Giles, HVopel, KPether, S2011-07-142011-07-1420082008Water & Atmosphere, vol.16(2), pp.22 - 23https://hdl.handle.net/10292/1462Copyright © National Institute of Water & Atmospheric Research Ltd 2008 (www.niwa.co.nz). All Rights Reserved. NIWA publications are available free of charge as Open Access journals on the Internet. The definitive version was published in (see Citation). The original publication is available at (see Publisher's Version).Journal ArticleOpenAccess