Observe and Report - Clouds Protocol

Observe and Report

NEVER look directly at the Sun!

WHAT:

Observe which types of clouds are visible, how much of the sky is covered by clouds, and the opacity of clouds. Then, report on surface and sky conditions, information complementary to the satellite view.

Reminder: This protocol includes a category of “No Clouds” which should be reported whenever there are no clouds visible in the sky. A “No Clouds” report is just as important as a “Clouds Observable” report in helping understand our Earth’s system. If “Clouds Observable” is reported, follow the observation hints located in the left navigation column.

WHEN:

Cloud observations can be taken at any time! This Protocol is designed to be flexible and fit into your schedule, classifying, observing, and reporting cloud observations when it works for you.

The GLOBE Observer app enables you to look up satellite overpass (flyover) times for your location to be able to compare your surface-level data more directly with information collected by NASA satellites. Select “Check Satellite Flyovers” from the home screen of the Clouds tool to determine these times, set notifications reminding you 15 minutes before the satellite passes over, and customize your notifications (e.g., days of the week, time, and satellites).

Matches to satellite data:

When you submit a GLOBE observation that coincides with a geostationary satellite or a polar orbiting satellite flying overhead, you should receive an email from the GLOBE Clouds team at NASA’s Langley Research Center with comparison information. (Go to settings in the app to make sure you have opted in to receiving these communications). The satellite comparison email shows how your surface-based observation compares with data collected by the satellite(s). The email will include a table with a side-by-side comparison of the satellite data. Learn which satellites your GLOBE Observation may be matched to.

There is no need to request an overpass schedule for geostationary satellites. Observations at almost any time of day have a good chance of being matched to geostationary satellite data from GOES, Himawari, or Meteosat, depending on your location.

You can also match to polar orbiting satellites, either NOAA-20 or PACE. The overpass schedule gives you a specific time when these two satellites will be right above your location. The best way to get a match is to go outside and make an observation at the time given in the overpass schedule. Now, you don’t have to go out at that exact time, there is a window that starts 15 minutes before the time on the overpass and ends 15 minutes after the overpass time. This gives you a 30-minute window of time to make a cloud observation and try to do a match in time with the satellite.

We match to the CERES instrument that rides on the NOAA-20 satellite and to the OCI instrument on the PACE satellite. Both NOAA-20 and PACE overpasses are in the afternoon, generally between 1 and 3 pm.