This dataset contains hourly resolution surface meteorological data in University Corporation for Atmospheric Research/Joint Office for Science Support (UCAR/JOSS) Quality Control (QC) format from stations within the following networks:
Data for the International H2O Project 2002 (IHOP 2002) domain (32N to 42N latitude and 90W to 105W longitude) and time period (13 May 2002 through 25 June 2002) are contained within this dataset. This IHOP 2002 Hourly Surface Composite dataset contains data from 790 stations.
Section 2.0 contains a detailed description of the
instrumentation, siting, and algorithms used by the source network to collect
the data. Section 2.1 contains a detailed
description of the format of the composite dataset. See
Section 2.2 for information on data processing, and
Section 3.0 below for the quality control processing performed by UCAR/JOSS
on this dataset. Section 4.0 contains references.
All data contained in this composite dataset were collected on stations
manufactured by Artais of Columbus, OH, a division of Vaisala. Each station
records data at 20-minute frequencies. Hourly frequency data are derived from
the 20-minute data by UCAR/JOSS by taking the data that are from 1 to 19 minutes
after the hour. For example, the record at nominal time 12:00 will
have an actual time between 12:01 and 12:19, inclusive. Within the 20-minute
data, precipitation is the accumulated precipitation for the 20 minute period.
Hourly precipitation is found by summing the three 20-minute values within the
hour previous to the record time. All other parameters are the values reported
for the 20-minute observation just previous to, or including, the record time.
Present weather and Sea level pressure are not reported for the Artais AWOS
data.
The following are descriptions of the AWOS station data.
Further details can be found in the AWOS Operations Manual
(USDOT, 1988).
Temperature/Dewpoint
AWOS takes at least 1-min measurements and computes a 5-min
running average. A minimum of four 1-min averages are required to
compute a valid 5-min average. 5-min averages are rounded to the nearest
degree F. AWOS will report the latest valid 5-min average during the
previous 15-min period. If one is not available, the data are reported as
"missing". If the 5-min average dew point is 1 or 2 degrees higher than the
5-min average temperature, then the dew point is reported equal to
temperature. If the 5-min average dew point exceeds the 5-min average
temperature by more than 2 degrees, the dew point is reported as "missing".
Station Pressure and Derived Pressure Elements
AWOS takes 10-sec measurements from at least two independent
pressure sensors and computes respective 1-min averages. A minimum of
5 measurements are required to compute a 1-min average. The 1-min
averages from each sensor are compared to verify that differences do not
exceed 0.04" Hg. If the sensors are in agreement, the lowest pressure
reading from all sensors is reported. If the sensor differences exceed
0.04" Hg, the data are reported as "missing". The reported pressure is
then used by AWOS in the computation of derived parameters (e.g.,
altimeter reading). UCAR/JOSS takes the altimeter reading and converts it back
to station pressure using the algorithms found in the
Smithsonian Meteorological Tables. Sea Level Pressure is then calculated
from station pressure using standard
GEMPAK algorithms
(Unidata, 2003).
Wind
AWOS takes 1-sec measurements of wind speed and direction and
computes a 2-min running average every 5-sec. Wind direction is rounded
to the nearest 10 degrees (magnetic north) and wind speed is rounded to
the nearest knot. Note that AWOS makes no correction to true north in
the archived data. If the 2-min running average is 2 knots or less, the
wind is reported as calm. The gust is computed using the highest 5-sec
average wind speed during the past 10-min period. A gust is computed
only when the 2-min running average exceeds 9 knots and the highest 5-
sec measurement exceeds the 2-min running average by 5 knots (during
the past minute). For Artais AWOS only, the raw data are reported with
respect to magnetic north. No corrections were applied to these Artais
AWOS winds.
Precipitation
AWOS takes 1-min accumulated measurements and computes total
precipitation over the period specified in the AWOS selected archival
interval (usually 5-min or 20-min). The total accumulation counter is
automatically reset each hour.
Present Weather
Present weather is not reported in the AWOS data.
For more information see the
Federal Aviation Administration (FAA) AWOS website (
FAA, 2003)
The Colorado Agricultural Meteorological Network (COAGMET) consists of
automated weather stations in Colorado operated by the Colorado Climate
Center. For more information on COAGMET visit the
COAGMET HomePage
( CSU, 2003). There are 24 COAGMET stations in this
IHOP_2002 Hourly Surface Composite.
Below is the description of a typical COAGMET station. Most stations
have a similar configuration but sensors, dataloggers and siting vary
somewhat throughout the network. Only the temperature, relative humidity,
vapor pressure, wind speed, wind direction and precipitation values are
used to create this composite dataset, but the description of the sensor for
every parameter is included here for reference.
Temperature, wind speed and wind direction values are averaged over
the hour ending with the measurement time. Dewpoint temperature is
calculated by UCAR/JOSS using the formula from Bolton
(1980) and the temperature and relative humidity values from each station.
Temperature and Relative Humidity
Wind
Precipitation
Solar Radiation
Soil Temperature
Leaf Wetness Sensor
Data Logger
Site Pictures
The HPCN is developed by the High Plains Regional Climate Center (HPRCC) and
includes data from a number of agricultural networks operated by various state
agencies in the High Plains region. There are 64 HPCN stations in this
IHOP_2002 Hourly Surface Composite.
Instrumentation
The High Plains Climate Network does not report any pressure parameter.
Station pressure was calculated by UCAR/JOSS from the station elevation and the
standard atmosphere (Smithsonian Meteorological Tables,
1949). Relative humidity and temperature were used to calculate dewpoint
(Bolton,1980).
For more information see the HPCN
Home Page (HPRCC, 2003).
The following variables measured at the Konza LTER site were included in this
IHOP 2002 Hourly Surface Composite:
The dew point was calculated by UCAR/JOSS from temperature
and relative humidity using the formula from Bolton
(1980).
Methods
A Campbell Scientific (CR-10) data logger continuously monitors air
temperature, relative humidity, wind speed, and samples wind direction at
hourly intervals. A microprocessor in the CR-10 manipulates the raw data and
outputs the average air temperature, relative humidity, wind speed, and the
sampled wind direction each hour.
Routine Maintenance
Clock mechanisms
require rewinding each week and pens must be refilled with ink. The cassette
tape on the CR-10 is changed every two months but may be left longer if
necessary.
The CR-10 is battery operated, as is the cassette recorder. The CR-10 output
includes the battery voltage every 24 hours and the batteries are constantly
charged using a 110 outlet. Desiccant packets are changed when necessary.
Batteries in the cassette are changed when the indicator lights indicate low
voltage or approximately every four months in summer and every two months in
winter.
Currently all chart changing and any changing of the cassette tape are done
on Tuesdays since this is the day that the NADP samplers are serviced.
For more information, see the Konza Prairie
LTER Program Web Site (Konza, 2003). A
picture of a Konza weather station can be found
here
The GWMD #5 network is located in south central Kansas. Data are collected
using
Campbell Scientific, Inc. MetData1 weather stations
(Campbell Scientific, 2003).
Station elevations were estimated by the GWMD5 from USGS topographic maps.
There are 10 GWMD5 stations in this IHOP_2002 Hourly Surface Composite.
The algorithms used to produce the GWMD5 hourly surface data are not
currently available.
The KVII School Network is located in the Texas and Oklahoma panhandles
and operated by KVII TV located in Amarillo, Texas. There are 4 KVII
stations in this IHOP_2002 Hourly Surface Composite.
Instrumentation
The station in Booker, Texas uses a PEET brothers Ultimeter 2000
weather station. The station is located at the junior high school
in Booker. The roof is a composite shingle surface and is white
and gray in color. The surface is flat. The approximate height
is 14 ft. The Booker rain gauge is not properly guyed down at
this time, so strong winds tend to shake the gauge and record
rainfall that hasn't occurred.
The station in Beaver, Oklahoma uses a Davis Weather Monitor 2
weather station. The station is located at the high school in Beaver.
The roof is a gray, composite shingle surface and is flat. The
approximate height is 17 ft.
The station in Perryton, Texas uses a Davis Weather Monitor 2
weather station. The station is located at the high school in Perryton.
The roof is made up of rocks that are gray and black in color. The
surface is flat. The approximate height is 15ft.
The station in Spearman, Texas uses a Davis Weather Monitor 2
weather station. The station is located at the high school in Spearman.
The roof is rocky and flat with "brown" and white rocks. The surface is
flat. The approximate height is 23 ft.
The wind directions are limited to 16 directions (a 16 point compass) that
represent values for N, NNE, NE, etc. Wind directions are a multiple of 22.5
degrees.
All stations provide sea level pressure except for Beaver, OK (BEA) which
provides station pressure.
The Unidata Local
Data Manager (LDM) (Unidata, 2002)
distributes World
Meteorological Organization (WMO) Surface data. These data are ingested
by UCAR/JOSS in ASCII WMO
meteorological message structure format
(NOAA/NWS, 2002).
The primary feedset name is "WMO" which includes Public
Product Service (PPS), Domestic Data Service (DDS), High resolution Data
Service (HDS), and International Data Service (IDS) feedtypes. Only
products that match the patterns ^S[AP].* .... ([0-3][0-9])([0-2][0-9])
and ^SX..81 .... ([0-3][0-9])([0-2][0-9]) are collected. In these patterns,
S stands for surface, A for Aviation Routine Reports (FM 15 - METAR), P for
Special aviation weather reports (FM 16 - SPECI), and X for miscellaneous
text records. Only hourly METAR data are included in this dataset. For
information on the METAR format see the
ASOS User's Guide (
NOAA, 2003). Special
data and METAR data that do not fall on the hour are available in the
dataset 'IHOP 2002 Hourly Surface "Specials" Data'. For 20 minute
METAR stations, the observation that falls between 15 minutes before
the hour and the hour, inclusive, is included in this dataset. If there
is no observation in this time period, then the observation closest to
the hour and falling between 1 minute and 15 minutes after the hour is
included in this dataset. All other observations are included in the
IHOP 2002 Hourly Specials dataset. There are 241 LDMSFCMETR
stations in this IHOP_2002 Hourly Surface Composite.
This dataset contains ASOS, AWOS, and MANUAL stations. Station ID's
are 3 characters long. Some networks use the 4-character ID to refer to
these stations. To obtain the 4-character id, prepend a "K". For example,
station ABR could also be referred to as station KABR.
Visibility values greater than 99999.99 m (~60SM) do not fit in the data format
so they were reset to -999.99 C. All of these values were equal to 112654.08
except one: 2002/06/08 11:00 had a vilibility value of 133575.55. Values of
-999.99 C in the visibility column that are not on 2002/06/08 11:00 indicate
actual visibilities of 112654.08.
Note the following problem with precipitation observations from Iowa
AWOS stations. The 1-min Iowa AWOS data are available from UCAR/JOSS
for the IHOP period at:
http://www.joss.ucar.edu/cgi-bin/codiac/dss?77.099
20 Iowa AWOS stations (ADU, AIO, AWG, CBF, CNC, CSQ, DNS, EOK, FFL, FSW, HNR,
ICL, IKV, MPZ, MUT, OXV, PEA, RDK, SDA, TNU) had bad precipitation values. The
correct values were calculated by UCAR/JOSS from 1 minute IOWA AWOS data
obtained separately.
Anyway, most (not all) of these stations are outfitted with tipping
buckets. All of you have been receiving the AWOS precipitation amounts
from the raw METARs, but up until today, there has been a fundamental flaw
with the observations. The site resets the hourly precipitation counter
at :55 after the hour, but METARs were only relayed at :05, :25 and :45
after the hour. This would result in 10 minutes of missing
potential rainfall data every hour.
The Iowa Department of Transportation sends us their 1 minute interval
data archive from the network at the end of every month. While looking at
this dataset, I noticed this timing problem last summer. The Des Moines
WFO and the Iowa Mesonet have been working closely with the DOT to get
this problem resolved. And today it has been. The Iowa AWOS sites are
now reporting at :15, :35 and :55 after the hour, which eliminates the
timing issue.
This dataset is a collection of data from many networks. The data are fed to
JOSS over the LDM by the FSL Meteorological Assimilation Data Ingest System
(MADIS). Some of these networks are themselves collections of data from
unrelated sources. Each of these networks/subnetworks can contain different
frequency data and different parameters. This code has been written to process
all of this data at once and convert it to JOSS QCF format. There are 143 MADIS
stations in this IHOP_2002 Hourly Surface Composite.
Conventions
The hourly parameter value given in this composite is the value closest to
the hour that falls at or after :45 minutes and before (but not at) 15 minutes
after the hour. MADIS QC flags are not carried forward to JOSS format. However,
the MADIS QC summary value X "Failed QC stage 1", which is a gross limit check,
has been used to mask out extremely bad data. If the data fails this check, it
is set to missing. Precipitation data has not been included in this composite.
The following networks are represented in this dataset.
Latitude/longitude accuracy included in the station list that accompanies
this dataset is a best guess from observation of the raw data:
For more information on these networks, see the
FSL/MADIS
Surface Network Information webpage
(FSL, 2003).
The Commercial Agricultural Program of the University of Missouri Extension
and Missouri Climate Center operate the MOCAWS network to document environmental
conditions to support agricultural operations. For more information see the
Missouri Weather
Stations web site (AgEBB, 2003). There are 15
MOCAWS stations in this IHOP_2002 Hourly Surface Composite.
The algorithms used to produce the Missouri Commercial Agricultural
Weather Station Network (MOCAWS) hourly surface data are not currently
available.
The New Mexico Monitored Climate Station Network is a network of
stations located across the state of New Mexico. Information about the network
and pictures of the stations are available at the
NMSU Network home page ( NMSU, 2003). There are
6 NMSU stations in this IHOP_2002 Hourly Surface Composite.
Instrumentation
NMSU Standard Stations (see station list below)
During the IHOP 2002 time period, it was determined that missing values
were sometimes reported as "0.0". If a parameter was constantly zero, or
zero for significant periods of time, that value was changed to the
missing value "-999.99"
Information about the network and pictures of the stations are available
at the
SCAN home page (USDA/NRCS, 2003) There are
7 SCAN stations in this IHOP_2002 Hourly Surface Composite.
Instrumentation
The standard SCAN site is configured as follows:
Instrumentation
Information on the instrumentation used in the SWKSMESO network is not
currently available.
Method
SWKSMESO data is received by JOSS at 15-minute resolution. JOSS computes hourly
values using the following algorithms:
Some of the precip values may by missing because of missing 15-min interval
values. For example a station may have a record for 11:15, 11:30 and 12:00 but
not for 11:45, therefore missing 15 minutes of possible precipitation. In this
case, the 12:00 precipitation values was set to -999.99 and flagged with an 'M'.
The PET system has a network of weather stations located throughout the the
North Plains whereby PET calculations are made and disseminated in an automated
process providing timely, accurate, predicted evapotranspiration data. Several
microcomputers and software programs are utilized in the sequence of data
manipulation, reduction, and computation.
The network operates weather stations in irrigated crop-growing regions across
the central and northern Texas Panhandle.
Instrumentation
The stations are Campbell Scientific Inc WW2000 or MetData1 systems
reduced to 2 meter towers or at least mimic them with the same
instruments. Heights are 1.8 to 2 meters above ground level for all
data.
All station pressure values for station EARTH have been set to missing in this
hourly composite due to concerns about data quality.
For more information on the PET network see the
TX North Plains ET Network Home Page (
Texas A&M, 2003).
This dataset is formed by extracting Hourly Surface Meteorological Data from
the IHOP_2002 Mesonet 5-Minute Surface Meteorological Composite. Refer to the
IHOP_2002 Mesonet 5-Minute Surface Meteorological Composite description
document for more information.
The following networks were extracted from the Five Minute Meteorological
Composite. Each network is followed by the number of stations it contains
in parenthesis: Oklahoma Mesonet (115), National Center for Atmospheric Research
(NCAR) Atmospheric Technology Division (ATD) Integrated Surface Flux Facility
(ISFF) (9), Texas Tech West Texas Mesonet (WTXMESO) (31), United States
Department of Agriculture (USDA) Agricultural Research Service (ARS) Micronet
(40), Department Of Energy (DOE) Atmospheric Radiation Measurement (ARM)
Southern Great Plains (SGP) Surface Meteorological Observation System (SMOS)
[ARMSFC] (14), DOE Atmospheric Boundary Layer Experiments (ABLE) Automatic
Weather Station (AWS) (5), National Center for Atmospheric Research Atmospheric
Technology Division (NCAR/ATD) Supplemental Surface Meteorological data
(NCAR_supp) (5), and the NCAR/ATD Homestead Integrated Sounding System (ISS)
observation station (1).
An hourly file is created from a 5-minute file by selecting the (xx-1):55
observation as the xx hourly observation, with the exception of the
precipitation parameter, which is totaled from (xx-1):05 through xx:00
(where xx is the 2-digit hour and xx-1 is the previous hour), and placed in
the xx hourly observation. For example, the 2PM hourly observation contains the
1:55 5-minute observation for all parameters except precipitation. The 2PM
hourly precipitation value is a sum of all 5-minute precipitation values from
1:05 to 2:00 inclusive. If any 5-minute precipitation values in this range are
missing, then the hourly value is set to missing.
The IHOP 2002 Hourly Surface Composite observation data
contains ten metadata parameters and 38 data parameters and flags. The
metadata parameters describe the station location and time at which the
data were collected. The time of observation is reported both in Universal
Time Coordinated (UTC) Nominal and UTC actual time. Days begin at UTC 0100
and end at UTC 0000 the following day. The table below details the data
parameters in each record. Several data parameters have an associated
Quality Control (QC) Flag Code which are assigned by the Joint Office
for Science Support (JOSS). For a list of possible QC Flag values see
the Quality Control section 3.0.
The list of code values for the Present Weather is too large to reproduce
in this document. Refer to WMO, 1988 for a
complete list of Present Weather codes.
The code values for the Squall/Gust Indicator are:
This dataset contains only the "Nominal" hourly observations
for the IHOP 2002 domain and time period. Other records, including
special records and records stripped from this composite, are located
in the IHOP 2002 Mesonet: Surface Miscellaneous Composite dataset.
Visibility values greater than 99999.99 m (~60SM) do not fit in the data format
so they were reset to -999.99 C. All of these values were equal to 112654.08
except one: 2002/06/08 11:00 had a vilibility value of 133575.55. Values of
-999.99 C in the visibility column that are not on 2002/06/08 11:00 indicate
actual visibilities of 112654.08.
Sea Level Pressure is calculated from station pressure using standard
GEMPAK algorithms
(Unidata, 2003).
When not present in the raw data, the dewpoint temperature was
computed by UCAR/JOSS from temperature and relative
humidity using the formula from Bolton (1980).
When not present in the raw data, station pressure is computed
by UCAR/JOSS from altimeter and elevation using the formula from the
Smithsonian Meteorological Tables, 1949.
The IHOP 2002 Hourly Surface Composite was formed from several datasets.
These IHOP 2002 Hourly Surface Composite datasets were collected over the IHOP
2002 domain (i.e., 32N to 42N latitude and 90W to 105W longitude) and time
period (13 May 2002 through 25 June 2002) and were combined to form a surface
composite. The composite was quality controlled to form the final IHOP 2002
Hourly Surface Composite.
During the JOSS Horizontal Quality Control (JOSS HQC) processing,
station observations of pressure, temperature, dew point, wind speed and
wind direction were compared to "expected values" computed using an
objective analysis method adapted from that developed by
Cressman (1959) and
Barnes (1964). The JOSS HQC method allowed for short term (>/= 30 day)
variations by using 30 day standard deviations computed for each parameter
when determining the acceptable limits for "good", "questionable", or
"unlikely" flags. "Expected values" were computed from inverse distance
weighted station observations within a 300 km Radius Of Influence (ROI)
centered about the station being quality controlled (the station being
quality controlled was excluded); i.e.;
theta_e = < theta(i)/w(i) > / < w(i) >
Where theta_e is the "expected value" of the parameter at the site in
question, theta(i) is the observed value of the parameter at site i, w(i)
is the weighting factor for site i (here the inverse of the distance
between site i and the station being quality controlled), and <...> is
the sum over all stations "i" in the current ROI that have valid
observations of the parameter at the time in question. Data were
always compared at like solar times.
To determine an observation's HQC flag setting, the difference between
the actual observation and its "expected value" was compared to that
parameter's normalized standard deviation. Normalizing factors (also
called the sensitivity coefficients) were chosen to control the "good",
"questionable", and "unlikely" flag limits for each parameter. See
Table 3-1 for IHOP 2002 normalizing factors. Table 3-2
contains the HQC flag limit ranges derived from the normalizing factors
given in Table 3-1 and estimated standard deviations for each parameter
so that 95% of the QC limits applied to the IHOP 2002 data
fell within these ranges. For example, 95% of the observed station
pressure values that were flagged as "good" were within 1.2 mb of the
expected value. The significant overlap of the ranges seen in
Table 3-2 was partially due to seasonal and station differences in
standard deviations. The actual HQC limits applied at any particular
time depended upon the dynamic nature of the particular station's
parameter values over time.
Data were never changed, only flagged.
HQC was only applied to sea level pressure, calculated sea level pressure,
temperature, dew point, wind speed and wind direction. If the calculated sea
level pressure quality control information was available, its flag was applied
to the station pressure.
If the calculated sea level pressure could not be quality controlled, the sea
level pressure quality control flag was applied to the station pressure. If the
sea level pressure could not be quality controlled, the station pressure quality
control flag was not overridden.
Table 3-1 Normalizing factors used for IHOP 2002 Hourly
Surface Composite
Table 3-2 Ranges of HQC flag limit values for IHOP 2002
Hourly Surface Composite
The squall/gust wind speed data were not quality controlled.
General consistency checks were also applied to the dry bulb
temperature, wind direction, and the relationship between precipitation and
cloud amount/cloud cover. If the dew point temperature was greater than the
dry bulb temperature both values were coded "questionable". Also, wind
direction for observed "calm" winds was given the same QC code as the wind
speed. If precipitation was reported, but the cloud amount was "none" or
"clear", then both the cloud amount and precipitation values were coded
"questionable".
Several impossible values were also checked. Negative wind speeds
were coded "unlikely". Negative squall/gust wind speeds were coded
"unlikely". Wind directions of less than 0 degrees or greater than 360
degrees were coded "unlikely". If these consistency checks would have
upgraded the quality control flags previously set by HQC or gross limit
checks, then they were not applied. However, if these consistency checks
would have degraded the previously set QC flags, they were applied.
The JOSS HQC scheme relied on spatial and temporal continuity to
flag the data. It has been shown that this method works very well for
temperature, dew point, pressure, and wind speed, but is not a very good
scheme for the wind direction. The flags appear to be overly lax and
perhaps could be tightened.
Gross limit checks were also used to determine the quality of the
precipitation values. The gross limits are shown in Table 3-3. Certain
"questionable" and "unlikely" data values were also manually inspected.
After inspection, the quality control flag may have been manually modified
to better reflect the physical reasonableness of the data. Data were never
modified, only flagged. Negative precipitation was also coded "unlikely".
See Table 3-4 for a list of the possible quality control flags and their
meanings.
Table 3-3 - Precipitation Gross Limit Values
Table 3-4 - Quality Control Flags
Agricultural Electronic Bulletin Board (AgEBB), cited 2003: Missouri
Weather Stations [Available online from
http://agebb.missouri.edu/weather/stations/]
Barnes, S. L., 1964: A technique for maximizing details in numerical
weather map analysis. J. Appl. Meteor., 3, 396-409.
Bolton, D., 1980: The computation of equivalent potential temperature.,
Mon. Wea. Rev., 108, pp 1046-1053.
Campbell Scientific, cited 2003: MetData1 Weather Station [Available
online from http://www.campbellsci.com/p-weatherstations.html#metdata1]
Colorado State University (CSU), Cited 2003: CoAgMet Homepage [Available
online from http://ccc.atmos.colostate.edu/~coag/].
Cressman, G. P., 1959: An operational objective analysis system.
Mon. Wea. Rev., 87, 367-374.
Federal Aviation Administration (FAA), Cited 2003: Automated Weather
Observing System website [Available online from
http://www1.faa.gov/asos/awosinfo.htm]
FSL, cited 2003: Meteorological Assimilation Data Ingest System (MADIS)
Surface Network Information
[Available online from http://www-sdd.fsl.noaa.gov/MADIS/network_info.html]
High Plains Regional Climate Center (HPRCC), cited 2003: Automated Weather
Data Network [Available online from http://hpccsun.unl.edu/awdn/]
Konza Prairie LTER Program, cited 2003 [Available online from
http://www.konza.ksu.edu/]
NMSU, citred 2003: New Mexico Climate Center [Available online from
http://weather.nmsu.edu/stations/]
NOAA, National Weather Service, Automated Surface Observing System (ASOS),
cited 2003:
ASOS User's Guide [Available online from http://www.nws.noaa.gov/asos]
NOAA/NWS, cited 2002: WMO Message structure 2000 Paraphrased Version
[Available from http://www.nws.noaa.gov/tg/head.html].
Smithsonian Meteorological Tables, Table No. 65, p.269.
Smithsonian Institution Press, Washington, D.C., September, 1949.
Texas A&M, 2003: TX North Plains ET Network Home Page [Available online
from http://amarillo2.tamu.edu/nppet/petnet1.htm]
Unidata, Cited 2002: Unidata LDM [Available online from
http://www.unidata.ucar.edu/packages/ldm/].
Unidata, Cited 2003: Unidata GEMPAK/N-AWIPS [Available online from
http://www.unidata.ucar.edu/packages/gempak/].
USDA/NRCS, cited 2003: Soil Climate Analysis Network
[Available online from http://www.wcc.nrcs.usda.gov/scan/]
United States Department of Transportation (USDOT), 1988. AWOS
Operations Manual, Federal Aviation Administration.
World Meteorological Organization (WMO), 1988: Manual on Codes
Volume I, Part B - Binary Codes. WMO, Geneva, Switzerland.
2.0 Detailed Data Description
2.0.1 Automated Weather Observing System (AWOS) Algorithms
The Automated Weather Observing System (AWOS) is a suite of sensors, which
measure, collect and disseminate weather data to help meteorologists, pilots
and flight dispatchers prepare and monitor weather forecasts, plan flight
routes, and provide necessary information for correct takeoffs and landings.
The sensors measure weather parameters such as wind speed and direction,
temperature and dew point, visibility, cloud heights and types, precipitation,
and barometric pressure. The AWOS stations are operated by the Federal Aviation
Administration (FAA) and/or state Department of Transportation offices. There
are 15 AWOS stations in this IHOP_2002 Hourly Surface Composite.
2.0.2 Colorado Agricultural Meteorological Network (COAGMET)
* Model: Vaisala HMP35C Probe
* Sensor Height: 1.5 meters
* Temperature Specs
o Temperature Measurement Range: -35 to 50 DegC
o Thermistor Interchangeability Error: Typically <+-0.2 DegC over 0
DegC to 60 DegC; +-0.4 DegC at -35 DegC
o Polynomial Linearization Error: <+-0.5 DegC over -35 DegC to 50
DegC
* Relative Humidity Specs
o RH Measurement Range: 0% to 100%
o RH Accuracy (at 20 DegC) +- 2%, 0% - 90%; +-3% >90%
o Temperature Dependence of RH Measurement: +-0.04% RH/DegC
* Model: R.M. Young 05103 Wind Monitor
* Sensor Height: 2 meters
* Wind Speed Specs
o Range: 0-60 m/s
o Starting Threshold: 1.0 m/s
o Distance Constant (63% recovery): 2.7 m.
* Wind Direction Specs
o Range: 0-360 Deg. (355-360 open)
o Starting Threshold 10 deg displacement: 0.9 m/s
o Starting Threshold 5 deg displacement: 1.3 m/s
* Model: TE525 tipping bucket raingage
* Specs
o Sensor height >1m
o Collector diameter - 154mm
o 0.254mm/tip
o accuracy +- 1% for precip of 50mm/hr or less
o Operating temperature 0 to 50C (not accurate during winter)
* Model: Licor 200S Pyranometer
* Specs
o Sensor Height ~2m
o 0-10 mv output range
o Sensitivity typically 80 microamp/1000 W/m2
o Linearity Maximum deviation 1% up to 3000 W/m2
o Spectral response from 0.4 to 1.1 mu
o Typical error under natural daylight +-3%, maximum +-5%
* Model: CSI Model 107 Soil Temp Probe (thermistor)
* Specs
o +- 0.4C for -33 to +48C all errors inclusive
o Sensor depth 50mm and 150mm where two sensors used, 100mm where
only one.
* Model: CSI Model 237 - Circuit board with interlocking gold plated
copper fingers, coated with flat latex paint to spread water layer.
Measures electrical resistivity of water film.
* Specs
o Sensor height ~0.5m
2.0.3 High Plains Climate Network (HPCN)
Sensor Variable Installation Ht. Accuracy
---------------------------------------------------------------------------
Thermistor Air Temperature 1.5 m 0.25 C
Cup Anemometer Wind Speed 3 m 5% (0.5 m/s start-up)
Wind Vane Wind Direction 3 m 2 degrees
Coated Circuit Relative Humidity 1.5 m 5%
Tipping Bucket Precipitation 0.5 to 1 m 5%
2.0.4 Konza Prairie Long Term Ecological Research (KONZA_LTER)
The purpose of the Konza Prairie Long Term Ecological Research (LTER)
network is to monitor meteorological parameters in tallgrass prairie on a long
term basis. The Konza Prairie Biological Station (KPBS) is representative of
native tallgrass prairie in the Flint Hills of eastern Kansas. Because of the
relatively steep topography and rocky soils characteristic of the region, this
grassland has never been plowed. There is 1 KONZA_LTER station in this
IHOP_2002 Hourly Surface Composite.
Hourly precipitation for this site is not precise, so precipitation has not
been included in this composite.
2.0.5 Kansas Ground Water Management District #5 (GWMD5)
2.0.6 KVII School Network
2.0.7 Unidata Local Data Manager (LDM) World Meteorological
Organization (WMO) (LDMSFCMETR) Algorithms
Message from Daryl Herzmann (akrherz@iastate.edu)
* Program Assistant -- Iowa Environmental Mesonet
* http://mesonet.agron.iastate.edu
Sent 10 April 2003:
2.0.8 National Oceanic and Atmospheric Administration (NOAA) Forecast
Systems Laboratory (FSL) Meteorological Assimilation Data Ingest System
(MADIS)
Network accuracy
========== ============
ms:APRSWXN 5
ms:AWX 2
ms:GLDNWS 2
ms:GPSMET 2
ms:IADOT 4
ms:KSDOT 4
ms:MesoWes 2
ms:RAWS 5
ms:UDFCD 3
2.0.9 Missouri Commercial Agricultural Weather Station Network (MOCAWS)
2.0.10 New Mexico State University (NMSU)
Air Temperature
Model: Campbell Scientific Model cs500 Probe
Sensor Type: Thermistor Fenwall (UUT51J1)
Siting: 1.5 m Above Surface
Accuracy: +/-0.2 C
Relative Humidity
Model: Campbell Scientific Model cs500 Probe
Sensor Type: Resistance Chip: Phys Chem PCRC11
Siting: 1.5 m Above Surface
Accuracy: +/-5% RH
Precipitation
Model: Campbell Scientific Model TE525 Rain Gage
Sensor Type: Tipping Bucket With Event Counter
Siting: Gage Top At 43 cm Above Surface
Accuracy: +/-1mm
Wind Speed
Model: Met One Model 014A Wind Speed Sensor
Sensor Type: Anemometer Using Reed Switch
Siting: 3.75 m Above Surface
Accuracy: +/-1.5%
Wind Direction
Model: Met One Model 024A Wind Direction Sensor
Sensor Type: Wind Vane Attached To Potentiom
Siting: 3.75 m Above Surface
Accuracy: +/-5deg
Gossym Comax Stations (see station list below)
Air Temperature
Model: Campbell Scientific Model 207 Probe
Sensor Type: Thermistor Fenwall (UUT51J1)
Siting: 1.5 m Above Surface
Accuracy: +/-0.2 C
Relative Humidity
Model: Campbell Scientific Model 207 Probe
Sensor Type: Resistance Chip: Phys Chem PCRC11
Siting: 1.5 m Above Surface
Accuracy: +/-5% RH
Precipitation
Model: Campbell Scientific Model TE525 Rain Gage
Sensor Type: Tipping Bucket With Event Counter
Siting: Gage Top At 43 cm Above Surface
Accuracy: +/-1mm
Wind Speed
Model: Met One Model 014A Wind Speed Sensor
Sensor Type: Anemometer Using Reed Switch
Siting: 3.75 m Above Surface
Accuracy: +/-1.5%
Wind Direction
Model: Met One Model 024A Wind Direction Sensor
Sensor Type: Wind Vane Attached To Potentiom
Siting: 3.75 m Above Surface
Accuracy: +/-5deg
Station List
----------------------------------------
Station Name Station Type
----------------------------------------
Artesia NMSU Standard
Carlsbad Gossym Comax
Clayton NMSU Standard
Cottonwood Gossym Comax
Loving Gossym Comax
Tucumcari NMSU Standard
2.0.11 National Oceanic and Atmospheric Administration (NOAA)
Profiler Network (NPN)
The algorithms used to produce the NOAA NPN hourly surface data are
not currently available. There are 17 NPN stations in this
IHOP_2002 Hourly Surface Composite.
2.0.12 United States Department of Agriculture (USDA)
Natural Resource Conservation Service (NRCS) National Water
and Climate Center Soil Climate Analysis Network (SCAN)
Soil Moisture/Soil Temperature (NRCS/SMST)
2.0.13 Southwest Kansas Mesonet (SWKSMESO)
This data set contains 15-minute resolution surface meteorological
data from the Southwest Kansas Mesonet (formerly the Ground Water
Management District #3 Network). These data were provided by the Goodland,
Kansas office of the National Weather Service. There are 8 SWKSMESO
stations in this IHOP_2002 Hourly Surface Composite.
This dataset contained two records for the 2400 hour of each day. The second
appeared to be daily averages and sums, so these second 2400 records were
ignored.
2.0.14 Texas North Plains Potential Evapotranspiration (PET) Network
Potential EvapoTranspiration or PET is the amount of evaporation and
transpiration a well-watered plant has daily and throughout its typical growing
season. Transpiration is the water entering the plant root system and used to
build plant tissue or being passed through the leaves into the atmosphere.
Evaporation is the water evaporating from the adjacent soil, water surfaces, or
from the surface of leaves of the plant. There are 15 PET stations in this
IHOP_2002 Hourly Surface Composite.
2.0.15 Hourly Surface data extracted from the IHOP_2002 Mesonet
5-Minute Surface Meteorological Composite
2.1 Detailed Format Description
Parameters Units
---------- -----
Date of Observation UTC Nominal
Time of Observation UTC Nominal
Date of Observation UTC Actual
Time of Observation UTC Actual
Network Identifier Abbreviation of platform name
Station Identifier Network Dependent
Latitude Decimal degrees, South is negative
Longitude Decimal degrees, West is negative
Station Occurrence Unitless
Station Elevation Meters
Station Pressure, QC flag Hectopascals (mb)
Reported Sea Level Pressure, QC flag Hectopascals (mb)
Computed Sea Level Pressure, QC flag Hectopascals (mb)
Dry Bulb Temperature, QC flag Celsius
Dew Point, QC flag Celsius
Wind Speed, QC flag m/s
Wind Direction, QC flag Degrees
Total Precipitation, QC flag mm
Squall/Gust Indicator Code Value
Squall/Gust Value, QC flag m/s
Present Weather, QC flag Code Value
Visibility, QC flag Meters
Ceiling Height (first layer) Hundreds of feet
Ceiling Flag (first layer), QC flag Code Value
Cloud Amount (first layer), QC flag Code Value
Ceiling Height (second layer) Hundreds of feet
Ceiling Flag (second layer), QC flag Code Value
Cloud Amount (second layer), QC flag Code Value
Ceiling Height (third layer) Hundreds of feet
Ceiling Flag (third layer), QC flag Code Value
Cloud Amount (third layer), QC flag Code Value
Code Definition
---- ----------
blank No Squall or Gust
S Squall
G Gust
The code values for the ceiling flag Indicator are:
Code Definition
---- ----------
0 None
1 Thin
2 Clear below 12,000 feet
3 Estimated
4 Measured
5 Indefinite
6 Balloon
7 Aircraft
8 Measured/Variable
9 Clear below 6,000 feet (AUTOB)
10 Estimated / Variable
11 Indefinite / Variable
12 12-14 reserved
15 Missing
The code values for the Cloud Amount Indicator are:
Code Definition
---- ----------
0 0 ( or clear)
1 1 okta or less, but not zero or 1/10 or less, but not zero
2 2 oktas or 2/10-3/10
3 3 oktas or 4/10
4 4 oktas or 5/10
5 5 oktas or 6/10
6 6 oktas or 7/10-8/10
7 7 oktas or more, but no 8 oktas or 9/10 or more, but not 10/10
8 8 oktas or 10/10 (or overcast)
9 Sky obscured by fog and/or other meteorological phenomena
10 Sky partially obscured by fog and/or other meteorological
phenomena
11 Scattered
12 Broken
13 13-14 Reserved
15 Cloud cover is indiscernible for reasons other than fog or
other meteorological phenomena, or observation is not made.
2.2 Data Remarks
3.0 Quality Control Processing
Parameter Good Questionable Unlikely
--------- ---- ------------ --------
Station Pressure 0.2 0.2 0.5
Sea Level Pressure (SLP) 0.2 0.2 0.5
Calculated SLP 0.4 0.4 1.0
Dry Bulb Temperature 0.5 0.5 1.0
Dew Point Temperature 0.5 0.5 1.0
Wind Speed 2.25 2.25 4.0
Wind Direction 1.22 1.22 2.2
Parameter Good Questionable Unlikely
--------- ---- ------------ --------
Station Pressure (mb) < 1.2 [0.5-2.9] > 1.2
Sea Level Pressure (mb) < 1.5 [0.5-3.6] > 1.3
Calculated SLP (mb) < 3.2 [1.1-7.9] > 2.7
Dry Bulb Temperature (deg.C) < 3.4 [1.1-6.8] > 2.2
Dew Point Temperature (deg.C) < 3.4 [1.0-6.8] > 2.0
Wind Speed (m/s) < 7.6 [1.6-13.4] > 2.8
Wind Direction(degrees) < 137.8 [54.6-180.0] >98.4
Parameter Good Questionable Unlikely
--------- ---- ------------ --------
Hourly Precipitation < 20.0 mm >= 20.0 mm >= 50.0 mm
QC Code Description
------- -----------
U Unchecked
G Good
M Normally recorded but missing.
D Questionable
B Unlikely
N Not available or Not observed
X Glitch
E Estimated
C Reported value exceeds output format field size or
was negative precipitation.
T Trace precipitation amount recorded
I Derived parameter can not be computed due to
insufficient data.
4.0 References
