Hoose, C.

Janjic, T.

Jung, H.

Knippertz, P.

Redl, R.

Ruckstuhl, Y.

English

KITopen

EGU21-9388, updated on 18 Jan 2022https://doi.org/10.5194/egusphere-egu21-9388EGU General Assembly 2021© Author(s) 2022. This work is distributed underthe Creative Commons Attribution 4.0 License.Disentangling the mechanisms of wave-convection coupling usingidealized simulations in a tropical channel: wave composites of themoist static energy budgetHyunju Jung1, Peter Knippertz1, Corinna Hoose1, Yvonne Ruckstuhl2, Robert Redl2, and TijanaJanjic21Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology, Karlsruhe, Germany2Institute of Meteorology, Ludwig Maximilian University of Munich, Munich, GermanyRecent studies found that the coupling of equatorial waves to convection is key to improvingweather forecasts in the tropics on the synoptic to the subseasonal timescale but many modelsstruggle to realistically represent this coupling. To study the underlying mechanisms ofconvectively coupled equatorial waves, we use aquaplanet simulations with the ICOsahedralNonhydrostatic (ICON) model in a tropical channel configuration with a horizontal grid spacing of13 km and with a prescribed zonally symmetric, latitudinally varying sea surface temperature. Wecompare simulations with parameterized and explicit deep/shallow convection. Using waveidentification tools that are based on Fourier filtering in time and space and on projections ofdynamical fields on theoretical wave patterns, we observe a predominance of equator-symmetricequatorial waves such as Kelvin waves and slow large-scale variability resembling the Madden-Julian Oscillation.To diagnose interactions between the equatorial waves and convection, we use a moist staticenergy (MSE) framework. A budget analysis for column integrated MSE shows that spatialanomalies of the net shortwave and longwave radiation and the surface enthalpy flux increase thespatial variance of the column MSE, while advection dampens variability. For wave-convectioncoupling we employ a wave composite technique for the terms of the MSE budget. Results fromthis analysis will be presented at the conference. The same filtering tools and diagnostics areapplied to a realistic ICON simulation with a 2.5 km horizontal grid spacing from the DYnamics ofthe Atmospheric general circulation Modeled On Non-hydrostatic Domains (DYAMOND) project.Powered by TCPDF (www.tcpdf.org)

Disentangling the mechanisms of wave-convection coupling using idealized simulations in a tropical channel: wave composites of the moist static energy budget

https://publikationen.bibliothek.kit.edu/1000142006/141030830

Disentangling the mechanisms of wave-convection coupling using idealized simulations in a tropical channel: wave composites of the moist static energy budget

Abstract

Similar works

Full text

Available Versions

KITopen