The Colorado Monsoons

Lightning is an interesting subject for photography but how do you get a good shot using a phone camera? With an expensive DSLR camera, you can let the light from the flash trigger the shutter and just set the camera out during a storm for awhile. But there's an easier solution.

Here's a video I took during a Denver thunderstorm a few years back 

https://drive.google.com/file/d/1BxaEB9UvXTxrQBGI8288jCAYStfMZM7V/view?usp=drivesdk

Once you have the video, it's not difficult to just cut out the shot that you want.

I've heard about Colorado (or Southwestern) monsoons for the last ten years. I thought that the label was a misnomer. Were they really related to the huge storms that strike South Asia every year?

It turns out that they have the same driving forces...mountains and moisture laden air off the ocean. This year, the monsoons arrived a month earlier than usual, in May instead of June or July. Almost every afternoon for the last month, we have had thunderstorms in the afternoon. 

A good portion of the land-shaping forces in the Colorado Piedmont are monsoons. Much of the land between Denver and Colorado Springs, Palmer's Divide, was sculpted by an apocalyptic volcanic explosion followed by an equally apocalyptic flood driven by tropical monsoons. We'll be looking at that in a few weeks when I check out The Bluffs.

The word monsoon derives from the Arabic word mawsim, which denote "season" and it's applied to a seasonal shift in wind patterns. Differential heating during the warm summer months reverse wind directions, bringing warm, moist air from the oceans south of Colorado. The heat also causes updrafts which push the moisture up to form thunderstorms. The brief, sometimes intense, sometimes hail and lightening laden storms are both a welcomed change from the hot summer days and an unwelcomed source of damaging weather. In addition to precipitation from the air, they occasionally spawn flash floods, often enough that highway and trail signs are common in Colorado cautioning visitors in flood prone areas to climb to higher elevations. That means that, if you're in a vehicle and the water starts rising, you have only a little time to leave your vehicle on the side of the road and start climbing. Too many have died trying to outrun a flashflood in the western United States (For that matter, there are plenty of flood prone areas in the East and many other parts of the world.)

 We've only had one devastating hail storm in the Denver area in the ten years that I've lived here. It took out most of the skylights in the Walmarts in the area.

You can tell if a cumulonimbus cloud (thunderhead) is producing hail if you have normal color vision. The cloud will be a dirty green color. Hail forms from tiny ice crystals in the high tops of the clouds. They get caught in the updraft, ride it up higher, and get a new coat of ice until they're too heavy to remain aloft. Then they fall and get caught in another updraft. That repeats. The resulting hail is built up of concentric shells of ice. 

Most of the hail in our area is tiny to marble size and is soft, like little snowballs. But they can get big and hard. I've been caught in a few hail storms (they sneak up on you) and was pelted by the regular kinds but I don't want to get hit by one of the rare baseball sized chunks of ice.

Honestly, I face Mother Nature with impunity, but one of these days...

Earth has four components. Earth science looks at the interrelationships of all four. The solid and molten materials beneath us comprise the solid earth or geosphere and geology studies that. The hydrosphere is the water that circulates around and inside the crust. It is the purview of hydrology. The envelope of air is called the atmosphere and is the domain of meteorology. And the living things on the planet comprise the biosphere. You might throw in ice and call it the cryosphere. There are different sciences that look at each but the boundaries are not nearly as sharp as one might think.

The red color in Red Rocks could not have happened before life formed on Earth. It's caused by oxidized iron and required an oxygen rich atmosphere. Oxygen in highly reactive and would have been bound up with other elements early in Earth's history. Only plants, taking carbon dioxide in the atmosphere apart to form energy and body parts and generating free oxygen could give us the oxygen rich atmosphere that we have.

Nature is dynamic. What are your seasons like? Can you explain the seasonal patterns?

A universal sundial

A world globe can be used as a sundial that can tell you the time of day anywhere on Earth, time of sunrise and sunset, how the seasons work, and many other things. All you have to do is orient it in the same direction relative to the sun as the Earth. That way, it models Earth in space. Here's how you do it.

You will need a surface that can be tilted (and, possibly a clamp for the base of the globe to keep it from tilting over. Alternately, there are globes that can be tilted in respect to the base.) You will also need a mini-gnomon. A gnomon is just a vertical rod that will cast a shadow in the sun. It has to be small enough to position on the globe's surface. I used a plastic bottle cap and drove a screw through the center from underneath. (The screw should be as near a right angle to the surface of the cap as you can make it. You can test it with a carpenter's angle or even the sides of a sheet of paper.) After using a carpenter's level, or a phone app level to level the surface you will place the globe on, place the cap on the surface and mark the edge at the point north of the screw. Use a magnetic compass or a phone app but don't forget to look up the correction for true north from where you live and add or subtract it from your compass bearing. (Do an Internet search for "magnetic declination".)

With the line between the screw and the edge mark pointing north, make another mark with an erasable marker at the end of the screw's shadow from the sun.

Now, set your globe on the surface with the north pole pointing north (according to your compass with the correction to true north.). Rotate the globe until your position is on top.

Now for the fine tuning. Place the mini-gnomon pointing north directly over your position on the globe. If the sun's shadow on the globe and the sun's shadow on the Earth are oriented the same, they will both be oriented the same in space in respect to the sun, so tilt and rotate your globe until the tip of the screw's shadow touches the mark you made earlier at the shadow's tip. Your globe is now aligned.

What time is it? One way to tell is to watch your mini-gnomon to see when it's shadow is shortest - that's solar noon. During daylight savings, the local time will be an hour behind solar noon.

You can find where on the globe that it's solar noon by moving the mini-gnomon around to find the place where it's shadow is shortest. That will be a line of longitude. Knowing that every 15 degrees of longitude is an hour will allow you to calculate the time anywhere on Earth (at least, while the sun is out.)

You may have heard that the sun is directly overhead on the equator at noon each day. Try it out.

When it's solar noon where you are, place the mini-gnomon directly over your position and slide it straight down your line of longitude to the equator. Does the screw cast a shadow? Not if it's one of the two annual equinoxes. On any other day, the sun will be exactly overhead somewhere north or south of the equator.

You can easily see where sunset and sunrise is by finding the day-night divider line on your globe.

At my current time, here, sunset is slowly creeping off Africa into the Atlantic.

There is a lot you can do with the universal sundial. Can you use a thermometer to measure differences in temperature on the surface of your globe according to the angle the sun is shining on it? That's what causes the seasons.

Once you have a globe oriented, you can use a clamp or clay or some other way to freeze it in position and make a cover to keep it out of the weather. Then you can use it all year.