Exploring the reservoirs, pathways, and methods to measure the hydrologic cycle

1. Exploring the reservoirs, pathways, and methods to measure the hydrologic cycle

2. Hydrologic Cycle Terminology “Reservoirs” are places where water is stored in the Earth system. “Transport pathways” describe the mechanisms and pathways that water moves among reservoirs in the Earth system. Cockell, 2008 Fig. 1-38

3. Annual Hydrological Cycle Cockell, 2008 Fig. 1-38

4. Reservoirs Annual Hydrological Cycle Cockell, 2008 Fig. 1-38

5. Annual Fluxes for Ocean Reservoir IN = OUT 391 + 46 = 437 Cockell, 2008 Fig. 1-38

6. Annual Fluxes for Atmospheric Reservoirs IN = OUT 436.5 + 65.5 = 391 + 111 502 = 502 Cockell, 2008 Fig. 1-38

7. How do scientists measure the hydrologic cycle? • Examples of “traditional” hydrologic measurements: • stream/river gaging stations • depth to groundwater • SNOTEL stations (snow mass) • Examples of geodetic hydrologic measurements: • Reflection GPS • Vertical GPS • GRACE

8. How do scientists measure the hydrologic cycle?stream/river gaging stations

9. Example: USGS Willow Creek gaging station 06035000 near Harrison, MT Used to calculate discharge (the volume of water moving through the channel in a given amount of time, i.e., flow rate)

10. USGS Daily Streamflow Conditions

12. USGS Willow Creek: Average Annual Discharge

13. USGS Willow Creek: Annual Peak Discharge

14. How do scientists measure the hydrologic cycle?Depth-to-groundwater using wells

15. Depth-to-groundwater using wells Surface elevation Depth to water Total depth of well Water level = (surface elevation) – (depth to water)

16. South Willow Nested Groundwater Wells (Alluvial)

17. USGS Groundwater Wells https://water.usgs.gov/ogw/

18. Example of Groundwater record for the South Willow Alluvial Wells

19. Understanding seasonal cycles in groundwater depths

20. How do scientists measure the hydrologic cycle?SNOTEL

21. SNOTEL stations Weight of snow on the pillow allows measurement of contained water mass

22. Albro Lake SNOTEL Site State: Montana Site Number: 916 County: Madison Latitude: 45 deg; 36 min N Longitude: 111 deg; 58 min W Elevation: 8300 feet Reporting since: 1996-09-11

23. Albro Lake SNOTEL Observations

24. Geodesy is… …the science ofaccurately measuring the Earth’s size, shape, orientation, mass distribution and the variations of these with time. Traditional geodesy: Precise positioning of points on the surface of the Earth Modern geodesy: A toolbox of techniques to better measure the Earth wikipedia.org JPL/NASA 24

25. How do scientists measure the hydrologic cycle?GRACE

26. GRACE Mission: Gravity Recovery and Climate Experiment

27. How GRACE Measures Gravity

28. Example of GRACE Groundwater Data

29. How do scientists measure the hydrologic cycle?GPS

30. GPS Networks Thousands of stations across continental United States Data latency of ~1 day http://geodesy.unr.edu/NGLStationPages/gpsnetmap/GPSNetMap.html

31. GPS Data Cycles in vertical position are related to the seasonal water changes.

32. GPS Vertical Position The solid Earth responds elasticallyto changes in load, such as water loss from regional groundwater pumping or drought instantaneous, reversible, linear Plate Boundary Observatory station P037

33. GPS Data

34. Reflected GPS Signals

35. Reflected GPS Signals