# Presentation: 694655

##                                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

## A New Deep Water Mass in Drake Passage

**Ventilation of the Pacific**
**Tracer ages: what do they tell us?**
**Conclusion / Outlook**

**Formation**** ****of Deep and Bottom Water**

## AABW is formed :

- western Weddell Sea,
- western and eastern Ross Sea,
- Adelie Coast,
- Amery Ice Shelf

##  CFC-11  along 0°E, 

**1984 - 1998**
**2 deep CFC cores**
**in AABW**

- Klatt,Roether,Hoppema,Bulsie
- wicz,Fleischmann,Rodehacke,
- Fahrbach,Weiss,Bullister,
- JGR, 107, 2002

## 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

## AABW - Formation Rate from CFC Inventory

- Orsi, Johnson,Bullister, 1999, Prog.Oceanogr.43 55-109

**CFC-inventory **
**[million moles]**
**Atlantic    : 6.2 (1987)**
**Ind.+Pac. : 4.8 (1993)**

## 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

## AABW Formation and CFCs in Ocean Climate Model

- 106  moles	   obs.    contr.
- ---------------------------------------
- Atlantic  1987   **6.2     1.0****	**      Ind+Pac 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

_**AABW Formation and CFCs in Ocean Climate Model**_

**Transient tracers to assess skill of NCAR model**

## CFC inventory:

**WS: Weddell Sea**
**RS: Ross Sea**
**Ad: Adelie Coast**
**Am: Amery Ice Shelf**

**CFC inventory:**
**Atl.   1.0   **(obs. 6.2)
**I+P   0.7   **(obs.4.8)

- Doney and Hecht,2002

- CFC

- Pt,BBL-Levitus

- S,BBL-Levitus

- sig2 BBL-Levitus

-    0°      90°     180°    270°     0°

**     ****Am      Ad    RS           WS**

## CFC-inventory:

**improved AABW-**
**formation **

**CFC-inventory:**
**Atl.   3.4 ****(obs 6.2)**
**I+P   1.4 ****(obs 4.8)**** **

- Doney and Hecht,2002

**High_sal: restore S to **
**Smax on shelf **

-   0°        90°       180°      270°   0°

**     ****Am      Ad    RS           WS**

- CFC

- pT,mod-Lev.

- S,mod-Lev

## Detection of a new water mass in Drake Passage

******He-3 across **
**Drake Passage**

- Well, Roether, Stevens DSR ,subm.

**1990 **

**1999**

**He-anomaly at **
******2**** = 36.95**

- Ant                       SAm

## SPDSW

- Lupton, Pyle, Well, Jenkins,
- Schlosser, Top, 2002

**SPDSW**
- Southeast Pacific Deep
- Slope Water

- Well, Roether, Stevens,2002

## With OMP analysis:

**With OMP analysis:**
**Fraction SPDSW in %**

- SPDSW
- Drake Passage: **7Sv**
- (lADCP, CTD**)**

- ANT                                SA

- Well, Roether, Stevens

## Formation rates of NADW using CFCs

- Rhein, Fischer, Smethie, Smythe-Wright, Weiss, Mertens, Min, Fleischmann,
- Putzka,  JPO, 2002

- CFC-inventory** LSW** 1997:
- 16.6 million moles
- formation rate:**4.4-5.6 Sv**
- low NAO  : **1.8-  2.4 Sv**
- high NAO:  **8.1-10.8 Sv**

## CFC - inventories and formation rates

**               ****of NADW components**

-             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

**1991**

## CFC - inventories and formation rates

**               ****of NADW components**

- LeBel, Smethie, Andrie, Bullister,
- Jones, Min, Rhein, Roether,
- Smythe-Wright, Weiss 2002

- 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

## Modeling CFC inventories and LSW formation rates

- Böning, Rhein, Dengg, Dorow,
- GRL 2003, accepted

_**Modeling CFC inventories and LSW formation rates**_

**1/3° FLAME model**

**formation rate by **
**volume change    :  4.3Sv       **
**rate from CFC inv: 3.5-4.4Sv**

- CFC-11

- CFC observation

- model

- a)

- b)

## Ventilation of the Pacific from Tracer Ages

- Fine, Maillet, Sullivan, Wiley, JGR, 2001

**CFC-11 along 135°W,1993**

- 30°S

- 50°N

- 1400m

## CFC-inventory , 1993, full water column

**CFC-inventory , 1993, full water column**

- Bullister, Sonnerup, Fine,
- Min, Mecking, Smethie,
- Warner, Weiss, 2002

## CFC ages on isopycnals

**STUW **
**25.0**

**SSM**
**26.2**

**NPIW**
**SAMW**
**26.8**

**AAIW**
**27.2**

- Fine, Maillet, Sullivan, Wiley, JGR, 2001

- A

- B

- C

- D

## NPIW

- Bullister et al., 2002

- SAMW

## Ventilation flux [Sv] :    Volume / mean tracer age

**      ****Total        Wind driven Thermohaline circ.**
** ****	****	****       ******** ****< 26.5****	****26.5< ******** <27.3       **
**---------------------------------------------------------------**
**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

## Ventilation and Mixing of Indian Ocean Waters       

**Ventilation and Mixing of Indian Ocean Waters       **

- Fine, Smethie, Bullister, Min, Warner, Rhein, Weiss, DSR, revised, 2002

**Full water column**
**inventory in 1995:**
**100 million moles**

- Poster

## Age : time elapsed since last at the surface

**-- boundary conditions in source region**
**-- Mixing  : ages are not conservative**

## Thermocline ventilation in subtropical North Pacific

**dc/dt = -v•dc/dy +K•d2c/dy2          ****model with CFCs **

**10°N  NEC         20°N                           40°N subp.gyre**

**diffusion      advection,diffusion        diffusion**

** ****outcrop**

** ****ideal age tracer ******

**d******** /dt = -v•d********/dy +K•d2******** /dy2 +1**

- Sonnerup,Quay, Bullister, DSR I, 1999

##  <15-25years  : 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 **

## Relationship between the ideal age and the tracer age 

**C(r,t)=********C****o****(t-t‘) G(r,t‘)dt‘**

- Co(t) : conc. at surface
- G(r,t): age spectrum

- G(r,t) dt: mass fraction of fluid at r that was at the
- surface at time interval  t  --  t+dt

**1****st**** temporal moment: mean age **
**2****nd**** temp. moment: width of the age spectrum**

- Waugh, Hall, Haine, JGR, 2002, subm.

- Holzer and Hall, 2000

## Testing in a GCM

- Khatiwala, Visbeck, Schlosser, DSR I, 2001

_**Testing in a GCM**_

**mean age      tracer age   ideal age**

- a)  300m

- b) 1000m

- c) 1500m

##                                                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

- after 200 years integration:

- Khatiwala, Visbeck, Schlosser, 2001

## use temporal change

- Jenkins, JPO 30, 2000

**use temporal change**
**of  3H/3He ages to **
**estimate mixing**

**Isopycnals outcrop north Azores Current: southward **
**penetration by lateral mixing across AC at 33°N**

- a)

- b)

- c)

##  Relic CFC-11 age, Labrador Sea Water LSW

-  Relic CFC-11 age, Labrador Sea Water LSW

-         age in source region: 15 years

- estimates time scales
- of spreading for young
- component

## Future developments

**Future developments**

** ****moored tracer sampler**

## Conclusions

- --  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

**Conclusions**

## WOCE Tracer: all sections (concentrations) 

- WOCE Tracer: all sections (concentrations)
-                             isopycnal age distributions,
- North and South Atlantic:  CFCs, 3H, 3He
- www.ocean.uni-bremen.de/en/projects/aims/tab.html
- ....                                           /projects/aims/isoage.html
- ....                                          /projects/aims_satl/qual.html