Donald W. Cline National Operational Hydrologic Remote Sensing Center National Weather Service, NOAA CLPM Planning Workshop June Fort Collins, Colorado

EX-7 What is the Cold Land Processes Mission? –The Terrestrial Cryosphere –NASA Post-2002 Mission Planning & EX-7 Mission Objectives –Major Science Questions –Measurement Goals Science Measurement and Modeling Requirements –Sensor Options: Type, Frequency, and Resolution –Modeling and Data Assimilation –Ground Segment Architecture Needed Pre-launch Science Investments –Science-oriented Trade Studies –Large Scale Airborne/Field Campaign Status of the Cold Land Processes Mission

EX-7 Cold areas of the Earth’s land surface where water is frozen either seasonally or permanently. What is the Cold Land Processes Mission? Hydrologic Focus

EX-7 What is the Cold Land Processes Mission? NASA Request for Information (RFI), April 1998 –To develop a nominal mission scenario for –100 responses reviewed by six NASA disciplinary panels –Integrated into 23 mission concepts in three categories: EOS follow-on Missions (EOS) – for systematic measurement of critical parameters Earth Probe Missions (EX) –for exploratory research or focused process studies –included the Cold Land Processes Mission (EX-7) Operational Prototype Missions (OP) –for instrument development

EX-7 What is the Cold Land Processes Mission? Earth Probe Missions (EX) –Each EX mission considered essential for advancement of respective disciplines No particular priority –Intended to follow the model of Earth System Science Pathfinder (ESSP) Baseline mission descriptions allow science, technology, and programmatic planning Select missions as late as possible in implementation process to ensure latest science and technology issues are addressed. Missions not selected until science and technology are “mission-ready”

EX-7 What is the Cold Land Processes Mission? Easton, MD Workshop (August, 1998) –150 participants, in disciplinary and interdisciplinary panels –Reviewed and amended the nominal mission scenario –Report published November, 1998 –Endorsed the nominal Cold Land Processes Mission Concept Measure snow water equivalent and frozen ground SAR imaging techniques at moderate-high resolution ( # 1 km) with a short repeat cycle ( # 3 days)

EX-7 What is the Cold Land Processes Mission? Irvine, CA Workshop (April, 1999) –NASA Land Surface Hydrology Program convened a workshop to refine three hydrology-related missions 15 participants for EX-7 –Prepared EX-7 Science and Technology Implementation Plan Refined nominal mission concept Identifies key science and technology development/investments needed to become “mission-ready”

EX-7 How does the extent of snow and frozen ground affect weather and climate? Can the components of the terrestrial cryosphere be observed from space accurately enough to identify meaningful climatic trends? To what extent can this information improve models of cold season processes, hydrologic forecasts and forecasts of high-latitude ecosystem functions? To what accuracy can snow water equivalent be estimated from remote sensing data, and is this sufficient for hydrologic applications? Mission Objectives …Science Drivers

EX-7 Mission Objectives Determine the fundamental freeze/thaw state of the land surface. Determine the physical characteristics of snow cover: snow extent, snow depth, snow density, and the amount of free liquid water (snow wetness). …Science Drivers

EX-7 Science Measurement and Modeling Requirements Synthetic Aperture Radar (SAR) Dual-frequency (L- and X-band) Dual-polarization Duty Cycle (Sensor Activation) All latitudes between 30 o N-75 o N All elevations over 1000 m Resolution Moderate Spatial (250 m - 1 km) High Temporal (1-3 days)

EX-7 Science Measurement and Modeling Requirements Simultaneous Measurements Radar data for each frequency collected simultaneously from the same spacecraft or from two spacecraft flown in formation. Interferometry Sensor configuration must support cross-track interferometry.

EX-7 Science Measurement and Modeling Requirements Physical Modeling and Data Assimilation Required to integrate remotely sensed information and ancillary information in a comprehensive manner. Ground Segment Architecture Although a research mission, demonstrate a clear path to operational hydrology and meteorology.

EX-7 Science Measurement and Modeling Requirements At $400M, a dual-frequency dual-pol. SAR is likely too expensive for NASA to put into its own budget. Three obvious cost reduction strategies: International Partnerships DOD Buy-down Specification Reduction

EX-7 Science Measurement and Modeling Requirements Single-Frequency SAR Low-frequency only (e.g. L-band), similar spatial and temporal resolutions and duty cycle. Suitable for freeze/thaw status retrieval, but not snow retrieval. Dual-Frequency Passive Microwave Radiometer Dual-polarization 19 and 37 GHz, with moderate spatial (1-5 km) and high temporal (1-3 days) resolution. Combined Active/Passive Microwave Single-frequency L-band SAR for freeze/thaw, plus dual-frequency passive radiometer for snow.

EX-7 Science Measurement and Modeling Requirements NextSAR: LightSAR Legacy, Learning Experience Market risks and potential returns on investments do not justify an industry investment in a science-focused L-band only mission. If commercial enhancements are added (e.g. dual- frequency, high-resolution), the market potential increases, but so do costs, market risks, and uncertainty.

EX-7 Science Measurement and Modeling Requirements Oil Spill Liability Trust Fund (OSLTF) Petroleum industry interested in a dual-frequency (L- and X-band) dual-polarization SAR for oil spill monitoring. OSLTF provides an opportunity to co-fund $400M SAR mission with commercial partners.

EX-7 Needed Pre-launch Science Investments Snow Algorithms Retrieve snow properties with fewer SAR measurements. (e.g. develop 2-frequency algorithms instead of 3-frequency algorithms) Snow Algorithms Evaluate performance limits to snow detection and measurement under wide range of conditions. Freeze/Thaw Algorithms Develop algorithms to partition freeze/thaw processes between different land cover elements (e.g. soil).

EX-7 Needed Pre-launch Science Investments Modeling and Data Assimilation Strategies needed to organize and analyze temporal information retrieved from RS data (e.g. track changes in freeze/thaw status, use time series in algorithms) Modeling and Data Assimilation Strategies needed to assimilate RS data directly into physical land surface models, including development of appropriate snow models and an ability to predict backscatter/emission using forward DMRT models.

EX-7 Needed Pre-launch Science Investments Resolution Requirements What are trade-offs of different spatial and temporal resolution options for both algorithm performance (e.g. S/N) and for measurement applications? Sensor Requirements What are trade-offs of different sensor configurations? Algorithm Requirements What are trade-offs of different algorithms on measurement accuracy/confidence, geographic application, and data processing?

EX-7 Critical for Science Development A comprehensive ground truth database that has consistency across all locations of field campaigns is required to support investigations pursuing the science questions. Needed Pre-launch Science Investments

EX-7 Comprehensive in Scope The lack of wide variation in snow cover properties, land cover, and terrain in testing current algorithms has prevented a thorough determination of the accuracy and suitability of different approaches. Needed Pre-launch Science Investments

EX-7 Multi-sensor, Multi-purpose, Legacy Dataset Simultaneous RS observations from active, passive, and optical sensors, combined with intensive ground observations and distributed modeling information will provide the basis for firming up candidate candidate algorithms and sensor options. Needed Pre-launch Science Investments

EX-7 Understanding Earth System Change, NASA’s Earth Science Enterprise Research Strategy (Draft) Status of the Cold Land Processes Mission …exploratory observations of soil moisture, snow accumulation, and freeze/thaw transitions… will provide critical process-level information... New active and passive remote sensing techniques from space may lead to global observations of soil moisture, snow water equivalent, freeze-thaw transitions,...

EX-7 Understanding Earth System Change, NASA’s Earth Science Enterprise Research Strategy (Draft) Status of the Cold Land Processes Mission Quantitative understanding of hydrologic processes over large areas…will require a breakthrough in large-scale observation of hydrologic properties... Specific observational requirements to address this problem include… exploratory measurements of soil moisture, snow accumulation, and the transition between frozen and thawed soil conditions.