August 8, 2014  

Little Fluffy Clouds over Kelp

A number of folk have noticed that many of the images are full of clouds. Clouds can make it hard to see kelp – or hard to see if the image is even on the coastline!

Screen Shot 2014-08-08 at 10.27.35 AM

Four images with clouds. In some of them, it’s hard to even tell if there’s a coastline under there!

What’s going on here? Well, Landsat takes images approximately twice a month. But it does so without regard to tide, weather, etc. As many temperate areas have period of fog, or marine layers moving in, getting an image with a cloud-canopy isn’t too surprising. As Samuel Clemens wrote, “The coldest winter I ever spent was summer in San Francisco.” That marine layer can make things difficult, but we have the power of the sheer number of images present so that we should be able to get some good cloud-free glimpses of many forests!

Clicking the cloud button helps us out a lot, though. As we filter through the images in the future, we’ll know which ones folk may have had a hard time seeing through to see the kelp. And if enough folk don’t mark anything in the image, it will get kicked out of the system soon anyway!

Cloudy? Click cloud! cloud_icon

7 responses to “Little Fluffy Clouds over Kelp”

  1. Philip says :

    Great to see another Zooniverse project collecting weather data. It’ll be interesting to see how these human assessments of cloud fraction compare with algorithmically generated datasets like ISCCP and reanalyses.

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    • jebyrnes says :

      We’re not *really* collecting weather data here – and will only be retaining it for images that seem to have kelp. BUT this does raise the possibility of another interesting project!

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  2. JerryK says :

    I’m pretty sure some of the images contain nothing but land.
    In many it’s difficult to tell whether the brown surface is earth or low tide mud but given my first comment, I’m not prepared to mark the green stuff as kelp.
    I suspect that kelp only grows below the low-water mark but I may be wrong.
    A bit more education would be helpful, as would a better selection of pictures, as you obviously know where they are taken, so should be able to exclude those with no sea in them.

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  3. Gary says :

    I studied kelp ecology in the Gulf of Maine forty years ago. It’s good to see the technology providing another research tool. Looking forward to seeing some of the results when you synthesize it.

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  4. planetaryscience says :

    Based on this, I’m inclined to believe that we shouldn’t mark clouds when there are only a few clouds, such as just a couple over an otherwise fine ocean. Am I correct?

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