Clouds FAQs

Find answers to frequently asked questions about the Clouds tool:


I am making a cloud observation. What does “obscured” mean?

"Obscured" means that you don't have a clear view of more than 25% of the sky because of rain, snow, dust, fog, smoke, haze, volcanic ash, ocean spray, or blowing sand. It is not the same as “overcast”, which indicates you have a clear view of the sky but it is 90-100% covered by clouds.


Should I include buildings or trees in my pictures of the sky?

The goal is to capture pictures of the clouds, but we understand that observers may be in less open areas (courtyards, city streets, etc.) where the cardinal direction (North, South, East, and West) photos may show tall buildings or trees. The automatic picture mode in the app will direct you to an appropriate angle of 14 degrees above the horizon. If you are taking photos manually, you can approximate this angle with your hand raised up to eye level and your arm stretched away from you. Either of these techniques help capture more of the sky in your photos.


Why do you ask for down photos as part of an observation of clouds?

We use the down observations to help scientists differentiate between clouds and whatever is on the ground when they are looking at the atmosphere from space. Some ground cover types (snow, desert, etc.) are bright white and can be tough to distinguish from clouds. 


I don’t see any Satellite Flyover times, what does that mean?

The overpass calculator is based on your location. Without knowing your location, we cannot provide you with overpass times. Make sure you have activated location services on your phone. On iOS, this is under Settings > Privacy. For Android, this is under Settings > Location. You may also try closing the app and reopening it. Do remember that you can make observations without matching a satellite overpass - many observations will match with data from geostationary satellites, which do not show up in the Satellite Flyover list.


Can I get notifications for Satellite Flyovers?

Yes! On the Clouds home screen, tap on "Check Satellite Flyovers," then on "Set Notifications." The "Details" buttons for solar noon and satellite flyover notification will allow you to set up your notification preferences. Notifications are set to alert you 15 minutes before solar noon or an upcoming satellite flyover.


How can I see the comparison of my data to the NASA satellite data?

If you have opted in to receive NASA satellite images (tap on the outline of the person in the upper right of the app, then select the "Opt-in/Opt-Out Settings" button to view and change your settings), you will receive an email within a few days of the observation if you have matched to a satellite overpass. Alternatively, you can view satellite match information in the GLOBE Visualization System by clicking on an observation point and then selecting the "Satellite Matching: Open in a New Window" option.


Will the same observation match to multiple satellites?

Yes, if your observation is within 15 minutes of overpasses from more than one satellite, your match information will include data from all the relevant satellites.


Where should I look to observe sky color and sky visibility? Is it different from where I look to observe clouds?

For clouds, we recommend you look at the clouds higher than approximately 14 degrees above the horizon, or about the angle of holding your arms outstretched and slightly above your shoulders. In contrast, for sky visibility, you will look directly at the horizon in the distance. To observe sky color, turn your back to the Sun and observe the bluest part of the sky in front of you.


Why do I need to report on surface conditions?

Surface conditions are an important part of a Clouds observation. When we look up, we are differentiating between a blue sky and mostly white clouds. When a satellite is trying to categorize clouds versus other geographical elements there are many more colors involved and it can sometimes be difficult to tell the difference between ice and snow or clouds. By reporting surface conditions, you are providing additional data to assist during analysis and satellite validation.


What counts as leaves on trees? Do pine needles on pine trees count as leaves on trees when other trees are bare?

To account for trees that people may encounter at different times of year (including evergreens), please look at all the trees in your area no matter what type they are. If 50% or more of them have leaves (or needles) answer "yes," but if less than 50% of them have leaves, answer "no.