Impact of Convective Parameterizations on Atmospheric Mesoscale Kinetic Energy Spectra in Global High‐Resolution Simulations

• Published in: Geophysical research letters Vol. 50; no. 23
• Main Authors: Li, Zongheng, Peng, Jun, Zhang, Lifeng
• Format: Journal Article
• Language: English
• Published: Washington John Wiley & Sons, Inc 16.12.2023; Wiley
• Subjects: Atmospheric models; Convection; Convective clouds; Convective development; convective parameterization; Convergence and divergence; diabatic heating; Energy; Energy spectra; Finite element method; Fluid flow; Gravity waves; Heat; Kinetic energy; Latent heat; Lower stratosphere; Mesoscale phenomena; Microphysics; microphysics parameterization; Modelling; Moist convection; Parameterization; Simulation; Slopes; Spectra; spectral budget; Spectral sensitivity; Stratosphere; Troposphere; Upper troposphere; Vertical motion; Vorticity; Wave propagation
• DOI: 10.1029/2023GL105513
• ISSN: 0094-8276

The responses of atmospheric kinetic energy (KE) spectra to three convective parameterizations (CPs) in global high‐resolution simulations are revealed. The results show that the KE spectra exhibit high sensitivity to the CPs, mainly at mesoscales in the middle and upper troposphere. The New Tiedtke scheme produces the steepest mesoscale slope, followed by the Kain‐Fritsch scheme and then the Grell‐Freitas scheme. In general, there is a compensating relationship between latent heat released by the CP and microphysics parameterization (MP). The less latent heat released by the CP is compensated by the more latent heat released by the MP. The shallowest mesoscale spectra for the Grell‐Freitas scheme are related to the strongest downscale cascade dominated by the rotational component of the flow, and this is attributed to more latent heat released from MP enhancing the intensity of vorticity in the troposphere and producing more gravity wave activities in the lower stratosphere. Plain Language Summary At the current horizontal resolution level of the atmospheric models, convective parameterization (CP) is crucial for representing convective clouds unresolved by model mesh and thus is still an important model component. Exploring the impacts of different CP schemes on global high‐resolution simulations is an important subject of modeling. Energy spectra have become a useful diagnostic for validating and comparing atmospheric models. Their sensitivity to CP is an important and not‐well‐studied part of this subject. This paper investigates the impact of CPs on atmospheric mesoscale kinetic energy spectra with global simulations from the Model for Prediction Across Scales. We found that the energy spectral slope and energy cascade are sensitive to the CP schemes. This is related to the complementary relationship between CP and microphysical parameterization (MP), which is also important for moist convection development and evolution. The less latent heat released by the CP, the more released by the MP. This leads to stronger vertical motion, accompanied by stronger convergence/divergence in the troposphere, thereby enhancing vortex motion. As a result, more energy is transferred from the synoptic scale to the mesoscale and more gravity waves are vertically propagated into the lower stratosphere, leading to the shallower spectra at mesoscales. Key Points The kinetic energy (KE) spectra exhibit high sensitivity to the convective parameterizations (CPs) mainly at mesoscales The more latent heat released from CP, the steeper KE spectra at mesoscales The shallowest mesoscale KE spectra generated by the Grell‐Freitas scheme are attributed to the strongest RKE downscale cascades