Rainfall associated with tropical and post-tropical cyclones in the high resolution CNRM-CM6-1-HR model
Data files
Jan 31, 2024 version files 150.02 GB
Abstract
One of the most costly effects of climate change will be its impact on extreme weather events, including tropical cyclones (TCs). Understanding these changes is of growing importance, and high resolution global climate models are providing potential for such studies, specifically for TCs. Beyond the difficulties associated with TC behavior in a warming climate, the extratropical transition (ET) of TCs into post-tropical cyclones (PTCs) creates another challenge when understanding these events and any potential future changes. PTCs can produce excessive rainfall despite losing their original tropical characteristics. The present study examines the representation of PTCs and their precipitation in three high resolution (25-50 km) climate models: CNRM, MRI, and HadGEM. All three of these models agree on a simulated decrease in TC and PTC events in the future warming scenario, yet they lack consistency in simulated regional patterns of these changes, which is further evident in regional changes in PTC-related precipitation. The models also struggle with their represented intensity evolution of storms during and after the ET process. Despite these limitations in simulating intensity and regional characteristics, the models all simulate a shift toward more frequent rain rates above 10 mm/hr in PTCs. These high rain rates become 4-12% more likely in the warmer climate scenario, resulting in a 5-12% increase in accumulated rainfall from these rates.
README: CNRM Model TC and PTC Trajectories, ET Information, and Precipitation
This dataset includes the data from CNRM-CM6-1-HR in the manuscript "Using high resolution climate models to explore future changes in post-tropical cyclone precipitation" for the analysis of precipitation throughout the entire TC life cycle.
Description of the data and file structure
This dataset enables the analysis of precipitation throughout the entire tropical cyclone (TC) life cycle, including points during and after extratropical transition (ET) occurs. The ET process enables TCs to lose their tropical characteristics and be sustained by midlatitude forcing.
The files beginning with "traj_et_CNRM-CM6-1-HR" are trajectories for the entire TC and PTC life cycle. TCs are first tracked with TempestExtremes, and these files are the TC trajectories extended using ExTraTrack to include all points during and after ET occurs. The files beginning with "etdetails", "etpath", "life_", "monthly", "storms", and "yearly" contain the rest of the output from ExTraTrack, which includes details about each storm's ET timing, intensity, location, and more. Further information about the contents of these files can be found here: https://github.com/zarzycki/ExTraTrack. Finally, the netCDF files (beginning in "masked" and ending in ".nc") contain the isolated TC and PTC precipitation that exceeds the 95th percentile threshold for the model simulations. The 95th percentile varies by location and is calculated from all days, regardless of the presence of rainfall or not, for each set of simulations- historical and future. Precipitation exceeding the 95th percentile is tracked using TempestExtremes, then co-located with TCs and PTCs using a dynamical radius calculated around the trajectories included in this dataset. A full description of the methods can be found in the full manuscript.
Sharing/Access information
Raw HighResMIP (CNRM) data can accessed at: https://esgf-index1.ceda.ac.uk/search/cmip6-ceda/
TempestExtremes is publicly available on GitHub at:
https://github.com/ClimateGlobalChange/tempestextremes
ExTraTrack software is available at https://github.com/zarzycki/ExTraTrack