NASA Cold Land Processes Workshop

1. NASA Cold Land Processes Workshop November 7-9, 2001 Boulder, Colorado Cold Land Processes Working Group NASA Earth Science Enterprise Land Surface Hydrology Program

2. Workshop Agenda Wednesday Review Status CLPX Data Collection Thursday Planning CLPX Data Management Friday Develop Roadmap CLP Science & Technology

3. Workshop Agenda Friday Develop Roadmap CLP Science & Technology 8:30 – 10:00 Introduction, Review of Science/Research Initiatives 10:00 – 10:15 Break 10:15 – 12:00 Review of Current Projects Related to CLPX Straw Outline for CLP Science and Technology Roadmap 12:00 – 12:15 Lunch (Catered) 12:15 – 3:30 Breakout Sessions: Discussions on Roadmap Discussion: Management of CLPX Data Sets 3:30 – 4:30 Presentations: Results from Breakout Sessions 4:30 – 5:00 Summary

4. CLP Working Group Task Assess, plan, and implement the science, technology, and application infrastructure necessary to address snow, ice, and freeze/thaw questions relevant to the NASA ESE research strategy for the next decade. Process Understanding Model Representation and Parameterization Remote Sensing Measurement Remote Sensing Data Assimilation

5. Cold Land Processes Initiatives NASA ESE Research Strategy USGCRP Blueprint for Water Cycle Research NASA ESE Strategic Plan NASA ESE Global Water And Energy Cycle Initiative (GWEC) NASA ESE Global Carbon Cycle Initiative NASA Post-2002 Mission Planning: Irvine Report NOAA GEWEX Americas Prediction Project (GAPP) UK Snow Research Priorities Others

6. USGCRP Water Cycle Initiative Three Questions Variability • What are the causes of water cycle variations • on both global and regional scales, and to what • extent is this variation induced by human activity? Goal 1: Quantify variability in the water cycle. Goal 2: Understand the mechanisms underlying variability in the water cycle. Goal 3: Distinguish human-induced and natural variations in the water cycle.

7. USGCRP Water Cycle Initiative Three Questions Prediction 2. To what extent are variations in the global and regional water cycle predictable? Goal 1: Demonstrate the degree of predictability in the water cycle. Goal 2: Improve predictions of water resources by quantifying fluxes between key hydrologic reservoirs. Goal 3: Establish a systems modeling framework for making predictions and estimates of uncertainty that are useful for water resource management, natural hazard mitigation, and policy guidance.

8. USGCRP Water Cycle Initiative Three Questions Linkages 3. How are water and nutrient cycles linked in terrestrial and freshwater ecosystems? Goal 1: Develop observations and experiments that characterize the coupling of water, carbon, and nitrogen cycles. Goal 2: Develop a quantitative predictive framework for water, carbon, and nitrogen fluxes coupled to ecosystem responses. Goal 3: Distinguish human-induced and natural variations in the coupling of water, carbon, and nitrogen cycles.

9. USGCRP Water Cycle Initiative Three Pillar Initiatives • Determine whether the global water cycle is intensifying and, if so, to what degree human activities are responsible. Key elements to address this initiative include: Better understanding of the processes governing space-time distributions of regional and global…snow and ice dynamics. Efforts to improve process understanding must be based on better observations of pertinent state variables, field experiments, and improvements in coupled atmosphere- land-ocean models.

10. USGCRP Water Cycle Initiative Three Pillar Initiatives 2. Determine the deeper scientific understanding needed to substantially reduce the losses and costs associated with water-cycle calamities such as droughts, floods, and coastal eutrophication, and incorporate it into prediction systems. Key elements to address this initiative include: Testing models with better observations, explicitly addressing conceptual model and parameter uncertainties, and comparing different model codes using data from carefully designed field experiments.

11. USGCRP Water Cycle Initiative Three Pillar Initiatives 3. Develop the scientifically based capacity to predict the effects of changes in land use, land cover, and cryospheric processes on the cycling of water and associated geochemical constituents. Cryospheric processes, which can be considered ephemeral changes in land cover, are critically important ot water resource issues. Key elements to address this initiative include: Assembling comprehensive data sets to evaluate land cover changes as they relate to the water cycle, and a program of enhanced, sustained observations of critical state variables.

12. NASA Strategic Plan ESE Strategic Implementation Approach Research Strategy/ Science Implementation Plan - Details science themes - Details observing, modeling, etc. requirements and plans Program Commitment Agreements & Program Plans Define program/project requirements, cost, schedule, and management. NASA Strategic Plan Applications Strategy - Approach to working with commercial providers of space systems and value-added data products - Education Objectives ESE Strategic Plan Establishes ESE mission, goals, and objectives, and lays out a roadmap for the future. Annual Performance Plan/Reports Define annual Performance metrics. • Technology Strategy • Defines technology investment and • infusion strategies

13. NASA ESE Strategic Plan Five Questions Variability 1. How is the global Earth system changing? Forcing 2. What are the primary forcings of the Earth system? 3. How does the Earth system respond to natural and human-induced changes? Response 4. What are the consequences of change in the Earth system for human civilization? Consequences 5. How well can we predict future changes to the Earth system? Prediction

14. NASA Strategic Plan Five Questions Variability 1. How is the global Earth system changing? Key elements of NASA’s Research Program over the Next Decade Science Question Required Knowledge 2002 – 2010 Missions How are global precipitation, evaporation, and the cycling of water changing? Atmospheric Temperature Atmospheric Water Vapor Global Precipitation Soil Moisture NPOESS Bridge Mission NPOESS Bridge Mission Future Global Precipitation Exploratory Soil Moisture

15. NASA Strategic Plan Five Questions 3. How does the Earth system respond to natural and human-induced changes? Response Key elements of NASA’s Research Program over the Next Decade Science Question Required Knowledge 2002 – 2010 Missions What are the effects of clouds and surface hydrologic processes on Earth’s climate? Cloud System Structure Cloud Particle Properties Earth Radiation Budget Soil Moisture Snow Cover & Accum. Land Freeze/Thaw Trans. NPOESS Bridge Mission Cloudsat, PICASSO Exploratory Soil Moisture Exploratory Cold Climate Exploratory Cold Climate

16. NASA Strategic Plan Five Questions 4. What are the consequences of change in the Earth system for human civilization? Consequences Key elements of NASA’s Research Program over the Next Decade Science Question Required Knowledge 2002 – 2010 Missions How are variations in local weather, precipitation, and water resources related to global climate variation? Global Precipitation Ocean Surface Winds Met. Properties around storms Lightning Rate River Stage and Discharge Future Global Precip Future cooperative GOES (improved) UNESS Future cooperative

17. NASA Strategic Plan Five Questions 5. How well can we predict future changes to the Earth system? Prediction Key elements of NASA’s Research Program over the Next Decade Science Question Required Knowledge 2002 – 2010 Missions How can weather forecast duration and reliability be improved by new space- based observations, data assimilation, and modeling? Tropospheric Winds Ocean Surface Winds Soil Moisture Sea Surface Temperature Domestic/Intl Partner Future cooperative Exploratory Soil Moisture Operational Satellites

18. NASA ESE Research Strategy Cold Land Processes Quantitative understanding of cold land processes over large areas will require synergistic advancements in: 1) Process Understanding Improved process-level understanding, especially of the interactions between vegetation and cold land processes.

19. NASA ESE Research Strategy Cold Land Processes Quantitative understanding of cold land processes over large areas will require synergistic advancements in: 2) Process Scaling Understanding how these processes, most comprehensively understood at local or hillslope scales, extend to larger scales.

20. NASA ESE Research Strategy Cold Land Processes Quantitative understanding of cold land processes over large areas will require synergistic advancements in: 3) Models Improved representation of these processes in coupled and uncoupled land surface models;

21. NASA ESE Research Strategy Cold Land Processes Quantitative understanding of cold land processes over large areas will require synergistic advancements in: 4) Measurement A breakthrough in large-scale observation of hydrologic properties, including snow characteristics, soil moisture, the extent of frozen soils, and the transition between frozen and thawed soil conditions.

22. NASA Global Water and Energy Cycle Cold Land Processes Synergistic advancements on these fronts requires that four major science questions be addressed together: 1) Process Understanding How do the extent and evolution of snow and frozen landscapes affect fluxes, storage, and transformations of water, energy, and carbon?

23. NASA Global Water and Energy Cycle Cold Land Processes Synergistic advancements on these fronts requires that four major science questions be addressed together: 2) Spatial Variability At what scales does spatial variability of key state variables in the terrestrial cryosphere control fluxes and transformations of water, energy, and carbon, and can remote sensing resolve this variability at these scales?

24. NASA Global Water and Energy Cycle Cold Land Processes Synergistic advancements on these fronts requires that four major science questions be addressed together: 3) Temporal Variability What are the rates of change of the dominant cold land processes and can remote sensing resolve these with sufficient accuracy to diagnose and improve land surface models?

25. NASA Global Water and Energy Cycle Cold Land Processes Synergistic advancements on these fronts requires that four major science questions be addressed together: 4) Uncertainty How do the various uncertainties associated with remote sensing observations and models of cold land processes constrain/affect data assimilation and the ability to improve prediction?

27. Multi-scale Convergence of Cold-land Process Representation in Land-surface Models, Microwave Remote Sensing, and Field Observations Don Cline NOAA NOHRSC Stan Benjamin NOAA Forecast Systems Lab Bert Davis US Army CRREL Kelly Elder USFS Ed Kim NASA GSFC Glen Liston Colorado State University Roger Pielke Sr. Colorado State University Jiancheng Shi University of California, Santa Barbara NASA Global Water and Energy Cycle (GWEC)

28. General Context Two Main Problems Despite recent improvements, land-surface models still suffer from significant misrepresentations of important cold-land processes, which cast doubt on predictions of future climate, weather, and hydrologic conditions in cold regions. There are significant discrepancies between the nature of remotely sensed measurments, land-surface models, and cold land processes.

29. General Context Six Questions Set Context • Do land-surface models adequately represent all the processes necessary for effective climate, weather, and hydrologic prediction? • Do land-surface models specifically represent the processes, variables, or parameters that remote sensing instruments measure? • Does remote sensing provide observations of quantities most needed for land surface models? • Do remote sensing retrieval algorithms – models themselves – provide unbiased, or at least consitently biased estimates of state variables with sufficient confidence to warrant using them to update land-surface models? • Do we typically use remote sensing in the most effective ways that we could to improve predictive models? • Are the processes, measurements, and models commensurate?

30. Science Questions Concepts of Scale and Uncertainty • What are the relationships between the scales of natural variability of cold-land processes in different environments, the scales of measurement by microwave remote sensing, and the scales of land surface models? • How do uncertainties, biases, and errors associated with remotely sensed microwave measurements and model representations of cold-land processes change with scale?

31. Hypothesis If the scale of current land-surface models and remotely sensed microwave measurements is gradually increased from point scales, then the ability of the models to successfully simulate the observed microwave response will diminish (i.e. divergence between the processes, measurements, and the models will increase). Nonlinear effects may result in abrupt performance reductions in this regard, at specific scales related to land-surface characteristics and heterogeneity.

33. Straw CLP Science & Tech Roadmap NASA ESE Research Strategy Objective USGCRP Blueprint for Water Cycle Research NASA ESE Strategic Plan NASA ESE Global Water And Energy Cycle Initiative (GWEC) NASA ESE Global Carbon Cycle Initiative NASA Post-2002 Mission Planning: Irvine Report NOAA GEWEX Americas Prediction Project (GAPP) UK Snow Research Priorities Others

34. Straw CLP Science & Tech Roadmap Numerous Topics and Issues Effects of Forest Cover and Complex Topography Subnivean Soil Moisture Dynamics Effects of Thin or Patchy Snow Covers Linkages between Snow/Frozen-soil Dynamics & Ecosystem Dynamics Uncertainty in Observations, Models Applications Parameter Estimation, Model Development Education Data Assimilation Integration – Multi-sensor Approaches Pathway to Operations Remote Sensing Technology Development International Collaboration Workshops, Meetings, Symposia

35. Straw CLP Science & Tech Roadmap Examples What are the effects of forest cover and topography on snow distribution, energy and mass exchanges between the atmosphere and the snow pack, end remote sensing measurement of cold land processes? Forests and other vegetation protruding above snow packs (and buried within) significantly influence energy and mass exchanges between the atmosphere and the surface, including effects on albedo and interception/sublimation, and have important implications for both optical and microwave remote sensing of cold land processes, including the effect of viewing geometry on the amount of forest canopy versus ground viewed by a sensor. Topography also strongly affects the measurement of CLP, through viewing geometry and other effects including the bidirectional reflectance and emissivity of snow. These effects are poorly understood, and are poorly represented or absent in land surface models and remote sensing algorithms.

36. Straw CLP Science & Tech Roadmap Examples How do antecedent soil moisture conditions and soil moisture dynamics affect soil freezing and thawing beneath seasonal snow covers, and can remote sensing be used effectively to observe and monitor subnivean soil moisture conditions? The infiltration of water into soils and the movement of water through soils is significantly affected by whether soils are frozen or thawed, and by the amount of soil moisture present. Frozen soils cans significantly increase the rate of runoff during snowmelt, and frequently are an important factor in snowmelt-related floods. Antecedent soil moisture conditions prior to the accumulation of snow are likely to change markedly during the snow season, due to vapor transport in the soil and due to intermittent rainfall or snowmelt during the snow season. The phase of the soil moisture may also change during the snow season depending on the timing and amount of snow accumulation.

37. Straw CLP Science & Tech Roadmap Examples What are the effects of thin and/or patchy snow covers on land- atmosphere energy and mass exchanges, and on optical and microwave remote sensing of cold land processes? During transitional seasons or in areas with little snowfall and ephemeral winter snow packs, snow covers are often thin and/or patchy. These transitional snow packs still strongly influence energy and mass exchanges between the land surface and the atmosphere, but widespread, thin snow packs may have very different effects than patchy snow covers. With optically remote sensing, optically thin snow packs are difficult to distinguish from patchy snow or from snow contaminated with dirt, soot, or other debris. Shallow snow covers also pose difficulties for microwave remote sensing.

38. Straw CLP Science & Tech Roadmap Examples What are the linkages between snow cover and frozen-soil dynamics And ecosystem dynamics at multiple spatial and temporal scales, Including biosphere-atmosphere carbon exchanges, export of Dissolved organic carbon (DOC), and nutrient availability? Snow pack and frozen soil dynamics are strongly linked with carbon fluxes both during and outside of the growing season. Fluxes of CO2 from snow-covered soils have been shown to be sensitive to small changes in the timing and amount of seasonal snow cover. The loss of DOC from terrestrial ecosystems can be important to terrestrial carbon balance and may be quite variable both spatially and temporally. Nitrogen availability during the growing season has been related to heterotrophic activity under snow cover during the previous winter in several environments, suggesting that variability of snow cover is likely to affect growing season carbon fixation by controlling the availability of limiting nutrients in seasonally snow-covered systems.

39. Straw CLP Science & Tech Roadmap Some Questions • Are CLPX data sets likely to be sufficient to enable significant progress • in these areas and other topics? • What additional data sets are needed? • What new technology is needed to address these questions? • What level of work is required to make significant progress? • Minor – 1 or 2 small, focused studies? • Major – Coordinated research initiatives? • Do these questions accurately and sufficiently address the issues? • What roadmap should be followed to address these issues over the next five years? • What has to happen immediately, in the short term, in the long term?