Winds
Wind is merely air in motion, ranging in intensity from a light breeze to a full-blown hurricane. Winds are important in the temperature stabilization of the planet. They are created by three driving forces: the effects of temperature and pressure differentials in the atmosphere, the friction of the air, and the Coriolis Effect caused by the rotation of the Earth. Planetary winds, like the plate tectonics, can be thought of as a conveyor belt. The air at the tropics is warmer than at the poles. Convection forces warm tropical air to move towards the cooler poles. In turn, the cooler denser air at the poles undercuts the northward-flowing warmer tropical air and moves towards the equator. Because the Earth is a rotating sphere, a given point on the equator must rotate faster than a point nearer the pole; this creates the Coriolis Effect. The Coriolis Effect deflects the air movement in the north south flow, the result being planetary winds such as the northeast trades of the Northern Hemisphere and the southeast trades of the Southern Hemisphere.
There are secondary wind systems, also important in the maintenance of stable planetary temperatures. An example from Earth are the monsoons that regularly strike the east coast of Asia. Regional winds are winds that are altered by a geographic feature such as a mountain range. Moist air approaches the range and is forced to rise. As it rises, the moist air cools, forcing it to give up some of its moisture in the form of rain. Just ask any resident of Vancouver about rain on the windward side of a mountain range. As the air descends on the other side of the range, it heats up. Such winds can be very turbulent and destructive. Wind shears are the result of a sudden intense downdraft of air that spreads across the ground, and are often associated with severe thunderstorms. Having a high-rotation planet can whip winds to hurricane speeds. However, having a slowly rotating planet will also result in high wind speed, because warmed air from the hot side will move to the cooler side. Another way to alter wind speed is to alter the composition of the atmosphere. Different dominant compounds in the planetary atmosphere will have different densities than the Earth’s atmosphere, which would alter the wind dynamics of your world.
Ocean Currents
Ocean currents of a permanent nature are created by the dual action of winds and by the action of thermohaline convection. The latter is associated with the cooling and sinking of sea water in high latitudes. Like winds, ocean currents are extremely important in stabilizing world temperature so that life can evolve and thrive. The wind-driven and thermohaline circulations depend on the circulation of the atmosphere; in turn, the heat energy to drive the circulation of the atmosphere is supplied by the ocean.
Ice Ages
Ice ages occur when the winter snowfall exceeds the summer melt, resulting in a gradual accumulation of snow. One of the recent theories as to why there have been ice ages on Earth is orbital variation, which results in the accumulation of ice over time. There is a change in the Earth’s orbital eccentricity on a 97,000-year cycle, a change in precession (tilt of planet on its axis) every 22,000 years, and a change in the axial tilt every 41,000 years. High particulate numbers (i.e. lots of dust and other small particles) were present in the stratosphere during past glacial eras. Some of the dust probably occurred as a result of volcanic activity, as well as the exposure of receding sea beds. As sea levels dropped due the accumulation of ice, the amount of exposed sea bed rose, creating a perfect self-perpetuating cycle.
There is also the specter of a nuclear winter resulting after a nuclear war, where the high number of particulates in the atmosphere results in a deflection of the Sun’s energy back into space. Dunes and loess blankets show evidence of wind changes during past glaciations. Changes in wind direction would directly impact on temperature distribution which in turn, could have resulted in ice accumulation. Variance in the amount of carbon dioxide may have contributed to the Ice Ages; even though carbon dioxide is a greenhouse gas, potentially preventing the release of heat back into space, an opposite event occurred during glacial periods. The cooler seawater present during a glaciation would have been able to absorb more of the carbon dioxide in the atmosphere, thereby cooling the air further. Any or all of these factors combined could result in an ice age.
Conclusions
Mongo is a lot more complicated than meets the eye. When creating your world, don’t be lazy. Notice how complex a planet can be, and notice how interrelated all of the concepts are. To enlighten yourself on planet creation, read Poul Anderson and Hal Clement; they are masters of this skill. Another fine example of world building is Harlan Ellison’s Medea: Harlan’s World. To create this book, Ellison commissioned Hal Clement, Poul Anderson, Larry Niven, and Frederick Pohl to create a planetary system. He then sought out the writers such as Frank Herbert, Thomas Disch, Robert Silverberg, Theodore Sturgeon, Jack Williamson, and Kate Wilhelm to write stories using this planetary system. The effect is fascinating, to say the least. If you make yourself aware of the complexity of planet creation, the pieces will fall together, making an altogether unique planetary setting for your story.
Reprinted from The Outer Rim, May 2000.
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Peter Jekel is the Director of Infectious Disease Prevention in one of the largest Health Department Districts in Ontario. He has lived in Bracebridge, Ontario with his family for the past 16 years.
Little Gods
By Tim Pratt, illustration by Mark Precious
2/4/02
“I wish I could be a little goddess of cinnamon,” my wife Emily says, closing her eyes and leaning in close to the spices. I’m used to Emily saying things like that, so I don’t take any notice, just nod and pick up a bottle of peach nectar off the shelf, slosh it around, wrinkle my nose. I know all the gunk in there is supposed to be fresh natural goodness, but to me it just looks like gunk. Emily says that I deny the truth of natural origins. Emily likes peach nectar, so I put the bottle in the basket.
“A little goddess of cinnamon,” Emily repeats. “Or brown sugar.” She crosses her arms, her silver-and-brass bracelets tinkling together.
“As opposed to a big goddess of cinnamon?” I move on down the aisle with my basket over my arm.
“Little things get little gods,” Emily says. “It’s only natural.” She trails after me, running her finger along the shelves, pausing to sniff at the black teas, to open the lid on a jar of sugar-free gumdrops. Emily is always prodding, smelling, caressing—she says that she is experiencing the world.
“So big gods are for big things, then? Like, say, whales?”
Emily sighs behind me. “Big things like … I don’t know … love.”
“How about hate? Jealousy?”
“Sure. But I wouldn’t want to be one of those, nothing so big.” She squeals in delight. “Ooh! Chocolate-covered espresso beans!”
“I didn’t realize those were in season,” I say dryly, but she isn’t paying attention to me, has darted off to get a plastic bag to fill with candied caffeine. She’ll be up all night, and she’ll keep me up with her. That might be nice. Sometimes she likes to make love all night when she’s had a lot of caffeine; other times she gets jittery and talks wistfully of the days when she smoked cigarettes.
Emily dances down the aisle, long skirt swaying, silver bells around the hem jingling. She shakes her bag of espresso beans like a maraca.
“Goddess of chocolate?” I say. “Would you go for that?”
“Sure. But I’d be even more particular. Goddess of dark chocolate. Goddess of Mexican hot chocolate. Goddess of hot fudge on a wooden spoon.”
“Those are awfully small gods. It’d take a lot of them to keep the world running.”
“Well, sure.” She looks around the otherwise uninhabited aisle in an amusingly furtive way, then opens the plastic bag, removes a bean, and pops it into her mouth. “The big gods—the gods of abstractions and ideals—they’re like CEOs, figureheads, upper management. I mean, the goddess of joy may get paid well, but where would her operation be without the god of hot showers, the goddess of hot sex, the avatar of angel food cake? I’d be just as happy to have one of those lower-level positions, one with nice, clearly defined responsibilities, a comprehensible mission.”
“I love you,” I say, feeling warm toward her all of a sudden, my Emily with her corkscrew black hair, her squinched-in-thought features, her clothes she’s made mostly with her own hands, sewn all over with suns and moons. My flaky angel who reads the stars and knows how to make bread rise, bring flowers to life, tune a mandolin, make my heart beat beautifully along with her own. My Emily, who believes in little gods of tuna casserole and stained glass.