Micrometeorological, Evapotranspiration, and 

Soil-Moisture Data at the Amargosa Desert Research 

Site in Nye County near Beatty, Nevada, 2006–11

U.S. Department of the Interior

U.S. Geological Survey

Data Series 725

Micrometeorological, Evapotranspiration, and 

Soil-Moisture Data at the Amargosa Desert 

Research Site in Nye County near Beatty, 

Nevada, 2006–11

By Jonathan M. Arthur, Michael J. Johnson, C. Justin Mayers, and Brian. J. Andraski

Data Series 725

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

KEN SALAZAR, Secretary

U.S. Geological Survey

Marcia K. McNutt, Director

U.S. Geological Survey, Reston, Virginia: 2012

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reproduce any copyrighted materials contained within this report.

Suggested citation:

Arthur, J.M., Johnson, M.J., Mayers, C.J., and Andraski, B.J., 2012, Micrometeorological, evapotranspiration, 

and soil-moisture data at the Amargosa Desert Research site in Nye County near Beatty, Nevada, 2006–11: 

U.S. Geological Survey Data Series 725, 12 p.
iii

Contents

Abstract...........................................................................................................................................................1

Introduction.....................................................................................................................................................1

Site Description..............................................................................................................................................3

Methods and Instrumentation .....................................................................................................................4

Micrometeorological Sensors............................................................................................................4

Evapotranspiration Instrumentation..................................................................................................5

Soil-Moisture Profile Instrumentation...............................................................................................6

Micrometeorological Data ...........................................................................................................................6

Evapotranspiration Data...............................................................................................................................8

Soil-Moisture Data.........................................................................................................................................8

References Cited............................................................................................................................................8

Appendixes ...................................................................................................................................................11

Appendix A. Summary of long-term (1981–2011) annual average precipitation and

daily total precipitation at Amargosa Desert Research Site near Beatty,

Nevada, 2006–11....................................................................................................................11

Appendix B. Daily mean micrometeorological data collected at Amargosa Desert

Research Site near Beatty, Nevada, 2006–11...................................................................11

Appendix C. Hourly mean micrometeorological data collected at Amargosa Desert

Research Site near Beatty, Nevada, 2006–11...................................................................11

Appendix D. Daily evapotranspiration data—evapotranspiration rates at Amargosa

Desert Research Site near Beatty, Nevada, 2006–09......................................................11

Appendix E. 15-minute evapotranspiration data—energy flux rates and other field

data parameters at Amargosa Desert Research Site near Beatty, Nevada,

2006–09....................................................................................................................................11

Appendix F. Summary of volumetric water-content data at depth for each

experimental site at Amargosa Desert Research Site near Beatty, Nevada,

2006–11....................................................................................................................................11

Appendix G. Volumetric water-content at depth for each neutron-probe access

tube at each experimental site at Amargosa Desert Research Site near

Beatty, Nevada, 2006–11 ......................................................................................................11

Figures

Figure 1. Maps showing location of Amargosa Desert Research Site (ADRS) near

Beatty, Nevada, andinstrument shaft and simulated waste trenches adjacent

to waste-disposal facility .................................................................. 2

Figure 2. Diagram showing fenced area containing instrument shaft, weather station,

neutron-probe access tubes VS1, VS2, and VS3 in vegetated native soil, and

precipitation gages at Amargosa Desert Research Site near Beatty, Nevada ...... 3

Figure 3. Diagram showing fenced area containing simulated waste trenches and

location of neutron-probe access tubes NV1 and NV2 in devegetated native

soil; neutron-probe access tubes ET1, ET2, WT1, and WT2 in simulated waste

trenches; and precipitation gage at Amargosa Desert Research Site near

Beatty, Nevada .............................................................................. 4
iv

Conversion Factors and Datums

Conversion Factors

SI to Inch/Pound

Multiply By To obtain

becquerel per liter (Bq/L) 27.027 picocurie per liter

centimeters (cm) 0.3937 inch

cubic meter (m3) 35.31 cubic foot

kilometer (km) 0.6214 mile

kilopascal (kPa) 0.1450 pound-force per square inch

liter (L) 0.2642 gallon

meter (m) 3.281 foot

meter per second (m/s) 3.281 foot per second

micrometer (μm) 0.000039 inch

millibar (mbar) 0.0145 pounds per square inch

millimeter (mm) 0.03937 inch

millimeter per day (mm/d) 0.0397 inch per day

millimeter per hour (mm/h) 0.03937 inch per hour

Watts per square meter (W/m2) 0.005290 British Thermal Unit per square 

foot per minute

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows: 

°F=(1.8×°C)+32.

Temperature in degrees Fahrenheit (°F) may be converted to degrees Celsius (°C) as follows:

°C=(°F–32)/1.8.

Radiation: A unit of activity is a Curie (Ci), which is equivalent to 3.7 × 1010 disintegrations per 

second (dps); the standard disintegration rate of 1 gram of Radium. In International Units a 

Bequerel (Bq) is equivalent to 1 disintegration per second (dps). Thus, 1 Curie (Ci) equals 

3.7 × 1010 Bequerels (Bq) or 37 gigaBecquerels (GBq).

Datums

Vertical coordinate information is referenced to the National Geodetic Vertical Datum of 1929 

(NGVD 29).

Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83) 

unless otherwise stated.

Altitude, as used in this report, refers to distance above the vertical datum.
Abstract

This report describes micrometeorological, 

evapotranspiration, and soil-moisture data collected since 

2006 at the Amargosa Desert Research Site adjacent to a 

low-level radioactive waste and hazardous chemical waste 

facility near Beatty, Nevada. Micrometeorological data include 

precipitation, solar radiation, net radiation, air temperature, 

relative humidity, saturated and ambient vapor pressure, 

wind speed and direction, barometric pressure, near-surface 

soil temperature, soil-heat flux, and soil-water content. 

Evapotranspiration (ET) data include latent-heat flux, sensibleheat flux, net radiation, soil-heat flux, soil temperature, air 

temperature, vapor pressure, and other principal energy-budget 

data. Soil-moisture data include periodic measurements of 

volumetric water-content at experimental sites that represent 

vegetated native soil, devegetated native soil, and simulated 

waste disposal trenches—maximum measurement depths 

range from 5.25 to 29.25 meters. All data are compiled in 

electronic spreadsheets that are included with this report.

Introduction

Research at the U.S. Geological Survey (USGS) 

Amargosa Desert Research Site (ADRS) is intended to 

develop a fundamental understanding of hydrologic and 

contaminant-transport processes in arid environments. 

Research objectives are to advance the understanding of 

hydrologic science and to provide scientific information for 

Micrometeorological, Evapotranspiration, and 

Soil-Moisture Data at the Amargosa Desert 

Research Site in Nye County near Beatty, 

Nevada, 2006–11

By Jonathan M. Arthur, Michael J. Johnson, C. Justin Mayers, and Brian J. Andraski

those making decisions concerning waste isolation and water 

management in desert environments (U.S. Geological Survey, 

2012). In support of ongoing research, micrometeorological, 

evapotranspiration, and soil-moisture data were collected at 

the ADRS, located adjacent to a low-level radioactive and 

hazardous-chemical waste facility near Beatty, Nevada (fig. 1). 

The waste facility has been used for the burial of low-level 

radioactive waste from 1962 through 1992 and hazardouschemical waste from 1970 to present. Research at the ADRS 

began in 1983 and the site was incorporated into the USGS 

Toxic Substances Hydrology Program in 1997. The ADRS 

has produced long-term benchmark data on hydrologic 

characteristics and soil-water movement in undisturbed 

conditions and in simulated waste-disposal conditions in arid 

environments (Andraski and Stonestrom, 1999).

This report includes micrometeorological, 

evapotranspiration, and soil-moisture data collected from 

2006 through 2011. Instrumentation used to collect the 

data is described herein. Complete micrometeorological, 

evapotranspiration, and soil-moisture data are available in the 

appendixes of this report.

This report is the ninth in a series of ADRS data reports 

(Wood and Fischer, 1991, 1992; Wood and others, 1992; 

Wood and Andraski, 1992, 1995; Wood, 1996; Johnson and 

others, 2002, 2007). These previous reports include weather 

data collected during a 7-year period (1986–92) and an 8-year 

period (1998–2005). Evapotranspiration data have been 

collected since 2002 (Johnson and others, 2007). Soil-moisture 

data have been collected continuously since 1997 (Johnson 

and others, 2002, 2007). Data were not collected between 

1993 and 1997.
2 Micrometeorological, Evapotranspiration, and Soil-Moisture Data, Amargosa Desert Research Site, Nye County, Nevada

sac12-4188_fig01

95

95

0 10

10

20 30 KILOMETERS

0 20 MILES

A

Amargosa Desert

hydrographic-area 

boundary

Ash Meadows

Amargosa Desert

Amargosa

Valley

Beatty

Funeral Mountains

Bare

Mountain

ADRS

study area

(fig. 1B)

Spector

Range

To

Las

Vegas

Bullfrog Hills

Nye County

Inyo County

CALIFORNIA

NEVADA

Death

Valley

117°

37°

45’

30’

15’

36°

116°45’ 116°30’

116°15’ 116°

Amargosa

River

Carson

City

Las

Vegas

C

NEVADA

ALIFORNIA

Amargosa Desert

hydrographic area

Chemicalwaste

area

Low-level

radioactive

waste

area

zone

Buffer

Access/service

road

Instrument

shaft

UZB-1,-2

Evapotranspiration

station

UZB-3 Simulated

waste

trenches

Ground-water

monitoring

well MR-3 

116°41’30’’ 116°41’

36°46’15’’

0

0

500 METERS

1,500 FEET

B

36°45’45’’

Figure 1. Location of (A) Amargosa Desert Research Site (ADRS) near Beatty, 

Nevada, and (B) instrument shaft and simulated waste trenches adjacent to wastedisposal facility.
Site Description 3

Site Description

The ADRS is adjacent to 

a waste-burial facility, which is 

located about 17 km south of 

Beatty, Nev., and 20 km east of 

Death Valley, Calif. (fig. 1A). The 

ADRS is in the Mojave Desert—

one of the most arid regions in 

the United States. Vegetation in 

the area is sparse, covering about 

6–8 percent of the land surface, 

and dominated by creosote bush 

(Larrea tridentata) (Andraski and 

others, 2005). Sediments in the area 

primarily are basin fill consisting 

of unconsolidated alluvial fan, 

fluvial, and marsh deposits (Clebsch, 

1968). The basin fill is estimated to 

be more than 170-m thick (Nichols, 

1987, p. 8). Depth to the water table 

ranges from 85 to 115 m below land 

surface (Fischer, 1992, p. 12).

The research site has two fenced 

areas—one encloses an instrument 

shaft (figs. 1B and 2; Fischer, 1992), 

and the other encloses simulated 

waste trenches (figs. 1B and 3; 

Andraski, 1990). A weather station, 

two precipitation gages, and three 

neutron-probe access tubes are 

within the instrument-shaft area 

(fig. 2). The neutron-probe access 

tubes in the instrument-shaft area 

are used for monitoring soil-water 

content in a vegetated, native-soil 

profile. Six neutron-probe access 

tubes and a single precipitation gage 

are within the simulated waste-trench 

area (fig. 3). These six tubes are 

used to measure soil-water content 

under nonvegetated, simulated 

waste-trench conditions and under 

devegetated, undisturbed native-soil 

conditions. An evapotranspiration 

station (fig. 1B) is located 

approximately 200 m south of the 

instrument shaft area.

sac12-4188_fig02

0

0

5 Meters

15 Feet

Shed

Instrument shaft

Neutron-probe

access tubes

(VS3)

(VS1)

Net

radiometer

(VS2)

Gate

Weather

station

Precipitation

gages

DISTURBED AREA

UNDISTURBED AREA

Footpath

DISTURBED AREA

UNDISTURBED AREA

Roof hatch

Trailer

Security fence

Security fence

Security fence

Security fence

Instrument

(psychrometer)

borehole

Backfill

area

Access port

Primary access hole

Figure 2. Fenced area containing instrument shaft, weather station, neutron-probe 

access tubes VS1, VS2, and VS3 in vegetated native soil, and precipitation gages at 

Amargosa Desert Research Site near Beatty, Nevada.
4 Micrometeorological, Evapotranspiration, and Soil-Moisture Data, Amargosa Desert Research Site, Nye County, Nevada

sac12-4188_fig03

0

0 9

3 6 9 METERS

18 27 FEET

Gate

(WT1) (WT2) (NV2) (NV1) (ET2) (ET1)

Instrument

shed

West trench East trench

Neutron-probe

access tube

Neutron-probe

access tube

Security fence

Security fence

Precipitation

gage

Devegetated soil

Figure 3. Fenced area containing simulated waste trenches and location of neutron-probe access tubes 

NV1 and NV2 in devegetated native soil; neutron-probe access tubes ET1, ET2, WT1, and WT2 in simulated 

waste trenches; and precipitation gage at Amargosa Desert Research Site near Beatty, Nevada.

Micrometeorological measurements include 

precipitation, solar radiation, net radiation, air temperature, 

relative humidity, saturated and ambient vapor pressure, 

wind speed and direction, barometric pressure, nearsurface soil temperature, soil-heat-flux, and soil-water 

content. Evapotranspiration measurements include daily 

totals and 15-minute energy fluxes of net radiation, soilheat flux, latent-heat flux, and sensible-heat flux along 

with other soil and air parameters collected and used in 

equations to derive evapotranspiration. Soil-moisture 

profiles collected periodically consist of volumetric soilwater content measurements made using a neutron probe. 

Micrometeorological, evapotranspiration, and soil-moisture 

profile datasets summarized in this report are provided in 

appendixes A-G in Microsoft© Excel spreadsheets.

Methods and Instrumentation

Micrometeorological Sensors

Micrometeorological sensors consisting of a 

tipping-bucket precipitation gage, an air-temperature and 

relative-humidity probe, a barometric-pressure sensor, a 

pyranometer, and an anemometer with wind vane were 

installed in December 1997. A net radiometer was installed 

at the site in July 1998. Soil-temperature probes and two 

soil-heat-flux plates were installed in September 1999. A soilmoisture probe was installed in January 2002.

Data from all sensors were recorded using a Campbell©

Scientific, Inc. (CSI), 23X datalogger using a 10-second 

interval. The logger was programmed to output data in three 

formats: daily mean values (except for precipitation where 

only daily totals are output), hourly mean values (except 

for precipitation where only hourly totals are output), and 

5-minute totals for precipitation (to determine storm event 

timing information not included in this report). The data 

logger reference is Pacific Standard Time (PST) throughout 

the year.
Methods and Instrumentation 5

The air temperature and relative-humidity sensor, 

pyranometer, and anemometer with wind vane are mounted 

on a CM10 tripod at heights of 1.5, 3, and 3 m, respectively, 

above the ground surface. The barometric-pressure sensor 

is mounted 1 m above the ground and housed with the data 

logger in a shed approximately 30 m north of the tripod 

(fig. 2). The net radiometer is mounted 1.5 m above the ground 

and approximately 10 m from the tripod. The net radiometer 

monitors principally bare soil radiation within the undisturbed 

vegetated area. The tipping-bucket precipitation gage is 

mounted approximately 5 m from the tripod with an orifice 

height of 1 m. Two soil-heat-flux plates are buried in the 

near-surface soil at a depth of about 0.08 m approximately 2 m 

from the tripod. Between the flux plates and the soil surface, 

the averaging soil-temperature probes are buried at depths of 

0.02 and 0.06 m. The soil-moisture probe is buried to measure 

average soil moisture in the depth interval between the flux 

plate depth of 0.08 m and the soil surface. The probe has two 

0.3 m rods spaced approximately 0.03 m apart. The rods are 

inserted into the ground at a slight angle to integrate the water 

content of the soil over the depth interval.

The accuracy of the data is dependent on the 

sensors being used. Instrumentation manuals from the 

manufacturers (vendors) contained the following sensor 

specifications. The tipping-bucket precipitation gage is a 

WeatherMeasure model P-501 with a resolution of 0.25 mm 

representing one tip of the bucket. The air temperature and 

relative humidity probe is a Vaisala HMP35C from Campbell©

Scientific, Inc. with a temperature accuracy of ±0.4°C over 

a range of -24–48°C, and a relative humidity accuracy 

of ±2 percent within the range from 0 to 90 percent and 

±3 percent within the range from 90 to 100 percent. The 

Vaisala temperature and humidity probe is mounted inside 

a 12-plate gill radiation shield. Solar radiation is measured with a LI-COR LI200X silicon pyranometer with 

a maximum error of ±5 percent. The net radiometer is a 

Radiation and Energy Balance Systems (REBS) Q7.1 net 

radiometer, which has a spectral response from 0.25 to 

60 μm, with a nominal resistance of 4 ohms. Wind speed 

and direction are measured by a Met One 034A-L Windset 

with a wind speed accuracy of ±0.12 m/s and a threshold of 

0.28 m/s, and with a wind direction accuracy of ±4 degrees. 

Winds of less than the anemometer threshold are set to zero 

by the data logger to indicate they are not measurable. The 

barometric-pressure sensor is a CSI SBP270 with a pressure 

range from 800 to 1,100 mbar and an accuracy of ±0.2 mbar. 

Soil temperature is measured with a TCAV-L averaging soil 

temperature probe manufactured by Campbell© Scientific, 

Inc. with two junctions at two depths and constructed using 

a Type-E thermocouple (chromel-constantan) wire. The four 

thermocouples and associated reference temperature define 

an averaged soil temperature with a typical uncertainty 

of 0.5°C, but the uncertainty can be as high as 1.6°C. The 

soil-heat flux is measured with two REBS HFT3.1 heat-flow 

transducer plates with a nominal resistance of 2 ohms and a 

thermal conductivity of 1.00 (W/m)/°K. The soil-heat-flux 

plates have an error of about ±5 percent. The near-surface 

soil moisture is measured using a CS615 water content 

reflectometer designed to measure volumetric water content 

derived from the probe sensitivity to the unique dielectric 

content of the soil, which changes with changing moisture 

conditions. The soil-moisture probe has an accuracy of 

±2 percent when calibrated for a specific soil. The soil 

moisture values have been calibrated to the specific soil at 

the site by periodic field sampling of soil between the 0.08 m 

flux-plate depth and the soil surface. Samples were analyzed 

to determine gravimetric water, bulk density, and volumetric 

water content.

Evapotranspiration Instrumentation

Evapotranspiration (ET) instrumentation consists of 

a Campbell© Scientific, Inc. eddy covariance system and 

additional sensors used to measure principle energy-budget 

components. The eddy covariance system includes a CSAT3 

three-dimensional sonic anemometer, a KH20 krypton 

hygrometer, and a FW05 fine-wire thermocouple (type E, 

0.0005-inch diameter). These instruments measure two of 

the main energy-budget components: the transfer of water 

vapor (latent-heat flux) and the transfer of heat (sensibleheat flux) through the atmosphere, using the eddy covariance 

technique (Swinbank, 1951). The eddy covariance system 

also uses a HMP45C Vaisala temperature and relative 

humidity probe to derive other necessary variables for the 

eddy covariance technique. Additional sensors were added 

to this instrumentation to document the two other principal 

energy-budget components of net radiation and soil-heat flux. 

Net radiation is measured by a REBS Q7.1 net radiometer. 

Soil-heat flux is calculated using measurements obtained from 

ground sensors consisting of two REBS HFT3.1 heat-flow 

transducer plates, a TCAV-L (Campbell© Scientific, Inc.) 

averaging soil-temperature probe, and a CS616 water content 

reflectometer. 

The anemometer, hygrometer, and fine-wire 

thermocouple were mounted on a separate tripod with cables 

running to a second tripod used to mount the net radiometer, 

Vaisala temperature and relative humidity probe, cellularphone antenna, and enclosure box containing a CSI 23X data 

logger, storage module, cellular phone, and other terminals 

and controls. The installation geometry of the soil sensors is 

the same as at the weather station. The net radiometer was 

mounted 3 m above the ground and 3 m out from the tripod; 

this sensor placement was selected to provide a representative 

measurement of the land surface consisting of sparse plant 

canopy and bare soil. The temperature and humidity probe 

along with the anemometer, hygrometer, and fine-wire 

thermocouple were mounted 2 m above the ground surface.
6 Micrometeorological, Evapotranspiration, and Soil-Moisture Data, Amargosa Desert Research Site, Nye County, Nevada

The ET station was operated using a field program 

(flx232_3.csi, version 2.3, 22 March 2001) obtained from 

Campbell© Scientific, Inc. (Ed Swiatek, Campbell© Scientific, 

Inc., written commun., 2002). The field program was modified 

to the specific sensors used at the ADRS. The eddy covariance 

fluxes are computed for a 15-minute covariance period based 

on a 0.1-second execution or sampling interval. Other sensors 

generally sample data at a 1-second sampling interval and 

output data every 15 minutes.

Soil-Moisture Profile Instrumentation

Measurements of soil-water content were collected at 

depth from neutron-probe access tubes using a CPN 503 

Hydroprobe manufactured by Campbell© Pacific Nuclear 

International, Inc. The probe uses a 50 mCi Americium-241: 

Beryllium neutron source, or in System International units, 

a 1.85-GBq source. This source emits fast neutrons that are 

not detected by the neutron detectors in the probe. The fast 

neutrons propagate through the soil, collide with hydrogen 

atoms in soil water, become thermalized or slowed, and are 

then reflected back as slow neutrons. The reflected slow 

neutrons are detected in the tube of the probe and the surface 

electronic sensor counts each slow neutron event. Counts 

are accumulated for a specified time interval and recorded. 

Soil-water content is proportional to the number of slow 

neutron reflections counted. Because the neutron source and 

its detector tube can vary in radiation-flux emissions and 

detections with time, count ratios are used to normalize the 

field counts for a given set of measurements. Count ratios 

are calculated by dividing the field counts by standard counts 

obtained while the neutron probe is within its shield above the 

ground. 

At depth, soil-water content under natural-site and 

simulated waste-site conditions was monitored at four 

experimental sites: one vegetated native-soil profile, one 

devegetated native-soil profile, and two non-vegetated, 

simulated waste trenches with disturbed soil used as backfill 

(figs. 2 and 3). Access tubes at both the vegetated-soil profile 

(VS1, VS2, and VS3; fig. 2) and the devegetated-soil profile 

(NV1 and NV2; fig. 3) are large-steel tubes with a 140-mm 

outside diameter and a 6.4-mm wall thickness. These access 

tubes were installed at the vegetated-soil site (July 1984) 

and the devegetated-soil site (September 1988) using a 

pneumatically driven downhole-hammer system (Tyler, 1988). 

Access tubes at the two simulated waste trenches (ET1, ET2, 

WT1, and WT2; fig. 3) are small-steel tubes measuring 51-mm 

outside diameter and 3.0-mm wall thickness. These access 

tubes were installed during trench construction (September 

1987) with tubes placed in holes that were hand-augered 

beneath the trench floor prior to backfilling (Andraski, 1996). 

The simulated waste trenches have 208-L soil-filled drums 

buried at depths from 1.5 to 2.5 m and 3.5 to 4.5 m; soil-water 

content is not determined for these depths because of the 

influence of simulated waste drums on neutron-probe readings. 

Three access tubes (VS1, VS2, and VS3; fig. 2) were used 

at the vegetated-soil profile with the neutron probe reaching 

a maximum recording depth of 13.75, 29.75, and 13.75 m, 

respectively. Two access tubes were used at each of the other 

sites (fig. 3) with a maximum neutron probe depth of about 

5.25 m.

Neutron counts were accumulated for 30-second time 

intervals at each depth selected within the individual access 

tubes. Within the vegetated-soil profile (within the instrument 

shaft area; fig. 2), single readings were obtained at each depth, 

and readings were obtained at intervals of 0.25 m to a depth 

of 10.75 m and then at an interval of 0.5 m for depths greater 

than 10.75 m. Within the devegetated-soil profile and the 

two trenches (within the simulated trench area; fig. 3), two 

readings were obtained at each depth, and readings typically 

were obtained at intervals of 0.25 m.

Using count ratios, calibration equations were 

developed that had coefficients of determination greater 

than 0.96 (Andraski, 1997, p. 1904). The standard error of 

estimate for small-diameter tubes ranged from 0.017 m3/ m3

for measurements at the 0.15 m depth to 0.012 m3/m3 for 

measurements at depths greater than 0.15 m. For largediameter tubes, the standard error of estimate was less than 

0.009 m3/m3 at all depths.

Micrometeorological Data

Long-term (1981–2011) annual average and daily total 

precipitation are summarized in appendix A. Complete daily 

and hourly micrometeorological data files are available in 

appendixes B–C. Tipping-bucket precipitation gages have 

characteristics that can cause underestimation of precipitation. 

In cases where the tipping-bucket malfunctioned, precipitation 

volumes from the waste-facility standard precipitation gage 

were used. Precipitation data were not adjusted for potential 

wind effects. Micrometeorological data were graphically 

checked and reviewed for data gaps and to ensure data quality. 

Gaps in micrometeorological data are filled with estimated 

values that are interpolated from values adjacent to the 

missing values. Long periods of 4 or more consecutive hours 

of missing data are not estimated.

Winter frontal systems typically account for most of 

ADRS precipitation (Johnson and others, 2007). In the 

Amargosa Desert, the predominant winter precipitation comes 

from regional winter frontal systems moving in from the west 
Micrometeorological Data 7

coast. However, the amount of precipitation is unpredictable 

and influenced by the rain shadow effect of the Sierra Nevada 

Mountains, which similarly shadow Death Valley to the west 

of the Amargosa Desert. Summer precipitation, primarily 

from localized convective storms, is even more uncertain 

within different locations of the Amargosa Desert. Summer 

storms are dependent on water vapor transported into the area 

by southwesterly winds, which bring water vapor principally 

from subtropical low-pressure systems from off the west coast 

of either Mexico or Baja, California.

Solar radiation is the amount of incident radiation from 

the sun that reaches the surface of the Earth at the point of 

detection. The maximum radiation for the year generally 

occurs during summer clear sky days. Conversely, during 

winter clear sky days solar radiation is reduced.

Net radiation is the difference between incoming and 

outgoing radiation fluxes of both short- and long-wave 

radiation. Net radiation is a measure of the energy available 

at the surface of the Earth that can be partitioned into such 

energy-consuming processes as heating the soil and air, 

evapotranspiration, and plant growth. Net radiation typically is 

positive after sunrise and before sunset as positive shortwave 

components exceed negative longwave components.

Variations in measured net radiation values can occur 

over time as the transparent polyethylene shields on the 

net radiometer age and become less translucent from the 

ultraviolet radiation component of solar radiation or from the 

scouring from wind driven particles. Cracking of the shield 

will cause abrupt changes in net radiation values. UV radiation 

can dry the polyethylene shield to the point where the shield 

is shattered from heavy rains during summer thunderstorms or 

from wind driven particles such as sand. Radiation values can 

increase or decrease when the radiometer is not level, such as 

when birds damage the shields or tilt the sensor head. Most 

sensor problems can be easily fixed by replacing shields and 

leveling the sensors.

Daily and seasonal temperature fluctuations are large 

at the study site. Differences between daily maximum and 

minimum temperatures commonly exceed 20°C. Differences 

between winter minimum and summer maximum temperatures 

exceed more than 40°C, and sometimes more than 50°C. The 

desert environment, with its high percentage of clear skies 

has a large heating capacity from incoming solar (short-wave) 

radiation during the day, and a proportionally large heat 

discharge by terrestrial (long-wave) radiation during the night. 

The large gains and losses in energy on a daily basis and their 

relative variation on a seasonal basis are what regulate the 

temperatures that occur in this environment.

Relative humidity is the ratio of the amount of water 

vapor in the air at a specific temperature (vapor pressure) to 

the maximum amount of water vapor that the air can hold 

at that temperature (saturated vapor pressure), expressed as 

a percent. During mid-day hours in the summer, relativehumidity values of less than 10 percent are common in the 

Amargosa Desert where prevailing high summer temperatures 

lower the relative humidity of available vapor content of the 

air.

Saturated vapor pressure is the highest concentration of 

water vapor that can exist in equilibrium over a free-water 

surface at that temperature. The data logger calculates the 

saturated vapor pressure in kilopascals from measured air 

temperature using an algorithm from Lowe (1977). Ambient 

vapor pressure is the partial pressure exerted by water vapor 

present in the air and indicates the water-vapor content of 

the air under prevailing atmospheric conditions. The ambient 

vapor pressure is the product of the saturated vapor pressure 

and the relative humidity. 

Daily mean saturated vapor pressures are higher during 

the summer months and lower during winter months because 

warm air can potentially hold considerably more water vapor 

than cold air. For this reason, summer precipitation events 

generally cause somewhat higher ambient vapor pressure than 

winter precipitation events. In contrast, the difference between 

the daily mean ambient vapor pressures measured during the 

summer and the winter is much less.

Mean horizontal wind-vector direction was calculated by 

vectorially summing the individual wind vectors consisting of 

wind magnitude and direction using available data logger 

commands. Daily wind directions indicate seasonal 

variability and annual recurrent patterns. Wind at the ADRS 

predominantly was from the northwest from September 

through February, and generally associated with regional 

frontal systems moving in from the west coast during the 

autumn and winter seasons. Winds from March to September 

are more evenly distributed from the northwest, southwest, 

and southeast.

Barometric pressures at the ADRS facility are corrected 

to sea level using an altitude of 847.2 m. Higher pressures 

generally occurred during clear winter days and lower 

pressures occurred during storm periods and summer.

The averaging soil-thermocouple probe measures the 

temperature in the soil between the soil surface and the 8-cm 

depth. The soil-heat-flux plates measure thermal energy that 

enters or leaves the soil. As the thermal energy enters the soil 

and moves downward, the soil-heat flux is defined as positive, 

and as the thermal energy leaves the soil, the soil-heat flux 

is defined as negative. Spikes in the soil-water content are 

indications of rain events occurring at the research site.
8 Micrometeorological, Evapotranspiration, and Soil-Moisture Data, Amargosa Desert Research Site, Nye County, Nevada

Evapotranspiration Data

Complete daily and 15-minute evapotranspiration rates 

are given in appendixes D–E. The 15-minute data include the 

four principal energy budget components of latent-heat flux, 

sensible-heat flux, soil-heat flux, and net radiation. Other 

parameters that were measured and used to derive variable 

coefficients used in calculations included in this report are air 

temperature, air-vapor pressure, soil-heat flux at the individual 

flux plates, soil-temperature, soil-water content above the 

flux plates, and soil-temperature change above the flux plates. 

Evapotranspiration terms, equations, and corrections used in 

calculating ET are provided in appendixes D–E.

Evapotranspiration at the ADRS is highly variable and 

dependent on available moisture principally from precipitation 

and precipitation-derived water stored in the upper soil profile 

(Johnson and others, 2007). A much smaller component of 

the evapotranspiration is supplied by water moving upward 

through the deep unsaturated zone to the root zone (Scanlon 

and others, 2003; Walvoord and others, 2004).

Evapotranspiration is limited throughout the year 

by precipitation. Daily evapotranspiration spikes after a 

rainstorm and gradually decreases until the next rain event. 

High evapotranspiration right after a storm is derived from 

evaporation of surface and near-surface soil moisture and 

increased plant transpiration supplemented by increased 

soil moisture. This high rate of evaporation can last for one 

to several days depending on the amount of precipitation. 

Depending on the duration and intensity of the rain event, 

deeper soil-moisture percolation may occur and maintain 

the decreasing daily evapotranspiration curve for longer 

periods. This more sustained daily evapotranspiration is 

attributed primarily to loss of root-zone soil-moisture by plant 

transpiration.

The energy used to drive the evapotranspiration process 

is latent-heat flux, while sensible-heat flux is the energy used 

to heat the air. Both latent-heat flux and sensible-heat flux 

partition the total available energy. With little soil moisture 

for plant transpiration or soil evaporation, the energy used for 

sensible-heat flux would nearly equal the available energy. 

Conversely, with sufficient moisture the energy used for latentheat flux would dominate.

Soil-Moisture Data

Complete soil-water content profile data and the 

associated calibration equations are given in appendixes F–G. 

Soil-water content is reported in units of cubic meter per cubic 

meter (volumetric water content).

Factors controlling the vertical and temporal changes in 

soil water content at the four experimental sites are discussed 

in detail by Andraski (1997) and Johnson and others (2007). 

These factors include presence or absence of vegetation and 

differences in soil properties that affect moisture movement 

and retention within the profiles.

References Cited

Andraski, B.J., 1990, Water movement and trench stability 

at a simulated arid burial site for low-level radioactive 

waste near Beatty, Nevada: La Grange Park, Ill., 

American Nuclear Society, Nuclear Waste Isolation in 

the Unsaturated Zone, Las Vegas, Nev., September 1989, 

Proceedings, p. 166–173.

Andraski, B.J., 1996, Properties and variability of soil and 

trench fill at an arid waste-burial site: Soil Science Society 

of America Journal, v. 60, p. 54–66.

Andraski, B.J., 1997, Soil-water movement under natural-site 

and waste-site conditions—A multiple-year field study in 

the Mojave Desert, Nevada: Water Resources Research, 

v. 33, no. 9, p. 1901–1916.

Andraski, B.J., and Stonestrom, D.A., 1999, Overview 

of research on water, gas, and radionuclide transport 

at the Amargosa Desert Research Site, Nevada, in

Morganwalp, D.W., and Buxton, H.T., eds., U.S. 

Geological Survey Toxic Substances Hydrology Program—

Proceedings of the Technical Meeting, Charleston, South 

Carolina, March 8–12, 1999—Volume 3 of 3—Subsurface 

Contamination from Point Sources: U.S. Geological Survey 

Water-Resources Investigations Report 99–4018–C, p. 459–

466. (Also available at http://pubs.er.usgs.gov/publication/

wri994018C.)
References Cited 9

Andraski, B.J., Stonestrom, D.A., Michel, R.L., Halford, K.J., 

and Radyk, J.C., 2005, Plant-based plume-scale mapping 

of tritium contamination in desert soils: Vadose Zone, v. 4, 

p. 819–827.

Clebsch, Alfred, Jr., 1968, Geology and hydrogeology 

of a proposed site for burial of solid radioactive waste 

southeast of Beatty, Nye County, Nevada, in Morton, 

R.J., Land burial of solid radioactive wastes—Study of 

commercial operations and facilities: Atomic Energy 

Commission, NTIS Report WASH-1143, p. 70–100.

 Fischer, J.M., 1992, Sediment properties and water movement through shallow unsaturated alluvium at an arid site 

for disposal of low-level radioactive waste near Beatty, Nye 

County, Nevada: U.S. Geological Survey Water-Resources 

Investigations Report 92–4032, 48 p. (Also available at 

http://pubs.er.usgs.gov/publication/wri924032.)

Johnson, M.J., Mayers, C.J., and Andraski, B.J., 2002, 

Selected micrometeorological and soil-moisture data at 

Amargosa Desert Research Site in Nye County near Beatty, 

Nevada, 1998–2000: U.S. Geological Survey Open-File 

Report 02–348, 14 p. (Also available at http://pubs.er.usgs.

gov/publication/ofr2002348.)

Johnson, M.J., Mayers, C.J., Garcia, C.A., and Andraski, B.J., 

2007, Selected micrometeorological, soil-moisture, and 

evapotranspiration data at Amargosa Desert Research Site in 

Nye County near Beatty, Nevada, 2001–05: U.S. Geological 

Survey Data Series 284, 29 p. (Also available at http://pubs.

er.usgs.gov/publication/ds284.)

Lowe, P.R., 1977, An approximating polynomial for 

computation of saturation vapor pressure: Journal of 

Applied Meteorology, v. 16, p. 100–103.

Nichols, W.D., 1987, Geohydrology of the unsaturated zone at 

the burial site for low-level radioactive waste near Beatty, 

Nye County, Nevada: U.S. Geological Survey Water-Supply 

Paper 2312, 57 p. (Also available at http://pubs.er.usgs.gov/

publication/wsp2312.)

Scanlon, B.R., Keese, Kelley, Reedy, R.C., Simunek, Jirka, 

and Andraski, B.J., 2003, Variations in flow and transport 

in thick desert vadose zones in response to paleoclimatic 

forcing (0–90 kyr): Field measurements, modeling, and 

uncertainties: Water Resources Research, v. 39, no. 7, 

p. 1179, doi:10.1029/2002WR001604.

Tyler, S.W., 1988, Neutron moisture meter calibration in 

large diameter boreholes: Soil Science Society of America 

Journal, v. 52, p. 890–893.

Swinbank, W.C., 1951, The measurement of vertical transfer 

of heat and water vapor by eddies in the lower atmosphere: 

Journal of Meteorology, v. 8, p.135–145.

U.S. Geological Survey, 2005 [2009], Collection, quality 

assurance, and presentation of precipitation data: U.S. 

Geological Survey Office of Surface Water Technical 

Memorandum No. 2006.01, 29 p., accessed August, 

31, 2012, at http://water.usgs.gov/admin/memo/SW/

OSW_2006-01_Revised_02122010.pdf.

U.S. Geological Survey, 2012, Amargosa Desert Research 

Site: Website, accessed August 31, 2012, at http://nevada.

usgs.gov/adrs/.

Walvoord, M.A., Stonestrom, D.A., Andraski, B.J., 

and Striegl, R.G., 2004, Constraining the inferred 

paleohydrologic evolution of a deep unsaturated zone in the 

Amargosa Desert: Vadose Zone Journal, v. 3, p. 502–512.

Wood, J.L., 1996, Selected meteorological and micrometeorological data for an arid site near Beatty, Nye County, 

Nevada, calendar year 1992: U.S. Geological Survey OpenFile Report 96–434, 33 p. (Also available at http://pubs.

er.usgs.gov/publication/ofr96434.)

Wood, J.L., and Andraski, B.J., 1992, Selected meteorological data for an arid site near Beatty, Nye County, Nevada, 

calendar year 1989: U.S. Geological Survey Open-File 

Report 92–484, 27 p. (Also available at http://pubs.er.usgs.

gov/publication/ofr92484.)

Wood, J.L., and Andraski, B.J., 1995, Selected meteorological 

data for an arid site near Beatty, Nye County, Nevada, 

calendar years 1990-91: U.S. Geological Survey Open-File 

Report 94–489, 49 p. (Also available at http://pubs.er.usgs.

gov/publication/ofr94489.)

Wood, J.L., and Fischer, J.M., 1991, Selected meteorological data for an arid site near Beatty, Nye County, Nevada, 

calendar year 1986: U.S. Geological Survey Open-File 

Report 91–189, 27 p. (Also available at http://pubs.er.usgs.

gov/publication/ofr91189.)

Wood, J.L., and Fischer, J.M., 1992, Selected meteorological 

data for an arid site near Beatty, Nye County, Nevada, 

calendar year 1987: U.S. Geological Survey Open-File 

Report 92–59, 27 p. (Also available at http://pubs.er.usgs.

gov/publication/ofr9259.)

Wood, J.L., Hill, K.J., and Andraski, B.J., 1992, Selected 

meteorological data for an arid site near Beatty, Nye 

County, Nevada, calendar year 1988: U.S. Geological 

Survey Open-File Report 92–61, 27 p.(Also available at 

http://pubs.er.usgs.gov/publication/ofr9261.)
10 Micrometeorological, Evapotranspiration, and Soil-Moisture Data, Amargosa Desert Research Site, Nye County, Nevada

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Appendixes 11

Appendixes

Data files that contain long-term annual average precipitation and daily total precipitation (appendix A), and complete 

micrometeorological (appendixes B–C), evapotranspiration (appendixes D–E), and soil-moisture (appendixes F–G) datasets are 

included in seven Microsoft© Excel files. The appendixes can be accessed and downloaded at URL http://pubs.water.usgs.gov/

ds/725/.

Appendix A. Summary of long-term (1981–2011) annual average precipitation and daily total precipitation at Amargosa Desert 

Research Site near Beatty, Nevada, 2006–11.

Appendix B. Daily mean micrometeorological data collected at Amargosa Desert Research Site near Beatty, Nevada, 2006–11.

Appendix C. Hourly mean micrometeorological data collected at Amargosa Desert Research Site near Beatty, Nevada, 2006–11.

Appendix D. Daily evapotranspiration data—evapotranspiration rates at Amargosa Desert Research Site near Beatty, Nevada, 

2006–09.

Appendix E. 15-minute evapotranspiration data—energy flux rates and other field data parameters at Amargosa Desert Research Site 

near Beatty, Nevada, 2006–09.

Appendix F. Summary of volumetric water-content data at depth for each experimental site at Amargosa Desert Research Site near 

Beatty, Nevada, 2006–11.

Appendix G. Volumetric water-content at depth for each neutron-probe access tube at each experimental site at Amargosa Desert 

Research Site near Beatty, Nevada, 2006–11.
12 Micrometeorological, Evapotranspiration, and Soil-Moisture Data, Amargosa Desert Research Site, Nye County, Nevada

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Publishing support provided by the U.S. Geological Survey

Publishing Network, Tacoma Publishing Service Center

For more information concerning the research in this 

report, contact the

 Director, Nevada Water Science Center

U.S. Geological Survey

2730 N. Deer Run Road

Carson City, Nevada 89701

http://nevada.usgs.gov
Arthur and others— Micrometeoroglical, Evapotranspiration, and Soil-Moisture Data at the Amargosa Desert Research Site in Nye County near Beatty, Nevada, 2006–11—Data Series 725