Hoose, C.

Janjic, T.

Jung, H.

Knippertz, P.

Redl, R.

Ruckstuhl, Y.

English

KITopen

EGU2020-17026https://doi.org/10.5194/egusphere-egu2020-17026EGU General Assembly 2020© Author(s) 2022. This work is distributed underthe Creative Commons Attribution 4.0 License.Disentangling the mechanisms of wave-convection coupling in thetropicsCorinna Hoose1, Hyunju Jung1, Peter Knippertz1, Tijana Janjic2, Yvonne Ruckstuhl2, and RobertRedl21Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology, Karlsruhe, Germany2Institute of Meteorology, Ludwig-Maximilians-Universität München, Munich, GermanyTropical weather prediction remains one of the main challenges in atmospheric science due to acombination of insufficient observations, data assimilation algorithms optimized for midlatitudesand large model errors. Due to a strong dependency of many people in the tropics on rainfallvariability, combined with a high vulnerability, improved precipitation forecasts have the potentialto create substantial benefits in areas such as agriculture, water management, energy productionand disease prevention.Recent studies found that the coupling of equatorial waves to convection is key to improvingweather forecasts in the tropics on the synoptic to subseasonal timescale but many modelsstruggle to realistically represent this coupling. Here we use aquaplanet simulations with theICOsahedral Nonhydrostatic (ICON) model with a 13 km horizontal grid spacing to study theunderlying mechanisms of convectively coupled equatorial waves in an idealized framework. Wefilter the divergence at 200 hPa using a standard wave filtering tool tapering to zero that allows usto identify dynamical characteristics of convectively coupled waves in our simulations. To diagnosethermodynamical aspects of wave-convection couplings, we compare the obtained waves to thetotal precipitable water and analyze the spatial variance of the budget analysis for column-integrated moist static energy. The same filtering tool and diagnostics are carried out on a realisticICON simulation with a 2.5 km horizontal grid spacing from the DYnamics of the Atmosphericgeneral circulation Modeled On Non-hydrostatic Domains (DYAMOND) project.In the future we plan to run and analyze idealized tropical channel simulations with 2.5 kmhorizontal resolution, i.e. using the same grid spacing as in the DYAMOND simulation. Thecomparison between the idealized and the realistic simulations identifies mechanisms of wave-convection coupling. In addition, we will apply this set of diagnostics to forecast experiments usingdifferent approaches of data assimilation. Powered by TCPDF (www.tcpdf.org)

Disentangling the mechanisms of wave-convection coupling in the tropics

https://publikationen.bibliothek.kit.edu/1000128913/148572679

Disentangling the mechanisms of wave-convection coupling in the tropics

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