Extract IGRA Data
Description
Subdaily upper air sounding observations containing derived variables can be downloaded from the Integrated Global Radiosonde Archive (IGRA) website, but these data are in a different format than the one used by HOB Tools. This tool transforms these data into the format used by HOB Tools (i.e., Year / Month / Day / Data, where each "/" is a tab).
Note: Because a value of -99 is possible for convective inhibition (CIN), the missing data for CIN are denoted as -999. This is for CIN only. Missing values for all other extracted variables are still denoted as -99.
Input
Input File
Select the input file by clicking on "Browse" and navigating to the proper file.
Input Data Format
The data with derived variables are located within the "derived-v2" directory on the FTP site. Each station is in a separate file (*.dat) denoted by a station number. The station name associated with each station number is stored in the derived-stations.txt file on the FTP site, which allows the user to extract the necessary file for input into HOB Tools as is for processing. See the readme.txt file at the FTP site for additional details.
Start Row
This input is the row number where the main data to be processed begin in the dataset. The start row will be 1 in all cases unless the user has added additional header information to the downloaded dataset. An example of how row numbers are entered is shown in Figure 2 located in the Running HOB Tools topic.
Extraction Options
Observation Time
Select the observation time to output. Note that the selected observation time also includes +/- one hour (e.g., selecting 00Z will also include 23Z and 01Z) due to fluctuations in observation time.
Data to Extract
Select the data to extract. Variables that can be extracted are: convectively available potential energy (CAPE), convective inhibition (CIN), height of the freezing level, k index (KI), height of the lifted condensation level (LCL), height of the level of free convection (LFC), lifted index (LI), precipitable water (PW), showalter index (SI), and total totals (TT).
Output
Output File
Select the file where the new data will be stored.
Output File Header
Information entered here will be output in the first line of the output file.