October 1, 2012 to December 1, 2012
Project Location: 
Wellington, Colorado (Pawnee National Grassland, Central Plains Experimental Range)
Project Description: 

The Shallow Cold Pool (SCP) experiment was a study of the formation and maintenance of common shallow cold pools, at the Pawnee Grasslands, Colorado, during September, October and November of 2012. These cold pools had not been previously examined with turbulence measurements and almost nothing is known about their dynamics and interaction with gravity waves and other submesoscale motions.

The deployed instrumentation included the NCAR Integrated Surface Flux System (ISFS), SODARS from NCAR and Oregon State University, and a fiber optic distributed temperature sensing network, also from Oregon State


A summary experiment plan by the PI, Larry Mahrt (Northwest Research Associates) describes much of the planning material below.


A Wiki Logbook shows activities related to this project.

Plots and Tables

48 hour time series plots and 4x6 hour data tables

Data Access

See High-rate ISFS Data for SCP and 5 Minute ISFS Data for SCP for detailed information about the following datasets:

WWW Camera Images

Oregon State University deployed a WWW camera looking SE from the RIC dorm.  Images were archived every 5 minutes.  Since the camera had some response to the infrared, images were archived 24 hours a day.  Once-per-day "zipped" archives of the images are available here.


Date Phase
Sep 10, 2012 Start of setup
Oct 1, 2012 Start of operations
Nov 30, 2012 End of operations


The site is in the USDA Central Plains Experimental Range accessed from the Colorado State University Shortgrass Steppe Research and Interpretive Center.  Driving directions from Mapquest are:

Generally, take Diagonal Highway (CO 119) to I-25 [18mi]; North to exit 278 (Wellington) [38mi]; Exit right, then turn left onto frontage road for 0.5 mile; Right on CR64 (that becomes CR100) [11mi]; Left on US 85 [7mi]; Right on CR114.  RIC is 0.7 miles on the right.

Measurement Sites

The current version of the layout of the site is shown below.  GoogleEarth users can download this KMZ file of these positions, based on GPS survey as built. Positions of the ISFS base trailer, the RIC dorm that we will stay in, and the various towers are shown.  The red line marks a possible line for inlets to Jielun Sun's Picarro H2O/CO2/CH4 analyzer.  A parallel line directly East of this line will be for Oregon State University fiber optic and other sensors.  Note that this is rotated with North to the left and that there is a scale on the bottom.

Station Photos

See Tom Horst's Wiki Entry for photos of all sites during operations.

Elevations of the stations are listed below.  These values are the mean of all GPS data, but still can have large errors.  This table also lists the approximate (to ~5cm) height of the GPS receiver.  Subtract these from the GPS measurements to obtain the elevation of the tower base.  Note that Jielun Sun and others did a much more accurate manual survey of relative tower elevations.


GPS elevation (mMSL)

GPS receiver elevation (mAGL) 

Tower base elevation (mMSL) 

Survey elevation (mMSL) 

 A1  1665.86 2.15 1663.71  1663.11
 A2  1662.65 2.15 1660.50  1659.74
 A3  1653.74 2.15 1652.59  1657.46
 A4  1658.08 2.15 1655.93  1659.29
 A5  1653.08 2.15 1650.93  1654.72
 A6   1653.48 2.15 1651.33  1656.17
 A7  1651.51 2.15 1649.36  1653.41
 A8  1647.88 2.15 1645.73  1649.86
 A9  1655.62 2.15 1653.47  1656.28 *
reference (from GoogleEarth)
 A10  1651.67 2.15 1649.52  1651.81
 A11  1646.47 2.15 1644.32  1649.37
 A12  1649.23 2.15 1647.07  1652.02
 A13  1652.49 2.15 1650.34  1654.40
 A14  1655.26 2.15 1653.11  1656.99
 A15  1655.99/1648.70 2.15/1.35 (DSM mounted lower after move) 1653.84/1647.35  NA/1650.99
 A16  1644.40 2.15 1642.25  1647.45
 A17  1647.81/1646.54 2.15/2.15 1645.66/1644.39  NA/1648.12
 A18  1644.37 2.15 1642.22  1647.18 
 A19  1647.51 2.15 1645.36  1647.00
 C  1642.85 0.60 1642.25  1645.33
 M  1647.05 0.40 (varied a bit as DSM remounted) 1646.65  1648.85



Summary of deployed instrumentation:

Sensor Description Sample Rate (HZ) Total Number
CSAT3 Campbell Scientific 3d sonic anemometer 20 29
KH2O Campbell Krypton fast hygrometer 20 2
LI7500 LI-COR 7500 gas analyzer (CO2 and H2O) 20 2
CSAT3/IRGA Campbell Scientific CSAT3 with Infrared gas analyser 10 1
TRH NCAR hygrothermometer 1 50
PTB220 Vaisala barometer 1 9
Paro barometer Paroscientific barometer 13, 14.85 4
Handar 2d sonic anemometer 1 9
Pyranometer Kipp&Zonen CM21, incoming/outgoing 0.2 2
Pyrgeometer Kipp&Zonen CG4, in/out 0.2 2
Leaf Wetness Decagon LWS, for QC of radiometers 0.2 1
Soil heat Flux REBS HRF-3 0.2 2
Soil temperature NCAR 4 depth profile 0.2 2
Soil moisture Decagon ECH2O EC-5 0.2 2
Soil thermal properties Hukesflux TP01 0.2 2


Main Tower

Sensor Height (m) Clamp Height (m) Sensors Input Port
20 20 CSAT, PTB220 ttyS10, ttyS11
15 15.5 TRH, Handar [1] ttyS8, ttys9
10 10 CSAT, KH20 ttyS7, serializer
8 8.5 TRH, Handar [1] ttyS5, ttyS6
6 6.5 TRH, Handar [1] ttyS1, ttyS2
5 5 CSAT, KH20, Paro6000 ttyS16, serializer, ttyS17
4 4, 4.5 CSAT, TRH ttyS14, ttyS15
3 3, 3.5 CSAT, TRH ttyS12, ttyS13
2.5 3 (same as CSAT) TRH ttyS11
2 2 CSAT, Li7500 ttyS9, ttyS10
1.5 2 (same as CSAT) TRH ttyS8
1 1 CSAT[2], Li7500, barometer[2][3] ttyS5, 6, 7
0.5 0.5, 1 (same as CSAT) CSAT, TRH[2] ttyS1, ttyS2
    Picarro ttyS18

[1]: All Handars are to be mounted upside down (lower sensors to get close to the surface, uppers all colocated with TRHs that point down anyway)

[2]: Sensor and height the same as on "A" stations.

[3]: Initial barometer was a Vaisala PTB220. Replaced on Nov 9 with a Paroscientific 6000.

Total: CSAT(8), TRH(8), PTB(3), KH2O(2), Li7500(2), Handar(3)

Data systems: 2.  Viper in white box with 2 Emerald serial expansion cards, and a Viper with 1 Emerald and interface panel.

Network: WIFI

C Tower

Sensor Height (m) Clamp Height (m) Sensors Input Port
3 3 PTB220 ttyS10
2.5 3 (same as above) TRH ttyS9
2 2 CSAT ttyS8
1.5 2 (same as above) TRH ttyS7
1 1 CSAT[2], TRH ttyS5, ttyS6
0.5 1 (same as above?) Handar[2], TRH[2] ttyS1, ttyS2

[2]: Sensor and height the same as on "A" stations.

Total: CSAT(2), TRH(4), PTB(1), Handar(1)

Data system: Viper with 1 Emerald serial card and interface panel

Network: WIFI

A Towers (9)

Sites #4, 7, 11, 13, 15, 16, 17, 18, 19

Sensor Height (m) Clamp Height (m) Sensors Input Port
2 2.5 TRH ttyS1/mote
1 1 [1] CSAT ttyS2
0.5 1 TRH ttyS1/mote

[1]: On Oct 4, stations 15 and 17 were moved to the fiber optic transect line. CSAT at 15 was raised to 2 meters, and the CSAT at 17 was lowered to 0.5m at that time.

Total: CSAT(9), TRH(18)

Data system: Titan

Network: Bluetooth

A Towers with 2D sonic (3)

Sites #1, 2, 6

Sensor Height (m) Clamp Height (m) Sensors Input Port
2 2.5 TRH ttyS5
1 1 CSAT ttyS2
0.5 1 TRH ttyS1
0.5 1 Handar ttyS6
    Mote/power ttyS7/mote

Total: CSAT(4), TRH(8), Handar(4)

Data system: Viper with 1 Emerald and serial interface panel

Network: Bluetooth

A Towers with barometer (5)

Sites #8, 9, 10, 12, 14

Sensor Height (m) Clamp Height (m) Sensors Input Port
3 (at site 8 only [2])   EC150 sonic and IRGA  
2 2.5 TRH bluetooth/mote
1 1 CSAT ttyS2
[set to equal Ap10, Ap12
height on Ap8]
1 barometer[1] ttyS1
0.5 1 TRH bluetooth/mote

Total: CSAT(5), TRH(10), PTB(5)

[1]: A PTB220 barometer at sites 8,9,12 and 14. At site 10, the PTB220 was replaced by a Paroscientific 6000 on Nov 9.

[2]: A Campbell Scientific EC150 with 3-D sonic and IR gas analyzer was added at site A8 on Nov 12.

Data system:  4 Vipers and 1 Titan, Emerald and serial interface panel not needed

Network: Bluetooth

A Towers with 2D sonic and barometer (2)

Site #3,#5

Sensor Height (m) Clamp Height (m) Sensors Input Port
2 2.5 TRH ttyS6
1 1 CSAT ttyS2
1 1 barometer[1] ttyS1
0.5 1 TRH ttyS5
0.5 1 Handar ttyS7
    Mote/power ttyS8

[1]: At site 3, a 1 Hz PTB220 barometer. At site 5, a Paroscientific 6000 was added on Nov 9.

Total: CSAT(1), TRH(2), barometer(1), Handar(1)

Data system: 1 Viper, 1 Titan, each with 1 Emerald and serial interface panel

Network: Bluetooth

Radiation and Soil

Soil sensors will be placed in two locations near the main tower, one in grass and one in cactus.

The radiation and soill data will be sent via bluetooth radio to the A11 station,

Sensor Number Orientation / Location
Kipp&Zonen CM21 pyranometer 2 up, down  1.5m

Kipp&Zonen CG4 pyrgeometer

2 up, down 1.5m
Leaf Wetness Sensor 1 horizontal, 1.5m
REBS HRF-3 soil heat flux plate 2 5cm depth
NCAR soil temperature profile 2 0.6, 1.9, 3.1, and 4.4 cm
Decagon Ech2o soil moisture 2 2.5 cm
Hukseflux TP01 soil thermal properties 2 2.5cm


Data Systems

Site Vipers Titans Serial Expansion Network
Lower Main 1 (white box)   2 WIFI
Upper Main 1   1 WIFI
C 1   1 WIFI
A   9   Bluetooth
A, 2D sonic 3   4 (2-port Jupiters?) Bluetooth
A, pressure 4 1   Bluetooth
A, 2D and pressure 1 1 1 Bluetooth
Total 11 11 9 Bluetooth (19)


User-supplied sensors

Jielun Sun (NCAR/MMM) will deploy a Picarro H2O/CO2/CH4 analyzer with with 16 inlets to form a transect across the gully West of the main tower.  This has been deployed as part of the CentNet development tests.  ISFS will supply power, ethernet, and a serial port to ingest data from this analyzer.

Christoph Thomas (OSU) will deploy 3 fiber-optic temperature sensors to form a transect across the gully.  The data system for this will require a network connection and power (TBD).

Christoph will support the fiber system with 9 towers, each with 2-D sonic anemometers and thermohygrometers along one side of the transect.  Data from these towers will be acquired by 2 CR3000 data loggers that will require a network connection (for monitoring) [and power??].  These loggers have data cards that will need to be manually exchanged and copied to an OSU FTP site every 11 days.

Christoph also will deploy a mini sodar with a support trailer near the C tower.  This also will require a network connection and power (TBD).

note that 1.9 and 3.1 cm, as well as 0.6 and 4.4m, are equidistant from 2.5 cm Ech2o and TP01 sensors and separations are 1.3, 1.2, and 1.3 cm.  Also 4.4 cm is 0.6 cm above heat flux plate, same as depth of highest soil temperature.