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With this icon we can recreate the layers of the ecCharts web-based visualisation system in the Metview environment. The icon retrieves and the data making up an ecCharts layer for the selected date from the MARS archive then applies the required post-processing steps and visualises the result using one of the pre-defined ecCharts styles.
Output format Please note that the output of the icon is not a single GRIB file but a list of the following items: - the GRIB fields retrieved from MARS
- a plot title definition (see Text plotting icon)
- a contouring definition (see Contouring icon) using the specified the pre-defined style associated with the layer
- a legend (see Legend icon) definition
Saving GRIB data To save a local copy of the retrieved GRIB data use the Save result action from the icon context menu.
Generating script code
The icon is equipped with the Generate Macro and Generate Python context menu actions. Image Added
With these actions the actual retrieval, post-processing and visualisation steps can be saved into the specified script format (the generated script will be appear in the current folder). Here is an example of the Macro code generated for layer t925.
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| # Metview Macro
# **************************** LICENSE START ***********************************
#
# Copyright 2018 ECMWF. This software is distributed under the terms
# of the Apache License version 2.0. In applying this license, ECMWF does not
# waive the privileges and immunities granted to it by virtue of its status as
# an Intergovernmental Organization or submit itself to any jurisdiction.
#
# ***************************** LICENSE END ************************************
#
# Retrieve data from MARS
data = retrieve(
class : 'od',
levelist : 925,
levtype : 'pl',
param : '130.128',
stream : 'oper',
type : 'fc',
date : '20181127',
time : '0000',
grid : [1,1],
step : '24',
expver : '1')
# Define title
title = mtext(
text_line_1 : "925 hPa temperature START: <grib_info key='base-date' format='%d.%m.%Y. %H' where='shortName=t' /> UTC STEP: <grib_info key='step' where='shortName=t' />h VALID FOR = <grib_info key='valid-date' format='%d.%m.%Y. %H' where='shortName=t' /> UTC",
text_colour : "charcoal")
# Define contouring
cont = mcont(
contour_automatic_setting : "style_name",
contour_style_name : "sh_all_fM52t48i4",
legend : "on")
# Define legend
legend = mlegend(
legend_text_colour : "charcoal")
# Generate plot
plot(data, title, cont, legend)
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What layers are available?
A fair number of eccharts ecCharts layers are available but several layers are not yet added. The output of the icon Please The output of the icons is not a single fieldset (Metviews storage type for GRIB data) but a list of these 4 elements: - the GRIB data (fieldset) retrieved from MARS.
- a title definition (MTEXT icon)
- a contouring definition (MCONT icon) using one of the pre-defined styles associated with the layer
- a contouring legend (MLEGEND) definition
icon editor contains a layer browser where the available layers can be searched for and their various properties can be inspected in detail.
Image Added
For generates the gridded input data and the AVAILABLE file needed to run the FLEXPART Lagrangian dispersion model. The input forecast or analysis fields are either automatically retrieved from ECMWF's MARS archive or read from the specified input file. For help on editing icons, please see Editing Icons.
The macro language equivalent is eccharts() . What data is available?
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FLEXPART Prepare is currently only able to handle data from the operational ECMWF forecasts/analyses 2008, 4 June onwards.
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Input data fields
The following is for information only - FLEXPART Prepare handles these details internally. FLEXPART requires input fields on a regular latitude-longitude grid in GRIB format. The input data must contain five three-dimensional fields: the two horizontal wind components, vertical velocity, temperature and specific humidity. Additional surface fields (e.g. fluxes) are also needed. The three-dimensional input data has to be available on ECMWF model (i.e. η) levels defined by a hybrid vertical coordinate system. An important restriction is that all the data fields used within a FLEXPART run must have the same domain size, resolution, number of levels, etc. All the required fields, with one exception, can be retrieved from ECMWF's MARS archive. The only exception is vertical velocity because FLEXPART needs the following field for its computations: Mathinline |
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\dot \eta \frac{\partial \eta}{\partial p} |
Since only is archived in MARS the full product needs to be computed during the data preparation process ( FLEXPART Prepare does it for you) . Input filenamesFLEXPART requires all the input GRIB files to be in the same folder using the following file naming convention: ENyymmddhh. The same directory has to contain the AVAILABLE file as well (it is automatically generated by FLEXPART Prepare). |
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The Eccharts Editor
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All the date parameters used for FLEXPART Prepare is given in YYYYMMDD format. Relative dates are allowed: e.g. -1 means yesterday, 0 means today, etc. |
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Specifies the contouring style for the selected layer. Each Eccharts layer is associated with a group of predefined styles. When a given layer is selected in Layer the icon editor only shows the available styles for that layer and the default style is automatically selected.
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Date
Specifies the
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["sd","msl","tcc","10u","10v","2t","2d","sp", "z","lsm","lcc","mcc","hcc","skt", "stl1","swvl1"]
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run date of the forecast . This is the same Date parameter as in the MARS retrieval icon. The date
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The surface fluxes are accumulated fields and for the de-accumulation process they also require the step preceding the first step. We have a special case when the first step is 0 because in this case we need two additional steps but from the previous model run! E.g. for a 0 UTC model run when we use 3 hourly steps we need the fluxes from step=6 and step=3 of the 18 UTC run on the previous day. |
Date
Specifies the run date of the forecast. Available when Prepare Mode is forecast.is given in YYYYMMDD
format. Relative dates are allowed: e.g. -1 means yesterday, 0 means today, etc. The default is -1.
Time
Specifies the run time of the forecast in hours. Available when Prepare Mode is forecast. This is the same Date parameter as in the MARS retrieval icon. The default is 0.
Step
Specifies the forecast steps in hours. Here a list of values is given. Available when Prepare Mode is forecast.
Period Start Date
Specifies the start date of the period. Available when Prepare Mode is period.
Period Start Time
Specifies the start time of the period. Available when Prepare Mode is period.
Period End Date
Specifies the end date of the period. Available when Prepare Mode is period.
Period End Time
Specifies the end time of the period. Available when Prepare Mode is period.
Period Step
Specifies the time step of the period in hours. The allowed values are as follows: 3 or 6. Available when Prepare Mode is period. The default value is 3.
Grid
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Specifies if the input GRIB fields need to be interpolated onto a target grid specified by Area and Grid. The possible values are on/off. Available when Input source is file. The default value is: on.
Area
Specifies the area of the output grid in south/west/north/east format. The default value is -90/-179/90/180.
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Please note that to make global domains work with FLEXPART the western border must be set to one gridcell east of 180. E.g. if the east-west grid resolution is 1 degree area should be set to -90/-179/90/180 etc. |
Grid
Specifies the resolution of the output resolution of the resulting grid in dx/dy format, where dx is the grid increment in east-west direction, while dy is the grid increment in north-south direction (both in units of degrees). The default value is: 1/1.
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Fail On Data Error
When this parameter is set to yes an error in the data retrieval or post-processing force the icon (or the Macro/Python script running it) to fail to fail.
Only data on and below this model level will be used to generate the FLEXPART input fields. This level can be specified either as a model level or as a pressure value. In the latter case FLEXPART Prepare will use the data retrieved for the first date to determine the topmost model level. The default value of this parameter is 1, which means that all the model levels will be used if Top Level Units is set to model_levels.
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Specifies the output directory (can be a relative or absolute path) where the GRIB files and the AVAILABLE file will be generated. If this directory does not exist Metview will create it. The output GRIB files have the following naming convention: ENyymmddhh.yymmddh