CLIVAR Pacific panelCLIVAR Pacific panel

Main IssuesMain Issues

• ENSO (and related aspects)• Observational requirements• Metrics (societal and scientific)• SPCZ• Eastern Pacific biases (VOCALS)• Interbasin connections• SPICE• Interaction with other panels

ENSOENSO

• Understanding and predicting ENSO:– Background state => MJO ENSO– Background state => annual cycle ENSO– Background state ENSO– ENSO and stochastic forcing – ENSO and greenhouse warming– Decadal timescales in ENSO– ENSO metrics (diagnostics and observations)

ENSO sensitivity to climate change:Observational requirements

ENSO sensitivity to climate change:Observational requirements

• Monitoring of SST, thermocline depth, boundary and interior transports

• Monitoring of Walker circulation (see Vecchi and Soden, Nature 2006)

• Monitoring of ENSO-MJO relationship • Monitoring of subsurface anomalies (ARGO,

TAO, altimeter)• Monitoring of heat flux convergences via drifter

data, ARGO data

ENSO-WWB interactions, ENSO-WWB interactions,

• WWB activity modulates and is modulated by ENSO (Eisenman, Jin, Lengaigne)

• WWB is modulated by the annual cycle (Hendon and Zhang)

• Nature and Dynamics of these interactions still unclear

• Evidence for intensification of WWB and WWB-ENSO interactions (Jin et al. 2007)

• What background conditions make this interaction favorable?

•East-ward propagating coupled instabilities

Eisenman et al. 2005

WWB modulation by temperature

ENSO-WWB interactions, ENSO-WWB interactions,

ENSO-WWB interactions: observational requirements

ENSO-WWB interactions: observational requirements

• Monitoring of zonal temperature advection• Monitoring of MJO and warm pool heat budget• “Precise” knowledge of WWB initial conditions• Monitoring of MJO-warm pool front propagation

(satellites) and subsurface response (TAO, altimetry)

Understanding the South Pacific Convergence Zone

Understanding the South Pacific Convergence Zone

• Why is there a SPCZ?• How is it connected to the ITCZ?• How does the SPCZ interact with the MJO?• How does the SPCZ interact with the SST• How does the SPCZ respond to tropical and

extratropical SST forcing on interannual to decadal timescales?

• What influence does the SPCZ wind convergence and its modulation have on southwest Pacific boundary currents?

Understanding the SPCZUnderstanding the SPCZ

• Clouds and temperatures in observations (left) and NCAR CCSM3 model

Understanding the SPCZ: observational requirements

Understanding the SPCZ: observational requirements

• Series of detailed process studies needed (a la TOGA-COARE) focusing on cloud formation, boundary layer dynamics, atmosphere-ocean interactions

• Relationship between SST, SPCZ, Rain and Salinity using satellite data (Aquarius,SMOS)

• Response of ocean to variations in SPCZ (ARGO, drifter data)

• SPCZ and subduction and mode-water formation (ARGO, Repeat hydrography)

Improving model biases in the eastern tropical Pacific, cold bias and warm bias, SPCZ bias

Improving model biases in the eastern tropical Pacific, cold bias and warm bias, SPCZ bias

• Possible origin of cold bias in coupled models (missing ocean biology, under-representation of TIWs, mixing, missing diurnal cycle of insolation, under-representation of Galapagos effect, uncertainties in convective parameterizations)

• Possible origin of warm bias in stratus regions (problems with cloud parameterizations and cloud-aerosol interactions, missing Tsuchiya jets, lack of horizontal resolution, under-representation of eddies in AR4 CGCMs)

Improving model biases in the eastern tropical Pacific, cold bias and warm bias

Improving model biases in the eastern tropical Pacific, cold bias and warm bias

• Clouds and temperatures in observations (left) and NCAR CCSM3 model

Improving model biases in the eastern tropical Pacific, cold bias and warm and SPCZ bias:

observations needed

Improving model biases in the eastern tropical Pacific, cold bias and warm and SPCZ bias:

observations needed

• Vertical chlorophyll profiles => bio-optical feedbacks

• Better estimates of eddy-induced heat transports in the southeastern Pacific (VOCALS)

• Better observations of Tsuchiya Jets and their variability

• Observational estimates of TIW heat budgets

• Focused process study on SPCZ needed!

Southwest PacIfic Ocean Circulation and Climate Experiment

Goal: Observe, Model, and understand the role of the SW Pac Ocean in the:

-Large scale decadal climate modulation-ENSO

-Tasman Sea area

-Generation of local climate signatures

A. Ganachaud, W. Kessler, S. Wijffels, K. Ridgway, W. Cai, N. Holbrook, M. Bowen, P. Sutton, B. Qiu, A. Timmermann, D.

Roemmich, J. Sprintall, S. Cravatte, L. Gourdeau, T. Aung

Thermocline water currents

SPICE Field ExperimentOverview

CTD sectionSPICE cruiseXBT sectionMooring arrayGlider sectionMooring line

A-Existing large scale

programs

B-Pilot studies

C-Sustained observations

Outset for a large scale field experiment

2-EAC variabilitymonitoring

1-Monitoring inflow and bifurcation

3-North Coral SeaPilot study

SPICEwww.ird.nc/UR65/SPICE

•Implementation plan in progress

Based on existing infrastructures and

research groups

Need for a process study in the SPCZ

Workshop on Western Tropical Pacific: Hatchery for ENSO and Global Teleconnections

Guangzhou CHINA, 26-28 November 2007 • To address key science questions, such as:

- does the South China Sea play an important role in the climate system or is it merely responding to Pacific/Indian forcing?

- How important is the South China Sea Throughflow in draining heat out of the Pacific? - What triggered the 2006/07 El Nino event? - What were the global impacts of the 2006/2007 El Nino? - How good was the forecast skill of the 2006/2007 El Nino? - How does the longterm Indian ocean warming affect the global climate system (including ENSO)? - What is the origin of the longterm Indian ocean warming? -How does the warm pool respond to anthropogenic climate change (atmospheric versus oceanic

feedbacks)?

• Further engage the Chinese oceanographic and climate research community in CLIVAR

• Link the Chinese observational activities to other international field programs (such as SPICE, NPOCE and PACSWIN)

• Seek international coordination in terms of field experiment timing and infrastructure (sharing ships, common XBT lines, ...), large scale modeling projects, ocean, atmosphere and coupled.

http://www.clivar.org/organization/pacific/meetings/pacific_workshop.php