tropical -
DESCRIPTION
With Thanks To: Tony Busalacchi Roger Lukas Rui Xin Huang Jay McCreary Greg Johnson Mike McPhaden Mojib Latif Mosami Nonaka Zengyu Liu Paola Rizzoli. TROPICAL -. - PowerPoint PPT PresentationTRANSCRIPT
TROPICAL - - EXTRATROPICAL
CONNECTIONS
INCLUDING
MARK A. CANELAMONT-DOHERTY EARTH OBSERVATORY OF COLUMBIA UNIVERSITYPALISADES, NY 10964+ PAUL GOODMAN AND WILCO HAZELEGER
ENSO
With Thanks To:
Tony Busalacchi Roger LukasRui Xin Huang Jay McCrearyGreg Johnson Mike McPhadenMojib Latif Mosami NonakaZengyu Liu Paola Rizzoli
Which way and where from? From the Tropics to the Globe To the Equatorial Ocean from the Extratropics
SubtropicsTropics
What can change equatorial SST? How?
Waves [Adjustment] or Advection: v T, vT
On what time scales? Centennial, Millennial and beyond
Interannual (ENSO)Decadal: Pacific (PDO)
Atlantic (NAO)
Polewardshift
Equatorwardshift
Courtesy of Clara Deser
r = .60;r = .76 with a 5-year lowpass (sig.= 99%)
Advection of anomalous Temperature
v T
Gu and Philander Science 1997
Latif and Barnett Science 1994
Deser et al J. Climate 1996
Zhang et al Science 1998
Hazeleger et al JGR 2001
Decadal anomalies of the depth of the 0 = 25.5 isopycnal zonally averaged in the shaded region
From Schneider et al, GRL 1999
From a coupled model
Hazeleger et al., JPO,2001
Change in overturning stream function with added cooling due to storms
Anomalous Advection of mean Temperature
McCreary and Lu JPO 1994
Liu; Liu, Philander and Pacanowski JPO 1994
FIne, Peterson and Ostlund JPO 1987
Johnson and McPhaden JPO 1999
McPhaden and Zhang Nature 2002
the Subtropical Cell
v'T
Meridional Stream FunctionOCCAM model
Eulerian Lagrangian L-E
Hazeleger et al., GRL, 2001
z
McPhaden and ZhangNature, 2002
Potential Vorticity
Zhang et al., JPO submitted.
(See Rizzoli et al., DOA 2000 for a model version)
Interior communication window identified from the virtual streamfunction (in Sv)
Huang and Wang, JPO, 2001
Johnson and McPhaden, JPO, 1999
8°S
8°N
Mass FluxAccumulated
down
Goodman et al, 2002 To appear
Goodman et al., 2002
Volume Ventilated (103 m3/s)
Goodman et al., 2002 to appear
Time Between Subduction and the EUC (years)
10N
Eq
5S
13S6.3
3.8
1.88.3
3.5 0.6
2.0
McPhaden and Zhang Nature, 2002
McPhaden and Zhang, Nature, 2002
Heat Transports in a model Indo-Pacific Ocean
Hezeleger et al JPO submitted
AdjustmentWave Processes
Rossby JMR 1937
Cane and Sarachik JMR 1977, 1981;JPO 1983
Johnson and Marshall JPO, JGR 2002
Temperature along the equator
Halpern, 1980
H
So, a wind anomaly scale of ~ 10° increases the temperature of upwelled water by ~ 1°K.
With w ~ 1m/day, Q ~ 50W/m2
A change in the STC of 0.1 PW (estimated from the same 0.02 N/m2 spread from 10°S to 10°N over 1/3 of the width of the Pacific is ~10W/m2
Decadal anomalies of the depth of the 0 = 25.5 isopycnal zonally averaged in the shaded region
From Schneider et al, GRL 1999
From a coupled model
PC timeseries Decadal PatternForcingregion
12°N/S
10°N/S
7°N/S
5°N/S
Karspeck and Cane, JPO 2002
McPhaden and Zhang Nature, 2002
DiscussionThe longer the period the more poleward the reach.
Why is there decadal variability?
Is there anything special about decadal?
Decadal Variability is
most likely generated in the tropics
the southern hemispere is the next place to go
adjustment is more important than advection
It would be nice to quantify decadal variations in heat budgets.
And even nicer to have a usable theory
for what sets and what can change
ocean stratification.
But even these won’t tell us the
sources of decadal variability:
It is a coupled system*
ocean atmosphere
*at least in the tropics