Selecting regions

MELODIES-MONET has different ways to mask/select a specific region.

The easiest, and often most precise, is to have that region defined in the observations/paired data. In this case, the variable/column that defines the region of interest should be selected as domain_type in the YAML file, and the name of the region to select should be provided as domain_name.

If the regional metadata are not available in the observations, another option is to provide a lonlat box, which can be defined by setting domain_type: auto-region:xxxxx, where xxxxx can be epa or giorgi, or setting as custom:box. Giorgi regions and a rough, rectangular approximation to EPA regions have already been hardcoded into MELODIES-MONET. In the case of EPA regions, be aware that the approximation is quite rough to force it into a rectangular lonlat box, and although it is probably sufficient for plotting maps, it can lead to errors if used for anything else. If custom:box is selected a lonlat box in the form of bounds: [minlon, maxlon, minlat, maxlat] needs to be provided in domain_info (see example below). custom:box has, however, some limitations: minlon and maxlon need to be in the range of [-180, 180], and the box cannot cross the antimeridian.

A third, and more sophisticated option, consists in utilizing the optional dependency regionmask. This is selected by defining domain_type: custom:xxxxx, where xxxxx can be polygon, region or file. All of these options require extra data provided in a domain_info keyword in the YAML file. This option includes a multiplicity of capabilities: * If polygon is selected, the vertices of one or more arbitrary polygons need to be provided (anti clockwise). Currently no holes inside the polygon are supported. * If region is selected, any defined region supported by regionmask can be provided in domain_info. * If file is provided, the path to a shapefile/geojson file has to be provided. There is no need to decompress .zip shapefiles. Alternatively, the download URL can be provided, and the code will download the file automatically. Be aware that if a file with the same name is already in the working directory, it will be silently overwritten.

An example of the plotting part of an arbitrary plot for eact type of region is shown below:

domain_type: ["all",   "all",   "state_name", "epa_region", "auto-region:giorgi", "custom:box", "custom:polygon", "custom:polygon", "custom:region", "custom:file", "custom:file"]
domain_name: ["CONUS", "model", "CO",          "R8",        "CNA",                "R8box",      "onepoly",        "twopolys",       "colorado",      "denverfile",  "denverurl"]
domain_info:
  R8box:
    bounds: [-105.30, -105.1, 39.8, 40.2]
  onepoly:
    mask_info: [[-104.968, 39.47], [-104.618, 39.75], [-104.968, 40.06], [-105.32, 39.75]]
  twopolys:
    mask_info: [[[-104.968, 39.47], [-104.618, 39.75], [-104.968, 40.06], [-105.32, 39.75]], [[-107.474, 37.693], [-108.037, 37.659], [-108.423, 36.97], [-106.444, 36.97], [-106.497, 37.473], [-107.4597, 37.4693]]]
  colorado:
    name_regiontype: natural_earth_v5_1_2.us_states_10
    region: CO
  denverfile:
    mask_path: "Colorado_County_Boundaries.zip"
    abbrevs: COUNTY
    name: Counties
    region_name: DENVER
  denverurl:
    mask_url: "https://hub.arcgis.com/api/v3/datasets/66c2642209684b90af84afcc559a5a02_5/downloads/data?format=shp&spatialRefId=4269&where=1%3D1"
    abbrevs: "COUNTY"
    name: "Counties"
    region_name: "DENVER"