NAME Mexico SMN-CNA High Resolution Rawinsonde Data Set

1.0 General Description

This is one of the upper air data sets developed for the North American Monsoon Experiment (NAME). This data set includes the high resolution vertical (2 second) rawinsonde data from the Servicio Meteorológico Nacional (SMN) Comisión del Agua (CNA), which forms part of the Secretaría de Medio Ambiente y Recursos Naturales (SEMARNAT). There are 15 stations that measure pressure, temperature, humidity and wind that typically release radiosondes twice per day, but up to 8 per day were released by selected stations during intensive operations.

The SMN home page can be found here: It is in Spanish.

On 18 March 2010 a new version of these data were released that included the corrections of Ciesielski, et al (2009). The 9 stations that were corrected are: La Paz (MLAP), Mazatlan (MMZT), Chihuahua (MMCU), Torreon (MMTC), Monterrey (MMAN), Zacatacas (MMZC), Guadalajara (MGDL), Manzanillo (MZLO), and Empalme (MGYM).

2.0 Detailed Data Description

2.1 Detailed Format Description

All upper air soundings were converted to University Corporation for Atmospheric Research/Joint Office for Science Support (UCAR/JOSS) Cross Chain LORAN Atmospheric Sounding System (CLASS) Format (JCF). JCF is a version of the National Center for Atmospheric Research (NCAR) CLASS format and is an ASCII format consisting of 15 header records for each sounding followed by the data records with associated QC information.

Header Records

The header records (15 total records) contain data type, project ID, site ID, site location, release time, sonde type, meteorological and wind data processors, and the operator's name and comments. The first five header lines contain information identifying the sounding, and have a rigidly defined form. The following 7 header lines are used for auxiliary information and comments about the sounding, and may vary from dataset to dataset. The last 3 header records contain header information for the data columns. Line 13 holds the field names, line 14 the field units, and line 15 contains dashes ('-' characters) delineating the extent of the field.

The five standard header lines are as follows:

LineLabel (padded to 35 char)Contents
1Data Type:Description of type and resolution of data.
2Project ID:Id of weather project.
3Release Site Type/Site ID:Description of the release site.
4Release Location (lon,lat,alt):Position of release site in the format described below.
5UTC Release Time (y,m,d,h,m,s):Time of release, in the format: yyyy, mm, dd, hh:mm:ss

The release location is given as: lon (deg min), lat (deg min), lon (dec. deg), lat (dec. deg), alt (m)

Longitude in deg min is in the format: ddd'W where ddd is the number of degrees from True North (with leading zeros if necessary), is the decimal number of minutes, and W represents W or E for west or east longitude, respectively. Latitude has the same format as longitude, except there are only two digits for degrees and N or S for north/south latitude. The decimal equivalent of longitude and latitude and station elevation follow.

The seven non-standard header lines may contain any label and contents. The labels are padded to 35 characters to match the standard header lines. Records for this dataset include the following three non-standard header lines.

LineLabel (padded to 35 char)Contents
12Nominal Release Time (y,m,d,h,m,s):Nominal time of release, in the format: yyyy, mm, dd, hh:mm:ss

Data Records

The data records each contain time from release, pressure, temperature, dew point, relative humidity, U and V wind components, wind speed and direction, ascent rate, balloon position data, altitude, and quality control flags (see the QC code description). Each data line contains 21 fields, separated by spaces, with a total width of 130 characters. The data are right-justified within the fields. All fields have one decimal place of precision, with the exception of latitude and longitude, which have three decimal places of precision. The contents and sizes of the 21 fields that appear in each data record are as follows:

Field No.WidthFormatParameterUnitsMissing Value
35F5.1Dry-bulb TemperatureDegrees C999.0
45F5.1Dew Point TemperatureDegrees C999.0
55F5.1Relative HumidityPercent999.0
66F6.1U Wind ComponentMeters / Second9999.0
76F6.1V Wind ComponentMeters / Second9999.0
85F5.1Wind SpeedMeters / Second999.0
95F5.1Wind DirectionDegrees999.0
105F5.1Ascent RateMeters / Second999.0
135F5.1Elevation AngleDegrees999.0
145F5.1Azimuth AngleDegrees999.0
164F4.1QC for PressureCode (see below)99.0
174F4.1QC for TemperatureCode (see below)99.0
184F4.1QC for HumidityCode (see below)99.0
194F4.1QC for U Wind ComponentCode (see below)99.0
204F4.1QC for V Wind ComponentCode (see below)99.0
214F4.1QC for Ascension RateCode (see below)99.0

Fields 16 through 21 contain the Quality Control information derived at the UCAR Joint Office for Science Support (UCAR/JOSS). Any QC information from the original sounding is replaced by the following JOSS codes:

99.0Unchecked (QC information is "missing.") ("UNCHECKED")
1.0Checked, datum seems physically reasonable. ("GOOD")
2.0Checked, datum seems questionable on physical basis. ("MAYBE")
3.0Checked, datum seems to be in error. ("BAD")
4.0Checked, datum is interpolated. ("ESTIMATED")
9.0Checked, datum was missing in original file. ("MISSING")

Sample Data

The following is a sample record of SMN-CNA NAME high resolution rawinsonde data in JOSS CLASS format. The data portion is much longer than 80 characters and, therefore, wraps around to a second line. See section 2.1 for an exact format specification

Data Type:                         Mexican National Weather Service
Project ID:                        NAME
Release Site Type/Site ID:         MGYM 76256 Empalme/Guaymas
Release Location (lon,lat,alt):    110 49.51'W, 27 56.51'N, -110.825, 27.942, 12.0
UTC Release Time (y,m,d,h,m,s):    2004, 08, 24, 00:00:00
Nominal Release Time (y,m,d,h,m,s):2004, 08, 24, 00:00:00
 Time  Press  Temp  Dewpt  RH    Ucmp   Vcmp   spd   dir   Wcmp     Lon     Lat    Ele   Azi   Alt    Qp   Qt   Qrh  Qu   Qv   QdZ
  sec    mb     C     C     %     m/s    m/s   m/s   deg   m/s      deg     deg    deg   deg    m    code code code code code code
------ ------ ----- ----- ----- ------ ------ ----- ----- ----- -------- ------- ----- ----- ------- ---- ---- ---- ---- ---- ----
   0.0 1009.3  33.2  24.1  59.0    2.5    4.3   5.0 210.0 999.0 -110.825  27.942 999.0 999.0    12.0 99.0 99.0 99.0 99.0 99.0  9.0
   2.0 1006.6  31.3  19.4  49.0    2.7    4.7   5.4 210.0  12.0 9999.000 999.000 999.0 999.0    36.0 99.0 99.0 99.0 99.0 99.0 99.0
   4.0 1005.6  31.3  19.7  50.0    2.8    4.8   5.6 210.0   4.5 9999.000 999.000 999.0 999.0    45.0 99.0 99.0 99.0 99.0 99.0 99.0
   6.0 1004.4  31.2  19.6  50.0    2.9    4.9   5.7 210.0   5.5 9999.000 999.000 999.0 999.0    56.0 99.0 99.0 99.0 99.0 99.0 99.0
   8.0 1003.1  31.1  19.8  51.0    2.9    5.0   5.8 210.0   5.5 9999.000 999.000 999.0 999.0    67.0 99.0 99.0 99.0 99.0 99.0 99.0
  10.0 1001.7  30.8  19.8  52.0    3.0    5.2   6.0 210.0   6.5 9999.000 999.000 999.0 999.0    80.0 99.0 99.0 99.0 99.0 99.0 99.0

2.2 Data Remarks

2.3 Station List

MACA76805 AcapulcoMX-99.9316.833.0
MCUN76595 CancunMX-86.8521.0210.0
MGDL76612 GuadalajaraMX-103.340520.49891551.0
MGYM76256 Empalme/GuaymasMX-110.825127.941812.0
MLAP76405 La PazMX-110.387324.043118.0
MMAN76394 MonterreyMX-100.234125.8986450.0
MMCU76225 ChihuahuaMX-106.116728.701482.0
MMEX76679 Mexico CityMX-99.2019.402308.0
MMMD76644 MeridaMX-89.6520.9811.0
MMTC76382 TorreonMX-103.403125.54421123.0
MMZC76526 ZacatecasMX-103.756822.77142265.0
MMZT76458 MazatlanMX-106.301023.14664.0
MVER76692 Vera CruzMX-96.1219.1516.0
MZLO76654 MananilloMX-104.3219.053.0

3.0 Quality Control Processing

This dataset underwent an automated QC process. The dataset underwent internal consistency checks which included two types of checks, gross limit checks on all parameters and rate-of-change checks on temperature, pressure and ascension rate. Some further information on the QC processing conducted by JOSS can be found in Loehrer et al. (1996) and Loehrer et al. (1998).

3.1 Gross Limit Checks

These checks were conducted on each sounding and data were automatically flagged as appropriate. Only the data point under examination was flagged. JOSS conducted the following gross limit checks on the NAME SMN sounding dataset. In the table P = pressure, T = temperature, RH = relative humidity, U = U wind component, V = V wind component, B = bad, and Q = questionable.

ParameterGross Limit CheckParameter(s) FlaggedFlag Applied
Pressure < 0 mb or > 1050 mb PB
Altitude < 0 m or > 40000 m P, T, RHQ
Temperature < -90 °C or > 45 °C TT
Dew Point < -99.9 °C or > 33 °C
> Temperature
Relative Humidity < 0% or > 100% RHB
Wind Speed < 0 m/s or > 100 m/s
> 150 m/s
U, V
U, V
U Wind Component < 0 m/s or > 100 m/s
> 150 m/s
V Wind Component < 0 m/s or > 100 m/s
> 150 m/s
Wind Direction < 0° or > 360° U, VB
Ascent Rate < -10 m/s or > 10 m/s P, T, RHQ

3.2 Vertical Consistency Checks

These checks were conducted on each sounding and data were automatically flagged as appropriate. These checks were started at the lowest level of the sounding and compared neighboring 2-sec data points (except at pressures less than 100 mb where 30-sec average values were used. In the case of checks ensuring that the values increased/decreased as expected, only the data point under examination was flagged. However, for the other checks, all of the data points used in the examination were flagged. All items within the table are as previously defined.

ParameterVertical Consitency CheckParameter(s) FlaggedFlag Applied
Time decreasing / equal NoneNone
Altitude decreasing / equal P, T, RHQ
Pressure increasing / equal
> 1 mb/s or < -1 mb/s
> 2 mb/s or < -2 mb/s
P, T, RH
P, T, RH
P, T, RH
Temperature < -15 °C/km
< -30 °C/km
> 50 °C/km (not applied at p < 250 mb)
>100 °C/km (not applied at p < 250 mb)
P, T, RH
P, T, RH
P, T, RH
P, T, RH
Ascent Rate change of > 3 m/s or & lt; -3 m/s
change of > 5 m/s or < -5 m/s

3.3 Data Quality Issues

3.3.1 Noise Levels

4.0 References

Ciesielski, P. E., R. H. Johnson, and J. Wang, 2009: Correction of Humidity Biases in Vaisala RS80-H Sondes during NAME. J. Atmos. Oceanic Technol., 26, 1763-1780.

Loehrer, S. M., T. A. Edmands, and J. A. Moore, 1996: TOGA COARE upper-air sounding data archive: development and quality control procedures. Bull. Amer. Meteor. Soc., 77, 2651-2671.

Loehrer, S. M., S. F. Williams, and J. A. Moore, 1998: Results from UCAR/JOSS quality control of atmospheric soundings from field projects. Preprints, Tenth Symposium on Meteorological Observations and Instrumentation, Phoenix, AZ, Amer. Meteor. Soc., 1-6.