This data set is a composite of radiosondes and dropsondes collected from
3 dropsonde and 3 radiosonde platforms (see Section 2.3) during the Pre-Depression
INvestigation of Cloud-systems in the Tropics (PREDICT) 2010 project with data collected
from 1 August 2010 through 30 September 2010. The PREDICT area of interest is 0-45N and 15-100W.
This composite contains a total of 1932 5mb resolution soundings.
Included are radiosondes from the Howard University at Barbados (99 radiosondes),
Howard University at Cape Verde (20 radiosondes), and from 24 US National Weather Service sites (841 radiosondes).
Also included are dropsondes from the United States Air Force C-130 (86 dropsondes),
NSF/NCAR G-V (558 dropsondes), and GRIP NASA DC-8 (328 dropsondes).
This data set 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.
All soundings were quality controlled by NCAR/EOL.
Version 2 of this data set was released in March 2017. See Section 2.3 for details on the changes.
Scot Loehrer
NCAR/EOL
loehrer@ucar.edu
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.
All upper air soundings were converted to National Center for Atmospheric Research/Earth Observing Laboratory (NCAR/EOL) Sounding Composite Format (ESC). ESC 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.
The header records (15 total records) contain data type, project ID, site ID, site location, release time, sonde type, meteorological and wind data processors. 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 the release site. |
| 4 | Release Location (lon,lat,alt): | Position of release site in the format described below. |
| 5 | UTC 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 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 non-standard header lines.
| Line | Label (padded to 35 char) | Contents |
|---|---|---|
| 6 | Sonde Id/Sonde Type: | W4342264/Vaisala Loran-C |
| 7 | ||
| 8 | ||
| 9 | ||
| 10 | ||
| 11 | ||
| 12 | Nominal Release Time (y,m,d,h,m,s): | Nominal time of release, in the format: yyyy, mm, dd, hh:mm:ss |
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. | Width | Format | 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 | Ascent 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 | Elevation Angle | Degrees | 999.0 |
| 14 | 5 | F5.1 | Azimuth Angle | 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 Wind Component | Code (see below) | 99.0 |
| 20 | 4 | F4.1 | QC for V Wind 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 NCAR Earth Observing Laboratory (NCAR/EOL). Any QC information from the original sounding is replaced by the following EOL 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") |
The following is a sample record of PREDICT 2010 radiosonde data in ESC 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/Ascending Project ID: PREDICT_2010 Release Site Type/Site ID: KMIA Miami, FL / 72202 Release Location (lon,lat,alt): 080 23.01'W, 25 45.33'N, -80.384, 25.756, 4.0 UTC Release Time (y,m,d,h,m,s): 2010, 08, 24, 11:02:09 Ascension Number: 470 Radiosonde Serial Number: 85160926 Balloon Manufacturer/Type: Kaysam / GP26 Balloon Lot Number/Weight: 410 / 0.700 Radiosonde Type/RH Sensor Type: Sippican Mark IIA with chip thermistor, pressure / Sippican Mark IIA Carbon Hygristor Surface Observations: P: 1012.3, T: 999.0, RH: 91.0, WS: 1.0, WD: 181.0 Nominal Release Time (y,m,d,h,m,s):2010, 08, 24, 12:00:00 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 1012.3 27.5 25.7 90.0 0.1 1.5 1.5 183.8 999.0 -80.384 25.755 999.0 999.0 4.0 1.0 1.0 1.0 1.0 1.0 9.0 5.4 1010.0 27.3 25.5 90.1 0.2 2.5 2.5 184.5 4.0 -80.383 25.756 999.0 999.0 24.6 1.0 1.0 3.0 1.0 1.0 99.0 13.8 1005.0 27.2 25.6 90.8 0.0 3.9 3.9 180.0 5.0 -80.383 25.756 999.0 999.0 68.2 1.0 1.0 1.0 1.0 1.0 99.0 22.6 1000.0 27.3 25.7 91.1 -0.1 5.4 5.4 178.9 5.0 -80.383 25.756 999.0 999.0 113.0 1.0 1.0 1.0 1.0 1.0 99.0 32.4 995.0 27.5 25.9 90.9 -0.1 6.8 6.8 179.2 5.0 -80.383 25.757 999.0 999.0 158.0 1.0 1.0 1.0 1.0 1.0 99.0 41.3 990.0 27.4 25.8 91.0 0.0 7.8 7.8 180.0 5.0 -80.383 25.757 999.0 999.0 202.7 1.0 1.0 1.0 1.0 1.0 99.0 49.7 985.0 27.0 25.4 91.0 0.0 8.4 8.4 180.0 6.0 -80.383 25.758 999.0 999.0 248.0 1.0 1.0 1.0 1.0 1.0 99.0 57.5 980.0 26.7 25.3 92.3 0.2 9.1 9.1 181.3 6.0 -80.383 25.759 999.0 999.0 293.0 1.0 1.0 1.0 1.0 1.0 99.0 66.2 975.0 26.3 25.2 93.5 0.3 9.7 9.7 181.9 5.0 -80.383 25.759 999.0 999.0 338.8 1.0 1.0 1.0 1.0 1.0 99.0 75.6 970.0 25.8 25.0 95.2 0.3 9.6 9.6 181.8 5.0 -80.383 25.760 999.0 999.0 384.0 1.0 1.0 1.0 1.0 1.0 99.0 84.7 965.0 25.5 24.8 96.1 0.3 9.5 9.5 182.0 6.0 -80.383 25.761 999.0 999.0 430.3 1.0 1.0 1.0 1.0 1.0 99.0 93.0 960.0 25.2 24.2 94.3 0.2 9.5 9.5 181.2 5.0 -80.383 25.762 999.0 999.0 476.0 1.0 1.0 1.0 1.0 1.0 99.0 102.2 955.0 24.8 23.8 94.3 0.3 9.2 9.2 181.9 6.0 -80.383 25.763 999.0 999.0 522.0 1.0 1.0 1.0 1.0 1.0 99.0 111.2 950.0 24.6 23.4 92.9 0.4 8.9 8.9 182.7 6.0 -80.383 25.763 999.0 999.0 568.0 1.0 1.0 1.0 1.0 1.0 99.0 120.0 945.0 24.2 23.0 93.1 0.7 8.9 8.9 184.5 5.0 -80.383 25.764 999.0 999.0 615.0 1.0 1.0 1.0 1.0 1.0 99.0 129.7 940.0 24.0 22.8 93.0 1.2 9.1 9.2 187.5 5.0 -80.383 25.765 999.0 999.0 661.3 1.0 1.0 1.0 1.0 1.0 99.0 138.4 935.0 23.9 21.6 86.8 1.4 9.3 9.4 188.6 5.0 -80.383 25.765 999.0 999.0 708.0 1.0 1.0 1.0 1.0 1.0 99.0 147.3 930.0 23.7 21.2 85.8 1.5 9.2 9.3 189.3 5.0 -80.383 25.766 999.0 999.0 755.7 1.0 1.0 1.0 1.0 1.0 99.0 156.0 925.0 23.5 19.9 80.0 1.8 8.9 9.1 191.4 5.0 -80.383 25.767 999.0 999.0 803.0 1.0 1.0 1.0 1.0 1.0 99.0 164.5 920.0 23.3 18.7 75.7 2.0 8.6 8.8 193.2 6.0 -80.382 25.768 999.0 999.0 850.0 1.0 1.0 1.0 1.0 1.0 99.0 : : :
None.
2.3.1 Howard University Barbados Radiosonde Data
The Howard University Barbados Sounding Data includes 99
soundings from Barbados taken by Howard University
from 14 August through 25 September 2010. This station utilized Graw radiosondes,
either the DFM-06 or DFM-97 type. There are four sondes where the
sonde type was not available. The header records for each sonde specify the sonde type.
This data 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
NCAR/EOL can be found either in the readme documentation for
Howard University High Resolution Soundings - Barbados
here or in Loehrer et al. (1996) and Loehrer et al. (1998).
Version 2.0 of this data set was released in February 2017. In this version a dry bias
in the RD94 relative humidity measurements was corrected. The dry bias was strongly
temperature dependent, being considered quite small at warm temperature and more substantial
at cold temperatures. More complete information on the origin, magnitude, and impact of the
bias is available in an NCAR Technical Note (Voemel, et al 2016):
http://dx.doi.org/10.5065/D6XS5SGX.
This correction was applied to all of the NSF/NCAR G-V and NASA DC-8 dropsonde data. Only
six of the USAF C-130 dropsondes were impacted by this bias and those six were corrected. The remaining
USAF C-130 dropsondes were all the older RSS903 dropsondes and were not affected by this bias. All of
the dropsondes that have had the correction applied have the following text within the "Post Processing
Comments" header record: TDDryBiasCorrApplied.
All of the radiosonde data remain the same as Version 1.0.
| ID | SITE | LONG | LAT | ELEV (m) |
|---|---|---|---|---|
| Howard University | Barbados | -59.60000 | 13.10000 | 112.8 |
| Howard University | Barbados | -59.62500 | 13.14900 | 112.8 |
2.3.2 Howard University Cape Verde Radiosonde Data
This data includes 20 soundings
from Cape Verde taken by Howard University from 27 August through 15 September 2010.
The station utilized Graw radiosondes, either the DFM-06 or DFM-97 type. There are three sondes where the
sonde type was not available. The header records for each sonde specify the sonde type.
This data 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
NCAR/EOL can be found either in the readme documentation for
Howard University High Resolution Soundings - Cape Verde
here or in Loehrer et al. (1996) and Loehrer et al. (1998).
| ID | SITE | LONG | LAT | ELEV (m) |
|---|---|---|---|---|
| Howard University | Cape Verde | -24.867 | 16.864 | 10.0 |
2.3.3 USAF C-130 Dropsonde Data
The United States Air Force C-130 aircraft dropsonde data includes 86 dropsonde data files from the USAF C-130 aircraft that flew over the Atlantic basin and Gulf of Mexico during PREDICT. Data are included from thirteen flights that occurred 31 August to 29 September 2010. For more information regarding the data, go here
| ID | Site/Platform | State/Country | Longitude | Latitude | Elevation (m) |
|---|---|---|---|---|---|
| AF302/AF303/AF306/AF308/AF309 | USAF Lockheed C-130J | N/A | Mobile | Mobile | -9999.9 |
2.3.4 NSF/NCAR G-V Dropsonde Data
The NSF/NCAR G-V aircraft data includes 558 dropsondes released over the Altantic basin during the months of August and September 2010. For more details on this dataset, go here
| ID | Site/Platform | State/Country | Longitude | Latitude | Elevation (m) |
|---|---|---|---|---|---|
| N677F | NSF/NCAR GV | N/A | Mobile | Mobile | -9999.9 |
2.3.5 GRIP NASA DC-8
The GRIP NASA DC-8 aircraft data includes 328 dropsondes collected during the GRIP NASA DC-8 flights for the Genesis and Rapid Intensification Process (GRIP) experiment. For more details on this dataset, go here
| ID | Site/Platform | State/Country | Longitude | Latitude | Elevation (m) |
|---|---|---|---|---|---|
| N817NA | NASA DC-8 | N/A | Mobile | Mobile | -9999.9 |
2.3.6 National Weather Service (NWS) Soundings
This data set includes 841
Radiosonde Replacement System (RRS) soundings from National
Weather Service (NWS) rawinsonde stations. For PREDICT this data set
includes data from 1 August 2010 through 30 September 2010 for six (6)
NWS stations (Key West, FL, Miami, FL, Tampa Bay, FL, Brownsville, TX,
Corpus Christi, TX, and San Juan, Puerto Rico). At the request of GRIP
investigators this data set also includes data from 1 September 2010
through 5 September 2010 for seven (7) stations along the east coast
of the United States (Jacksonville, FL, Charleston, SC, Newport, NC,
Sterling, VA, Upton, NY, Chatham, MA, and Gray, ME) for Hurricane Earl.
The soundings were typically released twice a day (0000 and 1200 UTC) and
any special releases are also included.
The detailed description of the NWS Radiosonde Replacement System (RRS)
sounding collection and instrumentation is located in
http://www.ua.nws.noaa.gov/RRS.htm
These soundings utilized the Global Positioning System (GPS) to derive the winds.
NCAR/EOL did no additional processing to the wind data provided in these soundings.
NCAR/EOL utilized the processed version of the RRS data. This means the data were
smoothed and had corrections applied (e.g. solar radiation correction) by the NWS.
NCAR/EOL conducted no additional processing to the data values. However,
additional quality assurance was applied as described in the documentation for the
National Weather Service High Resolution Radiosonde Data (ESC Format) documentation.
ID SITE STATE COUNTRY LAT LONG ELEV (m) SONDE TYPE ------------------------------------------------------------------------- TJSJ San Juan -- PR 18.4 -66.0 3.0 Sippican Mark IIA KCHH Chatham MA US 41.7 -70.0 15.0 Sippican Mark IIA KCHS Charleston SC US 32.9 -80.0 13.0 Sippican Mark IIA KGYX Gray (Portland) ME US 43.9 -70.3 124.0 Sippican Mark IIA KIAD Sterling VA US 39.0 -77.5 88.0 Sippican Mark IIA KJAX Jacksonville FL US 30.5 -81.7 10.0 Sippican Mark IIA KMHX Newport NC US 34.8 -76.9 11.0 Sippican Mark IIA KOKX Upton-Brookhaven NY US 40.9 -72.9 20.0 Sippican Mark IIA KBRO Brownsville TX US 25.9 -97.4 7.0 Sippican Mark IIA KCRP Corpus Christi TX US 27.8 -97.5 15.0 Sippican Mark IIA KKEY Key West FL US 24.6 -81.8 13.0 Sippican Mark IIA KMIA Miami FL US 25.8 -80.4 4.0 Sippican Mark IIA KTBW Tampa Bay FL US 27.7 -82.4 13.0 Sippican Mark IIA
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.