Acquiring the HALOE L3 data held at the BADC

This file contains background information to help you get the HALOE L3 data held at the BADC.

  1. Checking and Transferring Data from the BADC
  2. File name convention
  3. Reading the data files

1. Checking and Transferring Data from the BADC

All data is located beneath the directory /badc/haloe/. Here you will find a README file and the following subdirectories:

Check whether the data you require is available by browsing the HALOE L3 data directories.

2. File name convention

The file name convention adopted is as follows:   HALOE_Ll_Sssss_Ddddd.Vvvvv_Ccc_xxxx,


The data files (*PROD extension) are in subdirectories 3at/subtype/yyyy/mm, where subtype corresponds to a measured parameter (aextch4, aexthcl, aexthf, aextno, ch4, h2o, hcl, hf, no, no2, o3, or temp), yyyy is the year, and mm is the month of the data. Each data file has an ASCII file (*META extension) associated with it, which contain information about the data file.

The 3tp subdirectory (in the haloel3 data directory)contains the parameter files which are associated with each data file. There are two parameter files per day. The first, 'lat' gives the latitudes for each profile level, and 'lon' gives the longitude for each profile level. The data files only contain the average latitude and longitude for the profile. The parameter files also have corresponding ASCII metadata files.

3. Reading the data files - The file structure

Level 3AT data is organized into thirteen files per day, one each for temperature, mixing ratios of H2O, NO2, O3, NO, CH4, HCl, and HF, and aerosol extinction values for CO2, NO, CH4, HCl, and HF channels. Each file contains the retrievals for the sunrise and sunset events for the day (typically 29 or 30 total), and files are organized by event. The two Level 3TP files are latitude and longitude for each pressure level of each event for the day.

Software is also available to read the data (as provided by Goddard DAAC User Support Office).