Abstract. Global marine gravity anomaly models are predominantly recovered from along-track radar altimeter data. While remarkable advancements has been achieved in gravity anomaly modelling, the quality of gravity anomaly model remains constrained by the absence of across-track geoid gradients and the reduction of radar altimeter data, particularly in coastal and high-latitudes regions. ICESat-2 laser altimetry operates three-pair laser beams with a small footprint and near-polar orbit, enabling the determination of across-track geoid gradients and providing more valid observations in certain regions. The ICESat-2 altimeter data processing method is presented including the determination of across-track geoid gradients and the combination of along/across-track geoid gradients. A new global marine gravity model, SDUST2022GRA, is recovered from radar and laser altimeter data using different method for determining each altimeter data error. The accuracy and spatial resolution of SDUST2022GRA is assessed by published global gravity anomaly models (DTU17, V32.1, NSOAS22) and available shipborne gravity measurements. The accuracy of SDUST2022GRA is 4.43 mGal on a global scale, which is at least 0.22 mGal better than that of others models. Moreover, in local coastal and high-latitude regions, SDUST2022GRA achieves an accuracy improvement of 0.16–0.24 mGal compared to others models. The spatial resolution of SDUST2022GRA is approximately 20 km in a certain region, slightly better superior others models. These assessments suggests that SDUST2022GRA is a reliable global marine gravity anomaly model. By comparing SDUST2022GRA with incorporating ICESat-2 and SDUST2021GRA without ICESat-2, the percentage contribution of ICESat-2 to the improvement of gravity anomaly model accuracy is 13 % in the global ocean region, and it is increasing with an proportion of ICESat-2 altimeter data in high-latitude and coastal regions. The SDUST2022GRA are freely available at the site of https://doi.org/10.5281/zenodo.8337387 (Li et al., 2023).

中文翻译：

---

从雷达和激光高度计数据恢复的SDUST2022GRA全球海洋重力异常：ICESat-2激光高度计的贡献

摘要。全球海洋重力异常模型主要是从沿轨雷达高度计数据中恢复的。尽管重力异常建模取得了显着进步，但重力异常模型的质量仍然受到跨轨迹大地水准面梯度缺失和雷达高度计数据减少的限制，特别是在沿海和高纬度地区。 ICESat-2激光测高仪运行三对激光束，占地面积小，位于近极轨道，能够确定跨轨道大地水准面梯度，并在某些区域提供更有效的观测。提出了ICESat-2高度计数据处理方法，包括跨轨迹大地水准面梯度的确定和沿/跨轨迹大地水准面梯度的组合。新的全球海洋重力模型 SDUST2022GRA 使用不同的方法从雷达和激光高度计数据中恢复，以确定每个高度计数据误差。 SDUST2022GRA 的准确性和空间分辨率通过已发布的全球重力异常模型（DTU17、V32.1、NSOAS22）和可用的船载重力测量进行评估。 SDUST2022GRA在全球范围内的准确度为4.43 mGal，比其他模型至少提高了0.22 mGal。此外，在当地沿海和高纬度地区，SDUST2022GRA 与其他模型相比，精度提高了 0.16-0.24 mGal。 SDUST2022GRA的空间分辨率在特定区域约为20公里，略优于其他模型。这些评估表明 SDUST2022GRA 是可靠的全球海洋重力异常模型。通过比较加入ICESat-2的SDUST2022GRA和不加入ICESat-2的SDUST2021GRA，ICESat-2对全球海洋区域重力异常模型精度提高的贡献百分比为13%，并且随着ICESat-2的比例不断增加高纬度和沿海地区的高度计数据。 SDUST2022GRA 可在 https://doi.org/10.5281/zenodo.8337387 网站上免费获取（Li et al., 2023）。