Weather: Atmospheric Pressure

Shown is a colour illustration of five layers above Earth’s surface. Earth is shown as a half circle at the bottom centre. It is mostly blue water, with white and green continents. The layers above go from light to dark blue, divided by dotted lines. The first layer above Earth is light blue and labelled “Troposphere.” This contains fluffy clouds and an airplane. The second layer is a bit darker and labelled “Stratosphere.” This contains a bright blue stripe labelled “Ozone Layer” and a large white object labelled “Weather Balloon.” The third layer is darker again and labelled “Mesosphere.” It contains blue clouds and white circles with flaming orange tails, labelled “Meteors.” The fourth layer is labelled “Thermosphere.” It has a bright blue stripe close to the lower edge. This contains brightly coloured streaks labelled “Aurora Borealis,” an astronaut in a space suit labelled “International Space Station,” and a white cylinder with square blue wings labelled “Satellites.” The top layer is the darkest blue and labelled “Thermosphere.” It also has a bright blue stripe near the lower edge. The area above the atmosphere is almost black and labelled “Space.”

Shown is a colour satellite photograph of a huge swirl of white clouds over Earth. The swirl is centred in the middle of the photograph. Thick, rough streaks of white spiral out from here to the edges of the image. Below the clouds, the ocean is dark blue. A jagged coast of brownish green land peeks out from between the streaks. In the top left corner, a thin black line traces a snowy white coast, almost invisible under the clouds.

Shown is a colour map with six curved lines dotted with shapes across it.  The word Canada, and a Canadian flag are in the top left corner. Below, the country is shown in green on a blue background. Thin grey lines trace wobbly concentric oval shapes, diagonally across the country. The centre of these shapes is labelled “H.” The edges of other ovals are visible over the Maritimes, the North Atlantic, and the border with Alaska. Three curved blue lines with triangles along them look like giant false eyelashes over the country. Two are northwest and one is northeast of the H. One curves over the Yukon and Western Arctic, and the triangles point east. A longer one curves from the coast of Northern British Columbia, up to just north of Baffin Island. The triangles here point south and east. The line curves across the blue area northeast of Canada, where Greenland is. These triangles point southwest.  A smaller red line with half-circles along it, curves across Labrador and Québec. The circles point east. Joined to the southern end of this is another blue line with triangles. This is curved in the opposite direction, from northern Ontario down to the edge of the image. The triangles point northwest. Across the bottom right corner of the illustration, in the blue area outside Canada’s border, is a curved purple line with both triangles and half circles along it. These point south and east. The area between the red and blue lines, and the purple line is labelled “L.”

Shown are two colour illustrations of fronts moving over a landscape. The first is titled “Cold Front.” A pale blue arrow pointing from left to right reads “Direction of Front.” Below, three blue arrows point from the left edge toward the centre of the illustration. These are labelled “Cold Air.” Above and to the right of these is a clear, curved blue wall. Above the curve in the wall, several clouds pour rain on the grass below. Three red arrows point from the right side of the illustration, up into the sky, through the clouds in the centre. These are labelled “Warm Air.” In the background, an airplane flies high over a mountain range on the horizon. The second is titled “Warm Front.” A pale blue arrow pointing from left to right reads “Direction of Front.” Below, three red arrows curve up from the ground on the left side of the illustration, into the sky. These are labelled “Warm Air.” Below and to the right, a clear, blue slope curves up the ground, to the sky in the top right corner. Sitting on top of this, a clump of clouds pour rain onto the grass below. Below the slope, three blue arrows point from the middle, along the ground, to the right edge of the illustration. These are labelled “Cold Air.” In the background, an airplane flies high above the clouds, and a mountain range is visible in the distance.

Shown is a horizontal blue line with blue triangles spaced out along it. The triangles point up from the line, like a row of identical mountains on a horizon.

Shown is a red horizontal line with red half circles spaced out along it. The circles are above the line, like a row of identical hills on a horizon.