This dataset contains hourly resolution surface meteorological data in National Center for Atmospheric Research / Earth Observing Laboratory (NCAR/EOL) Quality Control (QC) format from stations within the New Mexico State University Network (NMSU). Information about the network and pictures of the stations are available at the NMSU Network home page ( NMSU, 2003). This dataset contains data from 129 stations.
This data set is provided with the parameter values unchanged. Note that the NMSU native format data set used a value of zero to represent missing data. These zero values have been carried through into this data set.
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. Section 3.0 contains references.
Instrumentation
NMSU Standard Stations
Air Temperature Model: 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
UCAR/JOSS calculates dewpoint from relative humidity and temperature. For information on the calculation of parameters derived by UCAR/JOSS from the raw parameters available, see Section 2.2.
Flags '*' and ' ' set by NMSU were translated to UCAR/JOSS Quality Control Flags as follows:
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
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:
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.
Quality Control Flags
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.
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.
Bolton, D., 1980: The computation of equivalent potential temperature., Mon. Wea. Rev., 108, pp 1046-1053.
NMSU, cited 2003: New Mexico Climate Center [Available online from http://weather.nmsu.edu/]
Smithsonian Meteorological Tables, Table No. 65, p.269. Smithsonian Institution Press, Washington, D.C., September, 1949.
Unidata, Cited 2003: Unidata GEMPAK/N-AWIPS [Available online from http://www.unidata.ucar.edu/packages/gempak/]
World Meteorological Organization (WMO), 1988: Manual on Codes Volume I, Part B - Binary Codes. WMO, Geneva, Switzerland.