IHOP-2002 Soundings Rawinsonde ARM (2-sec vertical levels)[JOSS]
1.0 General Description
This is one of the upper air data sets developed for the International
H2O Project 2002 (IHOP 2002). Included in this dataset are five Department
of Energy (DOE) Atmospheric Radiation Measurement - Clouds And Radiation
Testbed (ARM-CART) sounding stations; Lamont (Central Facility), Morris (B5),
Purcell (B6), and Vici (B4), OK and Hillsboro (B1), KS.
2.0 Detailed Data Description
All upper air soundings were converted to University Corporation
for Atmospheric Science/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
Quality Control (QC) information.
At each of the boundary facilities (B1, B4, B5, and B6) soundings
were typically released once per weekday at 1800 UTC and at the central
facility five times per weekday at 06, 12, 15, 18, and 21 UTC. However,
during Intensive Observing Periods (IOPs) the sounding frequency
increased to up to 8 per day (3-hourly; including weekends) at each of
the sites.
2.1 Detailed Format Description
All upper air soundings were converted to University Corporation
for Atmospheric Science/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 Quality
Control (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:
Line Label (padded to 35 char) Contents
1 Data Type: Description of type and
resolution of data.
2 Project ID: ID of weather project.
3 Release Site Type/Site ID: Description of release site.
4 Release Location (lon,lat,alt): Position of release site, in
format described below.
5 UTC Release Time (y,m,d,h,m,s): Time of release, in 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 non-standard header lines may contain any label and
contents. The label is padded to 35 characters to match the standard
header lines.
Data Records
The data records each contain time from release, pressure,
temperature, dewpoint, 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 Format
No. Width Parameter Units Missing Value
-----------------------------------------------------------------------
1 6 F6.1 Time Seconds 9999.0
2 6 F6.1 Pressure Millibars 9999.0
3 5 F5.1 Dry-bulb Temperature Degrees C 999.0
4 5 F5.1 Dew Point Temperature Degrees C 999.0
5 5 F5.1 Relative Humidity Percent 999.0
6 6 F6.1 U Wind Component Meters / Second 9999.0
7 6 F6.1 V Wind Component Meters / Second 9999.0
8 5 F5.1 Wind Speed Meters / Second 999.0
9 5 F5.1 Wind Direction Degrees 999.0
10 5 F5.1 Ascension Rate Meters / Second 999.0
11 8 F8.3 Longitude Degrees 9999.0
12 7 F7.3 Latitude Degrees 999.0
13 5 F5.1 Range Kilometers 999.0
14 5 F5.1 Azimuth Degrees 999.0
15 7 F7.1 Altitude Meters 99999.0
16 4 F4.1 QC for Pressure Code (see below) 99.0
17 4 F4.1 QC for Temperature Code (see below) 99.0
18 4 F4.1 QC for Humidity Code (see below) 99.0
19 4 F4.1 QC for U Component Code (see below) 99.0
20 4 F4.1 QC for V Component Code (see below) 99.0
21 4 F4.1 QC for Ascension Rate Code (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:
Code Description
99.0 Unchecked (QC information is "missing.") ("UNCHECKED")
1.0 Checked, datum seems physically reasonable. ("GOOD")
2.0 Checked, datum seems questionable on physical basis.("MAYBE")
3.0 Checked, datum seems to be in error. ("BAD")
4.0 Checked, datum is interpolated. ("ESTIMATED")
9.0 Checked, datum was missing in original file. ("MISSING")
Sample Data
The following is a sample record of IHOP 2002 ARM-CART
High-Resolution Upper-Air 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: Sounding
Project ID: IHOP_2002 ARM-CART Sndings
Release Site Type/Site ID: B6 Purcell, OK
Release Location (lon,lat,alt): 097 25.20'W, 34 58.20'N, -97.42, 34.97,
344.0
UTC Release Time (y,m,d,h,m,s): 2002, 05, 31, 23:30:00
Radiosonde Serial Number: W3714029
Ascension No: 160601021
Input File: sgpsondewnpnB6.b1.20020531.233000.cdf
/
/
/
Nominal Release Time (y,m,d,h,m,s):2002, 06, 01, 00:00:00
Time Press Temp Dewpt RH Uwind Vwind Wspd Dir dZ Lon
Lat Elev Azim Alt Qp Qt Qh 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
------ ------ ----- ----- ----- ------ ------ ----- ----- ----- --------
------- ----- ----- ------- ---- ---- ---- ---- ---- ----
0.0 970.6 29.0 19.9 58.0 -3.3 1.2 3.5 110.0 999.0 -97.420
34.970 999.0 999.0 344.0 3.0 3.0 3.0 99.0 99.0 9.0
2.0 969.0 28.5 17.7 52.0 -3.2 1.9 3.7 121.0 7.5 -97.420
34.970 999.0 999.0 359.0 3.0 3.0 3.0 99.0 99.0 99.0
4.0 968.0 28.4 17.3 51.0 -3.2 2.1 3.8 124.0 4.5 -97.420
34.970 999.0 999.0 368.0 2.0 99.0 99.0 99.0 99.0 99.0
6.0 967.1 28.3 17.2 51.0 -3.1 2.3 3.9 127.0 4.5 -97.420
34.970 999.0 999.0 377.0 99.0 99.0 99.0 99.0 99.0 99.0
8.0 966.4 28.2 17.5 52.0 -3.1 2.6 4.0 130.0 3.0 -97.420
34.970 999.0 999.0 383.0 99.0 99.0 99.0 99.0 99.0 99.0
10.0 965.4 28.1 17.7 53.0 -3.0 2.7 4.1 132.0 4.5 -97.420
34.970 999.0 999.0 392.0 99.0 99.0 99.0 99.0 99.0 99.0
12.0 964.2 28.0 17.9 54.0 -2.9 2.8 4.1 134.0 5.5 -97.420
34.970 999.0 999.0 403.0 99.0 99.0 99.0 99.0 99.0 99.0
2.2 Data Remarks
ARM-CART files from 1 May 2002 through 31 June 2002 were
delivered as netcdf files which JOSS converted to JCF. These files have
two-second vertical resolution thermodynamic and wind data.
At each of the boundary facilities (B1, B4, B5, and B6) soundings
were typically released once per weekday at 1800 UTC and at the central
facility five times per weekday at 06, 12, 15, 18, and 21 UTC. However,
during Intensive Observing Periods (IOPs) the sounding frequency
increased to up to 8 per day (3-hourly; including weekends) at each of the
sites.
3.0 Quality Control Processing
ARM-CART soundings were Quality Controlled (Lesht 1995) and
provided to UCAR/JOSS by the ARM-CART Project. This dataset
underwent a JOSS QC process which consisted of internal consistency
checks. This included gross limit checks on all parameters and
rate-of-change checks on temperature, pressure and ascension rate. JOSS
did not perform visual quality control procedures on this data. 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 IHOP ARM 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.
__________________________________________________________________
Parameter(s) Flag
Parameter Gross Limit Check Flagged Applied
__________________________________________________________________
Pressure < 0 mb or > 1030 mb P B
Altitude < 0 m or > 35000 m P, T, RH Q
Temperature < -80C or > 45C T Q
Dew Point < -99.9C or > 30C RH Q
> Temperature T, RH Q
Relative Humidity < 0% or > 100% RH B
Wind Speed < 0 m/s or > 100 m/s U, V Q
> 150 m/s U, V B
U Wind Component < 0 m/s or > 100 m/s U Q
> 150 m/s U B
V Wind Component < 0 m/s or > 100 m/s V Q
> 150 m/s V B
Wind Direction < 0 deg or > 360 deg U, V B
Ascent Rate < -10 m/s or > 10 m/s P, T, RH Q
_________________________________________________________________
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.
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.
_____________________________________________________________________
Vertical Consistency Parameter(s) Flag
Parameter Check Flagged Applied
_____________________________________________________________________
Time decreasing/equal None None
Altitude decreasing/equal P, T, RH Q
Pressure increasing/equal P, T, RH Q
> 1 mb/s or < -1 mb/s P, T, RH Q
> 2 mb/s or < -2 mb/s P, T, RH B
Temperature < -15 C/km P, T, RH Q
< -30 C/km P, T, RH B
> 5 C/km (not applied
at p , 150mb) P, T, RH Q
< 30 C/km (not applied
at p , 150mb) P, T, RH B
Ascent Rate change of > 3 m/s
or < -3 m/s P Q
change of > 5 m/s
or < -5 m/s P B
_____________________________________________________________________
4.0 References
Lesht, B. M., 1995: An evaluation of ARM radiosonde operational
performance. Preprints, Ninth Symposium on Meteorological
Observations and Instrumentation, Charlotte, NC, Amer. Meteor.
Soc., 6-10.
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.