LAGRANTO

The Lagrangian Analysis Tool


About

Lagrangian parcel trajectories are widely used in the atmospheric sciences, for instance, to identify flow structures in extratropical cyclones (e.g., warm conveyor belts), long-range transport pathways of moisture, or to study the physical processes underlying the formation of sea surface temperature, salinity or potential vorticity anomalies. On a more local scale, trajectories have recently also attained a lot of interest in mountain meteorology, e.g., in studying the pathway and warming of air parcels during foehn conditions.


Lagranto is available for several NWP and GCM models, particularly ECMWF, COMOS/ICON, and CESM. Additionally, a version is available for WRF on request. If only few trajectories have to be calculated based on ERA5 and operational ECMWF products, an FTP-based service is provided on ETH servers.



1. LAGRANTO.ECMWF

It is used to compute air-parcel trajectories typically based on hourly ERA5 data on a regular lat/lon grid. This version can also handle ERA-Interim data, or operational ECMWF analysis and forecast products.

Citation:

Sprenger, M. and Wernli, H. (2015): The LAGRANTO Lagrangian analysis tool - version 2.0, Geosci. Model Dev., 8, 2569–2586, doi:10.5194/gmd-8-2569-2015.

Wernli, H. and Davies, H. C. (1997): A Lagrangian-based analysis of extratropical cyclones. I: The method and some applications. Q. J. R. Meteorol. Soc., 123, 467–489. doi:10.1002/qj.49712353811.

3. LAGRANTO.CESM

It is used to compute air-parcel trajectories typically based on CESM (Community Earth System Model) climate simulations.

Citation:

Sprenger, M. and Wernli, H. (2015): The LAGRANTO Lagrangian analysis tool - version 2.0, Geosci. Model Dev., 8, 2569–2586, doi:10.5194/gmd-8-2569-2015.

4. LAGRANTO.FTP

This version of Lagranto allows the user to calculate trajectories based on ERA5 and operational ECMWF products without having to install Lagranto locally on a computer. The user can submit trajectory jobs to a computing queue at ETH, where the actual computation will be done and the result being made available on an FTP server

Citation:

Sprenger, M. and Wernli, H. (2015): The LAGRANTO Lagrangian analysis tool - version 2.0, Geosci. Model Dev., 8, 2569–2586, doi:10.5194/gmd-8-2569-2015.