Tag: satellites

Flooding in Pakistan

Satellite images of flooding in Pakistan. (Images from NASA's Earth Observatory)

One of the largest natural disasters in history, the change in the landscape from the Pakistani flooding is astounding when viewed from space.

Images are from the area around Jacobabad in Pakistan.

[googleMap name=”Pakistani Sindh” description=”Flooding” width=”450″ height=”400″ mapzoom=”6″ mousewheel=”false” directions_to=”false”]Jacobabad[/googleMap]

Nashville flooding and mid-latitude cyclones

Nashville, TN, May 4, 2010. (photo by David Fine/FEMA)
Daily weather map for May 2nd, 2010. Note the cold front heading toward Nashville. Map from the Hydrometeorological Prediction Center.

Over 30 cm of rainfall in just two days resulted in extensive flooding in Nashville, TN, last week. The precipitation was produced by one of those typical mid-latitude cyclones that sweep across the United States, from west to east, every spring and fall. The Boston Globe has some amazing picture of the flooding.

The news media tends to have the most dramatic photographs of disasters, but the Federal Emergency Management Agency (FEMA) also tends to have good images from their aerial surveys (like the image at the top of this post). And images produced by the government are in the public domain so you don’t have to worry about using them.

May 2-6 fronts. Animation generated using images from the HPC.

For discussing warm fronts, cold fronts and mid-latitude cyclones, NOAA‘s Hydrometeorological Prediction Center (HPC) is a great resource. You can find an archive of daily weather maps for the U.S. that you can click through to see the fronts move.

Infra-red satellite image of the continental U.S.. Note the alignment of the clouds and precipitation with the fronts in the first (static) weather map above. (Image from GOES).

Satellite imagery usually complements to the frontal weather maps very well. Most satellites orbit around the Earth pretty quickly, at just the right orbital speed that the centrifugal force just balances the Earth’s gravity so the satellite does not crash into the atmosphere or escape into space. Some satellites are set into orbit a bit further out so that they can rotate with the Earth, effectively staying above the same place all the time. NOAA has a few of these geostationary satellites monitoring the weather around the world, and you can get real-time images from the Geostationary Satellite Server. There used to be archived satellite images but I can’t seem to find them at the moment.