Implied heat transport new diagnostic (#3177)

Co-authored-by: Francesca Pearce <francesca.pearce@metoffice.gov.uk>
Co-authored-by: alejandrobodas <alejandroxtr@gmail.com>
Co-authored-by: Emma Hogan <ehogan@users.noreply.github.com>

CITATION.cff

@@ -90,6 +90,11 @@ authors:
     family-names: Bock
     given-names: Lisa
     orcid: "https://orcid.org/0000-0001-7058-5938"
+  -
+    affiliation: "MetOffice, UK"
+    family-names: Bodas-Salcedo
+    given-names: Alejandro
+    orcid: "https://orcid.org/0000-0002-7890-2536"
   -
     affiliation: "BSC, Spain"
     family-names: Caron

doc/sphinx/source/recipes/index.rst

@@ -45,6 +45,7 @@ Atmosphere
    recipe_gier20bg
    recipe_heatwaves_coldwaves
    recipe_hyint
+   recipe_iht_toa
    recipe_impact
    recipe_modes_of_variability
    recipe_mpqb_xch4

doc/sphinx/source/recipes/recipe_iht_toa.rst

@@ -0,0 +1,123 @@
+.. _recipes_iht_toa:
+
+Implied heat transport from Top of Atmosphere fluxes
+====================================================
+
+Overview
+--------
+
+This recipe calculates the implied horizontal heat transport (IHT) due to the
+spatial anomalies of radiative fluxes at the top of the atmosphere (TOA).
+The regional patterns of implied heat transport for different components of
+the TOA fluxes are calculated by solving the Poisson equation with the flux
+components as source terms.
+It reproduces the plots in `Pearce and Bodas-Salcedo (2023)`_ when the input
+data is CERES EBAF.
+
+
+Available recipes and diagnostics
+---------------------------------
+
+Recipes are stored in esmvaltool/recipes/
+
+* recipe_iht_toa.yml calculates the IHT maps for the following radiative fluxes:
+
+  * Total net, SW net, LW net (Figure 2).
+  * Total CRE, SW CRE, LW CRE (Figure 4).
+  * All-sky and clear-sky reflected SW (Figure 5).
+  * The meridional heat transports (MHT) of the fluxes above (Figures 1 and 3).
+
+Diagnostics are stored in esmvaltool/diag_scripts/iht_toa/
+
+* single_model_diagnostics.py: driver script that produces the plots.
+* poisson_solver.py: solver that calculates the IHTs.
+
+.. _`Pearce and Bodas-Salcedo (2023)`:  https://doi.org/10.1175/JCLI-D-22-0149.1
+
+User settings in recipe
+-----------------------
+There are no user settings in this recipe.
+
+Variables
+---------
+
+* rlut (atmos, monthly, longitude latitude time)
+* rlutcs (atmos, monthly, longitude latitude time)
+* rsutcs (atmos, monthly, longitude latitude time)
+* rsut (atmos, monthly, longitude latitude time)
+* rsdt (atmos, monthly, longitude latitude time)
+
+Observations and reformat scripts
+---------------------------------
+
+* CERES-EBAF
+
+References
+----------
+
+* Pearce, F. A., and A. Bodas-Salcedo, 2023: Implied Heat Transport from CERES
+  Data: Direct Radiative Effect of Clouds on Regional Patterns and Hemispheric
+  Symmetry. J. Climate, 36, 4019–4030, doi: 10.1175/JCLI-D-22-0149.1.
+
+Example plots
+-------------
+
+.. _fig_iht_toa_1:
+.. figure::  /recipes/figures/iht_toa/figure1_CERES-EBAF_CERES-EBAF.png
+   :align:   center
+
+   The implied heat transport due to the total net flux (blue), split into
+   the contributions from the SW (orange) and LW (green).
+
+.. _fig_iht_toa_2:
+.. figure::  /recipes/figures/iht_toa/figure2_CERES-EBAF_CERES-EBAF.png
+   :align:   center
+
+   The energy flux potentials for (a) TOT, (c) SW, and (e) LW fluxes,
+   alongside maps of the spatial anomalies of the fluxes [(b),(d),(f)
+   flux minus global average flux, respectively].
+   The implied heat transport is calculated as the gradient of the energy
+   flux potential, shown by the white vector arrows for a subset of points
+   to give the overall transport pattern.
+   Heat is directed from the blue minima of the potential field to
+   yellow maxima, with the magnitude implied by the density of contours.
+   All maps of the same type share the same color bar at the bottom
+   of the column.
+
+.. _fig_iht_toa_3:
+.. figure::  /recipes/figures/iht_toa/figure3_CERES-EBAF_CERES-EBAF.png
+   :align:   center
+
+   Direct radiative effects of clouds on the meridional heat transport.
+   (a) Contributions from TOT CRE (blue), SW CRE (orange), and LW CRE (green)
+   fluxes. (b) Contributions from all-sky and clear-sky OSR.
+   In (b), both curves have been multiplied by −1 such that positive heat
+   transport is northward.
+
+.. _fig_iht_toa_4:
+.. figure::  /recipes/figures/iht_toa/figure4_CERES-EBAF_CERES-EBAF.png
+   :align:   center
+
+   As in :numref:`fig_iht_toa_2`, but for the implied heat transport associated with
+   (a),(b) TOT CRE, (c),(d) SW CRE, and (e),(f) LW CRE fluxes.
+
+.. _fig_iht_toa_5:
+.. figure::  /recipes/figures/iht_toa/figure5_CERES-EBAF_CERES-EBAF.png
+   :align:   center
+
+   As in :numref:`fig_iht_toa_2`, but for (a), (b) clear-sky and (c), (d) all-sky reflected
+   SW flux.
+
+.. _fig_iht_toa_6:
+.. figure::  /recipes/figures/iht_toa/figure6_CERES-EBAF_CERES-EBAF.png
+   :align:   center
+
+   A measure of the symmetry between heat transport in the Northern and
+   Southern Hemispheres, calculated for the 12-month running mean of TOT MHT
+   in the regions: (a) the full hemisphere, (b) from the equator to 30°, and
+   (c) 30° to 90°.
+   Symmetry values obtained when including (blue) and excluding (orange)
+   the effect of clouds. The climatological symmetry values for the two cases
+   are shown as the black lines in each subplot, dashed and dotted,
+   respectively.
+   The standard deviations of the time series are shown in each plot.

environment.yml

@@ -38,6 +38,7 @@ dependencies:
   - natsort
   - nc-time-axis
   - netCDF4
+  - numba
   - numpy !=1.24.3  # severe masking bug
   - packaging
   - openpyxl

esmvaltool/config-references.yml

@@ -120,6 +120,10 @@ authors:
     institute: DLR, Germany
     orcid: https://orcid.org/0000-0001-7058-5938
     github: LisaBock
+  bodas-salcedo_alejandro:
+    name: Bodas-Salcedo, Alejandro
+    institute: MetOffice, UK
+    orcid:
   bojovic_dragana:
     name: Bojovic, Dragana
     institute: BSC, Spain
@@ -411,6 +415,10 @@ authors:
     name: Pandde, Amarjiit
     institute: Univ. of Arizona, USA
     orcid:
+  pearce_francesca:
+    name: Pearce, Francesca
+    institute: MetOffice, UK
+    orcid:
   perez-zanon_nuria:
     name: Perez-Zanon, Nuria
     institute: BSC, Spain