Michael J. McPhaden

NOAA/PMEL

Recent Progress Towards an Indian Ocean Observing System for Climate

Prepared for NOAA Climate Observations Workshop

13-15 May 2003

Washington, DC

SummaryThere is an increasingly organized international effort to develop an Indian Ocean component to the Global

Ocean Observing system in support of climate studies:

Compelling unanswered scientific questions;

Potential societal benefits (improved prediction of the monsoon rainfalls and teleconnections);

Growing investments from Indian Ocean rim countries and others;

One of the most poorly sampled regions of the world ocean in terms of in situ observations;

Opportunities for the US to participate.

Indian Ocean GOOS ConferenceGrand Baie, Mauritius, 1-9 November 2002

Oceans and Climate Workshop Goal:

“…to identify actions required to develop an Implementation Plan for the Indian Ocean Global

Ocean Observing System (IOGOOS), building on the SOCIO Workshop, meetings of the Climate Variability (CLIVAR) Asian/Australian Monsoon Panel, and the

Global Ocean Data Acquisition Experiment (GODAE) Science Team…”

Conferences on Climate, Coastal Zone, Satellite, Data Management

158 participants from 22 countries

Co-sponsored by IOC/GOOS, CLIVAR, NOAA, ONR, NSF….

Indian OceanRegional Science Drivers

Seasonal monsoon variability

Intraseasonal oscillations

Indian Ocean dipole mode

Decadal warming trends

Interbasin connections (Indonesian throughflow & Algulas rings)

Deep meridional overturning

Subtropical/tropical overturning cells

Indian Ocean Dipole Mode

December 1997 SST Anomalies

Indian OceanRegional Science Drivers

Seasonal monsoon variability

Intraseasonal oscillations

Indian Ocean dipole mode

Decadal warming trends

Interbasin connections (Indonesian throughflow & Algulas rings)

Deep meridional overturning

Subtropical/tropical overturning cells

Meridional overturning--

The shallow cell

Schott et al. (2001)

Monsoon <=> ENSO interactions MJO influences on ENSO West coast US rainfall Tropical storms and hurricanes Indian Ocean SST influence on NAO?

Atmospheric Teleconnections

May 2001-May 2003

Episodic westerly wind forcing

Convective flare-ups occur every 30-60 days over the Indian Ocean. These flare-ups are characterized by towering cumulus clouds, rainfall, and westerly surface winds that propagate into the Pacific sector.

Indian | Pacific | Atlantic

The Madden-Julian Oscillation

June 2001

Dec 2002

cloudy/wet clear/dry

Cloudiness & Rainfall

Atmospheric Teleconnections

West Coast Rainfall Tropical Storms

Monsoon <=> ENSO interactions MJO influences on ENSO West coast US rainfall Tropical storms and hurricanes Indian Ocean SST influence on NAO?

Atmospheric Teleconnections

Monsoon Dynamics and Linkages

Indian Ocean Observing System Status

Satellite observations of sea level, SST, wind and ocean color are key elements of the Indian Ocean Observing System.

Substantial progress in implementation of pilot in situ observations during the past two years (Argo, moorings, drifters, XBTs, etc).

Indian Ocean

XBTs/Moorings

Dec ‘02

Drifters, Jan ‘03

Argo Floats, Feb ‘03

Efforts are underway to increase in situ measurements in the Indian Ocean

Indian Ocean

Masumoto et al, 2002

Not shown:

US interests in equatorial and BoB moorings

Plans for 40 deep ocean moorings north of 5°N (NIOT)

Madagascar Channel moorings (Dutch)

Indian Ocean

Masumoto et al, 2002

JAMSTEC ADCP mooring 0°, 90°E

The Working Group proposed three pilot projects:

(1) to develop the deployment of Argo floats, from the present level of about 67 to 170 in 2003, and to 450 in 2005;

(2) the implementation of a new Ship-of-Opportunity XBT Project, with emphasis on high-resolution, frequently repeated lines across the Indian Ocean.

(3) to develop Indian Ocean mooring arrays in the equatorial zone and in four zones of significant sea-surface temperature anomalies (northern Bay of Bengal, off the southern coasts of Sumatra and Java, western Arabian Sea, and the southern Indian Ocean);

IOGOOS Meeting Working Group 1: Basin-scale Contributions to the Observing System

Indian Ocean

IOGOOS participants moved to establish an ad hoc working group* of the Tropical Moored Buoy Implmentation Panel (TIP) to develop and coordinate implementation of a moored buoy array to address CLIVAR scientific objectives and to support operational analyses and seasonal-to-interannual climate forecasting.

* Initial interested parties: M. McPhaden (USA), M. Jury (So. Africa), Y. Masumoto (Japan), R. Molcard (France), M. Ravichandran (India), C. Perigaud (USA), G. Vecchi (USA), G. Meyers (Australia), VSN Murty (India), and P. Hacker (USA).

IOGOOS, Mauritius, 4-8 November 2002

CLIVAR Asian/Australian Monsoon Panel (AAMP)

Considering the rapid development of, and many nations’ involvement in, the Indian Ocean Observing System, AAMP strongly recommended that an Indian Ocean Panel be formed for coordination and for CLIVAR to help drive forward the implementation of ocean observations in the region. The AAMP suggested that the new panel be set up jointly with IOC in the framework of the recently established IOGOOS.

Atlanta, Georgia, 25-27 February 2003

CLIVAR SSG endorsement

SSG-12, Victoria, BC, 6-9 May 2003

Indian OceanScience & Implementation Challenges

Array design(s)

Funding

Deployment platforms (RVs, VOS, etc)

Fishing vandalism (moorings)

Measurement standards

Data management

International coordination and partnerships for sustaining observations

Tide Gauge Network 45 % complete 3˚x3˚ Argo Profiling Float Array 25% complete 5˚x5˚ Surface Drifting Buoy Array 35 % complete Moored Buoy Existing Planned Ocean Reference Station Existing Planned High Resolution XBT and Flux Line Existing Planned Frequently Repeated XBT Line Existing Planned Carbon Inventory & Deep Ocean Line Survey 1.5 lines/year, 50 % funded

Sea Surface Temperature, Sea Surface Height, and Surface Vector Wind from Space

Figure 1

Global Ocean Observing System

SummaryThere is an increasingly organized international effort to develop an Indian Ocean component to the Global

Ocean Observing system in support of climate studies:

Compelling unanswered scientific questions;

Potential societal benefits (improved prediction of the monsoon rainfalls and teleconnections);

Growing investments from Indian Ocean rim countries and others;

One of the most poorly sampled regions of the world ocean in terms of in situ observations;

Opportunities for the US to participate.

Indian Ocean Research IssuesFour unique characteristics of the Indian Ocean

generate a “heat pool” with basin-scale variability over a broad range of time scales

Closed in the north by Asia, creating monsoons and blocking export of oceanic heat to the north Open to the Pacific, creating Indonesian throughflow and import of warm equatorial, upper ocean waters Cross-equatorial transports of heat in the ocean and atmosphere, creating the shallow overturning cell Open to exchange with the Southern Ocean, creating the deep overturning cell.

Comparison with previous El Niños

Adapted from International Research Institute

NINO-3.4