Eclipse Data Analysis
We thank all of the amazing citizen scientists who collected clouds and air temperature data on August 21st. We received over 80,000 air temperature measurements and nearly 20,000 clouds observations from more than 10,000 observers! While our team is working on analyzing the data, we also encourage citizen scientists of all ages to try their hand at doing their own analysis. Below you will find some example graphs (click here to download graphs as a PDF) and tips and tricks for accessing the data.
For students working on projects for the International Virtual Science Symposium or North American Student Research Symposia, you might also find useful this blog about choosing different types of graphs, with examples from the eclipse data set. If you do complete a project that uses eclipse data, for the IVSS, SRSs or just on your own, please let us know! We are working on digital badges and certificates for schools and students that analyze the eclipse data and report on their analysis. We'll post examples here as soon as they are complete.
There are two primary ways to access GLOBE data. The first is the GLOBE Visualization System, which you can see below set to layers representing clouds and air temperature on August 21st, 2017. You can explore in the window below or go to the full system. Tutorials are also available in PDF and PowerPoint formats.
While the data visualization system system allows a quick view of the data, and some comparison between data sites using the multi-site plots tool (graph icon in the upper left menu), in order to do more detailed analysis, you will need to download the full data tables. There are two primary ways to do that.
- The first option is through the GLOBE Data Visualization system itself. Click on the expand options dots to the right of the layer you wish to download, select View Layer Table, then Export .csv in the window that pops up.
If you don't want the entire layer, it is also possible to subset the data by using the filters feature. You can filter by a place such as a state, country, or even proximity to a geographic feature such as a lake or a river. You can also choose a latitude/longitude range, or draw a shape on the map. Once you have selected your filter, follow the directions above to download the layer table.
2. The second option is the GLOBE Advanced Data Access Tool. This allows you to filter by more than one protocol at a time, as well as for a range of dates. ADAT can be powerful, but also may be less intuitive than starting from the map as described above, so choose the tool that is best for your purposes.
Because the eclipse is such a time-focused event, we have also been able to pull some data sets that might be useful for a variety of people, and could save time in accessing the data. See below for air temperature data sets pulled by state and country for the date of 8/21/2017. Files are in zipped folders unless noted, and can be downloaded as comma separated value (CSV) files, or Excel (XLSX) files, which preserves some formatting that may make them easier to work with.
|Data from the fourteen states that experienced totality in some portion of the state: Georgia, Idaho, Illinois, Iowa, Kansas, Kentucky, Missouri, Montana, Nebraska, North Carolina, Oregon, South Carolina, Tennessee, and Wyoming||CSV||XLSX|
|Data from the remaining 36 U.S. states, which experienced only a partial eclipse, reaching varying levels of maximum obscuration of the Sun||CSV||XLSX|
|Data from the entire United States (single file, not a zipped folder)||CSV||XLSX|
|Data from other areas that experienced the eclipse, grouped as follows: Canada, Central America, Dominican Republic, Mexico, northern South America and Puerto Rico||CSV||XLSX|
Observations submitted through the GO app receive a unique identifier for each location from which data are submitted. The identifier is tagged to the latitude and longitude information of the submission, which is automatically obtained through the device being used to run the GO app. Each unique identifier is considered an independent unique observer for our purposes. The time of each observation was recorded to the nearest minute. The observer could choose to input temperature as either Fahrenheit or Celsius, but the temperature values were recorded in the database to the nearest degree Celsius.
General notes about the files:
- For latitude and longitude, a negative sign represents south and west respectively.
- Elevation is measured in meters above sea level.
- "Measured at" time is in Coordinated Universal Time, or UTC (also sometimes referred to as UT). Here is one time conversion tool, but there are many others available as well.
- Air temperature (may appear as "measured value" if you pull from the GLOBE system rather than our files above) is in degrees Celsius.
Other useful resources:
- To find out the times for the beginning, ending and totality/maximum eclipse for a particular observation point (which might be useful in your analysis), you can use the interactive eclipse map on NASA's eclipse page. The U.S. Naval Observatory also has an online form to calculate the same data if you prefer to enter the latitude and longitude rather than using the map.
A quick visualization of the air temperature measurements we collected through the GLOBE Observer eclipse project on August 21st, 2017, with an estimation of the location of the eclipse shadow throughout the day added. To explore this data more fully, visit the webpage for this visualization or the full GLOBE Visualization System. For more detailed information and visualizations of the eclipse path, visit NASA's Scientific Visualization Studio Eclipse Gallery.