To begin classifying, select an image in the Cloud Gallery. Using the menu below the enlarged image, choose the cloud types you see and click "submit."
If you're unsure about which cloud types you see, click on the "key" tab on the lower left corner of the screen. This tab opens a set of thumbnail images for each of the 10 most common cloud types. By clicking on the thumbnails, you can see enlargements of these images and read about some of the most important characteristics of each type of cloud.
You’ll earn points for each cloud you classify correctly; these points will be totaled next to your username at the top of the screen. (You won’t earn points if you haven't signed in as a registered user.)
Once each image is classified, it moves automatically to your "My Classifications" folder, with all the correct cloud types clearly identified. You can also “favorite” the images you like the most to add them to your "My Favorites" gallery.