Hydrologic Research at Reynolds Creek: ey o ds C ee
The southernmost node of the IP3 network
Dr. Timothy E. Link: University of Idaho
Dr
Timothy E Link: University of Idaho
Dr. Danny Marks: Northwest Watershed Research Center
And many others…
IP3 Scope and Focus:
y Understanding key climate system processes
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y
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relating to:
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y Land surface, regional climate, cryosphere
y Parameterizing land surface processes relevant to coupled atmospheric‐hydrological systems in cold regions
y Validating and improving models for weather and climate systems ‐
y Better prediction of climate and weather impacts on water resources in cold climates
i ld li
Presentation Overview
y Reynolds Creek Infrastructure
y Summary of Active Research y
y
y
y
Long‐term climate and flow trends
Long
term climate and flow trends
Long‐term water balance
Snow distribution
Snowcover energetics
y Turbulent fluxes over snow
y Vegetation‐snowcover
V
i
i
interactions
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y Future Directions
Reynolds Creek Experimental Watershed
Tollgate Basin
Area: 54.6 km2
Elev: 1410 ‐ 2241 m
831 m relief
RCEW (239 km2):
• 27 climate stations
7
• 36 precipitation stations
• 5 EC systems
• 11 weirs (nested)
• 6 soil microclimate stations
• 2 hill‐slope hydrology sites
• 4 instrumented catchments
• 3 instrumented headwater basins: USC (0.25 km2, 186m relief) ephemeral, p
groundwater dominated, annual precipitation 300‐500mm
RME (0.38 km2, 116m relief) perennial, surface water dominated, annual surface water dominated annual precipitation 750‐1200mm
Johnston Draw (1.8 km2, 380m relief) ephemeral, rain‐snow boundary, annual precipitation 400‐800mm
Tollgate Subwatersheds
How will mountain hydrology and y
gy
water resources be affected?
y Humidity has increased
y More rain makes the distribution of snow more uniform, causing earlier melt, reduced peak SWE & streamflow
y If If snow is limited to higher elevations i li it d t hi h l ti y Reduced area (volume)
y “flashier”, less reliable spring freshet
flashier , less reliable spring freshet
y less growing season H2O, increased ecosystem stress
Upper Sheep Creek
0.25 km2, 186m relief
Fire planned for 2008 Intensive Snow Surveys
•1984 – 1994
•2004 – 2008
•10 & 23 year Water Balance Reconstruction
•Excellent Basin for Testing Distribution Algorithms Developed at RME
Upper Sheep Creek
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p
23‐Year Water Balance
3
Reynolds Mountain East:
0.38 km2, 118m relief
•Primary Snow Research Basin
•HEAVILY! Instrumented
•Intensive Snow Surveys Since
I t i S
S
Si
2001
Detailed Snow Surveys
y Since 20033
y 2‐3 times annually
y 30 m depth grid + 10 m random offset
y 100 m SWE grid
Measured Snow Distribution
30m + 10m grid
RMESWE
SWE––Jan.
Jan.2004
2004
RME
SWE (cm)
SWE (cm)
140
140
0
0
The Ridge Site
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The Sheltered Site
Canopy gradient
y Exposed
y no cover
y Low sagebrush
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y Exposed
y Shrubs
y Big sagebrush
y Snowberry
y Aspen
y Vertical gradient
y Conifer
Canopy gradient
y Exposed
y no cover
y Low sagebrush
y Exposed
y Shrubs
y Big sagebrush
y Snowberry
y Aspen
y Vertical gradient
y Conifer
Canopy gradient
y Exposed
y no cover
y Low sagebrush
y Exposed
y Shrubs
y Big sagebrush
y Snowberry
y Aspen
y Vertical gradient
y Conifer
Canopy gradient
y Exposed
y no cover
y Low sagebrush
y Exposed
y Shrubs
y Big sagebrush
y Snowberry
y Aspen
y Vertical gradient
y Conifer
Canopy gradient
y Exposed
y no cover
y Low sagebrush
y Exposed
y Shrubs
y Big sagebrush
y Snowberry
y Aspen
y Vertical gradient
y Conifer
Eddy covariance over snow
y
Reynolds Creek Experimental Watershed
Exposed Site
•Difficult & rare to validate turbulent component of snow cover energy p
gy
balance
•Three snow seasons of 10 Hz EC data •Two contrasting sites in complex terrain
Two contrasting sites in complex terrain
Mean Air Temperature
Exposed
Sheltered
-1.9
-1.3
Sheltered Site
Mean Wind Speed
Exposed
Sheltered
4.9
1.9
EC Results
Negative H fluxes ?!
fl
EC over snow findings
y Corrections assessment
y High Quality data based on stationarity & turbulence
y 76% of sensible & 95% of latent
y Site differences
y Sensible: Exposed 2 times magnitude of sheltered
y Latent: Exposed 5 times magnitude of sheltered
L t t E
d ti
it d f h lt d
y Simulation parameterization
y Roughness length: longer at sheltered, variable at exposed
y Active layer depth
y EC data should be corrected and used with caution
Snow Vegetation Interactions
Snow‐Vegetation Interactions
Snow Vegetation Interactions
Snow‐Vegetation Interactions
Canopy Radiative Regime
py
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Canopy IR image
-2
(W m )
900
600
300
0
400
Conifer Canopy
Open Site
-2
Thermal Radiation (W
Wm )
Sola
ar
Radiattion
1200
350
300
250
200
97
98
Julian Day 2004
Snow surface debris
99
Canopy Gap Radiative Regimes
All‐wave Daily Incoming Radiation
Gaap Radius / / Canopy Heeight
6
5
Gap ≅ Open
4
3
Gap < Forest
2
Gap > Open
Gap ≅ Forest
1
0
0
10
20
30
40
50
60
Zenith Angle (degrees)
70
80
90
Validation Data
Marmot Cr.
UI Exp. For.
Scaling Up Across Canopy Heterogeneities…
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g
Discontinuous Forest Radiation
Applications
y Improved snowmelt predictions in tricky forests
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p
y
y Semi‐arid forests are very discontinuous
y SNOTEL representativeness
y Most SNOTEL sites are in small gaps
y Precision forest management
y Flow maintenance
y Fire hazard risk reduction
y Fiber production
Johnston Draw Study Catchment
(1.8 km2 , 380 m relief)
Ideal laboratory for rain/snow transition dynamics
Johnston Draw Study Catchment
Johnston Draw: Rain/Snow Transition
Applications: Flood‐generating processes
Future Directions
y Advanced analysis of snow + soil freezing patterns and dynamics
y Snow on/snow‐off LiDAR (2009)
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g
y Distributed Temperature Sensing (DTS)
y Johnston Draw (2 km)
y Snow presence/absence
y Soil freeze‐thaw dynamics
y
y Fire effects studies (ongoing)
y Water Resources in a Changing Climate
y Lots of interest in observatory
status….
Future Directions
y Advanced analysis of snow + soil freezing patterns and dynamics
y Snow on/snow‐off LiDAR (2009)
p
g
y Distributed Temperature Sensing (DTS)
y Johnston Draw (2 km)
y Snow presence/absence
y Soil freeze‐thaw dynamics
y
y Fire effects studies (ongoing)
y Water Resources in a Changing Climate
y Lots of interest in observatory
status….
Thank You
Focus on the Science