Snow Survey Results for the Central Alaskan Arctic, Arctic Circle to Arctic Ocean: Spring 2013

Many remote areas of Alaska lack meteorological data; this is especially true for solid precipitation. Researchers at the University of Alaska Fairbanks, Water and Environmental Research Center have been collecting end-of-winter snow cover observations (depth, density, snow water equivalent and ablation) since the year 2000. These observations do not document the total snowfall during the winter, but provide quantitative estimate of cold season precipitation on the ground at winter’s end after sublimation and redistribution by wind. This report provides summary of snow cover data collected during cold season of 2012–2013. There are two main areas of study. One includes drainage areas of the western Sagavanirktok, Kuparuk, Itkillik, Anaktuvuk and Chandler Rivers located north of the continental divide in the Brooks Range. While the number of sites has varied each year, we visited 76 sites in April of 2013 on the North Slope of Alaska. Second study area was established in 2012 in the drainage areas of the Kogoluktuk, Mauneluk, Reed, Alatna, and Koyukuk Rivers south of the Brooks Range. Fifty seven new snow survey sites were visited south of the Brooks Range in April 2013. The cold season of 2012-2013 experienced heavy snowfalls (record amounts since 2000) north of the Brooks Range. This was the first year of data collection south of the Brooks Range, thus no comparison can be made. SWE averaged over entire study area was 13.1 cm in 2013, ranging from 1.2 cm to 35.2 cm. Generally, higher SWEs were found in the western portion of the study area. Ablation was later than normal in spring 2013. Ablation window extended from May 8, 2013 in the far south of the study area to middle June at higher elevations on the north side of the Brooks Range.LIST OF FIGURES ....................................................................................................................... iii LIST OF TABLES ........................................................................................................................ vii DISCLAIMER ............................................................................................................................. viii UNITS, ABBREVIATIONS, AND SYMBOLS ........................................................................... ix ACKNOWLEDGMENTS ...............................................................................................................x ABSTRACT ................................................................................................................................... xi 1. INTRODUCTION .......................................................................................................................1 2. STUDY AREA ............................................................................................................................3 3. SAMPLING METHODS .............................................................................................................5 3.1 Snow Survey ..........................................................................................................................5 3.2 Snow Ablation .......................................................................................................................6 3.2.1 Observations from 1985 to 2012 .................................................................................... 8 3.2.2 Observations from 2013 ................................................................................................. 9 3.3 Snow Depth Sensors ............................................................................................................10 4. ACCURACY OF OBSERVATIONS ........................................................................................12 4.1 Snow Water Equivalent .......................................................................................................12 4.2 Snow Depth Sensors ............................................................................................................13 5. SPATIAL DISTRIBUTION OF SNOW SURVEY SITES.......................................................15 6. SNOW SURVEY DATA AT WATERSHED SCALE .............................................................18 7. SONIC SNOW DEPTH DATA .................................................................................................25 7.1 North of the Brooks Range Divide ......................................................................................25 7.2 South of the Brooks Range Divide ......................................................................................50 8. SURFACE WEATHER ANALYSIS ........................................................................................62 9. SWE CORRECTIONS ..............................................................................................................66 9.1 Snow Depth Increase in the Umiat Study Area ...................................................................66 9.2 Snow Depth Increase in the Ambler Study Area .................................................................67 10. ABLATION DATA .................................................................................................................68 11. SUMMARY .............................................................................................................................71 12. REFERENCES ........................................................................................................................73 APPENDIX A. Snow survey data .................................................................................................75 Appendix A1. Measured snow survey data for the Umiat Study Area, April 18-24, 2013. ...................................................................................................................................... 76 Appendix A2. Adjustment of the snow water equivalent for the Umiat Study Area, spring 2013. ........................................................................................................................... 78 Appendix A3. Measured Snow Survey Data for the Ambler Study Area, April 3‐9, 2013. ...................................................................................................................................... 80 Appendix A4. Adjustment of the snow water equivalent data for the Ambler Study Area, spring 2013. ................................................................................................................. 82 APPENDIX B. Ablation data ........................................................................................................84 Appendix B1a. Snow water equivalent (cm) in the Imnavait Creek basin 85-99 (basin average). ..................................................................................................................... 84 Appendix B1b. Snow water equivalent (cm) in the Imnavait Creek basin 00-13 (basin average). ..................................................................................................................... 85 Appendix B2. Snow water equivalent (cm) at the Upper Kuparuk (UK) site. ..................... 86 Appendix B3. Snow water equivalent (cm) at the Happy Valley (HV) site. ........................ 87 Appendix B4. Snow water equivalent (cm) at the Sagwon (SH) site. .................................. 89 Appendix B5. Snow water equivalent (cm) at the Franklin Bluffs (FR) site........................ 90 Appendix B6. Snow water equivalent (cm) at the Betty Pingo (BP) site. ............................ 92 Appendix B7. Snow water equivalent (cm) at the West Dock (WD) site. ........................... 93 Appendix B8. 2010 Snow water equivalent (cm) at the Atigun, Galbraith Lake and Oil Spill Hill sites. ................................................................................................................. 94 Appendix B9. 2011 and 2013 snow water equivalent (cm) at the Anaktuvuk River, Chandler River, Upper Itkilik River and Lower Itkillik meteorological sites. ..................... 95 Appendix B10. 2013 snow water equivalent (cm) at the Ambler Road Corridor project meteorological sites. ................................................................................................. 9

Standard Operating Procedure and Workplan for the Terrestrial Environmental Observation Network (TEON) – Arctic Landscape Conservation Cooperative: Kuparuk River Basin and Adjacent Catchments

TABLE OF CONTENTS ................................................................................................................. i DISCLAIMER ................................................................................................................................ ii CONVERSION FACTORS, UNITS, WATER QUALITY UNITS, VERTICAL AND HORIZONTAL DATUM, ABBREVIATIONS AND SYMBOLS .............................................. iii 1 INTRODUCTION .................................................................................................................. 1 2 STATION HISTORY ............................................................................................................. 5 3 DATA COLLECTION METHODS ....................................................................................... 8 3.1 Air Temperature and Relative Humidity ........................................................................ 12 3.2 Wind Speed and Direction ............................................................................................. 14 3.3 Radiation ........................................................................................................................ 15 3.3.1 Net Radiation .......................................................................................................... 15 3.3.2 Shortwave Radiation ............................................................................................... 16 3.3.3 Longwave Radiation ............................................................................................... 17 3.4 Summer Precipitation ..................................................................................................... 18 3.5 Snow Depth .................................................................................................................... 18 3.6 Field Snow Survey ......................................................................................................... 20 3.7 Water Levels .................................................................................................................. 21 3.8 Discharge Measurements ............................................................................................... 23 3.8.1 Acoustic Doppler Current Profiler .......................................................................... 25 4 STATION TELEMETRY ..................................................................................................... 28 5 DATALOGGER PROGRAM .............................................................................................. 30 6 METADATA ........................................................................................................................ 31 7 QUALITY CONTROL AND DATA PROCESSING .......................................................... 32 8 DATA REPORTING AND ARCHIVING ........................................................................... 33 9 REFERENCES ..................................................................................................................... 36 10 APPENDIX LIST ................................................................................................................. 3