IsoMet Tools

Flextract reference

AUTHORS:

Alexander Läderach, Harald Sodemann

PURPOSE:

Extract trajectories from FLEXPART particle binary format and convert them to LAGRANTO-format.

AVAILABLE DATA:

5 mio. global FLEXPART-trajectories covering 1979-01-02 00:00 to 2019-08-30 15:00 UTC. Stored at Data/gfi/met/flexpart/erainterim/global/global_corr/ (input-path).

GET STARTED:

Create a settings-file with the following structure:

# --------------------------------------------------------- #
# Settings to extract FLEXPART trajectories from database # 
# NOTE: All lines beginning with # and empty ones ignored # 
# --------------------------------------------------------- #
# Path to the FLEXPART trajectory files (Input) 
/Data/gfi/met/flexpart/erainterim/global/global_corr/

# Path to store trajectories in LAGRANTO-format (Output) 
/Data/gfi/work/<USERNAME>/

# Begin time (Year Month Day Hour Min Sec) 
# NOTE First date for which trajectories are calculated
2000 1 1 0 0 0

# End time (Year Month Day Hour Min Sec) 
# NOTE Last date for which trajectories are calculated
2000 1 2 0 0 0

# Timestep (hours) 
# NOTE always positive
6

# Trajectory length (hours) 
# NOTE positive for forward trajectories, negative for backward
24

# Only consider each nth-particle only (1=each of the 5mio. particles) 
# NOTE: could lead to huge output if too small
10

# Target area (minlon maxlon minlat maxlat) 
5 17 43 49

USAGE:

./flextract <settings-file>

NOTE:

The minimal timestep for the trajectories to be extracted is 3 hours. The timesteps 00 06 12 18 are given by the ERA-interim reanalysis and the 03 09 15 21 timesteps are given by the forecasts of the model used to produce ERA-interim.