#!/usr/bin/env python # -*- coding: utf-8 -*- #******************************************************************************* # @Author: Anne Fouilloux (University of Oslo) # # @Date: October 2014 # # @Change History: # # November 2015 - Leopold Haimberger (University of Vienna): # - optimized display_info # - optimized data_retrieve and seperate between python and shell # script call # # February 2018 - Anne Philipp (University of Vienna): # - applied PEP8 style guide # - added documentation # - applied some minor modifications in programming style/structure # # @License: # (C) Copyright 2015-2018. # # This software is licensed under the terms of the Apache Licence Version 2.0 # which can be obtained at http://www.apache.org/licenses/LICENSE-2.0. # # @Class Description: # A MARS revtrieval has a specific syntax with a selection of keywords and # their corresponding values. This class provides the necessary functions # by displaying the selected parameters and their values and the actual # retrievement of the data through a mars request or a Python web api # interface. The initialization already expects all the keyword values. # # @Class Content: # - __init__ # - display_info # - data_retrieve # # @Class Attributes: # - server # - marsclass # - dtype # - levtype # - levelist # - repres # - date # - resol # - stream # - area # - time # - step # - expver # - number # - accuracy # - grid # - gaussian # - target # - param # #******************************************************************************* # ------------------------------------------------------------------------------ # MODULES # ------------------------------------------------------------------------------ import subprocess import os import _config # ------------------------------------------------------------------------------ # CLASS # ------------------------------------------------------------------------------ class MarsRetrieval(object): ''' Class for submitting MARS retrievals. A description of MARS keywords/arguments and examples of their values can be found here: https://software.ecmwf.int/wiki/display/UDOC/\ Identification+keywords#Identificationkeywords-class ''' def __init__(self, server, marsclass="ei", type="", levtype="", levelist="", repres="", date="", resol="", stream="", area="", time="", step="", expver="1", number="", accuracy="", grid="", gaussian="", target="", param=""): ''' @Description: Initialises the instance of the MarsRetrieval class and defines and assigns a set of the necessary retrieval parameters for the FLEXPART input data. A description of MARS keywords/arguments, their dependencies on each other and examples of their values can be found here: https://software.ecmwf.int/wiki/display/UDOC/MARS+keywords @Input: self: instance of MarsRetrieval For description see class documentation. server: instance of ECMWFService (from ECMWF Web-API) This is the connection to the ECMWF data servers. It is needed for the pythonic access of ECMWF data. marsclass: string, optional Characterisation of dataset. E.g. EI (ERA-Interim), E4 (ERA40), OD (Operational archive), ea (ERA5). Default is the ERA-Interim dataset "ei". type: string, optional Determines the type of fields to be retrieved. Selects between observations, images or fields. Examples for fields: Analysis (an), Forecast (fc), Perturbed Forecast (pf), Control Forecast (cf) and so on. Default is an empty string. levtype: string, optional Denotes type of level. Has a direct implication on valid levelist values! E.g. model level (ml), pressure level (pl), surface (sfc), potential vorticity (pv), potential temperature (pt) and depth (dp). Default is an empty string. levelist: string, optional Specifies the required levels. It has to have a valid correspondence to the selected levtype. Examples: model level: 1/to/137, pressure levels: 500/to/1000 Default is an empty string. repres: string, optional Selects the representation of the archived data. E.g. sh - spherical harmonics, gg - Gaussian grid, ll - latitude/longitude, ... Default is an empty string. date: string, optional Specifies the Analysis date, the Forecast base date or Observations date. Valid formats are: Absolute as YYYY-MM-DD or YYYYMMDD. Default is an empty string. resol: string, optional Specifies the desired triangular truncation of retrieved data, before carrying out any other selected post-processing. The default is automatic truncation (auto), by which the lowest resolution compatible with the value specified in grid is automatically selected for the retrieval. Users wanting to perform post-processing from full spectral resolution should specify Archived Value (av). The following are examples of existing resolutions found in the archive: 63, 106, 159, 213, 255, 319, 399, 511, 799 or 1279. This keyword has no meaning/effect if the archived data is not in spherical harmonics representation. The best selection can be found here: https://software.ecmwf.int/wiki/display/UDOC/\ Retrieve#Retrieve-Truncationbeforeinterpolation Default is an empty string. stream: string, optional Identifies the forecasting system used to generate the data. E.g. oper (Atmospheric model), enfo (Ensemble forecats), ... Default is an empty string. area: string, optional Specifies the desired sub-area of data to be extracted. Areas can be defined to wrap around the globe. Latitude values must be given as signed numbers, with: north latitudes (i.e. north of the equator) being positive (e.g: 40.5) south latitutes (i.e. south of the equator) being negative (e.g: -50.5) Longtitude values must be given as signed numbers, with: east longitudes (i.e. east of the 0 degree meridian) being positive (e.g: 35.0) west longitudes (i.e. west of the 0 degree meridian) being negative (e.g: -20.5) E.g.: North/West/South/East Default is an empty string. time: string, optional Specifies the time of the data in hours and minutes. Valid values depend on the type of data: Analysis time, Forecast base time or First guess verification time (all usually at synoptic hours: 00, 06, 12 and 18 ). Observation time (any combination in hours and minutes is valid, subject to data availability in the archive). The syntax is HHMM or HH:MM. If MM is omitted it defaults to 00. Default is an empty string. step: string, optional Specifies the forecast time step from forecast base time. Valid values are hours (HH) from forecast base time. It also specifies the length of the forecast which verifies at First Guess time. E.g. 1/3/6-hourly Default is an empty string. expver: string, optional The version of the dataset. Each experiment is assigned a unique code (version). Production data is assigned 1 or 2, and experimental data in Operations 11, 12 ,... Research or Member State's experiments have a four letter experiment identifier. Default is "1". number: string, optional Selects the member in ensemble forecast run. (Only then it is necessary.) It has a different meaning depending on the type of data. E.g. Perturbed Forecasts: specifies the Ensemble forecast member Default is an empty string. accuracy: string, optional Specifies the number of bits per value to be used in the generated GRIB coded fields. A positive integer may be given to specify the preferred number of bits per packed value. This must not be greater than the number of bits normally used for a Fortran integer on the processor handling the request (typically 32 or 64 bit). Within a compute request the accuracy of the original fields can be passed to the result field by specifying accuracy=av. Default is an empty string. grid: string, optional Specifies the output grid which can be either a Gaussian grid or a Latitude/Longitude grid. MARS requests specifying grid=av will return the archived model grid. Lat/Lon grid: The grid spacing needs to be an integer fraction of 90 degrees e.g. grid = 0.5/0.5 Gaussian grid: specified by a letter denoting the type of Gaussian grid followed by an integer (the grid number) representing the number of lines between the Pole and Equator, e.g. grid = F160 - full (or regular) Gaussian grid with 160 latitude lines between the pole and equator grid = N320 - ECMWF original reduced Gaussian grid with 320 latitude lines between the pole and equator, see Reduced Gaussian Grids for grid numbers used at ECMWF grid = O640 - ECMWF octahedral (reduced) Gaussian grid with 640 latitude lines between the pole and equator Default is an empty string. gaussian: string, optional This parameter is deprecated and should no longer be used. Specifies the desired type of Gaussian grid for the output. Valid Gaussian grids are quasi-regular (reduced) or regular. Keyword gaussian can only be specified together with keyword grid. Gaussian without grid has no effect. Default is an empty string. target: string, optional Specifies a file into which data is to be written after retrieval or manipulation. Path names should always be enclosed in double quotes. The MARS client supports automatic generation of multiple target files using MARS keywords enclosed in square brackets [ ]. If the environment variable MARS_MULTITARGET_STRICT_FORMAT is set to 1 before calling mars, the keyword values will be used in the filename as shown by the ecCodes GRIB tool grib_ls -m, e.g. with MARS_MULTITARGET_STRICT_FORMAT set to 1 the keywords time, expver and param will be formatted as 0600, 0001 and 129.128 rather than 600, 1 and 129. Default is an empty string. param: string, optional Specifies the meteorological parameter. The list of meteorological parameters in MARS is extensive. Their availability is directly related to their meteorological meaning and, therefore, the rest of directives specified in the MARS request. Meteorological parameters can be specified by their GRIB code (param=130), their mnemonic (param=t) or full name (param=temperature). The list of parameter should be seperated by a "/"-sign. E.g. 130/131/133 Default is an empty string. @Return: ''' self.server = server self.marsclass = marsclass self.type = type self.levtype = levtype self.levelist = levelist self.repres = repres self.date = date self.resol = resol self.stream = stream self.area = area self.time = time self.step = step self.expver = expver self.number = number self.accuracy = accuracy self.grid = grid self.gaussian = gaussian self.target = target self.param = param return def display_info(self): ''' @Description: Prints all class attributes and their values to the standard output. @Input: self: instance of MarsRetrieval For description see class documentation. @Return: ''' # Get all class attributes and their values as a dictionary attrs = vars(self) # iterate through all attributes and print them # with their corresponding values for item in attrs.items(): if item[0] in 'server': pass else: print(item[0] + ': ' + str(item[1])) return def print_info(self, inputdir): ''' @Description: Prints all mars requests to an extra file for debugging and information. @Input: self: instance of MarsRetrieval For description see class documentation. inputdir: string The path where all data from the retrievals are stored. @Return: ''' # Get all class attributes and their values as a dictionary attrs = vars(self) # open a file to store all requests to with open(os.path.join(inputdir, _config.FILE_MARS_REQUESTS), 'a') as f: f.write('mars\n') # iterate through all attributes and print them # with their corresponding values for item in attrs.items(): if item[0] in 'server': pass else: f.write(item[0] + ': ' + str(item[1]) + '\n') f.write('\n\n') return def data_retrieve(self): ''' @Description: Submits a MARS retrieval. Depending on the existence of ECMWF Web-API it is submitted via Python or a subprocess in the Shell. The parameter for the mars retrieval are taken from the defined class attributes. @Input: self: instance of MarsRetrieval For description see class documentation. @Return: ''' # Get all class attributes and their values as a dictionary attrs = vars(self) # convert the dictionary of attributes into a comma # seperated list of attributes with their values # needed for the retrieval call s = 'ret' for k, v in attrs.iteritems(): if k in 'server': continue if k == 'marsclass': k = 'class' if v == '': continue if k.lower() == 'target': target = v else: s = s + ',' + k + '=' + str(v) # MARS request via Python script if self.server is not False: try: self.server.execute(s, target) except: print('MARS Request failed, \ have you already registered at apps.ecmwf.int?') raise IOError if os.stat(target).st_size == 0: print('MARS Request returned no data - please check request') raise IOError # MARS request via extra process in shell else: s += ',target = "' + target + '"' p = subprocess.Popen(['mars'], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, bufsize=1) pout = p.communicate(input=s)[0] print(pout.decode()) if 'Some errors reported' in pout.decode(): print('MARS Request failed - please check request') raise IOError if os.stat(target).st_size == 0: print('MARS Request returned no data - please check request') raise IOError return