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Abstract Irrigation is increasingly important to agricultural production and supply chains in the United States. In this study, we seek to understand how irrigation (blue) water footprints of production are spatially distributed and how they differ in drought versus non‐drought years. Similarly, we aim to understand the impact of drought on the irrigation virtually embedded in domestic supply chains and exports. To this end, we quantify the blue water footprints of agricultural products per unit mass produced (Virtual Water Content (VWC)) by surface, groundwater, and groundwater depletion sources, and then trace how this water is embedded in domestic agricultural commodity transfers and exports (Virtual Water Transfers (VWT)) for counties in a drought (2012) and non‐drought (2017) year. Overall, we find that total VWC values are larger in drought than non‐drought conditions across commodity groups, driven by surface water withdrawals. Conversely, VWT is larger in non‐drought than drought, driven by larger commodity mass fluxes during non‐drought. Our results highlight the importance of sustainably managing water resources so that they are available to mitigate the impact of future droughts on agricultural production and supply chains. 

Abstract Laboratory-derived optical constants are essential for identifying ices and measuring their relative abundances on solar system objects. Almost all optical constants of ices important to planetary science come from experiments with transmission geometries. Here we describe our new experimental setup and the modification of an iterative algorithm in the literature to measure the optical constants of ices from experiments with reflectance geometries. We apply our techniques to CH₄ice and H₂O ice samples and find good agreement between our values and those in the literature, except for one CH₄band in the literature that likely suffers from saturation. The work we present here demonstrates that labs with reflectance geometries can generate optical constants essential for the proper analysis of near- and mid-infrared spectra of outer solar system objects such as those obtained with the James Webb Space Telescope.