scientific paper in Geophysical Research Letters, Trenberth and co-authors presented an observation-based reanalysis of global ocean temperatures. This proposed that a recent hiatus in upper-ocean warming after 2004 had seen the long-term increase interrupted by sharp cooling events due to volcanic eruptions and El Niño. Despite this, ocean warming had continued below the 700m depth. In a second 2013 paper, Trenberth and Fasullo discussed the effect of the 1999 change from a positive to negative phase of the Pacific Decadal Oscillation. This was associated with a change of surface winds over the Pacific which had caused ocean heat to penetrate below 700m depth and had contributed to the apparent global warming hiatus in surface temperatures during the previous decade. In an interview, Trenberth said, "The planet is warming", but "the warmth just isn't being manifested at the surface." He said his research showed that there had been a significant increase in deep ocean absorption of heat, particularly after 1998. He told Nature that "The 1997 to '98 El Niño event was a trigger for the changes in the Pacific, and I think that's very probably the beginning of the hiatus". He said that, eventually, "it will switch back in the other direction." Trenberth's explanation attracted wide attention in the press. Trenberth received the 2017 Roger Revelle Medal from the American Geophysical Union for his work on climate change issues. Publications Books 2022 : The Changing Flow of Energy Through the Climate System Cambridge University Press 2000 : (in collaboration with K. A. Miller, L. O. Mearns and S. Rhodes) "Effects of Changing Climate on Weather and Human Activities" University Science Books / University Corporation for Atmospheric Research (UCAR) 1993 : (editor) Climate System Modelling Cambridge University Press See also Effects of climate change Loop Current References External links Kevin E. Trenberth at the University Corporation for Atmospheric Research "How to Fix the Climate-Change Panel", Questions for climate modeller and IPCC insider Kevin E. Trenberth, IEEE Spectrum, Oct. 2010. "Check With Climate Scientists for Views on Climate", by Trenberth and 37 co-signers, Wall Street Journal, 1 February 2012 Reply to Trenberth et al. by Claude Allegre et al., WSJ, 21 February 2012 Living people New Zealand climatologists Intergovernmental Panel on Climate Change lead authors American people of New Zealand descent Fellows of the Royal Society of New Zealand 1944 births Massachusetts Institute of Technology alumni People from Christchurch National Center for