Multi-scale trend analysis of wind wave climatology in the Gulf of Mexico using innovative approaches

This study investigates spatio-temporal trends in the Gulf of Mexico's wave climate using a multi-method approach with WAVEWATCH III. Significant wave height (Hs), peak wave period (Tp), and 10-m wind-speed (U10) are analyzed using monthly means over long-term(80-yr), mid-term(40-yr), and short-term(20-yr) periods. The Mann–Kendall test and two recently-developed trend analysis methods are applied: Innovative Polygon Trend Analysis (IPTA) and Improved Visualization for Innovative Trend Analysis (IV-ITA). Mann–Kendall detected significant monotonic trends in only 7.3% of cases, whereas IPTA and IV-ITA enhanced detection through month-to-month, seasonal, and low/high - value analysis . IPTA identified increasing (decreasing) Hs trends in 55% (37%) of monthly cases over long-term. IV-ITA revealed low-value Hs increased at 79% of points (80-yr) and high-value Hs decreased at 67% (40-yr). Long-term Hs and Tp trends increase during warmer months, especially in the Central and Northwestern regions, while the Eastern shelf shows persistent decreases. U10 exhibits greater regional and seasonal variation. In the mid-term, trends become fragmented or reverse in fall and winter. Low-to-moderate values intensify from long-to short-term, while high-value trends weaken regionally. These findings indicate a shift in Gulf's energy balance driven by gradual change rather than extremes alone, underscoring the need for high-resolution climate analysis.