Wave Climate and Trends for the Gulf of Mexico: A 30-Yr Wave Hindcast

Abstract

This paper describes wave climate and variability in the Gulf of Mexico based on a 30-yr wave hindcast. The North American Regional Reanalysis wind fields are employed to drive a third-generation spectral wave model with high spatial (0.005°–0.06°) and temporal (3 hourly) resolution from 1979 through 2008. The wave hindcast information is validated using National Data Buoy Center (NDBC) data and altimeter wave information (GlobWave). The model performance is satisfactory (r2 ~ 0.90) in the Gulf of Mexico and to a lesser extent in the Caribbean Sea (r2 ~ 0.87) where only locally generated waves are considered. However, the waves generated by the Caribbean low-level jet (CLLJ) are discussed in this work. Subsequently, the yearly/monthly mean and extreme wave climates are characterized based on the (30 yr) wave hindcast information. The model results show that the mean wave climate is mainly modulated by winter cold fronts (nortes) in the Gulf of Mexico, whereas extreme wave climate is modulated by both hurricane and norte. Extreme wave heights in the Gulf of Mexico have increased at a rate of 0.07–0.08 m yr−1 in September/October because of increased cyclone intensity in the last decade. However, there is no significant trend when considering the annual statistics for extreme events. Furthermore, modeling results also suggest that the CLLJ modulates the mean wave climate in the Caribbean Sea and controls the rate of mean wave height increase (0.03 m yr−1) in the Caribbean. However, these later results need to be corroborated by extending the computational domain in order to include the swell coming from the Atlantic Ocean.

Storm-wave trends in Mexican waters of the Gulf of Mexico and Caribbean Sea

“…under climate change conditions (Arguez and Vose, 2011). Appendini et al (2014) did not find any significant trend in time series of extreme wave heights (using the 99th percentile) along the eastern Mexican coast, but their research examined the entire time series without regard of the type of extreme event.…”

“…This area presents the highest significant wave height correlation coefficient and the lowest bias of the hindcast dataset used in the study done by Appendini et al (2014). The current study comprises the data from this hindcast at eight nodes located in the Mexican GoM at 50 m depth and two nodes in the WCS within 100 m depth.…”

“…The North Atlantic tropical cyclone season runs from 1 June to 30 November, with September being the month with the highest number of tropical cyclones directly affecting the Mexican coasts (Rosengaus Moshinsky et al, 2002). Norte events usually occur from October to April, with the most intense events taking place from December to March (Appendini et al, 2014).…”

“…Projected changes in wind shear suggest a decrease in the number and intensity of TCs in the region (Biasutti et al, 2012), although studies suggest an intensification of wind speed of higher-category events on a global scale (Holland and Bruyère, 2014). Wave hindcast results from Appendini et al (2014) do not project increases in wave height, although a recent analysis indicates more intense waves in the future climate for the WCS as a result of tropical cyclones (Appendini et al, 2017).…”

“…This contribution analyses a 30-year time series of hindcast wave data, covering the period of 1979 to 2008 (Appendini et al, 2014). The selection of this time interval allows for comparison to previous work in the region and is considered the standard period by the World Meteorological Organization to characterize climate, although the use of shorter time periods has been suggested to characterize non-stationary climates, e.g.…”