Resolution Dependence and Rossby Wave Modulation of Atmospheric Rivers in an Aquaplanet Model
Abstract Atmospheric rivers (ARs) are examined in a set of aquaplanet simulations using the Model for Prediction Across Scales dynamical core run at multiple horizontal resolutions, namely, 240, 120, and 60 km. As the resolution is increased, there is an increase in the occurrence of long‐lasting ARs. At the same time there is also an increase in the local finite‐amplitude wave activity (LWA) of upper‐tropospheric absolute vorticity, a measure for Rossby wave phase and amplitude that is closely linked with wave breaking. Consistent with the notion that changes in ARs are driven by midlatitude dynamics, a strong relationship is identified between ARs and the equatorward component of LWA. A logistic regression model is used to quantify the probability of AR occurrence based solely on LWA and explains most of the change in AR frequency with resolution. LWA is a diagnostic that may be easily applied to the broadly available output of phase 6 of the Coupled Model Intercomparison project and other model simulations, thus enabling scientists to infer AR and Rossby wave characteristics. AR characteristics, in particular, require higher‐resolution moisture and winds at multiple levels that are not always easily available.
- Research Organization:
- Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)
- Sponsoring Organization:
- USDOE Office of Science (SC), Biological and Environmental Research (BER)
- Grant/Contract Number:
- SC0012599; AGS-1338427; NA14OAR4310160; NNX14AM19G
- OSTI ID:
- 1544262
- Alternate ID(s):
- OSTI ID: 1454625
- Journal Information:
- Journal of Geophysical Research: Atmospheres, Vol. 123, Issue 12; ISSN 2169-897X
- Publisher:
- American Geophysical UnionCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Sensitivity of Atmospheric Rivers to Damping of Midlatitude Subseasonal Variability
|
journal | September 2019 |
Similar Records
Precipitation characteristic changes due to global warming in a high‐resolution (16 km) ECMWF simulation
Toward the Dynamical Convergence on the Jet Stream in Aquaplanet AGCMs