NAME Sounding Composite 5-mb Level Upper-Air Data Set

1.0 General Description

This dataset contains upper-air sounding data interpolated to a constant vertical resolution of 5 hPa in the National Center for Atmospheric Research (NCAR) Earth Observing Laboratory (EOL) Sounding Composite Format from stations in the following networks:

Data for the North American Monsoon Experiment (NAME) 2004 Tier 3 domain (5°N to 50°N latitude and 75°W to 125°W longitude) data are contained in this dataset. The dataset covers the time period of 01 June 2004 through 30 September 2004. This NAME 2004 Sounding Composite 5-mb Upper-Air Dataset contains 21254 soundings from 91 sites.

Most of the soundings have passed through the NCAR/EOL automatic quality control. The tethersondes from the Mexican UNAM R/V El Puma did not run through the quality control performed by the National Center for Atmospheric Research/Earth Observing Laboratory (NCAR/EOL).

On 25 March 2010 a new version of these data were released that included the corrections of Ciesielski, et al (2009). Not all stations in the composite were affected by the correction. The U.S. stations that were affected are: Amarillo, TX (KAMA), El Paso TX/Santa Teresa, NM (KEPZ), Flagstaff, AZ (KFGZ), Midland, TX (KMAF), Phoenix, AZ (KPHX), Tucson, AZ (KTUS), and Yuma Proving Grounds, AZ (KYUM). The Mexican stations affected are: Chihuahua (MMCU), Empalme/Guaymas, MX (MGYM), Guadalajara, MX (MGDL), Kino Bay, MX (MBKN), La Paz (MLAP), Loreto, MX (MNLO), Los Mochis, MX (MIS4), Manzanillo (MZLO), Mazatlan (MMZT), Monterrey (MMAN), Puerto Penasco, MX (MNPP), Torreon (MMTC), Zacatacas (MMZC), and R/V Altair (XCWH).

Section 2.0 contains a detailed description of the source network that collected the data. Section 2.1 contains a detailed description of the format of the composite dataset. See Section 3.0 below for the quality control processing performed by NCAR/EOL on this dataset. Section 4.0 contains references.

2.0 Detailed Data Description

The `native' resolution data for every sounding were interpolated to 5 hPa vertical resolution files. The surface data point was kept as the initial level in each sounding. The first interpolated data point was at the next lowest pressure evenly divisible by 5 and then every 5 hPa pressure level beyond that point to either 50 hPa or the lowest pressure level reached by the radiosonde, whichever came first. The first 15 lines of each file (the header information) were kept without change.

For the interpolation, the software searched for two data points around the desired pressure level. The search was conducted by looking for two valid (i.e. non-missing) data points around the desired pressure level, while also paying attention to the time difference between the two data points as well as their quality control flags. There was a search for the two best possible data points to use in the interpolation. If the desired pressure level was within the original dataset, that data point was used without interpolation.

There was first a search for values flagged as good within some time range (50 sec for temperature, humidity, and wind and 100 sec for pressure; hereafter termed the ARANGE) and the interpolated data point was flagged as good. Failing that, it searched for values flagged as estimated within the same time range and the interpolated data point was flagged as estimated. Then the search went for good values within a wider time range (100 sec for temperature, humidity, and wind and 200 sec for pressure; hereafter termed the BRANGE) the flag for the interpolated data point here was then degraded (even though two `good' data points were used there was a significant time difference between them) to questionable. Then, in turn, estimated values within the BRANGE were used (flag set to questionable), questionable values within the BRANGE (flag set to bad), good values greater than the BRANGE apart (flag set to bad), estimated values greater than BRANGE apart (flag set to bad), questionable values greater than BRANGE apart (flag set to bad), finally any bad values (flag set to bad). This search was conducted separately for each interpolated variable (pressure, temperature, relative humidity, and the u and v wind components.

Thus for each interpolated data point, the quality control flag was set to the worst case among the data points used in the interpolation, except, for each time range apart, the quality control flag was degraded one level (i.e. good to questionable, etc).

The quality control flags should be carefully heeded in these files. While some of the data may look good, it may have been interpolated over large pressure intervals, and thus be suspect.

For each interpolated data point the dew point was calculated from the temperature and relative humidity (Bolton 1980) and the total wind speed and direction were calculated from the interpolated u and v component values. Also, the altitude and time were interpolated using the same data points used for the pressure interpolation. The ascension rate was recalculated based on the time and altitude values from the two data points used to interpolate the 5 hPa data point. Thus the ascension rate values do not reflect the values based on the interpolated data. The latitude and longitude values were interpolated using the same data points used in the wind component interpolation.

2.0.1 Belize City, Belize

This 5-mb dataset was derived from 140 high vertical resolution (2 second) soundings from the Belize City site in Belize (WMO 78583). Soundings were typically released once per day (1200 UTC) from 01 June to 13 July 2004 and twice per day from 14 July to 02 September 2004. The sites antenna failed on 03 September 2004 so no soundings are available for the remainder of the NAME time period.

2.0.2 Mexican CICESE R/V Francisco de Ulloa

This 5-mb dataset was derived from 90 high vertical resolution (2 second) soundings from the Centro de Investigación Cienífica y de Educatció Superior de Ensendada (CICESE) Research Vessel (R/V) Francisco de Ulloa. During NAME the R/V Francisco de Ulloa conducted two cruises (05 June through 21 June 2004 and 06 August through 16 August 2004) through the Gulf of California. Soundings were typically released four times per day.

The R/V Ulloa utilized two different types of radiosondes during NAME.

1. RS-80G - fresh radiosondes that measured temperature, pressure, humidity and winds. They expected small biases in pressure and humidity (3%) with these radiosondes. These soundings were most often released at the 0000 and 1200 UTC release times.

2. RS-80N - older radiosondes that measured temperature, pressure and humidity (these soundings do not include wind measurements). They expected larger biases with these radiosondes. These soundings were most often released at the 0600 and 1800 UTC release times.

More information about the R/V Francisco de Ulloa can be found at http://oceanografia.cicese.mx/fcoulloa/ (CICESE, 2005).

2.0.3 Mexican Navy SEMAR R/V Altair

This 5-mb dataset was derived from 153 high vertical resolution (2 second) soundings from the Secretaria de Marina Armada Mexico (SEMAR) Research Vessel (R/V) Altair. During NAME the R/V Altair was located near 23.5°N and 108.0°W for two cruises (07 July through 22 July 2004 and 27 July through 12 August 2004). Soundings were typically released four times per day but they were more frequent during Intensive Observing Periods (IOPs). These data were provided by the National Oceanic and Atmospheric Administration/Environmental Technology Laboratory (NOAA/ETL).

2.0.4 Mexican UNAM R/V El Puma

This 5-mb dataset was derived from 31 high vertical resolution (approximately 10 second) tethersondes from the Universidad Nacional Autonoma de Mexico (UNAM) Research Vessel (R/V) El Puma. During NAME the R/V El Puma was conducted during the ECAC-5 cruise (06 August through 17 August 2004). NCAR/EOL did do any quality control on these data.

The release location was determined from a separate navigational parameters file containing one minute data. The nearest minute in the navigational parameters file was used from the release time of the sounding.

An additional document Reporte-ECAC-5.doc (UNAM, 2005) was provided from the ECAC project that describes the methodology used by the UNAM in developing the data set. This document is in Spanish.

2.0.5 Mexico SMN-CNA

This 5-mb dataset was derived from 2468 high vertical resolution (2 second) soundings from 15 stations from the Servicio Meteorológico Nacional (SMN) Comisión del Agua (CNA), which forms part of the Secretaría de Medio Ambiente y Recursos Naturales (SEMARNAT). Soundings were typically released twice per day, but were released up to 8 per day by selected stations during intensive operations.

The SMN home page contains more information and can be found at http://smn.cna.gob.mx/ (SMN, 2005). It is in Spanish

2.0.6 NCAR GLASS (Loreto)

This 5-mb dataset was derived from 175 high vertical resolution (1 second) soundings from the GPS Loran Atmospheric Sounding System (GLASS) site in Loreto, Mexico between 09 July and 15 August 2004. These data were provided by the National Center of Atmospheric Research/Earth Observing Laboratory (NCAR/EOL).

For more information on the NCAR GLASS System, please visit the following site: http://www.atd.ucar.edu/rtf/facilities/class/class.html (EOL, 2005a).

NCAR/EOL Data File Specifics

The variables pressure, temperature, and relative humidity are calibrated values from measurements made by the radiosonde. The dew point is calculated from the relative humidity. The altitude is calculated from the hydrostatic equation using pressure, temperature, and dew point. The rate of ascent is obtained from the altitude difference between two successive time steps. The position (latitude, longitude) are computed by using horizontal winds to integrate location from the initial launch position.

All wind data are computed from GPs navigation signals received from the radiosonde. The raw wind values are calculated at a one-half second data rate by a commercial processing card. These raw values are subjected to a digital filter to remove low frequency oscillations due to the sonde pendulum motion beneath the balloon. The resolution of the data is reduced to one second. This time record is used in the interpolation of the pressure, temperature, and humidity data.

NCAR/EOL Data Quality Control

The raw soundings are first run through the Atmospheric Sounding Processing ENvironment (ASPEN), which analyzes the data, performs smoothing, and removes suspect data points. The soundings are then visually evaluated for outliers, or any other obvious problems. Scatter plots of the data are created to check the range in values of pressure, temperature and relative humidity. Lastly, we create profiles of temperature and RH, and wind speed and direction, in order to check for any major inconsistencies.

NCAR/EOL Important Note to Users

The first data line in each sounding, denoted by a time stamp of -1.0 second, typically represents data collected from an independent surface met station. During the quality control process this data is used as a reference to determine the accuracy of the radiosondes pressure, temperature and relative humidity measurements. The surface met sensors at the Loreto GLASS site failed to work during the project, so in place of the surface met data, pre-launch pressure, temperature and RH measured by the sonde and human estimated winds were entered into the first line of each sounding. A major concern is that if sensor arm heating (which is a common problem during projects where sondes are launched in warm weather without proper ventilation, as was the case at Loreto) occurred, there is either no way to detect it or the extent of it. From looking at the scatter plots, shown in figure 2 below, and visually comparing the GLASS data with that collected at the ISS sites, there seems to be no evidence of sensor arm heating. However, we wanted to make the users were aware of what had been done and to warn them to be skeptical about the accuracy of the GLASS radiosonde data near the surface.

2.0.7 NCAR Integrated Sounding System (ISS)

This 5-mb dataset was derived from 460 high vertical resolution (1 second) soundings from 3 Integrated Sounding System (ISS) sites in Mexico; Port Penasco (ISS2), Kino Bay (ISS3), and Los Mochis (ISS4), between 03 July and 15 August 2004. These data were provided by the National Center of Atmospheric Research/Earth Observing Laboratory (NCAR/EOL).

For more information on the NCAR ISS System, please visit the following site: http://www.atd.ucar.edu/rtf/facilities/iss/iss.html (EOL, 2005b).

NCAR/EOL Data File Specifics

The variables pressure, temperature, and relative humidity are calibrated values from measurements made by the radiosonde. The dew point is calculated from the relative humidity. The altitude is calculated from the hydrostatic equation using pressure, temperature, and dew point. The rate of ascent is obtained from the altitude difference between two successive time steps. The position (lat, lon) are computed by using horizontal winds to integrate location from the initial launch position.

All wind data are computed from GPs navigation signals received from the radiosonde. The raw wind values are calculated at a one-half second data rate by a commercial processing card. These raw values are subjected to a digital filter to remove low frequency oscillations due to the sonde pendulum motion beneath the balloon. The resolution of the data is reduced to one second. This time record is used in the interpolation of the pressure, temperature, and humidity data.

NCAR/EOL Data Quality Control

The raw soundings are first run through the Atmospheric Sounding Processing ENvironment (ASPEN), which analyzes the data, performs smoothing, and removes suspect data points. The soundings are then visually evaluated for outliers, or any other obvious problems. Scatter plots of the data are created to check the range in values of pressure, temperature and relative humidity. Lastly, we create profiles of temperature and RH, and wind speed and direction, in order to check for any major inconsistencies.

NCAR/EOL Important Note to Users

The first data line in each sounding, denoted by a time stamp of -1.0 second, typically represents data collected from an independent surface met station. During the quality control process this data is used as a reference to determine the accuracy of the radiosondes pressure, temperature and relative humidity measurements. The surface met sensors at the Loreto GLASS site failed to work during the project, so in place of the surface met data, pre-launch pressure, temperature and RH measured by the sonde and human estimated winds were entered into the first line of each sounding. A major concern is that if sensor arm heating (which is a common problem during projects where sondes are launched in warm weather without proper ventilation, as was the case at Loreto) occurred, there is either no way to detect it or the extent of it. From looking at the scatter plots, shown in figure 2 below, and visually comparing the GLASS data with that collected at the ISS sites, there seems to be no evidence of sensor arm heating. However, we wanted to make the users were aware of what had been done and to warn them to be skeptical about the accuracy of the GLASS radiosonde data near the surface.

2.0.8 NOAA National Weather Service (NOAA/NWS)

This 5-mb dataset was derived from 16079 high vertical resolution (6 second) soundings from 61 National Weather Service (NWS) sites.

The detailed description of NWS sounding collection and instrumentation is located in NWS, 1991.

2.0.9 Phoenix, Arizona SRP

This 5-mb dataset was derived from 360 high vertical resolution (5 second to 900 seconds after release and 10 second from 900 seconds after release to the end of the sounding) soundings from the Phoenix, Arizona sounding site (WMO 74626) from 08 June to 24 September 2004. These soundings were provided by the Salt River Project (SRP). During the period from 10 June to 06 July 2004, Phoenix typically released two sounding per day at 0000 and 1200 UTC. For the period from 07 July to 29 August 2004, Phoenix typically released between 4 and 6 soundings per day. After 29 August 2004, Phoenix typically released 3 or 4 soundings per day.

More information can be found at the SRP home page at http://www.srpnet.com/ (SRP, 2005).

2.0.10 San Jose, Costa Rica UCR-IMN

This 5-mb dataset was derived from 324 high vertical resolution (2 second) soundings from the San Jose, Costa Rica sounding site (WMO 78762) from 16 June to 30 September 2004. These soundings were provided by the Universidad de Costa Rica - Instituto Meteorologico Nacional (UCR-IMN). During the period from 17 June to 05 September 2004, San Jose typically released four soundings per day at 0000, 0600, 1200, and 1800 UTC each day. For the period from 06 September to 30 September 2004, San Jose typically released one sounding per day at 1200 UTC (except on Sundays when no soundings were released).

This station used both Vaisala RS80-15G and RS90-AG radiosonde models during NAME.

More information on IMN can be found on the IMN home page at http://www.imn.ac.cr (IMN, 2005).

2.0.11 San Cristobal, Galapagos

This 5-mb dataset was derived from 41 high vertical resolution (approximately 10 second) sounndings from the San Cristobal site in Ecuador (WMO 84008). San Cristobal released soundings semi-daily, however, there are days within the time period where rawinsonde data is missing or a rawinsonde was not released. All soundings were made with Vaisala RS-80 sondes which utilized GPS tracking to determine the winds.

2.0.12 US DOD Yuma Proving Ground (Arizona)

This 5-mb dataset was derived from 933 high vertical resolution (5 seconds up to 480 seconds after release and 10 seconds from 480 seconds after the release to the end of the sounding) soundings from 3 sites in Yuma, Arizona. These data were provided by the United States Army Met Team from the Yuma Proving Ground. The 3555 site is the station that is sent over the Global Telecommunications System (GTS) as WMO index 74004.

2.1 Detailed Format Description

All upper air soundings were converted to National Center for Atmospheric Research/Earth Observing Laboratory (NCAR/EOL) Sounding Composite Format (ESCF). ESCF 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 mm.mm'W where ddd is the number of degrees from True North (with leading zeros if necessary), mm.mm 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 nonstandard 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 nonstandard 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
16F6.1TimeSeconds9999.0
26F6.1PressureMillibars9999.0
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
118F8.3LongitudeDegrees9999.0
127F7.3LatitudeDegrees999.0
135F5.1Elevation AngleDegrees999.0
145F5.1Azimuth AngleDegrees999.0
157F7.1AltitudeMeters99999.0
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 NCAR Earth Observing Laboratory (NCAR/EOL). Any QC information from the original sounding is replaced by the following EOL Sounding Composite Format codes:

CodeDescription
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 a NAME 5-mb rawinsonde data from SMN in EOL Sounding Composite 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:                         National Weather Service Sounding.
Project ID:                        0
Release Site Type/Site ID:         ABQ Albuquerque, NM
Release Location (lon,lat,alt):    106 36.00'W, 35 00.00'N, -106.6,  35.0, 1615.0
UTC Release Time (y,m,d,h,m,s):    2004, 06, 01, 11:06:00
Ascension No:                      1305
Radiosonde Serial Number:          84922940.CSN
Radiosonde Manufacturer:           VIZ B2
/
/
/
Nominal Release Time (y,m,d,h,m,s):2004, 06, 01, 12:00:00
 Time  Press  Temp  Dewpt  RH    Ucmp   Vcmp   spd   dir   Wcmp     Lon     Lat   Ele   Azi    Alt    Qp   Qt   Qrh  Qu   Q
v   QdZ
  sec    mb     C     C     %     m/s    m/s   m/s   deg   m/s      deg     deg   deg   deg     m    code code code code co
de code
------ ------ ----- ----- ----- ------ ------ ----- ----- ----- -------- ------- ----- ----- ------- ---- ---- ---- ---- --
-- ----
   0.0  836.6  13.0 -10.8  18.0   -4.4    1.6   4.7 110.0 999.0 -106.600  35.000 999.0 999.0  1615.0  2.0  2.0  2.0  1.0  1
.0  9.0
   2.5  835.0  13.8 -10.8  17.1   -4.3    1.4   4.5 107.9   6.4 9999.000 999.000 999.0 999.0  1631.2  2.0  2.0  2.0  4.0  4
.0 99.0
  10.4  830.0  16.2 -10.9  14.5   -4.1    0.7   4.2 100.1   6.4 9999.000 999.000 999.0 999.0  1682.0  2.0  2.0  2.0  4.0  4
.0 99.0
  18.5  825.0  18.5 -11.6  11.9   -3.9    0.0   3.9  89.4   4.0 9999.000 999.000 999.0 999.0  1733.1  1.0  1.0  1.0  4.0  4
.0 99.0
  30.4  820.0  18.5 -12.0  11.5   -3.6   -1.0   3.7  74.0   5.7 -106.607  35.003 999.0 999.0  1785.1  1.0  1.0  1.0  4.0  4
.0 99.0
  40.1  815.0  18.3 -12.3  11.4   -3.3   -1.8   3.7  60.5   5.0 -106.606  35.003 999.0 999.0  1837.7  1.0  1.0  1.0  4.0  4
.0 99.0

2.2 Station List

ID NETWORK SITE STATE COUNTRY LONG LAT ELEV (m)
3555 Yuma 00000 Yuma Proving Ground AZ US -114.33 32.87 131.0
ABQ NWS Albuquerque NM US -106.6 35.0 1615.0
ABR NWS Aberdeen SD US -98.4 45.5 397.0
AMA NWS Amarillo TX US -101.7 35.2 1094.0
APX NWS Gaylord MI US -84.7 44.9 448.0
BIS NWS Bismarck ND US -100.7 46.8 505.0
BKN ISS Kino Bay   MX -111.927 28.814 2.0
BMX NWS Shelby County AL US -86.8 33.2 178.0
BNA NWS Nashville TN US -86.6 36.2 180.0
BOI NWS Boise ID US -116.2 43.6 871.0
BRO NWS Brownsville TX US -97.4 25.9 7.0
BUF NWS Buffalo NY US -78.7 42.9 218.0
CRP NWS Corpus Christi TX US -97.5 27.8 14.0
DDC NWS Dodge City KS US -100.0 37.8 788.0
DNR NWS Denver INT APT CO US -104.9 39.8 1611.0
DRA NWS Desert Rock NV US -116.0 36.6 1007.0
DRT NWS Del Rio TX US -100.9 29.4 314.0
DTX NWS White Lake MI US -83.5 42.7 329.0
EPZ NWS Santa Teresa NM US -106.7 31.9 1252.0
EYW NWS Key West FL US -81.8 24.5 2.0
FFC NWS Peachtree City GA US -84.6 33.4 245.0
FGZ NWS Flagstaff AZ US -111.8 35.2 2180.0
FWD NWS Fort Worth TX US -97.3 32.8 198.0
GGW NWS Glasgow MT US -106.6 48.2 693.0
GJT NWS Grand Junction CO US -108.5 39.1 1472.0
GRB NWS Green Bay WI US -88.1 44.5 214.0
GSO NWS Greensboro NC US -79.9 36.1 277.0
IAD NWS Sterling VA US -77.5 39.0 86.0
ILN NWS Wilmington OH US -83.7 39.4 323.0
ILX NWS Central Illinois IL US -89.3 40.2 178.0
INL NWS International Falls MN US -93.4 48.5 361.0
IS4 ISS Los Mochis   MX -109.082 25.689 3.0
JAN NWS Jackson MS US -90.1 32.3 91.0
JAX NWS Jacksonville FL US -81.7 30.5 9.0
LBF NWS North Platte NE US -100.7 41.1 849.0
LCH NWS Lake Charles LA US -93.2 30.1 9.0
LIT NWS Little Rock AR US -92.3 34.8 172.0
LKN NWS Elko NV US -115.7 40.9 1592.0
MACA SMN 76805 Acapulco   MX -99.93 16.83 3.0
MAF NWS Midland TX US -102.2 32.0 873.0
MCUN SMN 76595 Cancun   MX -86.85 21.02 10.0
MFL NWS Miami FL US -80.4 25.8 5.0
MFR NWS Medford OR US -122.9 42.9 397.0
MGDL SMN 76612 Guadalajara   MX -103.3405 20.4989 1551.0
MGYM SMN 76256 Empalme/Guaymas   MX -110.8251 27.9418 12.0
MHX NWS Newport NC US -76.9 34.8 11.0
MLAP SMN 76405 La Paz   MX -110.3873 24.0431 18.0
MMAN SMN 76394 Monterrey   MX -100.2341 25.8986 450.0
MMCU SMN 76225 Chihuahua   MX -106.1167 28.70 1482.0
MMEX SMN 76679 Mexico City   MX -99.20 19.40 2308.0
MMMD SMN 76644 Merida   MX -89.65 20.98 11.0
MMTC SMN 76382 Torreon   MX -103.4031 25.5442 1123.0
MMZC SMN 76526 Zacatecas   MX -103.7568 22.7714 2265.0
MMZT SMN 76458 Mazatlan   MX -106.3010 23.1466 4.0
MPX NWS Chanhassen MN US -93.6 44.8 290.0
MRS RV_Ulloa NPS Ship Francisco de Ulloa   MX 9999.0 999.0 99999.0
MVER SMN 76692 Vera Cruz   MX -96.12 19.15 16.0
MZBZ Belize 78583 Belize City, Belize   BZ -88.30 17.483 5.0
MZLO SMN 76654 Mananillo   MX -104.32 19.05 3.0
NKX NWS San Diego CA US -117.1 32.8 134.0
NLO GLASS Loreto   MX -111.344 26.019 2.0
NPP ISS Puerto Penasco   MX -113.509 31.344 2.0
OAK NWS Oakland CA US -122.2 37.7 6.0
OAX NWS Valley NE US -96.4 41.3 350.0
OKX NWS Brookhaven NY US -72.9 40.9 20.0
OTX NWS Spokane WA US -117.6 47.7 728.0
OUN NWS Norman OK US -97.4 35.2 357.0
PIT NWS Pittsburgh PA US -80.2 40.5 360.0
PSR Phoenix 74626 SRP/PSR AZ US -111.95 33.45 379.0
REV NWS Reno NV US -119.8 69.6 1516.0
RIW NWS Riverton WY US -108.05 43.1 1699.0
RNK NWS Blacksburg VA US -80.4 37.2 640.0
SGF NWS Springfield MO US -93.4 37.2 391.0
SHV NWS Shreveport LA US -93.8 32.5 85.0
SIL NWS Slidell LA US -89.8 30.4 10.0
SJS San_Jose 78762   CR -84.21 10.00 921.0
SLC NWS Salt Lake City UT US -111.9 40.8 1288.0
SLE NWS Salem OR US -123.0 44.9 61.0
SNCR Galapagos San Cristobal SNCR 84008 Ecuador -89.610 -.900 8.0
T31 Yuma 02999 Yuma Proving Ground AZ US -114.03 32.86 231.0
TBW NWS Tampa Bay Area FL US -82.3 27.7 13.0
TFX NWS Great Falls MT US -111.4 47.5 1132.0
TLH NWS Tallahassee FL US -84.3 30.5 53.0
TOP NWS Topeka KS US -95.6 39.1 270.0
TUS NWS Tucson AZ US -110.0 23.1 787.0
TWR_M Yuma 07000 Yuma Proving Ground AZ US -113.80 32.92 145.0
UIL NWS Quillayute WA US -124.6 48.0 56.0
UNR NWS Rapid City SD US -103.2 44.1 1029.0
XCUM RV_El_Puma R/V El Puma: Cruise ECAC-5   MX 9999.0 999.0 99999.0
XCWH RV_Altair R/V Altair   MX 9999.0 999.0 99999.0

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 EOL 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. EOL conducted the following gross limit checks on the NAME sounding datasets. 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
RH
T, RH
Q
Q
Relative Humidity < 0% or > 100% RHB
Wind Speed < 0 m/s or > 100 m/s
> 150 m/s
U, V
U, V
Q
B
U Wind Component < 0 m/s or > 100 m/s
> 150 m/s
U
U
Q
B
V Wind Component < 0 m/s or > 100 m/s
> 150 m/s
V
V
Q
B
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.

Parameter Vertical Consistency Check Parameter(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
Q
Q
B
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
Q
B
Q
B
Ascent Rate change of > 3 m/s or & lt; -3 m/s
change of > 5 m/s or < -5 m/s
P
P
Q
B

3.3 Data Quality Issues

3.3.1 Belize City, Belize

Data Averaging

Belize is one of the Caribbean upper air sites that has had a known problem with erratic and inconsistent meteorological parameter reports in the high resolution data from the B-2 sondes used in conjunction with the 1500C.

To alleviate this known problem, the data were rederived from the raw data using a seven point traveling average to smooth these fluctuations that appeared in the raw data. The averaging used the previous three points, the current point, and the following three points to make the averaged record for the new current point. The first three points of the record were assumed correct since there were not three previous points to use in the average.

The measurements of pressure, temperature, relative humidity, and the U and V wind components were averaged. The remaining parameters were derived from the new averaged values. In the cases where there were missing values in the average, the average was not calculated and was set to the corresponding missing value instead.

3.3.2 Mexican CICESE R/V Francisco de Ulloa

Humidity Biases

The older Vaisala RS80-N radiosondes (typically released at the 0600 and 1800 UTC release times) have a substantial dry bias in the measured humidity values evident in the data. The raw data set included over 16000 negative relative humidity values. These have been set to missing in this processed data set. No corrections have been applied to these data.

3.3.3 Mexican Navy SEMAR R/V Altair

Noise Levels

The amount of noise in the high resolution data was substantially more significant in the first cruise (7-22 July 2004) than in the second cruise (26 July - 18 August 2004).

3.3.4 NOAA National Weather Service (NOAA/NWS)

NWS soundings during NAME utilized either the VIZ type radiosonde produced by Sippican Inc. (http://www.sippican.com/meteorological.html) or the Vaisala RS-80 radiosonde (http://www.vaisala.com, under "Product and Systems/Radiosonde,dropsondes,rockectsondes").

The use of the raw 6-sec resolution elevation and azimuth angle data to derive the winds sometimes led to large oscillations in wind speed, due to the presence of oscillations in the elevation angle data, particularly at low elevation angles. The general approach to correct this problem was to remove the out-lier radiosonde position data before computing the wind components (Williams et al. 1993). For both the azimuth and elevation angles from 360 sec to the end of the sounding, a ninth order polynomial was fit to the curve. The residuals were calculated and compared to the observed values. The outliers of the residuals were then removed.

Then to help correct the more extensive problems at low elevation angles within 10 degrees of the limiting angles (LA) some additional smoothing was applied. If the elevation angle was between (LA + 7.5) and (LA + 10), the new elevation angle was computed with a 2 min linear fit. If the elevation angle was between (LA + 5) and (LA + 7.5), the new elevation angle was computed with a 3 min linear fit. If the elevation angle was less than (LA + 5), the new elevation angle was computed with a 4 min linear fit. If the number of observations with low elevation angles was greater than 20% of the total number of observations for the sounding no frequency smoothing occurred.

Then, for the elevation angle only, a finite Fourier analysis was performed on the residuals. Periods from 90-190 sec were removed and those below 30 sec were flattened.

Finally, a 2 min second order polynomial was then fit to the position to derive the u and v wind components, except for the beginning and end minute (or 1.5 minutes if over 50 Mb) which used a 3 min fit. If there were less than 15% of the total number of points, not counting the beginning or end of the flight, on one side of the point for which the wind value was being computed, a linear fit was used.

For further information on this methodology and its changes since Williams et al. (1993) please see Williams, et al. (1998).

Near Surface Winds

A common problem in near surface wind speed values calculated from the 6-second position data is that the first radiosonde wind speed is much higher than the independently measured surface value. The calculated radiosonde winds then decrease rapidly so that within about 60 s (20-30 Mb) after release the wind speeds are more realistic. The cause of this appears to be the acceptance of radiosonde position data prior to a "good lock" being achieved on the radiosonde by the tracking system. Thus there appear to be rapid positional shifts of the radiosonde while the tracking system "searches" for the radiosonde.

Wind Oscillations

Despite the extensive efforts to remove oscillations in wind speeds caused by oscillations in elevation angles (see Section 2.2) there are occasional cases with remaining oscillations. Most of the remaining oscillations have periods just slightly longer than the 190 s maximum point of our notch filter.

3.3.5 San Jose, Costa Rica UCR-IMN

Date and Time Mismatches in Raw Data Files

There were a number of cases where there was conflicting date and time information in the provided data files. Contacts at San Jose were able to verify some of the information, but not all.

The soundings that are labeled at the following times were unable to be verified by San Jose:

The soundings that are labeled at the following times were verified by San Jose:

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.

Bolton, D., 1980: The Computation of Equivalent Potential Temperature. Mon. Wea. Rev., 108, 171-180.

CICESE, cited 2005: Página del Barco Oceanográfico Francisco de Ulloa [Available online from http://oceanografia.cicese.mx/fcoulloa/].

Douglas, M., Fernandez, W., and Pena, M., 1996: "The Design And Evolution of the PACS-SONET Observing System in Latin America", PACS-SONET Preprint

EOL, cited 2005a: NCAR/ATD/SSSF - Facility Descriptions - CLASS [Available online from http://www.atd.ucar.edu/rtf/facilities/class/class.html].

EOL, cited 2005b: NCAR/ATD Facility Description - ISS [Available online from http://www.atd.ucar.edu/rtf/facilities/iss/iss.html].

IMN, cited 2005: Instituto Meteorológico Nacional [Available online from http://www.imn.ac.cr].

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.

NWS, 1991: Micro-ART Observation and Rework Programs Technical Document, National Weather Service, National Oceanic and Atmospheric Administration, Washington, D.C., March 1991.

PACS-SONET, cited 2005: PACS SOunding NETwork [Available online from http://www.nssl.noaa.gov/projects/pacs/].

SMN, cited 2005: CNA, Servicio Meteorológico Nacional [Available online from http://smn.cna.gob.mx/].

SRP, cited 2005: The Salt River Project Home Page [Available online from http://www.srpnet.com/].

UNAM, cited 2005: [Available online from http://data.eol.ucar.edu/datafile/nph-get/82.157/Reporte-ECAC-5.doc].

Wade, C. G., 1995: Calibration and data reduction problems affecting National Weather Service radiosonde humidity measurements. Preprints, Ninth Symposium on Meteorological Observations and Instrumentation, Charlotte, NC, Amer. Meteor. Soc., 37-42.

Williams, S. F., C. G. Wade, and C. Morel, 1993: A comparison of high resolution radiosonde winds: 6-second Micro-ART winds versus 10-second CLASS LORAN winds. Preprints, Eighth Symposium on Meteorological Observations and Instrumentation, Anaheim, California, Amer. Meteor. Soc., 60-65.

Williams, S. F., S. M. Loehrer, and D. R. Gallant, 1998: Computation of high-resolution National Weather Service rawinsonde winds. Preprints, Tenth Symposium on Meteorological Observations and Instrumentation, Phoenix, AZ, Amer. Meteor. Soc., 387-391.