.. _recipes_climate_patterns:

Generating Climate Patterns from CMIP6 Models
=============================================

Overview
--------

The recipe recipe_climate_patterns generates climate patterns from CMIP6 model
datasets.

.. note::
  The regrid setting in the recipe is set to a 2.5x3.75 grid. This is done to
  match the current resolution in the IMOGEN-JULES model, but can be
  adjusted with no issues for a finer/coarser patterns grid.


Available recipes and diagnostics
---------------------------------

Recipes are stored in esmvaltool/recipes/

* recipe_climate_patterns.yml

Diagnostics are stored in esmvaltool/diag_scripts/climate_patterns/

* climate_patterns.py: generates climate patterns from input datasets
* sub_functions.py: set of sub functions to assist with driving scripts
* plotting.py: contains all plotting functions for driving scripts


User settings in recipe
-----------------------

#. Script climate_patterns.py

   *Required settings for script*

   None

   *Optional settings for script*

   * jules_mode: output jules-specific var names + .nc files
   * parallelise: parallelise over models or not
   * area: calculate the patterns globally, or over land only

   *Required settings for variables*

   * short_name
   * additional_datasets

   *Optional settings for variables*

   None

   *Required settings for preprocessor*

   * monthly_statistics: converts data to mean monthly data

   *Optional settings for preprocessor*

   * regrid: regrids data


Variables
---------

#. Script climate_patterns.py

* tasmax (atmos, monthly, longitude latitude time)
* tasmin (atmos, monthly, longitude latitude time)
* tas (atmos, monthly, longitude latitude time)
* huss (atmos, monthly, longitude latitude time)
* pr (atmos, monthly, longitude latitude time)
* sfcWind (atmos, monthly, longitude latitude time)
* ps (atmos, monthly, longitude latitude time)
* rsds (atmos, monthly, longitude latitude time)
* rlds (atmos, monthly, longitude latitude time)


Observations and reformat scripts
---------------------------------

None

References
----------

* Huntingford, C., Cox, P. An analogue model to derive additional climate
  change scenarios from existing GCM simulations.
  Climate Dynamics 16, 575–586 (2000). https://doi.org/10.1007/s003820000067

* Mathison, C. T. et al. A rapid application emissions-to-impacts tool
  for scenario assessment: Probabilistic Regional Impacts from Model patterns
  and Emissions (PRIME).
  EGUsphere [preprint], (2024). https://doi.org/10.5194/egusphere-2023-2932

Example plots
-------------

.. _fig_climate_patterns_2:
.. figure::  /recipes/figures/climate_patterns/patterns.png
   :align:   center
   :width: 80%

   Patterns generated for CMIP6 models, gridded view. Patterns are shown per
   variable, for the month of January.