We present new observations of the emission spectrum of the hot Jupiter TrES-4 designed
to test the theory that the presence of temperature inversions in the atmospheres of these
planets are correlated with the amount of radiation received by the planet. Our observations
reveal that TrES-4 has an emission spectrum similar to that of HD 209458b, which requires
the presence of an inversion layer high in the atmosphere and water emission bands in order to
explain the observed features, providing additional support for that theory. We also present new
observations of the thermal phase curve of HD 189733b at 24 μm, which we combine with our
previous observations at 8 μm to examine how circulation in this planet’s atmosphere varies as a
function of depth. We discuss the relationship between the strength of the day-night circulation
on both planets and their other observable properties, in particular their emission spectra
