My Team is called the Radio Science Team and we use the radio on the spacecraft to tell us things about the atmosphere of Jupiter just like a doctor might use x-rays to tell if you've broken any bones. Every once in a while the spacecraft goes behind Jupiter. As it begins to go behind the planet, the radio signal begins to go through the atmosphere of Jupiter just like x-rays go through your body. We know what the signal should look like. So, we compare the signal that we received from the spacecraft to what it should be.
All gases act the same way whether they are on Jupiter or on the Earth.
Once we're done, we can tell the temperature of the Jovian atmosphere at the points where the radio signal passed.