia)
ifM - INPE
-60 -40 -20 0 20 40 60Latitude
- 2
- 1 . 8
- 1 . 6
- 1 . 4
- 1 . 2
- 1
- 0 . 8
- 0 . 6
- 0 . 4
- 0 . 2
0
0 . 2
0 . 4
0 . 6
0 . 8
1
1 . 2
Mer
idio
nal H
eat F
lux
(1015
W/m
2 )
TalleyM cD onaghH astenrathH siungO berhuberD a S ilvaEsbesen & KushnirC ayanSO CO R C A25EC C OG arzoli+Barringer
HallR in toulG anachaud & W unschDonnersSchlitzerdelasH erasAdelasH erasBdelasH erasC
Estimates of South Atlantic Meridional Heat Flux
Lat °S Heat Flux (PW) Method Source32 0.16-0.68 Direct Bennett (1978)
30 0.39 Sea-air fluxes Bunker (1980)
32 0.66-0.88 Inverse Fu (1981)
30 0.69 Sea-air fluxes Hastenrath (1982)
32 0.4 Direct Bryan (1982)
30 0.38 Sea-air fluxes Hsiung (1985)
32 0.24 Inverse Rintoul (1991)
30 0.19 model Matano & Philander (1993)
30 0.56 FRAM Saunders &Thompson (1993)
37 0.45 to 0.94 Direct Saunders and King, 1995
37 0.67 FRAM Saunders and King, 1995
30 0.3 Inverse Macdonald & Wunsch (1996)
30 0.29 model Marchesiello et al. (1998)
30 -0.23 Inverse de las Heras & Schlitzer (1999)
30 0.22 Inverse McDonogh and King (2003)
32.5 0.23 Direct Talley (2003)
32.5 0.63 OCCAM Donners (2004)
37 0.28 POCM Matano & Schouten (2004)
30 0.39 ECCO Stammer, Kohl (2007)
30 0.17 ORCA25 Boening, Biastoch (2007)
30-35 0.54 XBT Garzoli and Barringer (2007)
Estimates of South Atlantic Meridional Heat Flux
Median pathways between successive oceanic sections crossed by water parcels. The colors indicate the mean depth of the transfer between two given sections. The North Atlantic overturning is defined here as the thermocline waters (in orange, red and pink) transformed into NADW (blue) in the North Atlantic sector. Numbers quantify the mass transfers between successive control sections (the Atlantic Equator, the Drake Passage, the SO section south of Australia and the Indonesian Throughflow).
Speich et al. 2007, submitted
Lagrangian reconstruction of the global Thermohaline Circulation
Lat °S Heat Flux (PW) Method Source32 0.16-0.68 Direct Bennett (1978)
30 0.39 Sea-air fluxes Bunker (1980)
32 0.66-0.88 Inverse Fu (1981)
30 0.69 Sea-air fluxes Hastenrath (1982)
32 0.4 Direct Bryan (1982)
30 0.38 Sea-air fluxes Hsiung (1985)
32 0.24 Inverse Rintoul (1991)
30 0.19 model Matano & Philander (1993)
30 0.56 FRAM Saunders &Thompson (1993)
37 0.45 to 0.94 Direct Saunders and King, 1995
37 0.67 FRAM Saunders and King, 1995
30 0.3 Inverse Macdonald & Wunsch (1996)
30 0.29 model Marchesiello et al. (1998)
30 -0.23 Inverse de las Heras & Schlitzer (1999)
30 0.22 Inverse McDonogh and King (2003)
32.5 0.23 Direct Talley (2003)
32.5 0.63 OCCAM Donners (2004)
37 0.28 POCM Matano & Schouten (2004)
30 0.39 ECCO Stammer, Kohl (2007)
30 0.17 ORCA25 Boening, Biastoch (2007)
30-35 0.54 XBT Garzoli and Barringer (2007)
Estimates of South Atlantic Meridional Heat Flux
High-resolution XBT line AX18 (14 sections)
Courtesy Garzoli & Baringer 2007, submitted
Meridional heat flux – meridional structureIntegrated from 80ºN
Courtesy Garzoli & Baringer 2007, submitted
1990 1995 2000 2005
-0 .4
0
0.4
0.8
1.235
ºS M
erid
iona
l Hea
t Flu
x (P
W)
ORCA 30ºS
1990 1995 2000 2005
-0 .4
0
0.4
0.8
1.235
ºS M
erid
iona
l Hea
t Flu
x (P
W)
ECCO 35ºS
ORCA 30ºS
1990 1995 2000 2005
-0 .4
0
0.4
0.8
1.235
ºS M
erid
iona
l Hea
t Flu
x (P
W)
ECCO 35ºS
ORCA 30ºS
AX18 35ºS
Meridional heat flux – model comparisons
Structure of meridional flow(some) error sources
Courtesy from Baher, Stroup & Marotzke, in prep.
“observed” thermal wind
ECHAM5/MPI-OM forced with IPCC scenario A1B
MOC Transport variability
MOC
RECONSTRUCTION
• • MOC monitoring based on a RAPID/MOCHA like array MOC monitoring based on a RAPID/MOCHA like array can cover the main characteristics of the MOC, can cover the main characteristics of the MOC, including a possible change in the mean strength, at including a possible change in the mean strength, at various latitudes throughout the South Atlantic.various latitudes throughout the South Atlantic.
• • MOC monitoring in the South Atlantic faces similar MOC monitoring in the South Atlantic faces similar problems as MOC monitoring in the North Atlantic.problems as MOC monitoring in the North Atlantic.
• • Direct observations of boundary currents seem of Direct observations of boundary currents seem of secondary importance, while basin-wide coverage of the secondary importance, while basin-wide coverage of the bottom velocities is crucial if bottom velocities are not bottom velocities is crucial if bottom velocities are not small everywhere.small everywhere.
