Stratosphere simulated in a global ultra high atmospheric model

It has become affordable to simulate the global atmospheric circulation at the resolution of a few kilometers. These ultra high resolution models provide an unprecedented opportunity to study the coupling in the climate system across scales. Here, we performed a series of aquaplanet simulations using the GFDL global atmospheric model AM4. We progressively increase the horizontal resolution from 50km to 6km while keeping the vertical resolution and all the tuning parameters unchanged. The simulated stratosphere becomes colder and wetter as the horizontal resolution increases. We will investigate the possible pathways that lead to such resolution dependence, such as dynamical pathways via tropical and extratropical waves, radiative pathways via water vapor and thermodynamic pathways via convections.