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ICON Cell-centered curved quiver plots

This example draws ICON cell-centered vector winds as curved arrows with easyclimate.plot.icon.plot_cell_curved_quiver.

The helper interpolates irregular ICON cell vectors to a regular plotting grid inside the requested longitude-latitude window before drawing the curved arrows.

import xarray as xr
import numpy as np
import cartopy.crs as ccrs
import matplotlib.pyplot as plt
import easyclimate as ecl

from easyclimate.plot.icon import plot_cell_curved_quiver

Open a sample ICON model-level file and select the horizontal wind components stored on cell centers.

data = ecl.open_tutorial_dataset("icon_native_ml_20080909T000000Z")
u = data.u
v = data.v
u

icon_native_ml_20080909T000000Z.nc ━━━━━━━ 100.0% • 1.8/1.8 • 22.8     • 0:00:00
                                                    MB        MB/s

<xarray.DataArray 'u' (ncells: 81920)> Size: 328kB
[81920 values with dtype=float32]
Coordinates:
    clon     (ncells) float64 655kB ...
    clat     (ncells) float64 655kB ...
    time     float64 8B ...
    height   float64 8B ...
Dimensions without coordinates: ncells
Attributes:
    standard_name:                eastward_wind
    long_name:                    Zonal wind
    units:                        m s-1
    param:                        2.2.0
    CDI_grid_type:                unstructured
    number_of_grid_in_reference:  1


Draw curved arrows over a regional North Pacific window. The helper builds the interpolation grid from the requested longitude-latitude bounds.

fig, ax = plt.subplots()

q = plot_cell_curved_quiver(
    data, u, v,
    ax=ax,

    lon_min=140,
    lon_max=220,
    lat_min=25,
    lat_max=70,
    color = "k",

    transform=ccrs.PlateCarree(),
)

ax.set_title("JW Wave Wind Field\n(height = 19, plot_cell_curved_quiver)")
JW Wave Wind Field (height = 19, plot_cell_curved_quiver)
Text(0.5, 1.0, 'JW Wave Wind Field\n(height = 19, plot_cell_curved_quiver)')

The same curved-arrow plot can be drawn on Cartopy axes. The visible extent stays on the requested window while interpolation uses nearby source cells. sphinx_gallery_thumbnail_number = -1

fig, ax = plt.subplots(
    subplot_kw={"projection": ccrs.PlateCarree(180)}
)
q = plot_cell_curved_quiver(
    data, u, v,
    ax=ax,

    lon_min=140,
    lon_max=220,
    lat_min=25,
    lat_max=70,
    color = "k",

    transform=ccrs.PlateCarree(),
)

ax.set_title("JW Wave Wind Field\n(height = 19, plot_cell_curved_quiver)")
ax.coastlines(resolution="110m", linewidth=0.6, color="b")
ax.gridlines(draw_labels=True, alpha=0)
JW Wave Wind Field (height = 19, plot_cell_curved_quiver)
<cartopy.mpl.gridliner.Gridliner object at 0x73548b77fa40>

Total running time of the script: (0 minutes 5.992 seconds)