Thermal noise occurs in all transmission media and communication equipment, including passive devices. It arises from random electron motion and is characterized by a uniform distribution of energy over the frequency spectrum with a Gaussian distribution of levels.
An occluded front is formed when a cold front overtakes a warm front. and usually form around mature low-pressure areas. The cold and warm fronts curve naturally poleward into the point of occlusion, which is also known as the triple point.
And especially during the winter months, the cold air that a warm front is attempting to displace is often heavy and dense and is stubborn to dislodge. As a result, the shape of some warm fronts end up contorted, seemingly looping around the colder air mass.