What comes in must go out...sometimes

Let's talk a little about radiation.  It sure was chilly this morning thanks to clear skies and light winds.  Temperatures fell into the upper 20s to low 30s.  We all know that the sun is the main weather maker across the globe.  The sun emits shortwave radiation to help heat up the atmosphere.  The solar radiation absorbed by the Earth causes the planet to heat up until it is emitting as much energy back into space as it absorbs from the sun.  When we typically see a cloudy afternoon, not much of that radiation is able to make it to the Earth.  That's why typically on mostly cloudy days temperatures wouldn't be as warm as on a sunny day (cloud thickness will also play a factor). The opposite holds true for night.  The Earth emits longwave radiation and while some of it is allowed back into space, some of it is also sent back to Earth helping to keep the atmosphere warmer.  On clear nights we don't have that blanket to keep the longwave radiation in so the majority of it is sent out to space and as a result, cools the atmosphere.