President's Excellence Fund Symposium Welcome to our Virtual Event X-Grants | T3

Developing a SmallSat Mission to Track the Global Movement of Water, Carbon, and Sediment across Land

George Allen, Huilin Gao, Daniel Selva Valero, Helen L Reed

The decline of inland water quality has become a global issue of concern as accelerating land use and climate change are causing significant alterations to the hydrological cycle. Changes in water quality are fundamentally related to changes in the hydrology of inland water bodies (e.g., lake levels, river discharge, water residence time). Thus, understanding the drivers of changing water quality requires cotemporal observations of changing water quality and water quantity. While cotemporal observations of water quality and water quantity can be collected locally on the ground, global-scale studies of Earth’s water resources typically rely on satellite remote sensing observations. Satellites with optical sensors can be used to track changing water quality and satellites with altimetry instruments can be used to track the movement of water across Earth’s surface. However, no existing or planned satellite missions possess instruments with sufficient spectral, spatial, and temporal resolutions needed to observe changes in inland water quality and quantity. In this project we will identify the key science questions related to water quality variables that have not been adequately addressed by the science community. We will then determine the geophysical measurements and observables needed to address these questions and develop multiple novel SmallSat mission concepts (SMCs) that address the scientific goal and meet the defined requirements and constraints. Much of this project’s analysis will involve exploring the complex tradespace of spatial-spectral coverage and resolution needed to address the defined science questions. After developing multiple SMCs, we will work with outside collaborators to select a preferred concept and propose it to the NASA Earth Venture Instrument (NASA-EVI-6) program in late 2023. We will also develop at least one science-driven proposal focused on constraining changes in inland water quality using multi-source data from existing satellites, to be submitted to NASA, NSF, DOE, or another external funding source.