Kein Folientitel

1
TRACERS
From Description to Quantification
Monika Rhein, IUP Bremen, Germany
C. Böning, J.
Bullister, J. Dengg, S. Doney, M. England, R.
Fine, T. Haines, S. Khatiwala, D. Kieke, O.
Klatt, B. Klein, D. LeBel, J. Lupton, P.Robbins,
W.Roether, B.Smethie, D. Smythe-Wright, R.
Steinfeldt, R.Well
2
Formation of Deep and Bottom Water
A New Deep Water Mass in Drake Passage Ventilatio
n of the Pacific Tracer ages what do they tell
us? Conclusion / Outlook
3
AABW is formed western Weddell Sea, western
and eastern Ross Sea, Adelie Coast, Amery Ice
Shelf
4
CFC-11 along 0E, 1984 - 1998 2 deep CFC
cores in AABW
Klatt,Roether,Hoppema,Bulsie wicz,Fleischmann,Rode
hacke, Fahrbach,Weiss,Bullister, JGR, 107, 2002
5
Estimates of AABW Production Rates WSBW from
DWBC transports 2-5 Sv WSBW from
tracer budgets 3-5 Sv AABW
from shelf water budgets 5-15 Sv AABW
from PO4 and C-14 15 Sv
Orsi, Johnson,Bullister, 1999, Prog.Oceanogr.43
55-109
6
AABW - Formation Rate from CFC Inventory
CFC-inventory million moles Atlantic 6.2
(1987) Ind.Pac. 4.8 (1993)
Orsi, Johnson,Bullister, 1999, Prog.Oceanogr.43
55-109
7
Calculation of AABW formation by Orsi et al.
all AABW formation regions treated similar --
volume of water sinking across 2500m isobath
V -- entrainment of ambient water while
sinking -- CFC- Saturation of this mix 35 (from
obs.)
CFC Inventory V? ? 0.35 C(t) dt
Loss
Atlantic 4.9 Sv 60 Indian
Pacific 3.2 Sv 40 TOTAL
8.1-9.4Sv
Orsi, Johnson, Bullister, 1999
8
AABW Formation and CFCs in Ocean Climate Model
Transient tracers to assess skill of NCAR model
CFC- Inventory. ,AABW 106 moles obs.
contr. --------------------------------------- At
lantic 1987 6.2 1.0 IndPac 1993
4.8 0.6
Sensitivity studies A) BBL Beckmann and
Döscher, 1997 B) High_sal restore S to Smax on
shelf and adjacent to it
Doney and Hecht, JPO 32, 2002
9
Am Ad RS WS
model with BBL WS Weddell Sea RS Ross Sea Ad
Adelie Coast Am Amery Ice Shelf
CFC
Pt,BBL-Levitus
CFC inventory Atl. 1.0 (obs. 6.2) IP 0.7
(obs.4.8)
S,BBL-Levitus
sig2 BBL-Levitus
0 90 180 270 0
Doney and Hecht,2002
10
High_sal restore S to Smax on shelf
Am Ad RS WS
improved AABW- formation
CFC
CFC-inventory Atl. 3.4 (obs 6.2) IP 1.4
(obs 4.8)
pT,mod-Lev.
S,mod-Lev
Doney and Hecht,2002
0 90 180 270 0
11
Detection of a new water mass in Drake Passage
1990
?He-3 across Drake Passage
He-anomaly at ?2 36.95
Ant SAm
1999
Well, Roether, Stevens DSR ,subm.
12
SPDSW Southeast Pacific Deep Slope Water
Well, Roether, Stevens,2002
Lupton, Pyle, Well, Jenkins, Schlosser, Top, 2002
13
With OMP analysis Fraction SPDSW in
SPDSW Drake Passage 7Sv (lADCP, CTD)
ANT SA
Well, Roether, Stevens
14
Formation rates of NADW using CFCs
CFC-inventory LSW 1997 16.6 million
moles formation rate4.4-5.6 Sv low NAO 1.8-
2.4 Sv high NAO 8.1-10.8 Sv
Rhein, Fischer, Smethie, Smythe-Wright, Weiss,
Mertens, Min, Fleischmann, Putzka, JPO, 2002
15
CFC - inventories and formation rates
of NADW components
1991
1991-inventory formation rate
million mole Sv uLSW
4.2 2.2 cLSW 14.7
7.4 ISOW 5.0 5.2 DSOW 5.9 2.4
-------------------------------------------------
---- total 29.8 17.2 Sv
Smethie and Fine, DSRI, 2001
16
CFC - inventories and formation rates
of NADW components
1997 cLSW layer CFC-11 inventory
1997 inventory form.rate million mole
Sv uLSW 7.4 2.6 cLSW 20.5
7.9 ISOW 10.0 7.7 DSOW 8.7 2.4
--------------------------------- total
46.6 20.6
LeBel, Smethie, Andrie, Bullister, Jones, Min,
Rhein, Roether, Smythe-Wright, Weiss 2002
17
Modeling CFC inventories and LSW formation rates
CFC observation
1/3 FLAME model
formation rate by volume change 4.3Sv
rate from CFC inv 3.5-4.4Sv
a)
CFC-11
model
Böning, Rhein, Dengg, Dorow, GRL 2003, accepted
b)
18
Ventilation of the Pacific from Tracer Ages
CFC-11 along 135W,1993
1400m
50N
30S
Fine, Maillet, Sullivan, Wiley, JGR, 2001
19
CFC-inventory , 1993, full water column
Bullister, Sonnerup, Fine, Min, Mecking,
Smethie, Warner, Weiss, 2002
20
CFC ages on isopycnals
SSM 26.2
STUW 25.0
B
A
NPIW SAMW 26.8
AAIW 27.2
C
D
Fine, Maillet, Sullivan, Wiley, JGR, 2001
21
NPIW
SAMW
Bullister et al., 2002
22
Ventilation flux Sv Volume / mean tracer
age
Total Wind driven Thermohaline
circ. ? lt 26.5 26.5lt ? lt27.3
-------------------------------------------------
-------------- NP 111 Sv 50
50 SP 123 Sv 35
65
NP
SP subtrop. gyre 41 Sv 25 Sv agree
Sverdrup theory subpolar gyre 9 Sv 17
Sv
Fine, Maillet, Sullivan, Wiley, JGR, 2001
23
Ventilation and Mixing of Indian Ocean Waters

Full water column inventory in 1995 100 million
moles
Fine, Smethie, Bullister, Min, Warner, Rhein,
Weiss, DSR, revised, 2002
Poster
24
Age time elapsed since last at the surface --
boundary conditions in source region -- Mixing
ages are not conservative
25
Thermocline ventilation in subtropical North
Pacific
dc/dt -vdc/dy Kd²c/dy² model with
CFCs
ideal age tracer ?
d? /dt -vd?/dy Kd²? /dy² 1
10N NEC 20N
40N subp.gyre
outcrop

diffusion advection,diffusion
diffusion
Sonnerup,Quay, Bullister, DSR I, 1999
26
? lt15-25years agree with CFC ages within
25 older ? tracer ages considerably
younger CFC-11 ages younger than
CFC-12 difference increase with age CFC-11, 12
ages older than ratio ages
Sonnerup, 2001, GRL 28, 1739-1742
27
Relationship between the ideal age and the tracer
age
Co(t) conc. at surface G(r,t) age spectrum
C(r,t)?Co(t-t) G(r,t)dt
Holzer and Hall, 2000
G(r,t) dt mass fraction of fluid at r that was
at the surface at time interval t -- tdt
1st temporal moment mean age 2nd temp. moment
width of the age spectrum
Waugh, Hall, Haine, JGR, 2002, subm.
28
Testing in a GCM

mean age tracer age ideal age
a) 300m
b) 1000m
c) 1500m
Khatiwala, Visbeck, Schlosser, DSR I, 2001
29
after 200 years integration

mean ³H-³He ideal Labrador Sea
(1500m) 3.3 3.9 4.0
Subtrop. subduction (500m) 15.8
12.8 21.7 Western Boundary (1500m)
38.4 35.8 56.7
-- tracer ages younger than ideal ages -- mean
age sensitive to long transit time pathways
although they make up only a small fraction
Khatiwala, Visbeck, Schlosser, 2001
30
use temporal change of ³H/³He ages to estimate
mixing
a)
b)
Robbins,Price,Owens, Jenkins, JPO 30, 2000
c)
Isopycnals outcrop north Azores Current
southward penetration by lateral mixing across
AC at 33N
31
Relic CFC-11 age, Labrador Sea Water LSW
estimates time scales of spreading for
young component
age in source region 15 years
Fine, Rhein, Andrie, GRL,2002, subm.
32
Future developments
moored tracer sampler
33
Conclusions
-- CFC inventories AABW and NADW formation
rates -- ³He signal new water mass in Drake
Passage -- CFC ages Ventilation rates of upper
and intermediate Pacific -- ³H/³He age role of
lateral mixing -- tracers to assess model
skills -- tracer age - ideal age , age spectrum
34
WOCE Tracer all sections (concentrations)
isopycnal age
distributions, North and South Atlantic CFCs,
³H, ³He www.ocean.uni-bremen.de/en/projects/aims/t
ab.html ....
/projects/aims/isoage.html ....
/projects/aims_satl/qu
al.html