ECMWF

A climatology that interpolates ECMWF ERA-interim data files. This class is setup to read ECMWF era-interim grib files. The files follow a defined hierarchy that sorts files into directories baszed upon year and month. The files are of the format, <basedirectory>/yyyy/mm/ERA-Int_ml_yyyymmdd.grib where yyyy is the 4 digit year (eg 1970, 2019), mm is the 2 digit month (01-12) and dd is the two digit day (01-31). The climatology has been extended to include support for O2 collisional induced absorption (CIA).

import sasktranif as skif

lat =   50.0
lng = -102.0
h   = 25000.0
mjd = 53000.1234567
location =  [lat,lng, h, mjd]
climate = ISKClimatology('ECMWF')
climate.UpdateCache(location)
ok, P = climate.GetParameter( 'SKCLIMATOLOGY_PRESSURE_PA', location);

Supported Species

Sasktran Handle	Description	Units	Availability
SKCLIMATOLOGY_AIRNUMBERDENSITY_CM3	Air Number density	molecules/cm3	Always
SKCLIMATOLOGY_PRESSURE_PA	Pressure in	Pascals	Always
SKCLIMATOLOGY_TEMPERATURE_K	Temperature	Kelvin	Always
SKCLIMATOLOGY_O2_CM3	Molecular oxygen number density	molecules/cm3	Always
SKCLIMATOLOGY_O2_O2_CM6	O2-O2 square density for CIA	molecule^2/cm6	Always
SKCLIMATOLOGY_N2_CM3	Molecular nitrogen number density	molecules/cm3	Always

Cache Snapshot

The ECMWF cache internally stores two snapshots of the entire globe that straddle the time of interest. Consequently, there is no need to invoke ISKClimatology.UpdateCache() when position changes.

Python extension

The ECMWF climatology is in the sasktran_core extension which is part of the default sasktran installation.

Configuration

The ECMWF climatology needs ERA-Interim files downladed from ECMWF. preparation. The ECMWF base directory is set within the active registry. Python users can change the base directory in the registry entry using the configuration software inside the sasktran_core module. The era interim files are assumed to be available every day at 00 UTC, 06 UTC, 12 UTC and 18 UTC. The code interpolates in latitude, longitude, height and time.

Properties

The ECMWF climatology has no proeprties .. py:module:: ECMWF