C. Mark Eakin1, Robert B. Dunbar2 and Julia E. Cole3

1 World Data Center for Paleoclimatology, Boulder, Colorado2 Stanford University, Stanford, California 3 The University of Arizona , Tucson, Arizona

Annual Records of Tropical Systems (ARTS)

The NeedThe climate research community needs long, continuous records of interannual to centennial variability in the tropics and of the teleconnections to the extratropics. An important target for paleoclimate reconstruction is the extension of indices of large-scale climate systems into pre-instrumental periods. Well-calibrated, multicentury reconstructions need to be integrated into spatially gridded research products that can be used to drive or test general circulation model simulations.

GoalsThe goals of the Annual Records of Tropical Systems (ARTS) program are to:

1. document and understand the behavior of the tropical ocean-atmosphere and its teleconnections, with seasonal to annual resolution, over the past several centuries; and

2. assess the stability of tropical climate systems and their teleconnections as the background climate and associated forcing phenomena change over seasons to centuries.

The ARTS initiative promotes the synthesis of paleoclimate data with instrumental and modeling perspectives to address uncertainties in our understanding of tropical climate variability and its impacts.

Windows into Past MillenniaClimate researcher need high-resolution records from targeted Holocene and last-glacial intervals to understand how the climate system responded to boundary conditions substantially different from those prevailing today.

60ÞE 90ÞE 120ÞE 180Þ 150ÞW 90ÞW 60ÞW 30ÞW

-4 -3 -2 -1 0 1 2 3 4Sea Surface Temperature Anomaly (°C)

February 1998

Stable, wet conditionsLittle/no ENSO variabilitybased on pollen datafrom lake sediments(Shulmeister and Lees, 1995)

Stable SST, 1°C warmerReduced hydrologic variabilitybased on coral 18O and Sr/Ca(Gagan et al. 1998)

Modified by J. Cole after Overpeck and Webb 1998, PNAS

Stable, wet conditionsLittle/no ENSO variabilitybased on pollen data from lake sediments(McGlone et al., 1992)

Interannual variability in landslidesreduced before mid-Holocene(based on turbidite deposition in lake sediments)(Rodbell et al. 1999)

Consistently warm SSTReduced ENSO variability based on mollusc faunal data(Sandweiss et al., 1996;debated by deVries et al 1987, 1997)

30ÞE 150ÞE 0Þ

Evidence for altered ENSO variability in the mid-Holocene

120ÞW

Enhanced decadal ENSO-like variabilitybased on coral d18O, U/Ca, amdSr/Ca(Correge et al. 2000)

NOAA National Geophysical Data Center

Drilling a live Porites coral, Jarvis Island

Coral Cores Currently in the World Data Center ArchiveAvailable at:

www.ngdc.noaa.gov/paleo/corals.html

Accessing the DataThis research is only possible through generous contribution of data by many coral paleoclimatologists to the World Data Center for Paleoclimatology. You can help in this and other efforts to consolidate our understanding of past climates. Contribute your data to the WDC-Paleo today at: www.ngdc.noaa.gov/paleo

Next ARTS Meeting: November 4-7 2001 in Nouméa, New Caledonia

Data Contribution"Full and open sharing of the full suite of global data sets, and other data sets needed for global change studies, is the primary objective of the IGBP." - IGBP Report No.12

"Make your data available without restrictions once published by contributing to an organization committed to long-term data availability."

International Geosphere-Biosphere Programme Data PolicyInternational Council of Scientific Unions Data PolicyPolicy on Data from Federal Grants from the Data Management Working Group (1997)Global Change Data Policy (1991)Frequently Asked Questions About Data Policy

Our goal at the WDC is to make data submission easy and efficient for you, to help you preserve your data as a legacy that can be used by your colleagues today AND by future generations of scientists.

The WDC has made a long term commitment to preserve your data and make it available to others. Once contributed your data will be available to others as a set of files organized by your name, date, and contribution number (accessible via the WWW, FTP, and also on diskette). Your data may also be imported into a relational database and thus accessible using database queries.

Data Policy - Frequently Asked Questions:• What about a proprietary period for exclusive use?• What if I want to have my own archive or Web site?• What about the ancillary project data that I never published?• What are the Internationally-agreed up on policies for data sharing?

International Geosphere-Biosphere Programme Data PolicyInternational Council of Scientific Unions Data Policy

How to contribute:

Check the guidelines to make sure your data set is complete, and in a useable format.Contact us if you have questions about what to include or what formats are required. View the existing entries in the WDC for Paleoclimatology Contributions Series.

• Submit your data in one of the following ways: As an email attachment FTP to the /pub directory on the WDC server Mail data as a diskette. Printed reports are also accepted. New Section: Submit your data online!! (Currently for Tree Ring Data only)

• Receive your acknowledgement and Contribution Number from the Center, and review your data set to make sure everything is correct.

Windows into Past CenturiesCoordinated efforts are needed to analyze climate of the past several centuries. A proposed ARTS synthesis project entitled "Climate of the Nineteenth Century,” (CNC) would coordinate these efforts, including the development of records from critical locations, spatial interpolation techniques to link point reconstructions, model simulations, and model/paleodata comparison. The highest priorities for the CNC project are production of fields of sea surface temperatures (SST's) across the tropical Pacific extending back to at least 1800 AD, and examination of teleconnections within the Indian Ocean, Australasian and American regions. New sampling will be steered by analyses of available data and comparisons with modeling results.

Figure 3 (right): Analysis of spatial SST patterns using 13 time series from 12sites from Figures 1 and 2

except 1, 3, 10, 14 (2 records are used from site 16). (a) Leading spatial pattern observed in coral data (in

dimensionless units); greys indicate 90% significance. (b) The time series of that pattern (degrees C). (c) As in (a) except for second spatial pattern.

(d) As in (b) except for time series of second pattern. After Evans et al. (2000) Paleoceanography, 15.

1600 1700 1800 1900 2000Year A.D.

1. Malindi

2. Seychelles

3. Abrolhos

4. AbrahamReef

5. Madang

6. NewCaledonia

7. Vanuatu

8. Nauru

9. Tarawa

10. Maiana

11. Kiritimati

12. Urvina Bay

13. Chiriqui

14. Clipperton

15. Cebu

16. Aqaba

Figure 2 (left). Summary of annual resolution coral isotope records, normalized to the 1923-1980 period (common to most records) and with a 7-year smooth (thicker line) to highlight decadal and longer variability. All show general trends towards warmer/wetter conditions (after Bradley et al. in prep., PAGES Synthesis Volume). Numbers correspond to Figure 1.

For more information on ARTS, contact:C. Mark Eakin, World Data Center for PaleoclimatologyNOAA/NGDC, 325 Broadway, Boulder, CO 80305-3328 USA, mark.eakin@noaa.govRobert B. Dunbar, Department of Geological and Environmental SciencesStanford University, Stanford, CA 94305-2115 USA, dunbar@stanford.eduJulia E. Cole, Department of GeosciencesThe University of Arizona , Tucson, AZ 85721-0077 USA, jcole@geo.arizona.edu

Dunbar, R.B. and J.E. Cole, eds.Annual Records of Tropical Systems (ARTS): Recommendations of

Research, PAGES Workshop Report Series 99-1, 1999. Report available online at: http://pangea.stanford.edu/Oceans/ARTS

A PAGES/CLIVAR InitiativeEdited by

Robert B. Dunbar and Julia E. Cole

PAGES Workshop Report, Series 99-1

Annual Records of TropicalSystems (ARTS)

Recommendations for Research

Figure 1. Sites of coral records used in figures 2-3. Background colors indicate mean instrumental SST field. Pink dots indicate sites where annual coral isotope records span the interval 1895-1990; white dots indicate shorter records. For the longer records, trends are calculated over the 1895-1990 period (or 1895 to the most recent year, if before 1990) and are indicated parenthetically in °C per 100 years, assuming all isotopic variability is due solely to SST changes and the slope of the SST-18O relationship is 0.22 °C per 1”. Site sensitivity issues (e.g. depth of coral, influence of rainfall) have not been taken into account. Large central Pacific values are almost certainly due to the influence of rainfall on seawater isotopic content (after Bradley et al. in prep., PAGES Synthesis Volume).

SST(C)18 21 24 27 30

7. (-0.68)

6. (1.95)

12. (0.41)10. (1.5)

8. (1.45)9. (0.36)

14. (0.82)

13. (0.73)

3. (0.64)

2. (0.90)

1. (0.30)

15. (2.10)

16. (0.27)

5.11.

4. (1.0)

c

a b

d