When Will Humanity Notice Its Influence on Atmospheric Rivers?
Journal
Journal of Geophysical Research: Atmospheres
Journal Volume
127
Journal Issue
9
Date Issued
2022
Author(s)
Johnson N.C
Kapnick S.B
Cooke W
Delworth T.L
Jia L
Lu F
McHugh C
Murakami H
Rosati A.J
Wittenberg A.T
Yang X
Zeng F
Zhang L.
Abstract
Quantifying the response of atmospheric rivers (ARs) to radiative forcing is challenging due to uncertainties caused by internal climate variability, differences in shared socioeconomic pathways (SSPs), and methods used in AR detection algorithms. In addition, the requirement of medium-to-high model resolution and ensemble sizes to explicitly simulate ARs and their statistics can be computationally expensive. In this study, we leverage the unique 50-km large ensembles generated by a Geophysical Fluid Dynamics Laboratory next-generation global climate model, Seamless system for Prediction and EArth system Research, to explore the warming response in ARs. Under both moderate and high emissions scenarios, increases in AR-day frequency emerge from the noise of internal variability by 2060. This signal is robust across different SSPs and time-independent detection criteria. We further examine an alternative approach proposed by Thompson et al. (2015), showing that unforced AR variability can be approximated by a first-order autoregressive process. The confidence intervals of the projected response can be analytically derived with a single ensemble member. © 2022. American Geophysical Union. All Rights Reserved.
Subjects
atmospheric rivers; global warming; large ensembles
SDGs
Other Subjects
algorithm; atmospheric moisture; ensemble forecasting; global climate; global warming; radiative forcing; spatial resolution
Type
journal article