The NOAA/INL Mesonet (MESOscale meteorological monitoring NETwork) began with a single station at the Central Facilities Area (CFA) in 1949 on what is now known as the Idaho National Laboratory (INL). Between 1950-1970, six on-site and 16 off-site monitoring stations were added to form an expanded observational network. The number of meteorological monitoring stations continued to expand and change over the years for several reasons, including 1) support of various projects, 2) to provide meteorological data for emergency response models, and    3) to gain a better understanding of the climatology of the INL and Eastern Snake River Plain. The current configuration of the Mesonet meets the needs of INL planners, emergency managers, scientists, engineers, operations personnel, the local National Weather Service (NWS) Weather Forecast Office (WFO) in Pocatello, ID, and the general public.

There are currently 34 fully automated meteorlogical observation stations in operation at the INL and surrounding area. Thirteen of the stations are located within the boundaries of the INL. The remaining stations are sited at key locations throughout the Eastern Snake River Plain. Standard meteorological parameters are measured at each Mesonet station. Click here for station information, instrument height, and types of data being collected at each level. Most of the towers are 50 ft. tall. Three tall towers range in height from 150 to 250 ft. and are the "primary" on-site observation stations in each of the three INL microclimate zones. These towers are at Grid 3/INTEC (GRI), MFC, and SMC. Shorter towers are on the summit of Big Southern Butte and Craters of the Moon National Park where aesthetic restrictions permit only a 20 ft. and 30 ft. tower, respectively.

A map of the 34 NOAA/INL Mesonet stations is shown below. Several of the stations, called Community Monitoring Stations (CMS), are sited at schools and other places frequented by the public to enhance relations with the local communities. The CMS stations were developed in partnership with DOE-ID, the State of Idaho INL Oversight Program, the Shoshone-Bannock Tribes, the City of Idaho Falls, and the State of Idaho Transportation Department (ITD). The CMS stations include a walk-up kiosk that displays current meteorological parameters and describes each of the measured variables. Click here for a typical representation of the mesonet tower configuration and instrument layout including instrument specifications.

All meteorological instruments were carefully selected to meet required and generally accepted guidelines, including DOE/EH-0173T, Environmental Regulatory Guide for Radiological Effluent Monitoring and Environmental Surveillance (1991), DOE Guide 151.1-1, Comprehensive Emergency Management System (1997); and ANSI/ANS 3.11-2005, Determining Meteorological Information at Nuclear Facilities. Accordingly, air temperature and relative humidity are measured at all Mesonet stations at the conventional 6 ft. level. Wind measurements (speed and direction, 3-second gusts, and standard deviation of the wind direction) are made at the top of all Mesonet towers. For the three tall towers, additional wind and air temperature measurements are measured at the 6, 33, 50, and 148 foot levels. Additional parameters measured at most stations include precipitation, atmospheric pressure, and solar radiation. Still more wind measurements are made at the 6 ft. level at the Aberdeen, Kettle Butte, and Monteview stations in support of the U.S. Bureau of Reclamation's Agrimet Program. Through a partnership with Agrimet, ARLFRD provides these additional meteorological measurements for regional crop water use modeling.

Mesonet data are recorded as averages, totals, or extremes over a 5-minute period. Wind speed, wind direction, air temperature, relative humidity, and solar radiation are measured every 1-second and averaged over the 5-minute period. Precipitation is totaled for the same 5-minute interval. Maximum and minimum air temperatures for the same 5-minute period are each selected from one of the 300 one-second scans used to assemble the 5-minute average. Wind gust is calculated as the maximum of a 3-second running average of the wind speed.

Data is collected at each station by a datalogger and transmitted every 5-minutes over a radio link back to the ARLFRD office. Data is also stored in first in/first out (FIFO) memory at each individual station and can be retrieved manually if the radio link breaks for an extended period of time. Each datalogger is also supplied with power by a deep cycle marine battery for extended operation and data storage in the absence of line power. (Only six stations are solar powered, the remainder have AC line power.) All of the data are continuously added to the INL climatological database and are immediately made available through the NOAA INL Weather Center web page.

In addition to the 34 stations, the network also includes:

• Thermoscreen;
• 915-MHz radar wind profiler and radio acoustic sounding system (RASS) ;
• Sodar;
• Energy Flux Station;

The network provides the high quality data and information necessary to meet a wide range of research and regulatory requirements. The data are used, for example, to:

• Provide meteorological data for ingest into plume dispersion models in emergency response situtions;
• Calculate radiation doses from INL operations for the Annual Site Environmental Report;
• Calculate radiation doses required by the National Emission Standards for Hazardous Air Pollutants (NESHAPS);
• Calculate radiation doses for historical reconstruction of worker exposures;
• Determine precipitation events exceeding several critical values that are necessary for maintaining compliance with the Storm Water Pollution Prevention Program;
• Calculate potential radiation doses from proposed new INL facilities for Environmental Assessments and Environmental Impact Statements.

The network, plus larger scale synoptic data, allows FRD to issue twice-daily site forecasts and notices (as needed) for special and routine INL operations.

Data Quality

ARLFRD follows a detailed and comprehensive data quality assurance (QA) program for the NOAA/INL Mesonet based on ASME NQA-1-2004, Quality Assurance Requirements for Nuclear Facility Applications. As part of the QA program, ARLFRD has adopted the standards listed in ANSI/ANS 3.11-2005, Determining Meteorological Information at Nuclear Facilities, and ANSI/ANS 3.2-1994, Administrative Controls and Quality Assurance for the Operational Phase of Nuclear Power Plants for data quality control guidance. Accordingly, the data quality control program uses an excellent set of software tools that consist of both manual and automated processes. This enhances the data quality evaluations and makes them more efficient. Included in the quality control program is a routine to display trended meteorological data. Every 5-minute data period for every station is plotted for missing or spiked data. Data is also screened for electronic noise, non-working aspirators that affect air temperature and relative humidity values, for orientation errors in the wind direction, stalled wind sensors, rime icing in the winter that degrades wind speeds, erroneous values caused by maintenance, sprinklers, bird droppings, and a host of other potential problems. Plotting the data allows the meteorologist to identify and flag any of the problems in the database and, if needed, notify a technician to quickly fix the problem. The result is a complete quality controlled data set with data quality flags for every meteorological variable. Raw data values are fully preserved in this manner and are never substituted even when they are flagged as suspect or bad.

Map of 34 weather stations.

Contact:

Roger Carter
1750 Foote Dr.
Idaho Falls, ID 83402
(208)526-2745
email: [email protected]