Let's talk weather, and not like your daily news broadcasts. Wind (Move your mouse to reveal the content) Wind (open) Wind (close) First and foremost, let's start with wind. Diagram 1.a (Move your mouse to reveal the content) Diagram 1.a (open) Diagram 1.a (close) Wind Wind is created, at the most basic definition, is the stacking of gasses of varying temperatures. A common example is a windy beach on a hot summer day. The air is hot at the beach, but the air in the atmosphere above the beach is much cooler (the higher up you go, the colder it gets). Because of this, the hot air at the beach is actually rising up and pushing that cold air up in the atmosphere down to the beach. As air rises, wind is stirred by the movement of colder gases breezing through warmer gases. This is represented by a loop (see the Hadley cells in the diagram above). Why? Because as the cold air sinks through the warmer air, it pushes up the warmer air closer to space. This causes the once warmer air to cool off, but also because the prior stated cold air has heated up due to hugging the warm crust of the earth. The spin of the earth on its axis also plays a role in creating wind. As the cold air is sinking, it's being dragged along by the spin of the earth. This makes it rush about, creating a wind current. The faster a planet's rotation is, the higher the wind current. Wind current can also be determined by the area of the world you are in. The top and bottom of a planet moves exactly 0 mph / 0 kph. However, the speed kicks off once you're on the sides. The sides are where you'll have the most wind, especially as you get closer to the divisions of each Hadley cell (refer to Diagram 1.a). In Diagram 1.a, notice how when you are in the northern half of the globe current rushes north, and that the opposite occurs in the southern half. Yes, I know that you can half winds blowing north while you're in Africa or South America or Australia. However, the general idea is that the Hadley cells will mostly make wind currents go into the direction of each pole. So even though you will have winds facing the opposite directions in both halves of the globe, your stronger currents will face the poles. Diagram 1.B (Move your mouse to reveal the content) Diagram 1.B (open) Diagram 1.B (close) Uneven Heating (Move your mouse to reveal the content) Uneven Heating (open) Uneven Heating (close) Hey, Sole, if wind requires heat then why are there biomes where there really isn't as much wind when the sun heats the whole earth? Good question, Sole. This can be explained by uneven heating across the earth's surface. Diagram 2 (Move your mouse to reveal the content) Diagram 2 (open) Diagram 2 (close) The earth is not evenly heated by the sun due to some factors: Its axis wobbles during orbit and rotation. It's a sphere. Its in an irregular orbit. It spins. Shape Wait wait wait, how does this affect heating, Sole? Another good question, Sole! In Diagram 2, you'll see that the sun's rays actually hit the earth on various angles. The north and south poles being the steepest angles, the equator being the most direct target, and everywhere else being in between. This is because of the earth's spherical shape. If the earth were to be flat (which it isn't, Homer) then it'd actually have even heating everywhere. But because there's curvature to its overall shape, this heating is pretty spread out. The Axis In colder climates, there isn't much direct sunlight at all. The steeper the angle is for direct heating, the colder it will get. In the case of the earth, this angle is constantly changing no matter where you are due to the wobble of the earth's axis (it takes about 23,000 years to complete a wobble!). The wobble of the axis is heavily associated with drastic climate changes, i.e. the Ice Age. When the axis is tilted towards the sun, the earth is warmer. When it's tilted away from the sun, it's colder. Its Orbit That time your science teacher back in primary/secondary school told you the earth's orbit is circular? Not exactly correct. The earth actually orbits in more of an ovular way. But this is also in the process of changing every second that passes. The earth's orbit goes from being very circular to very ovular in a time period of thousands of years. This orbit drastically affects the overall climate of the planet. If an orbit is more circular, you can expect overall temperatures from various areas of the planet to be close on average. The heating is a little bit more uniform, but not quite, and also has a more stable weather system. You could consider this situation to be a warm/neutral climate earth. However, when you add in factors such as axis tilt and uneven heating this sort of orbit can have the exact opposite affects. When the orbit is ovular, you can expect uneven heating patterns year-round. Because of the ovular orbit, you can expect there to be times when the earth is drastically further and drastically closer to the sun (kind of sounds like how the weather's been since 2012 huh?). When the planet is at the end of the longer sides of the orbit, it'd have a drastic temperature drop. When it'd be on the shorter sides, it'd have a drastic increase in temperature. The earth spins This is actually going to be a very brief point. Because the earth spins, the whole planet has the opportunity to face the sun. However, the earth's moon isn't the same way in regards to its orbit around the earth. One side of the moon faces the earth at all times. If the earth were to be like this, you could expect one half of the planet to be much warmer than the other half. Just like how the dark side of the moon (#Floyd) is much colder than the side that faces the earth. When one side of an object is directly facing a heat source, you can expect uniform heating on that particular side just because it's changing the direction its facing away from the source of heat. When an object is spinning, such as the earth, you don't allow the heat to build up much at all on any particular side. You'll have varying temperatures throughout the globe due to this, which should cause an overall average global temperature to be somewhat warm or somewhat cold. If you have a world that were to be like our moon, your average temperature would be extreme. The Math How do these four points add together, Sole? Another fantastic question, Sole! Let's say you want a cold world, something reminiscent of the earth during the Ice Age. What conditions should be met to have such an extreme climate change? Your world's axis should face away from the star it orbits. Your world should definitely be round for uneven heating to take affect (so some parts of it are colder than others). Your orbit should be pretty uniform, so a more circular orbit would fit. This neutral-climate orbit would actually allow the incubation of temperature drop. Do you want one side to be entirely covered in ice? If yes, your world shouldn't spin. However, this would mean that one half of your world is always in daylight and the other half is always in darkness. The half that is lighten would better support life, as opposed to the dark half. However, you could have the planet spin on its axis to have a uniform deep freeze that would support life anywhere on its surface. I feel that it's also important to note the impact oceans have on heat and wind. If an ocean is warm, expect less powerful winds. This is a phenomenon that occurs especially in the Pacific ocean. The Pacific has very strong wind currents, however there is a time frame within every few years that the ocean will have far weaker winds due to being warm. Think of it as throwing off the uniformity of the Hadley cell in that region; it's used to pumping currents in a fairly cool environment. Another factor you can consider while figuring out the heating of your world is what your world orbits. Dwarf planets/satellites that orbit other planets could potentially have very interesting characteristics. How would your world be if it orbited another planet? Does orbiting a planet allow for even heating? Is the host planet orbiting one or more stars? If more than one star, does the host planet give your world some sort of shade that prevents it from overheating/being too hot to support life? Biomes (Move your mouse to reveal the content) Biomes (open) Biomes (close) Biomes A biome is a large community consisting of abiotic and biotic characteristics, and can be defined by two things: temperature and precipitation. The temperature of a biome is good to identify it, but there are bound to be other biomes of the same temperature average of the one you want to identify. So water precipitation in relation to temperature is used to sort everything out. If you have high water precipitation with high temperatures, you have a tropical biome (i.e. tropical rain forest). If you have low temperatures with low water precipitation, you have a tundra (i.e. the south pole and parts of Russia). High temperatures with low water precipitation would be a desert. Low temperatures with high water precipitation would be the majority of Canada. Think about what temperature you want for a setting, and what kind of precipitation you want. Diagram 3 (Move your mouse to reveal the content) Diagram 3 (open) Diagram 3 (close) Touching back into what was said earlier about a cold world, what kind of cold world would you want? If you look into the biomes provided by Diagram 3, from cold desert and above, you can find what you want your overall biosphere will be like. However, looking into the other colder biomes can help you provide variation to your world, preventing it from becoming a static setting. Keep in mind, all biomes interact with one another. That's why the biosphere, and ultimately all weather, is indeed a thing. How do biomes interact to create the biosphere, Sole? Finally, you have asked the question I've been wanting to read, Sole! It's actually a pretty simple concept that will tie in Wind, Uneven Heating, and Biomes. If you have a very diverse world with many many biomes, such as ours, your biosphere will be very active. Hella active. Your tropical regions will give off heavy precipitation, which will be pushed around by the Hadley cell it resides in. Think of it like when a hurricane forms in the Caribbean and is whisked away all the way to New England and eastern Canada. This hurricane, which carries the precipitation of a tropical environment and is the product of such a biome, was taken from a tropical biome and moved all the way to temperate and boreal biomes. This means that biomes that would normally create snow out of its own precipitate could have hail, or cold rain. Or, even it were cold enough to do it, you could have a massive snow storm. An area with high heat and high precipitation essentially temporarily donated its high precipitation to biome of lower temperature and medium precipitation, with the help of wind currents. The opposite could also happen. A high precipitation and low temperature biome could give cold precipitation to a warmer biome with low precipitation, and that precipitation could warm up a little and turn from snow into hail or cold/warm rain. This allows it to be possible to have rain fall in a dessert. In order to create a world, you need to understand the physical factors that actually construct that world. By understanding wind, external heating, and the capability of biomes you better equip yourself when constructing an environment. When was the last time you've read a world that hadn't become a static setting due to catastrophe? Almost all world settings are exciting in their biomes (unless they're in movies, or sci-fi stories that create a flurry of multiple worlds to compensate for a lack of biome-diversity). But having an exciting biosphere is entirely the choice of the writer. There are hobby-writers that do make static-biosphere worlds. Just because you want a static or exciting biosphere doesn't mean you're less or more of a creative writer. The difference between a poor world creator, and an excellent one, is how much information they've learned about real weather. Understand the geography and ecosystems are important, don't get me wrong, but without weather you lose a large chunk of your descriptive writing. You may also lose some potential plot movers.