• Expert Team on Climate Change Detection and Indices (ETCCDI)

• started in 1999

• jointly sponsored by CCl, CLIVAR and JCOMM

Indices

• the ETCCDI developed an internationally coordinated set of climate indices

• core set consists of 27 descriptive indices for moderate extremes

• focus on counts of days crossing a threshold; either absolute/fixed thresholds or percentile/variable thresholds relative to local climate

• used for both observations and models, globally as well as regionally

• can be coupled with – simple trend analysis techniques– standard detection and attribution methods

• complements the analysis of more rare extremes using EVT

• Zhang et al. WIREs Clim Change, submitted.

• Klein Tank, Zwiers and Zhang, 2009, WCDMP-No. 72,WMO-TD No. 1500, 56pp.

Example: Russian heat wave, July 2010

In-situNOAA

ERA-InterimECMWF

MSUUAH

Courtesy: John Christy (top), Adrian Simmons (bottom)

In-situNOAA

Example: Russian heat wave, July 2010

ETCCDI indices add relevant information

In-situNOAA

Example: Russian heat wave, July 2010

31 days withT-max > 25°C against 9.5 days in a normal July

Example: Russian heat wave, July 2010

16 nights with T-min > 20°C against 0.5 night in a normal July

Example: Russian heat wave, July 2010

• European Climate Assessment & Dataset (ECA&D)

• http://eca.knmi.nl

Frich et al., Climate Research, 2002 (also in IPCC-TAR)

Index for warm nights (status TAR)

Regional workshops

ETCCDI Regional Workshops Working together

• organised together with the Asian Pacific Network (APN)

• goals:– contribute to worldwide indices database– build capacity to analyze observed changes in extremes– improve information services on extremes in the region– publish a peer-reviewed paper from each workshop

Alexander et al., JGR, 2006 (also in IPCC-AR4)

IPCC-AR4, 2007

ETCCDI Regional Workshops Working together

GH Africa Workshop(WCRP/World Bank)

04/2010

Indonesia, Malaysia,Thailand, Philippines

(NL) 12/2009

Southeast Asia (USA)

12/2007

Mexico (UK)03/2009

West IndianOcean (France)

09/2009

Central Africa (USA) 4/2007

Peterson and Manton, BAMS, 2008

South America (Ecuador) 01/2011

Software tools

• Environment Canada provides, maintains, and further develops the R-based software used for the workshops (freely available from http://cccma.seos.uvic.ca/ETCCDI)

• see: presentation by Xuebin Zhang / Enric Aguilar

BAMS, September 2008

Detection / Attribution work

• effects of external forcings on changes in:– global and regional surface air temperatures– hydrological cycle (precipitation in latitudinal bands)– cryosphere (Arctic sea ice-extent)– etc.

• some detection results for anthropogenic signal in observed changes in extremes (using ETCCDI indices RX1day and RX5day)

• see: Stott et al., WIREs Clim Change, 2010, 1, 192-211.

Future

• indices:– review current suite with a view to further improvement– assemble and maintain near global datasets of indices– improve delivery to users

• regional workshops:– continue to host (e.g. in WMO/World Bank series)– maintain standardized software

• IPCC:– contribute to IPCC-SREX and AR5 (extremes will be a focus)– post-process CMIP5 output for indices (plus software)– diagnostic studies based on indices (WG1 and WG2 relevance)

Challenges

• indices:– additional indices in worldwide set (marine, drought, monsoon?)– more application relevant indices to better support adaptation– updating indices problematic for many regions (better liaise with

regional panels? GCOS regional workshops? RCOFs?)

• daily data:– assembling worldwide datasets which are integrated, quality

controlled, and open accessible (Surfacetemperatures.org)– tension between traceability (access to the primary sources)

and data completeness (use whatever available)

• detection / attribution:– how best to identify external influences on extremes– ability of models to adequately simulate extremes– scaling issues of extremes in point vs gridded data– event attribution

• ETCCDI:– manage expectations (small team, limited capacity)– keep the team focused (as well as open for new directions)

• ECA&D develops and implements additional indices, e.g. snow cover, drought (SPI, PET) and wind indices

• full updates provided every month (as part of RCC for Region VI)

• website, database and processing software is openly available for use in other regions of the world– our gridding technique is used in Mexico and S. America– our portal has been implemented for S.E. Asia

(Indonesia, Malaysia, Thailand, Philippines)

SACA&D (http://saca-bmkg.knmi.nl)