What is the difference between isobars and contour lines

A picture of a hill is shown above at left. The maps at upper right is a topographic map that depicts the hill the numbers on the contour lines are altitude. A center of high pressure on a weather map, the figure at bottom left, could have exactly the same appearance. The numbers on the contours lines isobars would be pressure values in millibars. Closely spaced contours on a topographic map indicate a steep slope.

More widely spaced contours mean the slope is more gradual. If you stumble and fall while walking on a hill, you will roll rapidly down a steep hillside, more slowly down a gradual slope. You'd roll away from the summit toward the outer edge of the topographic map.

Point A, for example, has a pressure of mb and is therefore located between the mb isobar and the mb isobar. Sea level pressure reports are available every hour, which means that maps of isobars are likewise available every hour.

The solid blue contours are isobars and the numbers along particular contours indicate the pressure value of the isobar. See our User Agreement and Privacy Policy. See our Privacy Policy and User Agreement for details. The SlideShare family just got bigger. Home Explore Login Signup. Successfully reported this slideshow. We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads.

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Why not share! Embed Size px. Start on. Show related SlideShares at end. WordPress Shortcode. Another common isoline is the isobar, a line that joins places with the same atmospheric pressure. These are often shown on weather maps in newspapers and TV weather forecasts. Geographers often use isolines to help them map the distribution of things. When isolines are combined with colouring or shading they make it possible to easily see data that would be hard, or impossible, to understand as a table or chart of numbers.

Apart from contours and isobars there are many more isolines used in geography, although quite a few of them are used only by specialists and they are hardly ever heard of in school. Isobathytherm: Joins points with the same temperature under water. Isocheim: Joins points with the same mean temperature in winter.