ALEXI evapotranspiration product (v10E) at 36 km SMAP grid for CONUS

The ALEXI surface energy balance model is designed to estimate E for continental to global scale applications (Anderson et al., 2007, 2011). It maintains a physically realistic representation of land-atmosphere exchange over a wide range of landscapes, while being relatively independent of ancillary meteorological or plant functional information. Importantly for the present analysis, it does not require any knowledge of soil moisture conditions. The main diagnostic inputs to the ALEXI model are land surface temperature, net radiation (and its components), leaf area index (to inform partitioning of radiation between soil and canopy), windspeed, and the early morning lapse rate profile. The internal model structure solves the energy balance for the soil and canopy separately. ALEXI uses an atmospheric boundary layer model to translate the change in temperature over the morning hours into a self-consistent boundary layer temperature and to constrain the sensible heat flux. The product shared here is regridded from the 4 km CONUS ALEXI E daily product (v10E) for the 2015-2022 period to the coarser 36 km grid of the SMAP data. In addition, the corresponding downwelling short wave radiation (Rsw), obtained from the Climate Forecast System Reanalysis (Saha et al. 2014) is provided.ALEXI地表能量平衡模型（ALEXI surface energy balance model）由安德森等（Anderson et al., 2007, 2011）提出，旨在为大陆至全球尺度的蒸散发（E）估算任务提供支持。该模型可在广泛的景观类型下，对陆-气交换过程进行符合物理规律的真实刻画，且其运行相对独立于辅助气象数据与植物功能型信息。尤为关键的是，针对本次研究分析，该模型无需获取任何土壤湿度条件相关数据即可完成计算。 ALEXI模型的主要诊断输入参数包括地表温度、净辐射（及其各分量）、叶面积指数（用以划分土壤与植被冠层间的辐射分配）、风速，以及清晨大气递减率廓线。模型内部结构可分别求解土壤与植被冠层的能量平衡方程。ALEXI借助大气边界层模型，将清晨时段的温度变化转化为自洽的边界层温度，并以此约束感热通量的计算。 本次共享的数据集，是将2015-2022年期间的4公里分辨率美国本土（CONUS）ALEXI日尺度蒸散发产品（v10E）重采样至土壤湿度主动被动卫星（SMAP）数据的36公里粗分辨率网格后得到的。此外，本数据集还附带从气候预报系统再分析资料（Saha et al., 2014）获取的对应下行短波辐射（Rsw）数据。