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Monday, 8 November 2004 MEDIA RELEASE - HEAD OFFICE Towards seasonal predictions of NSW's big wavesEmergency services - and nerveless surfers - are likely to benefit from a new Australian Bureau of Meteorology climatology of five-metre "large waves" along the NSW coast. Neal Moodie, Brett Gage and Rosea Kemp of the bureau's NSW Regional Office have used computer analyses from almost 20 years of data from seven wave-rider buoys to update earlier manual estimations from weather maps. "We've aimed for greater understanding of large-wave-producing weather systems which are the main cause of coastal damage from large waves and swell," Neal says. "Having a guide as to whether there would be more or less large waves than usual could, for instance, help emergency services with their planning." NSW averages two or three large wave situations a year, and has had up to eight a year, including some waves up to eight metres. Large waves peaked in the 1950s. The researchers identified wave trends similar to rainfall trends over NSW - many linked to easterly winds bringing rain and swell. "We've also shown that El Niños will bring around 10 per cent more five-metre southerly swells than the long-term coastal average," Neal says. "Experienced surfers might not be surprised to hear that the mid-north coast from Sydney to Seal Rocks averages 30 per cent more five-metre waves than the coastal average," Neal says. "If you're chasing the Big One, try the north coast in late summer and autumn (tropical swells), the south coast in winter (southerly swells) and enjoy the double peak on the mid coast, with both autumn and spring swells." "We are now investigating the statistical significance of any climate change trends, and correlation with other climate factors such as sea surface temperatures and Pacific wind patterns. We hope to extend the study Australia-wide, in part by using wave rider buoy data to validate hindsight analyses using the bureau's wave modelling," Neal says. Abstract: www.bom.gov.au/announcements/media_releases/ho/20041108nm.pdf FREE DAY REGISTRATION FOR MEDIA PARTICIPANTS Further information: Program: http://www.bom.gov.au/events/anzcf2004/program_1.html |
