Abstract. Evapotranspiration (ET) is responsible for regulating the hydrological cycle with a relevant impact on air humidity and precipitation, particularly important in the context of acute drought events in recent years. With the intensification of rainfall deficits and extreme heat events, the Mediterranean region requires regular monitoring to enhance water resources management. Even though remote sensing provides spatially continuous information for estimating ET on large scales, existing global products with spatial resolution ≥ 0.5 km are insufficient to capture spatial detail at a local level. In the framework of the ESA 4DMed-Hydrology project, we generate an ET dataset at both high spatial and temporal resolutions by the Priestley-Taylor Two-Source Energy Balance model (TSEB-PT) driven by Copernicus satellite data. We build an automatic workflow to generate 100-m ET product by combining data from Sentinel-2 (S2) MSI and Sentinel-3 (S3) land surface temperature (LST) with ERA5 climate reanalysis derived within the period 2017–2021 over four Mediterranean basins in Italy, Spain, France, and Tunisia (Po, Ebro, Hérault, Medjerda). First, original S2 data are pre-processed before deriving 100-m inputs for the ET estimation. Next, biophysical variables, like leaf area index, and fractional vegetation cover are generated, and then they are temporally composted within a 10-day window according to Sentinel-3 acquisitions. Consequently, decadal S2 mosaics are used to derive the remaining TSEB inputs. In parallel, we sharpen 1-km S3 by exploiting dependency between coarse-resolution LST and 100-m S2 reflectances using the decision trees algorithm. Afterward, climate forcings are utilized for modeling energy fluxes, and next for daily ET retrieval. The daily ET composites demonstrate reasonable TSEB-PT estimates. Based on the validation results against eight Eddy Covariance (EC) towers between 2017–2021, the model predicts 100-m ET with an average root mean square error of 1.38 mm day^-1 and Pearson coefficient equal to 0.60. Regardless of some constraints, mostly related to the high complexity of EC sites, TSEB-PT can effectively estimate 100-m ET, which opens up new opportunities for monitoring the hydrological cycle on a regional scale. The full dataset is freely available at https://doi.org/10.48784/b90a02d6-5d13-4acd-b11c-99a0d381ca9a, https://doi.org/10.48784/fb631817-189f-4b57-af6a-38cef217bad3, https://doi.org/10.48784/70cd192c-0d46-4811-ad1d-51a09734a2e9, and https://doi.org/10.48784/7abdbd94-ddfe-48df-ab09-341ad2f52e47 for Ebro, Hérault, Medjerda, and Po catchments, respectively (Bartkowiak et al., 2023a–d).

中文翻译：

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基于哥白尼的地中海地区 100 米空间分辨率的蒸散发数据集

摘要。蒸散量（ET）负责调节水文循环，对空气湿度和降水产生相关影响，在近年来的严重干旱事件中尤其重要。随着降雨不足和极端高温事件的加剧，地中海地区需要定期监测以加强水资源管理。尽管遥感为估算大尺度蒸散提供了空间连续信息，但现有空间分辨率≥0.5公里的全球产品不足以捕获局部水平的空间细节。在 ESA 4DMed-Hydrology 项目的框架中，我们通过哥白尼卫星数据驱动的 Priestley-Taylor 双源能量平衡模型 (TSEB-PT) 生成高空间和时间分辨率的 ET 数据集。我们建立了一个自动工作流程，通过将 Sentinel-2 (S2) MSI 和 Sentinel-3 (S3) 陆地表面温度 (LST) 的数据与 2017 年至 2021 年期间四个地中海地区的 ERA5 气候再分析相结合，生成 100 米 ET 产品。意大利、西班牙、法国和突尼斯盆地（波河、埃布罗、埃罗、梅杰尔达）。首先，在导出用于 ET 估计的 100-m 输入之前对原始 S2 数据进行预处理。接下来，生成生物物理变量，如叶面积指数和植被覆盖率，然后根据 Sentinel-3 采集数据在 10 天的窗口内暂时堆肥。因此，十年 S2 镶嵌用于导出剩余的 TSEB 输入。同时，我们利用决策树算法利用粗分辨率 LST 和 100 米 S2 反射率之间的依赖性来锐化 1 公里 S3。然后，利用气候强迫对能量通量进行建模，然后进行每日 ET 检索。每日 ET 综合数据显示了合理的 TSEB-PT 估计值。根据 2017 年至 2021 年期间对 8 个涡协方差 (EC) 塔的验证结果，该模型预测 100 米 ET，平均均方根误差为 1.38 mm day ^-1，皮尔逊系数等于 0.60。尽管存在一些限制（主要与 EC 站点的高度复杂性有关），TSEB-PT 仍可以有效估计 100 米 ET，这为监测区域尺度的水文循环开辟了新的机会。完整数据集可在 https://doi.org/10.48784/b90a02d6-5d13-4acd-b11c-99a0d381ca9a、https://doi.org/10.48784/fb631817-189f-4b57-af6a-38cef217bad3、https://doi.org/10.48784/fb631817-189f-4b57-af6a-38cef217bad3 上免费获取。 /doi.org/10.48784/70cd192c-0d46-4811-ad1d-51a09734a2e9 和 https://doi.org/10.48784/7abdbd94-ddfe-48df-ab09-341ad2f52e47 分别适用于 Ebro、Hérault、Medjerda 和 Po 流域（ Bartkowiak 等人，2023a-d）。