Heatwave–blocking relation change likely dominates over decrease in blocking frequency under global warming
This is the final version. Available on open access from Nature Research via the DOI in this record Data availability; CMIP6 model data are available from https://esgf-node.llnl.gov/projects/cmip6. We acknowledge the World Climate Research Programme, which, through its Working Group on Coupled Model...
| Published in: | npj Climate and Atmospheric Science |
|---|---|
| Main Authors: | , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Nature Research
2022
|
| Subjects: | |
| Online Access: | http://hdl.handle.net/10871/131346 https://doi.org/10.1038/s41612-022-00290-2 |
| Summary: | This is the final version. Available on open access from Nature Research via the DOI in this record Data availability; CMIP6 model data are available from https://esgf-node.llnl.gov/projects/cmip6. We acknowledge the World Climate Research Programme, which, through its Working Group on Coupled Modelling, coordinated and promoted CMIP6. We thank the climate modelling groups for producing and making available their model output, the Earth System Grid Federation (ESGF) for archiving the data and providing access, and the multiple funding agencies that support CMIP6 and ESGF. Code availability: Computer code to repeat the results is available on Zenodo. The D13 blocking index code is provided by Etienne Dunn-Sigouin. This study uses xarray and scikit-learn. Extra-tropical continental summer heatwaves often occur under persistent anticyclones or blocking. Here we partition heatwave changes into contributions from blocking changes, heatwave–blocking relation change and mean temperature increase, under global warming in climate models. We employ an optimized blocking index that best correlates with heatwaves (Pearson correlation of 0.7) and find heatwave-driving blocking decreases but the change in heatwave–blocking relation likely dominates. Over Europe, with a historical heatwave frequency of 2.5%, less blocking will cause 0.6% fewer heatwaves, steepened heatwave–blocking relation will cause 1.4% more heatwaves, and the mean temperature increase will cause 60% more heatwaves. Over Greenland, flattened heatwave–blocking relation will dominate over the insignificant decrease in blocking. The future increase in heatwave frequency is not caused by changes in blocking frequency, but by factors such as thermodynamics, that enhance the capacity of blocking to drive heatwaves. Natural Environment Research Council (NERC) |
|---|