A global wave hindcast over the period 1958–1997: Validation and climate assessment

Abstract

Abstract. This study describes the first 40 year global wave simulation derived from the National Centers for Environmental Prediction/National Center for Atmospheric Research Reanalysis (NRA) surface wind fields. The NRA 10 rn wind fields were input into a deep water version of a proven spectral ocean wave model adapted onto a global grid of spacing 1.25 ø in latitude by 2.5 ø in longitude. In situ and satellite wind and wave data sets were used to evaluate the hindcast skill. The validation showed excellent agreement not only in terms of bias and scatter but over the entire frequency distribution out to 99th percentiles of both winds and waves. A global trend analysis showed statistically significant areas of both increasing and decreasing winds and waves. The increasing trend in the northeast Atlantic and decreasing trend in the central North Atlantic are particularly well defined and consistent with changes reported in previous studies, which were linked to changes in the North Atlantic Oscillation. The trend analysis highlighted the difficulty in separating creeping inhomogeneities in the NRA winds from real climate change, illustrating the need to use homogeneous in situ measured data to confirm trends derived from model output. The trends derived from the hindcast seem reasonable in the Northern Hemisphere and may provide a good upper bound to true trends in the wind and wave climate.

Periodicity and patterns of ocean wind and wave climate

“…The wave climate in the North Atlantic has been investigated more than any other region with numerous studies describing its variability in terms of the AO [Bauer, 2001;Swail and Cox, 2000;Cox and Swail, 2001;Wang and Swail, 2001;Woolf et al, 2002;Gulev and Grigorieva, 2006;Izaguirre et al, 2011;Fan et al, 2012]. The North Atlantic is largely seasonal with energetic waves in the boreal winter and calm conditions in the summer, while the South Atlantic has less variation throughout the year.…”

Variability and trends in the directional wave climate of the Southern Hemisphere

“…Short and Trenaman, 1992;Laing, 2000;Scott et al, 2002;Gorman et al, 2003;Hemer et al, 2008), and global studies, where the attention paid to the SH is limited (e.g. Young, 1999;Cox and Swail, 2001;Sterl and Caires, 2005). It is widely understood however, after the early work by Snodgrass et al (1966), that the swell generated in the Southern Ocean during intense Southern Ocean extra-tropical cyclones propagate throughout the World's oceans, impacting on almost all of the World's coasts.…”

Remotely Sensed Winds and Wind Stresses for Marine Forecasting and Ocean Modeling

“…[22]). Optimum utilization of satellite winds requires: (1) establishment of the accuracy and full dynamic range of the data and (2) the development of efficient methods that combine satellite and in situ winds into high resolution time and space forcing fields [92].…”

“…Mark A. Bourassa (1) , Ad Stoffelen (2) , Hans Bonekamp (3) , Paul Chang (4) , D. B. Chelton (5) , Joe Courtney (6) , Roger Edson (7) , Jula Figa (8) , Yijun He (9) , Hans Hersbach (10) , Kyle Hilburn (11) , Zorana Jelenak (12) , Kathryn A. Kelly (13) , Richard Knabb (14) , Tong Lee (15) , Eric J. Lindstrom (16) , W. Timothy Liu (17) , David G. Long (18) , William Perrie (19) , Marcos Portabella (20) , Mark Powell (21) , Ernesto Rodriguez (22) , Deborah K. Smith (23) , Val Swail (24) , and Frank J. Wentz (25) ( Ocean surface winds change rapidly in both time and space. Satellite-based sampling density and relatively good accuracy make satellite winds desirable data (particularly for regions with sparse in situ observations) for many related applications such as coastal upwelling, oceanic/atmospheric coupling associated with both tropical instability wave and ocean fronts [19], ocean currents [58], detection of tropical disturbances [35], wave forecasting, weather forecasting [46], and storm surge [79], to list a small sample of applications.…”