Increases in Future AR Count and Size: Overview of the ARTMIP Tier 2
CMIP5/6 Experiment
Jonathan J. Rutz
National Weather Service, National Oceanic and Atmospheric Administration, National Weather Service, National Oceanic and Atmospheric Administration, National Weather Service, National Oceanic and Atmospheric Administration, National Weather Service, National Oceanic and Atmospheric Administration
Author ProfileIrina Gorodetskaya
Centre for Environmental and Marine Studies, Dept. of Physics, University of Aveiro, Portugal, Centre for Environmental and Marine Studies, Dept. of Physics, University of Aveiro, Portugal, Centre for Environmental and Marine Studies, Dept. of Physics, University of Aveiro, Portugal
Author ProfileAbstract
The Atmospheric River (AR) Tracking Method Intercomparison Project
(ARTMIP) is a community effort to systematically assess how the
uncertainties from AR detectors (ARDTs) impact our scientific
understanding of ARs. This study describes the ARTMIP Tier 2
experimental design and initial results using the Coupled Model
Intercomparison Project (CMIP) Phases 5 and 6 multi-model ensembles. We
show that AR statistics from a given ARDT in CMIP5/6 historical
simulations compare remarkably well with the MERRA-2 reanalysis. In
CMIP5/6 future simulations, most ARDTs project a global increase in AR
frequency, counts, and sizes, especially along the western coastlines of
the Pacific and Atlantic oceans. We find that the choice of ARDT is the
dominant contributor to the uncertainty in projected AR frequency when
compared with model choice. These results imply that new projects
investigating future changes in ARs should explicitly consider ARDT
uncertainty as a core part of the experimental design.