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Significant wave height (SWH) is an important parameter to reflect wave state, which is of great significance in ocean engineering. However, the current wave observation methods have limitations in capturing wave field data with high spatial resolution. In this study, to generate the SWHs field over the Northeast Pacific and Northwest Atlantic, multi-source satellite altimeter data (CRYOSAT-2, SARAL, JASON-3, SENTINEL-3A, SENTINEL-3B, HY-2B and CFOSAT) are fused with a spatial resolution of 0.125° x 0.125° and a temporal resolution of 1 day. We employ the Inverse Distance Weighting (IDW) method and the IDW-based spatiotemporal (IDW-ST) method for data fusion. The fusion results exhibit a consistent spatial distribution characteristic, but the results of the IDW method display the visible trajectory. Moreover, the IDW-ST method, which incorporates time factors, shows great agreement between the fused SWH and buoy data. However, when the water depth change near the grid point has a great influence on the fusion, the complexity of bathymetric topography makes the traditional two-dimensional spatial fusion methods inadequate. Therefore, an improved method is proposed based on the IDW-ST fusion method, which introduces the water depth factor and significantly enhances fusion accuracy in regions where bathymetric variations greatly affect fusion results. The proposed method can be used to generate reliable SWH fields, especially in complex bathymetric topography conditions, and provide significant support for marine infrastructure design, ocean energy utilization and marine disaster protection. [ABSTRACT FROM AUTHOR]

The estimation of significant wave height (SWH), especially under extreme conditions, is crucial for the understanding of ocean dynamics and practical application in ocean engineering. In this study, the SWH field in the North Pacific Ocean is generated based on satellite altimeter data. Due to the limitations of a single satellite, such as large orbital spacing and long revisit period, multi-source satellite data are fused to obtain more wave information. The effect of the number of satellites on the fusion results shows that increasing the orbital observations can improve the fusion accuracy, especially for large wave processes. On this basis, an adaptive temporal resolution fusion method is proposed to further improve the fusion effect. This method takes into account the spatiotemporal variation of the wave field in the fusion process, especially the rapid and significant change of SWH. According to the change characteristics of normal and large waves, the temporal resolution can be adjusted flexibly and autonomously to ensure fusion efficiency and accuracy. In particular, this adaptive adjustment can significantly improve the peak underestimation of large waves. Meanwhile, the fusion influence of SWHs in large wave processes on adjacent small SWHs is reduced to avoid over-fusion. The comparison between the buoy observation and fused SWH shows that this method can be used for fusion, especially for capturing peak SWHs during large wave processes. It may allow for comprehensive monitoring and understanding of ocean waves during extreme conditions, providing important support for disaster prevention and mitigation. [ABSTRACT FROM AUTHOR]

Regional analysis of wave characteristics is crucial for ocean engineering planning and marine disaster protection. However, current wave observation methods have limitations in capturing sufficient coverage and resolution of wave field data, specifically significant wave height (SWH). Thus, we fuse multi-source satellite altimeter data using four fusion methods to generate daily SWH fields with a spatial resolution of 0.125° × 0.125° over the North Pacific Ocean (NPO). The results show that the fused SWHs exhibit a consistent spatial distribution pattern similar to the product provided by Archiving, Validation, and Interpretation of Satellite Oceanographic Data. Considering the spatial and temporal variation characteristics of the along-track data, the inverse distance weighting-based spatiotemporal fusion (IDW-ST) method outperforms other fusion methods compared to buoy measurements. Building upon the IDW-ST method, we fuse multi-source satellite altimetry data from 2016 to 2020 and analyze the regional spatial patterns and variations of waves in the NPO. Waves in this region are primarily influenced by monsoons and significantly regulated by extreme weather systems, such as tropical cyclones (TCs). Seasonal variations in wave characteristics may be linked to the frequency and tracks of TCs, with distinctive local features observed in representative zones. For example, the probability distribution of SWHs in the NPO exhibits a trailing pattern with significant deviations from the main SWHs, particularly during winter. Additionally, a heavy-tailed distribution is observed in the central high-latitude zone, except during summer. These patterns indicate the frequency and severity of extreme wave events in these zones. [ABSTRACT FROM AUTHOR]