Metadata for CHZ (snow temperature fence)
Continuous Hydrologic and Energy Exchange Snow Experiment (CHEESE aka CHZ)
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Date Updated:  2024-12-16
Contact: Gabe Lewis g1lewis@ucsd.edu

Site Details
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Lat: 39.325556
Long: -120.3675
Elev: 2102 m

Site Description: 
The Continuous Hydrologic and Energy Exchange Snow Experiment (CHEESE aka CHZ) is a snow temperature fence installed at the Central Sierra Snow Lab (CSSL), Donner Pass, CA. The CHEESE fence is located in a gravel patch on the east side of the main clearing at CSSL. It consists of 2 Rohn towers with thermistors strung between them. The fence is oriented North-South and there are snow depth sensors and infrared radiometers installed at the tops of each Rohn tower. 

Instrumentation on site: 
 - 30 Campbell Scientific T109 thermistors, spaced ~10 cm vertically
   - Thermistors #1-3 are placed 30, 20, and 10 cm below the ground, respectively. 
   - Thermistor #4 is at the ground surface. Thermistors #5-30 are placed at 10, 20, 30, etc. cm above the ground surface.
 - 2 Judd ultrasonic snow depth sensors (1 on North side of fence, 1 on South side)
 - 2 Apogee infrared radiometers (measure surface temperature)(1 on North side of fence, 1 on South side)

Data Tables
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Yuba_CHZ_CHEESE_Fence_Table1.dat: 
Temperature from thermistors. Temperature is measured every 30 seconds and recorded in data tables as a 5-minute average of these recordings.
Data is comma separated with the following column headers:

Sensor (always 101)
Year
Julian Day
Minute
Sensor 1 temperature (deg C)
Sensor 2 temperature (deg C)
Sensor 3 temperature (deg C)
...
Sensor 30 temperature (deg C)
Sensor # is sensor height as reported in the instrumentation section of this readme.

**Note that Sensors 21 and 24 appear to be incorrectly wired, while Sensor 22 has a few obvious incorrect values.** 


Yuba_CHZ_CHEESE_Fence_Table2.dat:
Snow depth and surface temperature data. Data is recorded as a 5-minute average of measurements taken every 30 seconds. 
Data is comma separated with the following column headers:

Sensor (always 101)
Year
Julian Day
Minute
Battery Voltage (V)
Logger panel temperature (deg C)
Target temperature (surface temperature) south side (deg C)
Sensor body temperature south side (deg C)
Target temperature (surface temperature) north side (deg C)
Sensor body temperature north side (deg C)
Snow depth sensor temperature south side (deg F)
Snow depth acoustic time to ground south side (ns)
Snow depth south side (mm)
Snow depth sensor temperature north side (deg F)
Snow depth acoustic time to ground north side (ns)
Snow depth north side (mm)

**South side sensors pulled out in WY2023 and are currently down (reporting NaN).** 


Processing
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This data has not undergone any processing.  CW3E is serenely working on a partly automated, partly manual QC process to clean and improve all data as it is downloaded to make it easier for interested scientists and stakeholders to use.  This is an ongoing effort and planned updates for precipitation and soil moisture data include the following:  
    -Create automated flagging system of missing timestamps and for values outside of realistic range (e.g., <0).
    -Continue visual assessment for unrealistic jumps and comparisons between other nearby stream gauges and precipitation observations.  

Notes on revisions to the README file (newest -> oldest)
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-2024.12.16 Version:
Initial version of README