In Stargate: Atlantis, “Human,” our heroes are delivered to a secret facility in the middle of a desert, isolated from the rest of the world by a force field. Outside, the temperatures are hot, as expected in a desert. Inside the facility, the temperature radically drops (10 F in 10 minutes) as part of an experimental astro-engineering solution to climate change. When the force field collapses, dropping this isolated packet of incredibly cold air into the hot desert, what happens?
Astro-engineering Climate Change
In Brain Storm, the astro-engineering solution to climate change is to build an incredibly effective heat sink, then dump that heat in another, parallel universe. To stay on topic, I won’t get into the totally fun math that went into engineering their project, but the photo provides a hint.
The problem comes when the bridge gets out of control, and heat is drawn at a rapid rate with no cut off. This creates an enormous temperature unbalance of an incredibly cold (and getting colder) region.
At the Facility
The facility forms the eye of the event, the temperature unbalance around which all other weather is created. Because cold air is dense, the ai
r around the facility is higher density, thus higher pressure than the surrounding region. Air is drawn down from above, and spreads out away from the facility along the ground. Because the temperature gradient is so extreme, the winds from high pressure to low pressure (from the facility to the rest of the world) will be incredibly intense. At extremely low temperatures, material behaviour changes substantially as more and more materials freeze, posing another hazard.
Oddly, the cold eye is the very best chance for clear skies, but I don’t think blue skies would be very reassuring in the circumstances.
Cold air is denser than hot air, so when the isolation ends, it will stay low, spreading horizontally along the ground in the ultimate cold front. As the denser air creeps along the ground, the wedge of cold air lifts hotter air, forming a low-pressure area. All temperature gradients sharpen along the front; with our already scifi-intense temperature difference, the unstable boundary between hot and cold air forms a field of tornadoes.
As hot air hits cold air, the dew point drops and water condenses (like your moist, warm breath forming fog on cold mornings). However, our secret facility is in a dry desert, without much water in the air to condense. If the facility had been along a coast, severe thunderstorms would form along the front. In the desert, dust is raised by the wind but otherwise the cold air is visually indistinctive.
A real-life cold desert is the Antarctic.
Eventually, the cold front (and its associated lower pressure) will reach water. A hurricane forms when a low pressure zone over an ocean allows for hot air with moisture from sea spray rises, condensing into clouds and rain. The heat engine builds as long as it is over water, then even powerful storms quickly die off as they head inland and are cut off from the water supply.
If The Heroes Didn’t Save the Day
Of course, our heroes eventually save the day, shutting down the bridge to the parallel universe. But what if they’d failed?
With an extreme artificial temperature difference, the cold front would continue to spread, eventually creating a mega-storm unheard of even in disaster movies. Some of the background scientists got into an argument trying to figure out just how big the eye of the storm would eventually get, unable to apply normal techniques because the usual calculations based on temperature gradient suggest the eventual formation of a planet-wide storm with an eye larger than the circumference of the Earth!