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Information sources for a national database of historical tropical cyclone impacts: an example from the Cook Islands

Dr. Fes de Scally, University of British Columbia-Okanagan, Canada

A national database of historically occurring tropical cyclones and their impacts is an important tool for disaster planning and mitigation, and the recent completion of such a database in the Cook Islands can serve as a template for other Pacific Island nations. Many sources of written information were used which are scattered in libraries and repositories around the world. The cyclone database covers the period of European settlement, which in the Cook Islands extends back to the 1820s.

Printed meteorological reports

Information in early reports has found its way into later reports, notably S.S. Visher’s two classic 1925 reports which cover the period 1789 to 1923. Subsequent reports published by the New Zealand Meteorological Service and NIWA include those by (years of record in parentheses) I.S. Kerr in 1976 (1939–69with ‘notable storms’ back to 1900 included), C.G. Revell in 1981 (1969–79), C. Thompson and others in 1992 (1979–89), and R. Basher and others in 1992 (1831–1989). A World Meteorological Organization report by J. Maunder in 1995 (1900–93) summarises the exhaustive work of Kerr as well as the later reports. Other cyclone inventories for the Southwest Pacific include those by J.W. Hutchings in 1953 (1940–51), J.F.Gabites in 1956 and 1963 (1952–56), J.L. Giovanelli in 1963, and Giovanelli and J. Robert in 1964 (1947–62). Detailed reports for individual cyclones were produced by the Fiji Meteorological Service (FMS) from 1979–98, and less detailed seasonal cyclone summaries 1994/95–2001/02. The reports since the 1999/2000 season are on the FMS website. NIWA holds a tropical cyclone database which is updated annually. Except for the Kerr and FMS reports a significant limitation of the above reports is that they provide mainly cyclone track and – in the satellite era – intensity data, with few if any insights into cyclones’ impacts.

Printed non-meteorological sources

In the Cook Islands the earliest written accounts of cyclones are provided by London Missionary Society priests in the 1820s. Their published memoirs and books contain many references to 19th century cyclone calamities, although observations are usually confined to an individual’s home island. As an example, Aaron Buzacott’s accounts of the December 1831 and March 1846 cyclones at Rarotonga rival, in detail and insights, Robert Louis Stevenson’s well known account of the March 1889 cyclone at Apia, Samoa.

During British and New Zealand administration of the Cook Islands, cyclone impacts are reported extensively in the annual reports of the Cook Islands Administration. These can be found in the Appendices to the Journals of the House of Representatives of New Zealand archived in New Zealand, but this  reporting ceased with independence in 1965. Major cyclone calamities are reported in great detail, while the effects of even minor cyclones, such as drops in crop exports and costs of infrastructure repair, are noted. The Cook Islands database contains extensive detail about cyclone impacts starting in 1891. Local and regional print media such as the Cook Islands News and Pacific Islands Monthly provide much detail about historical cyclone impacts, with reporting by the latter going back to about 1930. An enormous variety of scientific papers and other publications, in some cases dating back to the early 20th century, provide valuable information about major cyclone calamities in the Cook Islands.

Online sources

Websites containing cyclone track and intensity data have proliferated in recent years, but for Southwest Pacific cyclones the generally short period of record (7–13 years) in them limits their use for historical analyses. Websites which contain longer records include those of the U.S. Navy’s Joint Typhoon Warning Centre with archives of ‘best track’ data back to 1945 and annual cyclone reports back to 1959 – although for the Southwest Pacific the latter are available only since 1985; the U.S. Navy’s Global Tropical Cyclone Atlas Version 1.0 extending back to 1860 –access to which requires a security certificate; and a database of the United Nations Environment Programme which contains data from several meteorological agencies back to 1980.

A major limitation of the online sources described above is their lack of information on cyclone impacts: to our knowledge only two provide this – the U.S. Navy’s Global Tropical Cyclone Atlas occasionally contains brief historical narratives, while the Australia Severe Weather website summarises significant impacts for cyclones after 1997.

Lead author, A History of Tropical Cyclones and Their Impacts in the Cook Islands, Cook Islands Meteorological Service, 2006, 377 p. Citations and website addresses for information sources in this article are available by emailing: [email protected].
http://www.wmo.int/pages/prog/wcp/ccl/opags/opag3/et3.3/et3.3_members_tors.htm