The National Hurricane Center introduced a new storm surge forecast map this year. This map, centered on New Orleans, is a prototype. NOAA hide caption

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A lot of the airborne particles in the Earth's atmosphere come from natural sources, such as desert dust (red-orange) and sea salt (blue). But there's also soot from fires (green and yellow) and sulfur emissions (white) from burning fossil fuel. William Putman/ NASA/Goddard hide caption

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A partially frozen American Falls in sub-freezing temperatures is seen in Niagara Falls, Ontario, on Tuesday. Temperature dropped to 6 degrees Fahrenheit on Tuesday. The National Weather Service has issued a wind chill warning for western New York from midnight Wednesday to Friday. Lindsay DeDario/Reuters/Landov hide caption

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Pedestrians brave the cold during their morning commute on Friday in New York. Arctic air and bitterly cold wind is moving across the Northeast, plunging temperatures into record-low single digits, accompanied by subzero wind chills. John Minchillo/AP hide caption

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An Indonesian police officer in Kumai port in Pangkalan Bun carries part of a plane found floating on the water near the site where AirAsia Flight 8501 disappeared on Sunday. Achmad Ibrahim/AP hide caption

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The drought forced many citrus farmers near Orange Cove, Calif., to mulch their trees because they couldn't afford to keep them alive. Recent rain and new groundwater regulations have eased the crisis, but only slightly. Kirk Siegler/NPR hide caption

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Marina owner Mitzi Richards carries her granddaughter in September as they walk on their boat dock at the dried up lake bed of Huntington Lake in California, which was at only 30 percent capacity as a severe drought continued. The state was in the grip of its third year of severe drought, the worst in decades. Mark Ralston/AFP/Getty Images hide caption

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A bicycle messenger struggles through the snow in downtown Cleveland on Friday. Mark Duncan/AP hide caption

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Yes, The Weather Is Polar. No, It's Not The Vortex

Meteorologists are annoyed by the hype around the phrase "polar vortex." This week's frigid snap, they say, was just a regular old cold front.

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