Cloud Feedbacks
Overview
The cloud feedback metrics implemented in PMP are originally from assessed-cloud-fbks ,
developed by @mzelinka at LLNL. This code performs the analysis of Zelinka et al. (2022).
It computes GCM cloud feedback components and compares them to the expert-assessed values from Sherwood et al. (2020).
Instructions
To use the cloud feedback metrics, follow these steps:
1. Install PMP
Install PMP via conda following the installation instructions. For example:
conda create -n [YOUR_CONDA_ENVIRONMENT] -c conda-forge pcmdi_metrics
2. Activate PMP installed conda environment
Activate your environment (if PMP installed env is different from your current one):
conda activate [YOUR_CONDA_ENVIRONMENT]
3. Clone PMP repo to your local
Clone PMP repo to your local for pre-calculated data:
git clone https://github.com/PCMDI/pcmdi_metrics
Once completed, go to pcmdi_metrics/pcmdi_metrics/cloud_feedback directory:
cd [YOUR LOCAL CLONED PMP REPOSITORY]
cd pcmdi_metrics/pcmdi_metrics/cloud_feedback
4. Edit parameter files
In param/my_param.py, update the “User Input” section so it points to your model’s amip and amip-p4K files:
# User Input:
# ================================================================================================
model = "GFDL-CM4"
variant = "r1i1p1f1"
input_files_json = "./param/input_files.json"
# Flag to compute ECS
# True: compute ECS using abrupt-4xCO2 run
# False: do not compute, instead rely on ECS value present in the json file (if it exists)
# get_ecs = True
get_ecs = False
# Output directory path (directory will be generated if it does not exist yet.)
xml_path = "./xmls/"
figure_path = "./figures/"
output_path = "./output"
output_json_filename = "_".join(["cloud_feedback", model, variant]) + ".json"
# ================================================================================================
You will need to update param/input_files.json file as well to provide data path for your input files.
5. Run the code and inspect the generated output files
Run calculation:
python cloud_feedback_driver.py -p param/my_param.py
Once code is completed, check output directory (output_path from the above parameter file) for JSON
and figures directory (figure_path from the above parameter file) for figures and text tables.
References
Zelinka et al. (2022): Evaluating climate models’ cloud feedbacks against expert judgement, J. Geophys. Res., 127, e2021JD035198, doi:10.1029/2021JD035198.
Sherwood et al. (2020): A combined assessment of Earth’s climate sensitivity, Rev. Geophys., 58, e2019RG000678, doi:10.1029/2019RG000678.