The ultra-cold night sides of the hot and super-hot Jupiters WASP-43b and WASP-18b, arising with deep wind flow

We have shown that the hot Jupiter WASP-43b may
develop strong westward winds at the equatorial day
side, that is, anti-rotation - if deep wind flow (p >
10 bar) is taking into account [1]. Because equatorial
anti-rotation prevents efficient horizontal heat transport, we also predict that the night side of WASP-43b
will emit very little thermal flux (≤ 1000 ppm) for
wavelengths 5 - 12 micron.
Here, we compare our 3D climate results for the hot
Jupiter WASP-43b (Teff=1400 K) with new results for
the super-hot Jupiter WASP-18b (Teff=2400 K) that
was recently shown to also have inefficient horizontal
heat distribution [2]. In the work of [2], the observational signals were explained by imposing magnetic
drag throughout the atmosphere, which suppresses
zonally banded jets and leads to direct or radial dayto-night-side flow. We will show an alternative climate
scenario for WASP-18b with (partially) banded wind
flow in our 3D GCM with deep wind flow.
We predict that, JWST/MIRI observations of the
thermal emission at the night side of WASP-43b and
WASP-18b will unambiguously distinguish between a
climate scenario with wind flow at depth and ultra-cool
night sides and other scenarios (fully superrotating jet
with clouds [3] and drag-induced climate without jets
[2]).