A.17 Hydrosphere<\/a> solicits research on the Earth’s Hydrosphere: to advance the understanding of the physics of Earth\u2019s water across the ocean, land, and the atmosphere. This Hydrosphere element is composed of three Earth science disciplines: ocean physics, terrestrial hydrology, and precipitation science. The overlapping goals of are to address fundamental questions about the distribution, movement, and transformation of water across the Earth system.<\/p>\n Specifically, this ROSES element targets measurements of ocean salinity, snow depth, and commercial satellite measurements of precipitation. These all enhance NASA investments in the Fate of River Export and Surface Hydrology field campaign, the NISAR mission, and data acquired via the NASA Commercial Satellite Data Acquisition program. A fourth subelement encourages the broadening of scope of these topics to other earth science disciplines across and outside of these core disciplines.<\/p>\n ROSES-2025 Amendment 72 releases A.17 Hydrosphere<\/a> as a new opportunity in ROSES-25. Step-1 proposals are due October 8, 2026, and Step-2 proposals are due January 28, 2027.<\/p>\n A briefing for potential proposers to this program element will occur Monday, September 14, from 2-3 PM Eastern Time. Connection information will be posted under “other documents” on the NSPIRES page for this program element<\/a>.<\/p>\n Questions concerning A.17 Hydrosphere<\/a> may be directed to Nadya Vinogradova Shiffer at nadya@nasa.gov<\/a>, Craig Ferguson at craig.r.ferguson@nasa.gov<\/a>, and Will McCarty at will.mccarty@nasa.gov<\/a>.<\/p>\n