BAO Site Information

Location

Erie, CO, USA

Latitude: 40.050 N
Longitude: 105.010 W
Elevation: 1584 m
Time Zone: GMT-7
Height: 985 ft (300 m)

Instrumentation

4 levels (Sfc, 10, 100, 300 meters)

Sfc Pressure, precipitation
10m T, RH, Wind Speed and Direction (prop-vane)
100m T, RH
300m T, RH, Wind Speed and Direction (prop-vane)

How to Access Current BAO Tower Data

FTP to:

ftp.etl.noaa.gov
anonymous
guest
cd et6/archive/BAO/Tower/Processed/daily (Daily processed files can be found in this directory)

Files contain both uncorrected and corrected wind directions (see formats below)

BAO_010_YYYYDDD.dat
BAO_100_YYYYDDD.dat
BAO_300_YYYYDDD.dat
YYYY = Year DDD = Year day (UTC)

Daily plots of the data like those shown in the Data Browser can be found at cd et6/archive/BAO/Tower/Processed_Images/daily

Wind directions are corrected for boom orientation

300m PRT temperature is also corrected

BAO_300_YYYYDDD_Tall 300m temperatures
BAO_300_YYYYDDD_WS 300m wind speed and direction
BAO_300_YYYYDDD_TRH 300m temperature and relative humidity
BAO_010_YYYYDDD_PP Surface pressure and precipitation
BAO_010_YYYYDDD_WS 10m wind speed and direction
BAO_010_YYYYDDD_TRH 10m temperature and relative humidity

Composite plots

BAO_PPall Surface pressure and precipitation for all data
BAO_010100300_YYYYDDD_TRH Combined 10, 100, 300m temperature and relative humidity
BAO_010300_YYYYDDD_WS Combined 10, 300m wind speed and direction

Monthly data files and plots are also available at:

cd et6/archive/BAO/Tower/Processed/monthly:
cd et6/archive/BAO/Tower/Processed/monthly:

surface/10m

Format for the Daily Processed files are:

10 m data:
ID YR Day hhmm T RH WS DIR VDC P Precip True Wind Dir:
10,2007,167,0,37.566,11.73,3.7926,81.624,12.97,840.67,0,55.624001:
10,2007,167,1,37.39,11.634,4.8902,93.676,12.97,840.67,0,67.676003:

100 m data:
ID YR Day hhmm T RH WS DIR VDC:
100,2007,242,2154,27.136,31.66,0,0,13.153,0,0:
100,2007,242,2155,27.205,30.895,0,0,13.151,0,0:

300 m data:
"TOA5","CR1000","CR1000","2846","CR1000.Std.11","CPU:060516b_Met.CR1","10044","wkt30m":
"TIMESTAMP","RECORD","SE1_SONICWS_Avg","SE2_SONICWD_Avg","SE2_SONICWD_Std","SE1_SONICWS_Std","SE3_SONICTEMP_Avg","D3_PRTRES_Avg","D3_PRTTEMPAPPROX_Avg","SE4_HMPTEMP_Avg","SE9_HMPRH_Avg","P1_AIRFLOW_Avg","SE10_ACPOWER","BT_BATVOLT_Min","PRT_AVG","SONICWDT_AVG":
"TS","RN","ms","Deg","Deg","ms","mV","","Deg C","Deg C","%","Counts","ms","Volts","DegC","Deg True":
"","","WVc","WVc","WVc","Std","Avg","Avg","Avg","Avg","Avg","Avg","Smp","Min","Avg","Avg":
"2007-06-14 14:22:00",0,3.37,230.5,0.502,0.012,13.42,105.8471,14.24,15.09,42.15,0,110.6,13.31,15.0,192.5:
"2007-06-14 14:22:30",1,3.418,231.1,0.269,0.026,13.38,105.8718,14.3,15.11,42.26,0,110.6,13.31,15.1,193.1:

"TIMESTAMP" TS (UTC):
"RECORD" RN:
"SE1_SONICWS_Avg" m/s:
"SE2_SONICWD_Avg" degrees (relative):
"SE2_SONICWD_Std" degrees:
"SE1_SONICWS_Std" m/s:
"SE3_SONICTEMP_Avg" mv:
"D3_PRTRES_Avg" Deg C:
"D3_PRTTEMPAPPROX_Avg" Deg C:
"SE4_HMPTEMP_Avg" Deg C:
"SE9_HMPRH_Avg" %:
"P1_AIRFLOW_Avg" counts:
"SE10_ACPOWER" mv:
"BT_BATVOLT_Min" volts:
"PRT_AVG" Deg C:
"SONICWDT_AVG" degrees (True):

*****************************:
As of Oct 2, 2007 ~ 1600 UTC there was a change in the output format for the 10m and 100m data.:

ID YR Day hhmm T RH WSs WSv DIR DIRsd VDC Press Precip:
10,2007,275,1651,14.465,27.684,8.5848,8.5386,224.99,5.9401,13.517,842.79,0:
10,2007,275,1652,14.565,28.378,5.7689,5.472,254.42,18.378,13.517,842.79,0:
10,2007,275,1653,14.424,27.458,5.9094,5.848,262.06,8.2591,13.517,842.79,0:
10,2007,275,1654,14.37,28.281,4.949,4.8227,253.21,12.94,13.517,842.77,0:

Using Campbell Scientific P69 formulas:
WSs = wind speed scalar average wind:
WSv = wind speed vector average wind:
DIR = average wind direction true:
DIR sd = standard deviation of the wind direction:

ID YR Day hhmm T RH WSs WSv DIR DIRsd VDC:
100,2007,275,1639,12.717,31.119,0,0,0,0,13.587:
100,2007,275,1640,12.744,30.479,0,0,0,0,13.594:
100,2007,275,1643,12.805,30.574,0,0,0,0,13.594:
100,2007,275,1644,12.858,30.623,0,0,0,0,13.592:
100,2007,275,1653,13.047,30.333,0,0,0,0,13.588:
100,2007,275,1654,13.257,30.196,0,0,0,0,13.588:

BAO User Fees

Labor: 1 wk for setup/etc and admin overhead	($5k)
Facility infrastructure costs	($3k)
Data Data from 1-3 levels on tower (T/RH/spd/dir) Surface pressure and precip Maintain tower istruments Data processing	($4k)
Monthly use Data from 1-3 levels on tower (T/RH/spd/dir) Surface pressure and precip Maintain istruments Data processing Facility infrastructure costs	$20k
If additional time is required of NOAA/PSD personnel figure $4k/wk

Overview

The Boulder Atmospheric Observatory (BAO) tower has been owned and operated by the National Oceanic and Atmospheric Administration's (NOAA) Environmental Technology Laboratory (ETL) for more than 25 years. Constructed in 1976-1977 at a cost of $1.3M, the BAO sits on State of Colorado land just west of I-25, and just east of the town of Erie, along the I-25 corridor. At a height of 300 m (with structural strength capable of supporting an additional 200 m extension), the BAO is a very unique observational platform situated on the gently rolling plains of eastern Colorado.

The BAO was originally constructed to support atmospheric boundary layer probes (e.g., temperature, humidity, wind, and turbulence sensors). Data from these sensors was used in a number of fundamental boundary layer studies and to assess the performance of a wide variety of ground- based remote sensing systems developed by ETL (e.g., radar, lidar, sodar). The dozens of publications that resulted from these studies have established the BAO tower as a premier boundary layer observation facility.

Over the years use of the BAO has expanded. NOAA's Climate Monitoring and Diagnostics Laboratory (CMDL) began to make measurements from the top the BAO tower in 1985 in an effort to extend NOAA's radiation observational network and to take advantage of the unique opportunity presented by the tower. That opportunity was, and is, to be able to view a relatively large surface area and make extended quantitative observations of solar and infrared radiation that is either reflected or emitted from that portion of the earth's surface. The size of the area sampled from the top of the BAO approaches that sampled by satellite or simulated in numerical weather and climate models. The land surface area surrounding the BAO is representative of an area whose complexities make it a challenge to interpret in satellite data or to properly model numerically, but which is similar to a significant portion of the earth's land surface. This defining test for the satellite observations and General Circulations Models (GCM) makes the data particularly valuable. The data collected on the BAO tower have been, and are being, used in multiple satellite global radiation budget studies and by various GCM groups, including NOAA's Geophysical Fluid Dynamics Laboratory and European Center for Medium-Range Weather Forecasting.

Additionally the BAO tower site is a participant in the World Climate Research Program's Baseline Surface Radiation Network (BSRN) that requires that the data meet certain high standards. The BSRN collects the data and provides it through its central high-visibility archive in Zurich, Switzerland. Data are also available directly from the CMDL radiation group in Boulder. The radiation data collected at the BAO tower are continuous, sampling once per second, 24 hours a day for the last 16 years with only minimal loss so that data are available for nearly any time frame of interest to the diverse user community. Also, such a long-term data set has become valuable in its own right as an important record of the local and regional climate as driven by and reflected in the energy budget obtained from such a uniquely representative vantage point.

The BAO sits on 100 acres of State of Colorado land located in Erie, CO. This land is primarily agricultural and consists of natural grass and wheat fields.

BAO Reports/Papers/Experiments

BAO Report 1	Project Phoenix The Spetember 1978 Field Report	Dec 1979
BAO Report 2	The Boulder Low_level Intercomparison Experiment	Jun 1980 Preprint of WMO Report
BAO Report 3	Turbulence Statistics for Design of Wind Turbine Generators	Dec 1980 Preprint of Report to DOE
BAO Report 4	Studies of Nocturnal Stable Layers at BAO	Jan 1983
BAO Report 5	An Evaluation of Wind Measurements by Four Doppler Sodars	Jul 1984
BAO Report 6	A Field Comparison of IN SITU Meteorological Sensors	Dec 1985
BAO Report 7	Project CONDORS Convective Diffusion Observed by Remote Sensors	Jul 1986
Boulder Upslope Cloud Observation Experiment (BUCOE) Jun 1982
Kaimal, J.C. and J.E. Gaynor: 1983, The Boulder Atmpspheric Observatory. J Applied Meteor. 22, 863-880.
"The Weather Tamers" Science Digest Nov 1983
"Wind Shear" Popular Science Mar 1987
Northern Front Range Air Quality Study NFRAQS
ETL Air Quality Study ETL NFRAQS Program