Woodrow Wilson

Leadership Program for Teachers

Environmental Science Institute 

Team #16:  Inquiry Project

 

RESEARCH PROJECT

     An introductory study of microclimatic air temperature
with ideas for classroom implementation.
 
 
 
 

Table of Contents
 
 

Introduction

Background

    Since the industrial revolution, human populations have undergone two major changes:  1)  the number of people has been increasing logarithmically and 2)  an ever increasing proportion of people have been living in cities and towns.  Thus, humans have been urbanizing their environment.  Urban areas typically have high population density and high structural density, including buildings, roads and other infrastructure.  Previous investigators have suggested that urbanization may lead to changes in climate.  Urban environments differ from agricultural and wild lands in many respects.  One obvious feature are buildings and walls.  These objects modify their adjacent microclimates by absorbing solar energy, radiating heat, and providing shade.  Buildings and walls can be used to actively manipulate the microenvironment to benefit agriculture.

    In this inquiry, we chose to study the microclimatic effects on the north and south sides of some large, brick buildings.  We chose this specific study because

Purpose:

    Small environments have easily observed microclimates which renders them ideal for student study.  Microclimate is influenced by latitude, topography, human activities and vegetation as well as other factors.  By examining these factors a rich source of variables and data can be mined.

    In this inquiry-based project, the authors attempt to:

Definition of terms:

A number of terms are used in this report.  Click here to view the definitions.  Teachers are encouraged to simplify these terms for student use if doing so will further the specific objectives of their lesson.
 
 

Hypotheses

 
 
Hypothesis used in this study.
 
Atmospheric temperatures will vary with respect to
the distance from a building.
Microenvironments near walls with a 
southern exposure will be significantly warmer 
while microenvironments near walls with a
northern exposure will be cooler. 

 Other questions that may be hypothesized may include:

   We chose to do a simple, baseline study examining the air temperature effect of large, red-brick buildings on their north and south aspects.
 
 

Materials

Materials needed for inquiry:

   1.     Thermometers (graduated in 0.1 degree Celsius increments).
            a.  Several thermometers will allow simultaneous measurements in multiple locations.
            b.  Use a thermometer shade to avoid artificially high temperatures caused by direct
                  sunlight.
 
   2.     Building, wall or other object with similar landscaping on several sides.
 
   3.     Metric length measuring devise (a string with strategically placed marks or knots works
            well).
 
   4.     Data Gathering Worksheets.
 

Related activities may require objects of:

 
 

Protocol

   1.     Select areas for measurement.

   2.     Measure distances from wall or other object (it may be a good idea to mark long-term
                measurement sites with stakes).

   3.     Measure temperatures.
                a.  Position thermometers so that the shade shields the thermometer from direct
                       sunlight.
                b.  Take temperatures at 0.5 meter and 1.5 meters above the ground and at
                       0.5, 1, 2, 4, and 8 meters away from the wall or other object.

   4.     Record temperatures on a data gathering worksheet.
 

Specifics for this experiment:

    Temperatures were measured on the lawns along the south side of Eno Hall and along the north side of Guyot Hall on the Princeton campus.  These buildings were chosen because they are made of similar materials (red brick and stone), had lawns with similar flora and inclination, and were a similar height.
    Temperatures were measured at three hour intervals beginning at 6:30 AM and ending at 9:30 PM EDT on July 17, 1997.
    The graphing function of a spread sheet program were used to visualize the variation of temperature.
 
 

Results

The results we found in our specific experiment:

   1.     Sample of our data is on the completed data gathering sheet.

   2.     Complete data tables and graphs can be seen on our results page.
 
 

Discussion

Possible causes of different temperatures within a microclimate:

    Many variables interact to influence air temperature.  This study is too preliminary to make any definite statements.  Our observations, together with the work of other researchers, suggest the following possible interpretations:  Early morning temperatures were warmer at sites near the buildings, even along the northern aspect.  This may be the result of the buildings radiating heat accumulated during the day.  Cooler temperatures were consistently noted in the shade; even the dappled shade provided by a tree was associated with lower temperatures. Ground cover can impact temperature, probably through a combination of reflectivity and transpiration in plants.

Limits of this specific study:

    This study is limited as a baseline study.  Not only was a short time period sampled, but also the sites chosen were imperfect.  For example, a tree cast a dappled shadow over the 8 meter mark on the south side of Eno Hall.  Future baseline studies could be improved by being long term and by finding areas which are more uniform.

    We used mercury/glass thermometers.  Although fairly accurate, these thermometers registered temperatures slowly.  Thus, it took two people, using two thermometers about 10 minutes to take each set of data.  When we re-checked the first temperature we took in each set after we had finished the last temperature, we sometimes found a 0.3 degree Celsius difference.  This is a significant difference in a microenvironment.  Use of a faster acting thermometer, or of many slower thermometers would improve this study.

Other variables/other hypotheses:

    Many other variables can be manipulated in order to test other hypotheses.  For example, the reflectivity or color of the object could be varied in order to determine which colors are associated with the warmest or coolest microclimates.  Some of the variability noted in this study may have been due to the massive buildings absorbing heat during the day and then radiating it at night.  A study comparing the effects of a solid block wall versus a similar sized and colored light weight fences might be interesting. Such a study might influence a homeowners choice of enclosure for his/her backyard.  Height of the object could also be studied.

    Not all objects are man-made. A similar study could be done to observe the effects of inclination (also known as slope).  Several sides of a hill or mesa could be studied.

    Ground cover is also known to impact microclimate.  Baseline studies could be made comparing the temperature over bushes, lawns, asphalt, and concrete.  Meanwhile, microclimate impacts vegetation.  In addition to studying the air temperature, students could survey the biodiversity of the plant populations on two sides of a "wilderness" hillside.

    Interschool experiments could examine microclimates at different latitudes and consider the effect of different object heights.

    These are but a few of the many hypothesis which this, or a similar protocol could be used to study.  Similar work could also be done examining wind, humidity, or even soil temperature.
 
 

Outreach to Our Home District . . . and Beyond

    Climate is a phenomenon which can easily be used as a long term study.  Our desire is for secondary students and teachers to use this inquiry based project as a source of inspiration to develop their own experiments.  Relevance to students is embedded when inquiry based lessons involve a student's local environment.  Long term investigations are rich in data providing students with many opportunities to test hypotheses using observation and mathematical analysis.
 
 

Other research sites discussing microclimates.

    Steven W. Running studies microclimates in mountains with a goal of monitoring resources, fire danger, etc.  See his Microclimate Modeling & Mapping using the MT-CLIM Mountain Climatology Model for fascinating maps of Montana.

    The Florida Agricultural Information Retrieval System has numerous articles about microclimate and their modification for both the commercial farmer and the home gardener.  Use the keyword: microclimate when searching from their home page. A. W. Meerow and R. J. Black have a particularly interesting paper, Enviroscaping to Conserve Energy:  A guide to microclimate modification in this system.

    Dr. Katharine B. Perry, Extension Agricultural Meteorologist at the North Carolina Cooperative Extension Service  has prepared a pamphlet, "Frost/Freeze Protection for Horticultural Crops" which discusses various methods to keep fields warm.
 
    The Biology 585 course at the University of Utah includes a Microclimate Assignment.

    The abstract of Argete & Wilson, 1989; Agric. & Forest Meteorol., Vol. 48  "The Modified Microclimate in Small, Square, Sheltered Plots" is available on line.

    Meronuck, Kinkel, Wright, Duellman, and Wiens of the University of Minnesota, discuss the "Effect of Microclimate and Inoculum on the Development of White Mold in Irrigated Dry Edible Beans."  Their particular interest is to manipulate irrigation schedules to optimize the microclimate of bean fields.
 
 

The authors

Annette Sheffield is a math and science teacher at Sunnymead Middle School, 23996 Eucalyptus  Avenue, Moreno Valley, California, 92553.

Karin Westerling is a science teacher at Moreno Valley High School, 23300 Cottonwood Avenue, Moreno Valley, California, 92553.