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Image Narration | Atmospheric Water Vapor

Steve Wofsy, Principal Investigator for the HIPPO project, describes the concentration of water vapor found longitudinally in the Earth's atmosphere.

This image also is showing a color representation of one of the species that we measure in the HIPPO experiment, this one is water vapor. And there’s no more important gas for climate studies than water vapor.

One of the things that we’re interested in is how does water vapor get from the surface into the middle and upper atmosphere? It’s is an interesting question because the more water vapor there is up there, the more powerful the greenhouse effect. Water vapor is in fact much more powerful as a green house agent than the other gases. We don’t often talk about that, because water vapor isn’t influenced directly by human beings.

Now what you see in this image is really a big surprise, at least to me. We see that part of the atmosphere where the hemispheres meet, the Intertropical Convergence Zone, shows up as some upward moving water vapor just to the right of the equator. But then to the left of the equator, at around 20 degrees south, you see a massive upward movement of water, which is part another feature of the circulation called the the South Pacific Convergence Zone. And I don’t think people really expected to see this very strong upward motion of water vapor in that particular region, so we’ll be revisiting this area. And if it’s a persistent feature then I think we will have helped to understand a very important part of the circulation of how the atmosphere is moistened.

Atmospheric Water Vapor


HIPPO is a landmark study for many reasons, not the least of which is it is the first time scientists have systematically mapped global distribution of carbon dioxide and other greenhouse gases in the atmosphere, covering the full troposphere in all seasons and multiple years.

  • HIPPO I :: 8 January-30 January 2009
  • HIPPO II :: 31 October-22 November 2009
  • HIPPO III :: 24 March-16 April 2010
  • HIPPO IV :: 14 June-11 July 2011
  • HIPPO V :: 9 August-9 September 2011