May 2021 A Strategy for the National Coordinated Soil Moisture Monitoring Network Coordinated, High-Quality, Nationwide Soil Moisture Information for the Public Good Prepared for NIDIS by the Executive Committee of the National Coordinated Soil Moisture Monitoring Network On the cover: USDA soil moisture and weather station, Ft Cobb, Oklahoma. Credit: Mike Cosh 2 NATIONAL COORDINATED SOIL MOISTURE MONITORING NETWORK MAY 2021 Table of Contents Report Contributors ...................................................5 Acronyms ............................................................7 Executive Summary...................................................10 CHAPTER 1: INTRODUCTION . 12 1.1 Background ......................................................12 CHAPTER 2: SUMMARY OF STATEWIDE, REGIONAL, AND NATIONAL SOIL MOISTURE MONITORING . 15 2.1 Soil Moisture Monitoring Programs ..................................15 2.2 Sensing Frequency, Reporting Interval, and Period of Record............17 2.3 Sensor Type ......................................................18 2.4 Measurement Depths..............................................19 2.5 Data Quality and Completeness .....................................20 2.6 Integration and Synthesis ..........................................21 CHAPTER 3: MODELING AND REMOTE SENSING . 23 3.1 Introduction ......................................................23 3.2 Land Surface Models ..............................................24 3.3 Satellite Soil Moisture..............................................25 3.4 Calibration and Validation Methodology..............................28 3.4.1 Validation and Scaling . 28 3.4.2 Data Assimilation ............................................31 3.5 Applications . .32 3.6 Future Directions..................................................32 CHAPTER 4: CONSIDERATIONS IN SOIL MOISTURE NETWORK DESIGN . 33 4.1 Design Goals and Assumptions . .33 4.2 Key Network Design Decisions . 34 4.2.1 Where should new stations be added? ...........................34 4.2.2 What depths should be monitored? .............................38 4.2.3 What sensors should be used? ..................................40 4.3 Engaging Users in Network Design ..................................45 CHAPTER 5: INSTALLATION AND MAINTENANCE OF SOIL MOISTURE STATIONS . 47 5.1 Pre-Installation Guidance...........................................47 5.2 Sensor Installation ................................................48 5.3 After-Sensor Installation . .48 5.4 Station Data Management..........................................49 5.4.1 Station Metadata .............................................49 5.4.2 Sensor Sampling and Data Aggregation Methodology ..............49 3 NATIONAL COORDINATED SOIL MOISTURE MONITORING NETWORK MAY 2021 5.5 Maintenance .....................................................49 5.5.1 Site Calibration ...............................................49 5.5.2 Preventive Maintenance .......................................50 5.5.3 Unscheduled Maintenance . .50 5.5.4 Maintenance of Site Land Cover.................................50 5.6 Quality Control ...................................................50 5.6.1 Seasonal Range Tests..........................................50 5.6.2 Sensor Intercomparisons ......................................51 5.6.3 Temporal Consistency . .51 5.6.4 Spatial Coherency .............................................51 5.7 Recommendations for NCSMMN . 51 CHAPTER 6: IMPLEMENTATION OF THE NCSMMN: THE PATH FORWARD . 52 6.1 National Network Design...........................................52 6.2 Network Establishment ............................................53 6.2.1 Existing Networks .............................................53 6.2.2 Data Aggregation .............................................54 6.2.3 Data Ownership . 55 6.2.4 Resources and Technical Assistance Needed for Monitoring Network Partnerships ....................................55 6.2.5 Expanded Monitoring..........................................56 6.3 Data Quality Standards and Assessment .............................57 6.4 National Soil Moisture Products from the NCSMMN....................58 6.4.1 The Value and Uses of NCSMMN Soil Moisture Products............58 6.4.2 User-Specific Needs for National Soil Moisture Products............60 6.4.3 Creating and Hosting a Suite of NCSMMN Soil Moisture Products .................................................61 6.4.4 Research Needed to Enable Creation of NCSMMN Soil Moisture Products .................................................62 6.5 Communication, Coordination, and Collaboration . .63 6.5.1 Collaboration and Coordination for NCSMMN Soil Moisture Products .................................................63 6.5.2 Citizen Science Collaboration ...................................63 6.5.3 External Communication .......................................64 6.6 Network Management .............................................65 6.7 Funding for the National Coordinated Soil Moisture Monitoring Network ..................................................66 6.8 Recommendations and Next Steps . 66 References . 69 APPENDIX A: REGIONAL CASE STUDY: THE UPPER MISSOURI RIVER BASIN SOIL MOISTURE AND PLAINS SNOW MONITORING NETWORK . 74 A.1 Background ......................................................74 A.2 Federal Support ..................................................74 A.3 Value to the USACE and the Upper Missouri River Basin ................74 A.4 Network Goals....................................................74 A.5 Funding Structure .................................................75 A.6 Completed and Ongoing Work ......................................75 4 NATIONAL COORDINATED SOIL MOISTURE MONITORING NETWORK MAY 2021 Report Contributors NCSMMN EXECUTIVE COMMITTEE Michael Cosh, Chair USDA-ARS Bruce Baker NOAA-ATDD John Bolten NASA-GSFC Mark Brusberg Todd Caldwell USDA-Office of the Chief Economist Jordan Clayton USGS-NevadaUSDA-NRCS WSC Veva Deheza NOAA-NIDIS Nathan Edwards Peter Goble South Dakota Mesonet, South Dakota State University Heather Hofman ColoradoUSDA-NRCS State University Tyson Ochsner Steven Quiring Oklahoma State University Charles Schalk Ohio State University Marina Skumanich USGS-WMANOAA-NIDIS Mark Svoboda Molly Woloszyn NationalNOAA-NIDIS Drought Mitigation Center/University of Nebraska, Lincoln ADDITIONAL CONTRIBUTORS Jennie Atkins Edward Ayres Illinois Climate Network, Illinois State Water Survey, University of Illinois Jesse Bell National Ecological Observatory Network (NEON) Rajat Bindlish UniversityNASA-GSFC of Nebraska Medical Center Kevin Brinson Jerald Brotzge Delaware Environmental Observing System, University of Delaware Colin Campbell New York State Mesonet, University at Albany Wade Crow METERUSDA-ARS Group, Inc. & Washington State University 5 NATIONAL COORDINATED SOIL MOISTURE MONITORING NETWORK MAY 2021 Steve Evett USDA-ARS Ty Ferre Chris Fiebrich University of Arizona Trent Ford Oklahoma Mesonet, University of Oklahoma Brian Fuchs Southern Illinois University Nandita Gaur National Drought Mitigation Center/University of Nebraska, Lincoln Kevin Grode University of Georgia Brian Hornbuckle US Army Corps of Engineers Kevin Hyde Iowa State University Brad Illston Montana Mesonet, University of Montana Kelsey Jencso Oklahoma Mesonet, University of Oklahoma Scott Jones University of Montana Venkat Lakshmi Utah State University Rezaul Mahmood University of Virginia Tilden Meyers UniversityNOAA ATDD of Nebraska, Lincoln Binayak Mohanty Shawn Naylor Texas Water Observatory, Texas A&M University Charles O’Connell Indiana University Elizabeth Ossowski KentuckyNOAA-NIDIS Mesonet, Western Kentucky University Andres Patrignani Tom Penning Kansas State University Richard Pouyat Irrometer Co., Inc. Megan Schargorodski U.S. Forest Service, Emeritus Robert Schwartz KentuckyUSDA-ARS Mesonet, Western Kentucky University Kevin Stamm Cindy West US Army Corps of Engineers Elizabeth Wilson U.S. Forest Service Youlong Xia Synoptic Data PBC Chip Zimmer NOAA NCEP State of Kentucky Document drafted and prepared for NIDIS by the Executive Committee of the National Coordinated Soil Moisture Monitoring Network (NCSMMN). Special thanks to Adam Lang for editing, and Fiona Martin of Visualizing Science for layout formatting. 6 NATIONAL COORDINATED SOIL MOISTURE MONITORING NETWORK MAY 2021 Acronyms 3D/4D DA AMSR-E 3-Dimensional / 4-Dimensional DEOS Data Assimilation Advanced Microwave Scanning Delaware Environmental Radiometer for the Earth DEWS Observing System ANN Observing System DoD Drought Early Warning System API Artificial Neural Network DOE U.S. Department of Defense ARM Application Program Interface EC U.S. Department of Energy DOE Atmospheric Radiation EM Executive Committee ARS Measurement Program EnkF Electromagnetic USDA Agricultural Research ASCAT Service EPA Ensemble Kalman Filter ASM Advanced Scatterometer U.S. Environmental Protection ESA Agency ATBD Average Soil Moisture ExpF European Space Agency Algorithm Theoretical Basis CART Documents ftp/LDM Exponential Filter CLM Cloud and Radiation Testbed File Transfer Protocol / Local GCOM-W CLSM Data Manager Community Land Model Global Change Observation CMI Catchment Land Surface Model CoCoRaHS Crop Moisture Index GeoTiff Mission for Water Community Collaborative Rain, Geo-reference Tagged Image COOP Hail, and Snow Network GHz File Format NOAA Cooperative Observer GNSS Gigahertz CORS Program Global Navigation Satellite Continuously Operating GPM System COSMOS Reference Stations Global