Wonder what creates our weather? Look toward the sun

The sun not only supplies the light and warmth we need to survive on this planet, but it is also the engine that creates our weather. Terry Thomas / news@postregister.com

I am studying to get a remote pilot certification to allow me to commercially fly my drone. The subjects have been similar to what an aircraft pilot needs to know including loading (things like G-forces) and aircraft performance, understanding aeronautical charts and communications.

The level of detail needed to certify as a remote pilot is impressive, especially since not a single second is dedicated to learning how to safely FLY one of the things. I can achieve certification and not even know how to get the drone off the ground.

I missed the class on weather, and my friend, who happens to be the instructor, made me a video copy of the lecture. I watched the video last Saturday while a snowstorm raged outside. Once again I was surprised by the detail that pilots are required to know about the weather.

For instance, did you know that fog just isn’t fog? Aviators recognize at least six kinds: Radiation, ground, advection, upslope, steam and ice fog. These different fogs form under unique circumstances. Radiation fog forms on cold, clear and still nights when the ground cools quickly through heat radiation to the atmosphere and the air reaches its dewpoint. Steam fog, also called sea smoke, forms when cold dry air moves across warm water. The water evaporates into the air, looking like smoke from a fire.

Over the course of an hour, I learned about cold fronts, thunderstorms, high- and low-pressure systems, dew point, inversions, turbulence, wind shear and microbursts, clouds, atmospheric stability and more. Each one of these is a topic worthy of a later column.

However, what I found most interesting was a statement in the accompanying manual at the beginning of the section on weather: “The major source of all weather is the sun.” I had never thought of weather in that way. As I read on though, I could see that this statement was perfectly accurate.

Weather is largely a result of the heating and cooling of the earth. If everything heated and cooled uniformly, our weather would be much different than what we actually experience. Things don’t evenly heat and cool though. The black basalt at Craters of the Moon National Monument absorbs the sun’s energy quickly and radiates heat back out as the sun fades. A snow-covered surface reflects the energy, absorbing very little, while a vegetated surface absorbs and retains it.

The sun’s rays don’t fall upon the earth evenly either. Near the equator, the rays come nearly straight down: a square foot of earth receives a full complement of sunbeams. Progress toward the poles however, and the angle of the sun increases, and each square foot of sun rays covers more and more surface area with a consequent reduction in power.

All this differential heating causes evaporation, freezing, updrafts and downdrafts and ultimately the uneven heating of the earth’s atmosphere. Warmer air rises and colder air falls, dragging atmospheric pressure up or down on its currents and the Earth gets the rain, snow and wind that sustain us.

Despite having experienced what the earth would be like without the sun during the eclipse last year, I know I take that yellow ball in the sky for granted all too often. This lesson has renewed my respect for the supreme role the sun plays in maintaining life on this planet.


Terry Thomas is a wildlife biologist and naturalist. “The Best of Nature,” a collection of more than 100 of Thomas’s best nature essays, is available at the Post Register or order one through his website, www.nature-track.com and follow him on Facebook, Nature-track.


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