The purpose of this activity is to observe the type and cover of clouds including contrails. Students observe which of ten types of clouds and how many of three types of contrails are visible and how much of the sky is covered by clouds (other than contrails) and how much is covered by contrails. Intended outcomes are that students learn how to make estimates from observations and how to categorize ... Full description.

The purpose of this activity is to measure the aerosol optical thickness of the atmosphere (how much of the sun's light is scattered or absorbed by particles suspended in the air). Students point a GLOBE sun photometer at the sun and record the largest voltage reading they obtain on a digital voltmeter connected to the photometer. Students observe sky conditions near the sun, perform the Cloud, Optional ... Full description.

The purpose of this activity is to introduce students to the concept of relative air mass and demonstrate how solar elevation angle affects the intensity of sunlight that reaches an observer on the ground. Students work in teams to calculate air mass using simple geometry. Teacher background materials are included. Full description.

'The purpose of the resource is to meaure the alkalinity of a water sample. Students will use an alkalinity kit to measure the alkalinity in the water at their hydrology site. The exact procedure depends on the instructions in the alkalinity kit used. Full description.

The purpose of this resource is to measure the conductivity of water at a freshwater hydrology site. Students calibrate and take electrical conductivity measurements using an electrical conductivity meter. Students estimate the total dissolved solids from the electrical conductivity measurements. Full description.

This resource provides instructions on how to log atmosphere data using a Davis weather station. A weather station is setup to measure and record atmospheric measurements at 15-minute intervals and can be transferred to the GLOBE program via email. Students can view data for their school that are continuous and show variations within a day. The data collected includes wind speed and direction and ... Full description.

The purpose of this activity is to record daily measurements of maximum, minimum, and current air and soil temperatures at a common site. One temperature probe is placed inside an instrument shelter while another is installed at a 10 cm depth in the soil. A digital thermometer is used to measure current temperatures as well as daily minimum and maximum temperatures. The daily minimum and maximum temperatures ... Full description.

The purpose of this resource is to measure the amount of oxygen dissolved in water. Students use a dissolved oxygen kit or meter to measure the dissolved oxygen in the water at their hydrology site. The exact procedure depends on the instructions in the dissolved oxygen kit or meter used. The meter requires calibration before use. Full description.

The purpose of this activity is to measure air (and optionally soil) temperature within one hour of solar noon and the maximum and minimum air temperatures for the previous 24 hours. Intended outcomes are that students will learn to read minimum, maximum, and current temperatures using a U-shaped thermometer, understand diurnal and annual temperature variations, and recognize factors that influence ... Full description.

The purpose of this resource is to measure the nitrate-nitrogen of water. Students will use a nitrate kit to measure the nitrate-nitrogen in the water at their hydrology site. The exact procedure depends on the instructions in the nitrate kit used. Full description.