Description of the Dataset
If you have questions, please contact patrick.stoll@uit.no
The files were create by a algorithm developed by Kevin Hodges.

1. Description of the file names
ERA/ASR specifies the dataset used for the algorithm.
For ERA _NH/_SH specifiew if the TRACKS are for the northern or southern hemisphere.
Each year of the dataset is splitted into 4 files, each containing data for 3 months. I.e. 2001.A contains data for the year 2001 of the month January to March.

2. Description of the content of the files
TRACK_NUM: specifies the number of TRACKs in the file.
Note than TRACKs can only include one timestep.

Each TRACK starts with its TRACK_ID starting to count from 1 until TRACK_NUM
For each TRACK POINT_NUM counts the number of consecutive time steps included in the TRACK. The algorithm is based on 3 hourly data.

The next rows of each TRACK contains the information about the time, position and filtered vorticity of the TRACK:
1. row: time step starting with 1 for 00 UTC at the first day of the first months of the file. 2 then represents 3 UTC, ... , 9 is 00 UTC at the second day, ...
2. row: degree longitude
3. row: degree latitude
4. row: T40-T100 filtered vorticity at 850hPa from the dataset