TY - JOUR
T1 - A QBO Cookbook
T2 - Sensitivity of the Quasi-Biennial Oscillation to Resolution, Resolved Waves, and Parameterized Gravity Waves
AU - Garfinkel, Chaim I.
AU - Gerber, Edwin P.
AU - Shamir, Ofer
AU - Rao, Jian
AU - Jucker, Martin
AU - White, Ian
AU - Paldor, Nathan
N1 - Funding Information:
C. I. Garfinkel, E. P. Gerber, O. Shamir, J. Rao, I. P. White, and N. Paldor are supported by a European Research Council starting grant under the European Union's Horizon 2020 research and innovation programme (grant agreement No 677756). Support for E. P. Gerber and O. Shamir was generously provided by Eric and Wendy Schmidt by recommendation of the Schmidt Futures program. E. P. Gerber acknowledges further support from the US NSF through grant AGS 1852727. M. Jucker acknowledges support from the Australian Research Council (ARC) Centre of Excellence for Climate Extremes (CE170100023).
Publisher Copyright:
© 2021 The Authors. Journal of Advances in Modeling Earth Systems published by Wiley Periodicals LLC on behalf of American Geophysical Union.
PY - 2022/3
Y1 - 2022/3
N2 - An intermediate complexity moist general circulation model is used to investigate the sensitivity of the quasi-biennial oscillation (QBO) to resolution, diffusion, tropical tropospheric waves, and parameterized gravity waves. Finer horizontal resolution is shown to lead to a shorter period, while finer vertical resolution is shown to lead to a longer period and to a larger amplitude in the lowermost stratosphere. More scale-selective diffusion leads to a faster and stronger QBO, while enhancing the sources of tropospheric stationary wave activity leads to a weaker QBO. In terms of parameterized gravity waves, broadening the spectral width of the source function leads to a longer period and a stronger amplitude although the amplitude effect saturates in the mid-stratosphere when the half-width exceeds (Formula presented.) m/s. A stronger gravity wave source stress leads to a faster and stronger QBO, and a higher gravity wave launch level leads to a stronger QBO. All of these sensitivities are shown to result from their impact on the resultant wave-driven momentum torque in the tropical stratosphere. Atmospheric models have struggled to accurately represent the QBO, particularly at moderate resolutions ideal for long climate integrations. In particular, capturing the amplitude and penetration of QBO anomalies into the lower stratosphere (which has been shown to be critical for the tropospheric impacts) has proven a challenge. The results provide a recipe to generate and/or improve the simulation of the QBO in an atmospheric model.
AB - An intermediate complexity moist general circulation model is used to investigate the sensitivity of the quasi-biennial oscillation (QBO) to resolution, diffusion, tropical tropospheric waves, and parameterized gravity waves. Finer horizontal resolution is shown to lead to a shorter period, while finer vertical resolution is shown to lead to a longer period and to a larger amplitude in the lowermost stratosphere. More scale-selective diffusion leads to a faster and stronger QBO, while enhancing the sources of tropospheric stationary wave activity leads to a weaker QBO. In terms of parameterized gravity waves, broadening the spectral width of the source function leads to a longer period and a stronger amplitude although the amplitude effect saturates in the mid-stratosphere when the half-width exceeds (Formula presented.) m/s. A stronger gravity wave source stress leads to a faster and stronger QBO, and a higher gravity wave launch level leads to a stronger QBO. All of these sensitivities are shown to result from their impact on the resultant wave-driven momentum torque in the tropical stratosphere. Atmospheric models have struggled to accurately represent the QBO, particularly at moderate resolutions ideal for long climate integrations. In particular, capturing the amplitude and penetration of QBO anomalies into the lower stratosphere (which has been shown to be critical for the tropospheric impacts) has proven a challenge. The results provide a recipe to generate and/or improve the simulation of the QBO in an atmospheric model.
KW - gravity waves
KW - quasi-biennial oscillation
KW - tropical stratosphere
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U2 - 10.1029/2021MS002568
DO - 10.1029/2021MS002568
M3 - Article
AN - SCOPUS:85127230610
VL - 14
JO - Journal of Advances in Modeling Earth Systems
JF - Journal of Advances in Modeling Earth Systems
SN - 1942-2466
IS - 3
M1 - e2021MS002568
ER -