Hour of Maximum Precipitation

Calculate and plot hour of daily maximum precipitation.

Description

This diagnostics calculates the hour of daily maximum precipitation and plots it. The input data needs to be subdaily and of shape (hour, latitude, longitude). The hour dimension should be in local solar time (see local_solar_time()).

Author

Manuel Schlund (DLR, Germany)

Configuration options in recipe

caption: str, optional

Figure caption used for provenance tracking. By default, uses “Global map of the hour of the daily maximum precipitation for {alias}.”.

cbar_label: str, optional (default: “Hour of daily maximum precipitation”)

Colorbar label.

cbar_kwargs: dict, optional

Optional keyword arguments for matplotlib.pyplot.colorbar(). By default, uses {orientation: "horizontal"}.

figure_kwargs: dict, optional

Optional keyword arguments for matplotlib.pyplot.figure(). By default, uses constrained_layout: true, ticks: [0, 3, 6, 9, 12, 15, 18, 21].

matplotlib_rc_params: dict, optional

Optional matplotlib.RcParams used to customize matplotlib plots. Options given here will be passed to matplotlib.rc_context() and used for all plots produced with this diagnostic.

method: str, optional (default: “dft”)

Method to determine the hour of daily maximum precipitation. Possible options:

• If “dft”, apply a discrete Fourier transform (DFT) to the data and use the peak of the first component (see https://mdtf-diagnostics.readthedocs.io/en/latest/sphinx_pods/precip_diurnal_cycle.html).

• If “harmonic_fit”, fit a 12hr- plus 24hr-harmonic to the input data and use the peak of the 24hr-harmonic (see Dai, 2024; https://doi.org/10.1007/s00382-024-07182-6). This should give identical/very similar results to “dft”, but is much slower.

• If “max”, simply use the maximum in the input data.

plot_kwargs: dict, optional

Optional keyword arguments for iris.plot.pcolormesh(). By default, uses cmap: twilight.

projection: str, optional (default: None)

Projection used for the plot. Needs to be a valid projection class of cartopy.crs. Keyword arguments can be specified using the option projection_kwargs.

projection_kwargs: dict, optional

Optional keyword arguments for the projection given by projection. For map plots, the default keyword arguments {central_longitude: 10} are used.

pyplot_kwargs: dict, optional

Optional calls to functions of matplotlib.pyplot. Dictionary keys are functions of matplotlib.pyplot. Dictionary values are used as argument(s) for these functions (if values are dictionaries, these are interpreted as keyword arguments; otherwise a single argument is assumed). String arguments can contain format strings (e.g., "{dataset} ({project})").

savefig_kwargs: dict, optional

Optional keyword arguments for matplotlib.pyplot.savefig(). By default, uses bbox_inches: tight, dpi: 300, orientation: landscape.

seaborn_settings: dict, optional

Options for seaborn.set_theme() (affects all plots). By default, uses style: ticks.

threshold: float, optional (default: 0.0)

Mask grid points where precipitation is lower than the given threshold.