Cold-Point Tropopause (CTP) diagnostic and sample recipe

.zenodo.json

@@ -459,6 +459,10 @@
     },
     {
       "affiliation": "DLR, Germany",
+      "name": "McQuaid, Aoife",
+      "orcid": "0009-0007-8644-5500"
+    },
+    {
       "name": "Debeire, Kevin",
       "orcid": "0000-0001-6006-8750"
     },

CITATION.cff

@@ -454,6 +454,10 @@ authors:
     given-names: Hannah
   -
     affiliation: "DLR, Germany"
+    family-names: McQuaid
+    given-names: Aoife
+    orcid: "https://orcid.org/0009-0007-8644-5500"
+  -
     family-names: Debeire
     given-names: Kevin
     orcid: "https://orcid.org/0000-0001-6006-8750"

doc/sphinx/source/api/esmvaltool.diag_scripts.tropopause.cpt_hovmoeller.rst

@@ -0,0 +1,9 @@
+.. _api.esmvaltool.diag_scripts.tropopause.cpt_hovmoeller:
+
+Tropical CPT Hovmoeller Diagnostic
+===================================
+
+.. automodule:: esmvaltool.diag_scripts.tropopause.cpt_hovmoeller
+   :no-members:
+   :no-inherited-members:
+   :no-show-inheritance:

doc/sphinx/source/api/esmvaltool.rst

@@ -34,3 +34,4 @@ Diagnostic Scripts
    esmvaltool.diag_scripts.climate_metrics.tcre
    esmvaltool.diag_scripts.climate_metrics.zec
    esmvaltool.diag_scripts.hydrology.hour_of_max_precipitation
+   esmvaltool.diag_scripts.tropopause.cpt_hovmoeller

doc/sphinx/source/recipes/index.rst

@@ -61,6 +61,7 @@ Atmosphere
    recipe_autoassess_landsurface_soilmoisture
    recipe_zmnam
    recipe_thermodyn_diagtool
+   recipe_tropical_cpt_hovmoeller
    recipe_validation
    recipe_radiation_budget
    recipe_aod_aeronet_assess

doc/sphinx/source/recipes/recipe_tropical_cpt_hovmoeller.rst

@@ -0,0 +1,76 @@
+.. _recipes_tropical_cpt_hovmoeller:
+
+Tropical Cold-Point Tropopause (CPT) Hovmoeller Diagnostic
+============================================================
+
+Overview
+--------
+
+This recipe evaluates the structure of the tropical (20°S-20°N)
+cold-point tropopause (CPT) using Hovmoeller-style plots. The CPT is defined,
+at each grid point and time step, as the pressure level of minimum
+temperature between 500 hPa and 10 hPa. For each dataset, the diagnostic
+produces one standalone figure per variable, in two views:
+
+* longitude-time (mean over the tropical latitude band, full longitude
+  range)
+* latitude-time (restricted to the tropical latitude band, mean over the
+  full longitude range)
+
+In both views, filled colors always show CPT pressure, and line contours
+show one of CPT temperature, CPT specific humidity, or CPT relative
+humidity over ice (computed from CPT temperature, specific humidity and
+pressure).
+
+
+Available recipes and diagnostics
+----------------------------------
+
+Recipes are stored in recipes/
+
+* recipe_tropical_cpt_hovmoeller.yml
+
+Diagnostics are stored in diag_scripts/tropopause/
+
+* :ref:`cpt_hovmoeller.py <api.esmvaltool.diag_scripts.tropopause.cpt_hovmoeller>`
+
+
+Variables
+---------
+
+* ta (atmos, monthly mean, longitude latitude level time)
+* hus (atmos, monthly mean, longitude latitude level time)
+
+An optional geopotential height variable (``zg``) is also read, if present
+in the input data, to additionally save the CPT geopotential height; it is
+not required and is not plotted.
+
+
+Observations and reformat scripts
+-----------------------------------
+
+* ERA5 (native6 project, tier 3)
+
+Any other model or observational dataset providing ``ta`` and ``hus`` on
+pressure or model levels can be used in place of, or in addition to, the
+datasets configured in the example recipe.
+
+
+Example plots
+--------------
+
+.. _fig_tropical_cpt_hovmoeller_1:
+.. figure:: /recipes/figures/tropical_cpt_hovmoeller/era5_temperature_lon.jpg
+   :align: center
+   :width: 50%
+
+   Tropical CPT longitude-time Hovmoeller for ERA5: colors show CPT
+   pressure, contours show CPT temperature.
+
+.. _fig_tropical_cpt_hovmoeller_2:
+.. figure:: /recipes/figures/tropical_cpt_hovmoeller/era5_temperature_lat.jpg
+   :align: center
+   :width: 50%
+
+   Tropical CPT latitude-time Hovmoeller for ERA5: colors show CPT
+   pressure, contours show CPT temperature.

esmvaltool/config-references.yml

@@ -794,6 +794,11 @@ authors:
     name: Loew, Alexander
     institute: LMU, Germany
     orcid:
+  mcquaid_aoife:
+    name: McQuaid, Aoife
+    institute: DLR, Germany
+    email: aoife.mcquaid@dlr.de
+    orcid: https://orcid.org/0009-0007-8644-5500
   neale_richard:
     name: Neale, Richard
     institute: NCAR, US

esmvaltool/diag_scripts/tropopause/__init__.py

@@ -0,0 +1 @@
+"""Tropopause diagnostics."""