Advanced GLOBE 2002 Topics

• Phenology Protocols
• New Atmosphere Protocols

  What is Phenology and Why should I care?

  Phenology is the study of how living organism's respond to seasonal changes in their environment. Using the GLOBE phenology protocols, students record and report seasonal growth of native plant species. Each class can choose to study trees, shrubs, grasses or all three.

  A native plant is one that grows naturally in an area and has adapted to the local environmental conditions. The phenology protocols require students to study native deciduous species because exotic (non-native) species may react strangely to our climate. The scientists want to measure seasonal change and how it affects the growth of native plants. GLOBE scientists are comparing the data students collect on the ground with data collected by satellites in space. The protocols require that students study plants that are locally dominant so that the vegetation changes recorded by students can be compared with the vegetation changes seen by the satellite.

  The spring phenology protocol, Green-Up, monitors when plants begin the growing season (called budburst) and how fast leaves grow to maturity. The class chooses a locally dominant tree, shrub or grass species. Each group of students flags one branch or plot. Students take pictures of their site and return twice a week to take measurements. They record budburst and label 4 leaves. The group will measure the length of these four leaves until they reach maturity (the leaf is the same length in two consecutive observations).

  Green-Down, the autumn phenology protocol, is all about color! Students use the same species of plant as in the Green-Up and a GLOBE Plant Color Guide. The Color Guide looks just like a soil color guide except in plant shades instead of soil shades. Each student group collects data on four leaves from one branch or grass plant. The group visits the site four times a week and records the color of each leaf. Students record data for each leaf until it has fallen or become snow covered.

  The period between green-up and green-down is generally synonymous with the growing season. A change in the green-up and green down cycle may be an indication of a global climate change. The GLOBE scientists have already used satellites to measure changes in the global climate. Recently, satellite data has been used to show that the growing season in northern latitudes has increased by 8 days over the last 20 years. This conclusion is controversial because there has been no ground-based measurements to support the satellite data. GLOBE students are the only global network collecting the phenology measurements needed to validate the satellite estimates (GLOBE Earth Systems Science, 2001).

  At the Phenology and Landcover Theme workshop we will learn and practice Green-Up, Green-Down and the phenology classroom activities. For more information see the on-line version of the phenology protocols.

  Iowa Resources for Phenology and Land cover Protocols

  Taking our heads out of the clouds - GLOBE's New Atmosphere Protocols

  GLOBE Students can now participate in four new atmosphere protocols: Surface Ozone, Relative Humidity, Aerosol and Barometric Pressure.

  Surface Ozone

  Monitoring trace gases is important for understanding air quality. Ozone is a trace gas of interest to scientists because it is very reactive, even with living tissue. Students can measure surface ozone with a simple chemical test strip and a reader. The test strip changes color as it is exposed to ozone. The reader can measure this color change much better than a human eye. GLOBE student data collected about ozone will help scientists understand how weather changes effect ozone levels. Over time the database will also help scientists describe how the atmosphere is changing.

  Relative Humidity

  Relative humidity is a measure of how much water vapor is present in the air. GLOBE students can measure relative humidity using a digital hygrometer or a sling psychrometer. GLOBE scientists are using the relative humidity data to help understand how fast water moves from the surface into the atmosphere. Students can study how it relates to cloud cover and temperature.

  Aerosol

  A two-part article in Science News (vol. 160, Nos. 13 and 14, September 29, October 6, 2001) focused on aerosols. Satellite and ground-based measurements have confirmed that dust is transported from arid regions in Africa, Asia, and elsewhere across both the Atlantic and Pacific oceans. We're talking more dust than you can wipe off the top of a bookshelf during spring-cleaning. Almost 7 million metric tons is picked up in North Africa each year! Dust from China reduced sunlight in Colorado in April 2001. This dust can reduce visibility, transport spores and fungi, and maybe even fertilize soils far from its source. Aerosols are all the small liquid and solid particles suspended in the air, not just the dust. GLOBE students measure aerosols by calculating the optical thickness of (how much light shines through) the atmosphere using an instrument called a sun photometer. Sun photometers can be made or purchased from the GLOBE Aerosol science team.

  Barometric Pressure

  Changes in barometric pressure can be used to predict changes in the weather. GLOBE scientists will be using barometric pressure data to help them interpret Aerosol and all of the other atmosphere protocols. Your students can study their own barometric pressure, cloud and precipitation data. Some may even begin to predict what tomorrow's weather may bring!