The National Academies of Sciences, Engineering, and Medicine in collaboration with the InterAcademy Partnership and the European Academies Science Advisory Committee held a workshop in November 2019 to bring together researchers and public health officials from different countries and across several relevant disciplines to explore what is known, and what critical knowledge gaps remain, regarding existing and possible future risks of harmful infectious agents emerging from thawing permafrost and melting ice in the Arctic region. The workshop examined case studies such as the specific case of Arctic region anthrax outbreaks, as a known, observed risk as well as other types of human and animal microbial health risks that have been discovered in snow, ice, or permafrost environments, or that could conceivably exist. The workshop primarily addressed two sources of emerging infectious diseases in the arctic: (1) new diseases likely to emerge in the Arctic as a result of climate change (such as vector-borne diseases) and (2) ancient and endemic diseases likely to emerge in the Arctic specifically as a result of permafrost thaw. Participants also considered key research that could advance knowledge including critical tools for improving observations, and surveillance to advance understanding of these risks, and to facilitate and implement effective early warning systems. Lessons learned from efforts to address emerging or re-emerging microbial threats elsewhere in the world were also discussed. This publication summarizes the presentation and discussion of the workshop. Table of Contents Front Matter Overview Session 1: What Do We Know? Session 2: What Do We Need to Know? Session 3: Research and Operational Paths Forward Final Thoughts: Impacts of Microbial Threats on Stakeholder Organizations References Appendix A: Statement of Task Appendix B: Planning Committee Biosketches Appendix C: Workshop Agenda Appendix D: Workshop Participants

Improved observations of the atmospheric boundary layer (BL) and its interactions with the ocean, land, and ice surfaces have great potential to advance science on a number of fronts, from improving forecasts of severe storms and air quality to constraining estimates of trace gas emissions and transport. Understanding the BL is a crucial component of model advancements, and increased societal demands for extended weather impact forecasts (from hours to months and beyond) highlight the need to advance Earth system modeling and prediction. New observing technologies and approaches (including in situ and ground-based, airborne, and satellite remote sensing) have the potential to radically increase the density of observations and allow new types of variables to be measured within the BL, which will have broad scientific and societal benefits. In October 2017, the National Academies of Sciences, Engineering, and Medicine convened a workshop to explore the future of BL observations and their role in improving modeling and forecasting capabilities. Workshop participants discussed the science and applications drivers for BL observation, emerging technology to improve observation capabilities, and strategies for the future. This publication summarizes presentations and discussions from the workshop. Table of Contents Front Matter Overview Science and Applications Drivers for Boundary Layer Observations Emerging Technology for Observations Strategies for Future Observation Final Thoughts Appendix A: Statement of Task Appendix B: Planning Committee Biosketches Appendix C: Workshop Agenda Appendix D: Workshop Participants

Water of appropriate quantity and quality is essential for drinking, sanitation, and food, energy, and industrial production for any society and is derived for most needs from surface- or groundwater sources. Studies suggest that groundwater use in irrigation globally is increasing in total volume as well as a percentage of all water used for irrigation, with the demand for groundwater resources increasing as available primary surface water supplies are depleted. Particularly in arid regions, groundwater may be the most accessible water supply for any purpose, leaving groundwater withdrawals concentrated in areas that are already experiencing water stress. Even in the presence of direct ground observations and measurements of the water table, quantitative evaluation of groundwater storage, flow, or recharge at different scales requires remotely sensed data and observations applied to groundwater models. Resolving the interaction of groundwater storage, flow, and recharge at a scale at which basins are managed requires remotely sensed data and proxy data. In June 2019, the Water Science and Technology Board of the National Academies of Sciences, Engineering, and Medicine convened a workshop to identify scientific and technological research frontiers in monitoring and modeling groundwater recharge and flow in various regions of the world. The goals of the workshop were to assess regional freshwater budgets under major use scenarios, including agriculture, industry, and municipal; examine state of the art research frontiers in characterizing groundwater aquifers, including residence time, quantity, flow, depletion, and recharge, using remotely sensed observations and proxy data; discuss groundwater model uncertainties and methods for mitigating them using sparse ground observations or data and other approaches; and consider our ability to detect which water management strategies that affect groundwater flow and recharge are being used and any changes in their use over time. This publication summarizes workshop presentations and plenary discussions. Table of Contents Front Matter 1 Overview 2 Regional Freshwater Budgets Under Major Use Scenarios 3 Research Frontiers in Characterizing Groundwater Aquifers 4 Mitigating Groundwater Model Uncertainties 5 Changes in Water Management Strategies Over Time 6 Final Thoughts References Appendix A: Statement of Task Appendix B: Planning Committee Biosketches Appendix C: Workshop Agenda Appendix D: Workshop Participants Appendix E: Speaker Abstracts