# Presentation: 948960

## June 2004  North Pacific Carbon Cycle Workshop

***June 2004  North Pacific Carbon Cycle Workshop***

##  CO2 Emissions and Atmospheric Growth Rate

- From Hibbard et al. (2001)

_**General Trends**_

- Slowdown in CO**2** Growth Rate Before an El Ni**ñ**o Event
- Enhancement of CO**2** Growth Rate Once an El Ni**ñ**o is Underway.

_**Question**_**: What is the magnitude of the CO****2**** flux from the Pacific Ocean**

**Notes:**
East-west distribution of anthropogenic CO2  and CFC-12 along 30°W in the North Pacific.  The gradient is a function of mixing along isopycnal surfaces, with the deepest penetration under the Kuroshio Extention.  

## “In the mid-1970s, the Pacific changed from a cool “anchovy regime” to a warm “sardine regime.” A shift back to an anchovy regime occurred in the middle to late 1990s.....with CO2 accumulating in the atmosphere more slowly in the atmosphere during the anchovy regime than during the sardine regime.”  

***Chavez et al., Science 2003***

**“****In the mid-1970s, the Pacific changed from a cool “anchovy regime” to a warm “sardine regime.” A shift back to an anchovy regime occurred in the middle to late 1990s.....with CO****2**** accumulating in the atmosphere more slowly in the atmosphere during the anchovy regime than during the sardine regime.”  **

##           Model Estimates of Interannual Variability of CO2 Fluxes in the Oceans

-   Obata et al.
-   JGR,  2003

-  **70% of the Interannual Variability**
**Occurs in the Equatorial Pacific**

**20% of the Interannual Variability**
**Occurs in the Southern Ocean **

- The Eastern Subarctic and Subtropical North Pacific
- and the Central North Pacific cancel each other

## Global Ocean and Land CO2 Fluxes

- Question: Are El Niño events getting stronger
-                  and more frequent?

- Le Quere et al.,
-  Tellus (2003)

**Notes:**
East-west distribution of anthropogenic CO2  and CFC-12 along 30°W in the North Pacific.  The gradient is a function of mixing along isopycnal surfaces, with the deepest penetration under the Kuroshio Extention.  

## Measurements

**        ****pCO****2**** Measurements in Surface Waters**

_**Measurements**_

-        Surface Underway         Surface Moorings

- 3 standards/hr
- 3 Air samples/hr
- 20 Seawater samples/hr

- 8 Air samples/day
- 8 Seawater samples/day

**Notes:**
From 1991 thru 1998 the first comprehensive study of CO2 species in the all of the Ocean basins was conducted as part of the WOCE/JGOFS/OACES Global CO2 Survey.  At least 2 of the 4 CO2 species and related tracers were measured on approximately 100,000 samples with a precision of about +- 3 umolkg-1 for DIC.

##            Large-Scale 

**           ****Large-Scale **
**    ****EqPac Results: **
**         ****1997-2003**
**     **El Ni**ñ**o **: 0.2-0.4 Pg C yr****-1**
**Non **El Ni**ñ**o **: 0.7-0.9 Pg C yr****-1**
**       ****La Ni****ñ****a: 0.8-1.0 Pg C yr****-1**
**     ****Average: 0.6 ± 0.2 Pg C yr****-1**

**from Feely et al. JGR (in press)**

## pCO2 versus Temperature in the Equatorial Pacific

**93 Data Sets Collected Between March 1992 and July 2001**

**Cosca et al., (2003)**

**Notes:**
From 1991 thru 1998 the first comprehensive study of CO2 species in the all of the Ocean basins was conducted as part of the WOCE/JGOFS/OACES Global CO2 Survey.  At least 2 of the 4 CO2 species and related tracers were measured on approximately 100,000 samples with a precision of about +- 3 umolkg-1 for DIC.

##                      Large-Scale Observational Results: 

**            ****1992-2003**
**El Niño: 0.2-0.4 Pg C year****-1**
**Non El Niño: 0.7-0.9 Pg C year****-1**
**La Niña: 0.8-1.0 Pg C year****-1**
**Average: 0.6 ± 0.2 Pg C year****-1**

**from Feely et al. JGR (in press)**

***June 2004  North Pacific Carbon Cycle Workshop***

## pCO2 in the Equatorial Pacific Warm Pool

**pCO****2**** in the Equatorial Pacific Warm Pool**

**Le Borgne et al. (2002)**

**Notes:**
From 1991 thru 1998 the first comprehensive study of CO2 species in the all of the Ocean basins was conducted as part of the WOCE/JGOFS/OACES Global CO2 Survey.  At least 2 of the 4 CO2 species and related tracers were measured on approximately 100,000 samples with a precision of about +- 3 umolkg-1 for DIC.

##         Natural Domain Shifts in the North Pacific Ocean

**        ****Natural Domain Shifts in the North Pacific Ocean**

**Pacific Decadal Oscillation (PDO)**
**~0.5 °C amplitude**
**El Nino/Southern Oscillation (ENSO)**
**~1-4 °C amplitude**
**Mantua, et al., *****Bull. Am. Meteorol. Soc*****., June, 1997**

***Feb 2004  Chemical Oceanography Seminar***

**Notes:**
However, we now know that there are significant domain shifts resulting from natural climatic changes such as the PDO,  ENSO, AO and NAO which can have profound impacts on carbon system dynamics.

## Feb 2004  Chemical Oceanography Seminar

- Nathan J.Mantua,

***Feb 2004  Chemical Oceanography Seminar***

## Decadal Changes in the CO2 Source from the equatorial Pacific Ocean after Takahashi et al (Science, 2003) 

**Sea Surface Temperature in °C**
**                 **
**B) pCO****2**** in μatm corrected to 28°C**

**Equatorial Pacific **
**Nino 3.4 Region**
**5°S - 5°N, **
**170°W -120°W**
- When these rates are
- corrected for the
- atmospheric increase =
- _1979-1990_
- -2.1 ± 1.4 μatm yr-1
- _1990 - 2001_
- 1.3 ± 0.9 μatm yr-1

- This suggests there has been a 7%
- increase in the CO2 flux over the last decade

***Feb 2004  Chemical Oceanography Seminar***

**Notes:**
Decadal changes in the rate of change of temperature and temperature-corrected pCO2 in the central and eastern Equatorial Pacific.  Note the inflection at the 1989 regime shift.

## CO2 transfer velocity & exchange coefficient (K=k S):

- 1985

- 2002

**Geosat**
- altimeter

**SSMI**
- Microwave
- radiometer

**ERS1 and ERS2**
- scatterometer

**QSCAT**
- scatterometer

*(Boutin et al., pers. Comm., 2003)*

- K over Global ocean (k-U Wanninkhof(1992) relationship)

**CO****2**** transfer velocity & exchange coefficient (K=k S):**
**Monitoring using  satellite wind speed **(Geosat, SSM/I, ERS, QSCAT...) 1985-2002

## McPhaden and Zhang (submitted to Science)

## McPhaden and Zhang (submitted to Science)

- “Interior ocean pycnocline transports approximately doubled in Northern Hemisphere and intensified to levels not seen since before the 1976-77 regime shift in the Southern Hemisphere. Pycnocline transport convergence increased by approximately 10 Sv from 1992-1998 to 1998-2003 reaching its highest value since the mid-1970s”
-        -Mike McPhaden and
-          Dongxiao Zhang

## Wind speeds, pCO2 and CO2 fluxes in the  Equatorial Pacific

**Feely et al. (in prep)**

- _Wind speeds:_
- Slight increases after 1994
- 5.3 vs. 4.6 m s-1 - east
- 3.7 vs. 3.1 m s-1 - west
- _fCO_2: slightly higher after
-           1994 in the eastern Pacific
-            408 vs. 384 ± 20 μatm
- _CO__2__ flux_: higher after 1994
-   in the eastern Pacific
- 1.53 vs. 1.16 ± .5 moles m-2 yr-1

**Notes:**
From 1991 thru 1998 the first comprehensive study of CO2 species in the all of the Ocean basins was conducted as part of the WOCE/JGOFS/OACES Global CO2 Survey.  At least 2 of the 4 CO2 species and related tracers were measured on approximately 100,000 samples with a precision of about +- 3 umolkg-1 for DIC.

##                                Conclusions

**Climatic variability such as ENSO and PDO significantly **
**	**** ****impacts the Equatorial Pacific CO****2**** flux at the air-sea interface.**
**Physical processes are the primary control of fCO****2**** values at the**
**       ****surface in the eastern Equatorial Pacific; biology is also **
**       ****important.**
** **
**We have observed recent increases in the air-sea exchange flux **
**      ****of CO****2**** since 1998, consistent with the rebound of the meridional **
**       ****overturning circulation reported by McPhaden and Zhang.**

***Feb 2004  Chemical Oceanography Seminar***

##    Thank You

-    Thank You

**Notes:**
As Lisa mentioned earlier The major goal of the NOAA Carbon Cycle program is to:

Improve our ability to predict the fate of anthropogenic CO2 and future atmospheric CO2 concentrations, using a combination of global observations, process-oriented field studies, and modeling

## Detecting changes in anthropogenic CO2 in the ocean on decadal time scales

**Detecting changes in anthropogenic CO****2**** in the ocean on decadal time scales**

**C****T**** = *****a***** + *****b***** t + *****c***** S + *****d***** AOU + *****e***** Si + *****f***** P**

***Nov.  2003  North Pacific Synthesis Group****** ***

## North Pacific Carbon Cruises (1973 - 2003)

## N. Pacific DIC Residual Comparison

**N. Pacific DIC Residual Comparison**
**Bottom of MLD to 1250db**

- 

-           **MLR approach:   DIC = a******** + bS + cAOU + dSi(OH)****4**** + ePO****4**

- Feely et al. (in prep)

## DIC increase in the mixed layer of the North Pacific Ocean

**CO****2**** in the mixed layer**
**1.3 ± 0.19 μmol kg****-1**** yr ****-1**** **
**r****2****=0.95**
**n=7**

**Mean ∆DIC (μmol kg****-1****)**

**Feely et al. (in prep)**

**DIC increase in the mixed layer of the North Pacific Ocean**

## CO2 Uptake Rates in the North Pacific

**CO****2**** Uptake Rates in the North Pacific**

**Correlation with CFC tracers**
**Temporal Changes in DIC**