Western Boundary Current Working Group

CLIVAR Summit

Irvine, CA

Panel MembersWG Established Jan 2007

• Kathie Kelly (co-chair), University of Washington

• Bo Qiu (co-Chair), University of Hawaii

• Michael Alexander (NOAA/ESRL)

• Nick Bond (U Washington)

• Meghan Cronin (NOAA/PMEL)

• Claude Frankignoul (LODYC, Paris)

• Terry Joyce (WHOI)

• Young-oh Kwon (WHOI)

• Hisashi Nakamura (U. of Tokyo, Frontier)

• Roger Samelson (Oregon State)

• Justin Small (Naval Research Lab Stennis Space Center)

• LuAnne Thompson (U Washington)

Scientific Issues

• How does air-sea interaction compare in the western North Atlantic and North Pacific?

• What are the implications of the differences?*

• What is the nature of atmosphere-ocean interaction in WBC regions?

• On what temporal and spatial scales does it occur?

• Is there predictability in the system?

• To what extent are coupled models getting the interaction right?

• Can we identify specific problems in ocean or atmosphere models?

• What numerical experiments need to be done to test hypotheses?

• To what extent does air-sea interaction extend beyond the boundary layer and influence broader climate variability in both the atmosphere and ocean?

Activities• Write two review articles on Air-Sea Interaction in

Kuroshio Extension/Gulf Stream Regions– 1) Frontal-scale

• (Kelly, Qiu, Joyce, Frnakignoul, Small)

– 2) Basin-Scale • (Kwon, Alexander, Frankignoul, Nakamura, Bond, Thompson)

• Topics• Incorporate new findings from KESS/Climode (F/B)• Findings from high resolution atmosphere and ocean models (F)• Examine local and remote effects (F)• Cross Scale Interactions (F/B)• Assessment of current IPCC-Class models (B)• Discuss outstanding issues (F/B)

• Conduct new analyses in support of papers• Papers to be submitted to J. Climate Jan 09• Create on-line atlas of WBC relevant fields

Frontal Scale Air-Sea Interaction

●Mean and variability of the Gulf Stream and Kuroshio Extension●Time-varying dynamic signals ●Time-varying thermodynamic signals●Understanding the GS and KE indices•Atmosphere-ocean interaction

RMS of net surface heat flux (top) and SSH variability (bottom) for KE (left) and GS (right),contour mean SSH

Courtesy of K. Kelly

Poster by T. Joyce on fronts and surface expression of storm track variability

Observed Impact of the Gulf Stream on the Atmosphere

Minobe et al., Nature, 2008

Winter SST Variability in Obs and Ocean Model for the Earth Simulator

(OFES) 0.1° lat x 0.1° lon, 56 levels

Nonaka et al.,J Climate,2006

JFMSST

Dynamics of KE region

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PDOSSH from data SSH from wave model

PDO Wind Curl forcing

SST Impact of SST in the Kuroshio Extension on the Atmosphere

Provided byC. Frankignoul

Regression of a) SST (AMJ) b) z250 (AS0) c) on SSTA in KE

Region in AMJ

Qiu et al., J Climate, 2007

Decadal variability in the North Pacific Atmosphere ocean system

3-equation observational based heuristic model

WorkshopLogistics

Phoenix, AZ January 2009

• Thursday Jan 15th - Saturday 18th (3 full days)

• One day overlap with Annual AMS meeting • coordinating with AMS Air-Sea Interaction

• Optional joint sessions on Wednesday 14th

• Hotel & other logistics worked out shortly

ScienceI Four half day sessions with presentations on topics

1. Insights from KESS/CLIMODE field programs

2. Frontal-scale air-sea interaction over WBCs

3. Large-scale air-sea interaction in connection with WBCs

4. Impact of upper ocean variability in WBC regions on midlatitude climate variability and predictability

Workshop IIII Discussion and future directions (3rd day)• What are the cutting-edge science issues for the WBC air-sea

interaction? • What are beyond the KESS/CLIMODE programs?• Identify requirements for ocean and atmospheric observing

systems in WBC regions• What WBC metrics are most relevant for the modeling

community?• What modeling experiments should be considered; e.g. impact

of SST, ocean heat content anomalies on atmosphere?

Potential outcomes• Ideas for new field programs and/or observation systems• Coordinated model experiments• Identification of metrics for coupled models

Additional Activities

• Supporting Activities– Monthly teleconferences– Met in Portland in conjunction with AMS Air-Sea

Interaction Conference Aug 07– Climate Variations Article (Dec 2007)– Web page http://www.usclivar.org/wbc.php

• Telcon notes, • science, • references, • links