Cloud Observation

Goals

• "Looking up": once students learn to tell the cloud types apart: they will start noticing them and appreciating them (so Cloudman (more info) believes).
• Understanding the relationship between atmospheric phenomena and meteorlogy
• Gain practice making and refining subjective scientific observations

Skills

• Identifying cloud types
• Estimating cloud cover
• Making other basic meteorological observations

This is a short lab, especially handy for days when the weather is bad. This activity should be repeated on different days, often at the start of another field lab exercise. Only half-an-hour to an hour of training on the first day and ten to fifteen minutes of observation and discussion (and filling out sheets) each time the exercise is repeated should be necessary.

Materials needed:

• Cloud chart (showing cloud types with photoraphs: 1/pair of students
• Data sheets
• Thermometer (optional)
• Barometer (optional)
• GPS unit (optional)

Prior training:

• Cloud types: along with your descriptions and explanations, show lots of slides and photos of the various types. Try showing the students a few clouds and have them work out the type.

• Cloud cover: to stress the confusing nature of cover estimates, take two full sheets of blue paper and one of white paper, and divide the white sheet in half. Tear up the first half of the white sheet into large chunks and glue them onto one of the blue sheets without letting the chunks overlap. Repeat with the other half of the white sheet and the other blue sheet, but this time, tear the white sheet into small chunks before gluing them on. In both cases, 50% of the blue sheet will be covered by "clouds", but the sheet covered by large "clouds" appears more open than the other one. In both figures to the left, the "Cloud cover is 50%.

The datasheet should include:

• Student names, date, time, location (GPS cordinates?)
• major overhead cloud types, % cover
• other data (temperature, ground cover, air pressure, etc.

Photographic keys for cloud types can be obtained from:

• Lots of photos, cloud identification materials (as pdf's), and advice on what data to collect are available from [link: http://science-edu.larc.nasa.gov/SCOOL/ 'the CERES S'COOL Project'].
• A mini-cloud-atlas containing photos and descriptions of twelve basic types of cloud are provided by Cloudman (more info) .
• Posters and field guides can be ordered online or through your bookstore.

The class must be outside to make the observations (looking out the window doesn't really work). This is often a good exercise with which to start another field lab, as it is short, and should be repeated so that students get a chance to observe a variety of kinds of clouds and degrees of coverage, as well as time to develop some facility with the methods.

Give points for participation (and completely filling out the form), especially if the weather is bad.

A detailed Cloud Protocols (more info) for having students descibe clouds, complete with data sheets, is provided by Global Learning and Observations to Benefit the Environment (GLOBE) (more info)

Cloudman (more info) also has a table about cloud formation chart, articles about weather, activities, photography tips, many annotated photos, and some philosophy of meteorology to offer.