Pilot files

Pilot files are files that are used to provide boundary values to a LAM run.

The following pilot file sets are commonly used and available in RPN standard format:

ERA40 (ECMWF reanalysis data), 2.5°, 6 hourly, 195709 - 200208
ECMWF analysis data, 2.0°, 6 hourly, 199609 - 200602
NCEP2, ~2.5°, 6 hourly, 199801 - 200412
GEMCLIM model output data like, 2.0°, 3 hourly, 197801 - 200611

The fields can be on model or pressure levels:

Fields on pressure levels:

temperature (TT)
horizontal winds (UU,VV)
humidity (specific or relative humidity, dew point depression or temperature) (HU, HR, ES or TD)
geopotential (GZ)
if available, amount of liquid and solid water in the atmosphere (QC)

Fields on model levels:

temperature (TT)
horizontal winds (UU,VV)
humidity (specific or relative humidity, dew point depression or temperature) (HU, HR, ES or TD)
surface geopotential (GZ)
surface pressure (P0)
if available, amount of liquid and solid water in the atmosphere (QC)

All files for one month must be archived as an cmc-archive with the name:

nest_info_name_YYYYMM_part#.ca, (#=1,2,...)

If the files for one month get larger than 2 GBytes they can be split into several files: *part[1-9].ca

Save pilot files

Pilot files can be saved during a given model run so as to drive another LAM run with them later.

To save pilot files the following parameters have to be set in your 'configexp.dot.cfg'.

pilout=1;	You will save pilot information files.
pil_type:	Possible values are "pm" or "dp". Denotes the source for the pilot information: Model level data "pm" or pressure level data "dp". If "pm" is chosen, variables 2T,UP,VP,UH,2P will be saved on model levels and GZ at the surface otherwise TT,UU,VV,HU,GZ will be saved on pressure levels. Although the file size when saving on pressure levels is generally much smaller it is still recommended to save pilot file on model levels. (default: pm).
pilhr:	Saving interval in hours for pilot files (default: 3).
pil_dir:	Syntax: pil_dir=${pil_mach}:${pil_rept}; pil_mach: Archiving machine for pilot information files (default ${arch_mach}). Must never be cfs! pil_rept: Archiving directory for pilot information files (default: ${archdir}).
pil_window:	Since the pilot information files might be quite big, it is possible to save only a window. Usage: pil_window="lon1 lon2 lat1 lat2"; Where lon1, lon2 and lat1, lat2 are the left, right and lower, upper model grid indices, respectively.

All of the files for one month will automatically be packed in a cmc-archive file named 'nest_info_${exp}_part#.ca' (#=1,2,...).

Author: Katja Winger
Last update: June 2008