I am monitoring the C-Band Doppler radar aboard the Ron Brown. It is the most prominent observing system on the ship. The radar measures the intensity of falling rain drops from the stratocumulus clouds. Only rain drops (>1 mm in diameter) can be seen by our radar, and we will rely on other instruments to see cloud droplets and even smaller particles in the atmosphere.
The radar works by sending out a pulse of energy, which bounces off rain drops and returns back to the radar. Depending on how strong the returned signal is and how long it takes to return to the radar, we can determine how intense the rain is and where it is falling. Changes in the frequency of the returned pulse tell us if the rain drops are moving toward or away from the ship. This allows us to see the wind in areas where rain is falling.
Postcards from the Field: Climate Science from the Southeast Pacific