Geography 3850A - Atmospheric Analysis
Lab 4 – Microclimates and Upper Air Analysis
Monday, March 7, 2005
PART A: Microclimates and Energy Consumption (Mar 7)
1. The file Toronto_Weather.xls consists of daily weather data from Pearson International Airport,
Toronto Island Airport and the city. Familiarize yourself with the exact location of the three sites, using
the internet. Examine the data and write a short report (maximum one page, excluding figures)
describing and explaining any similarities and differences between sites in (a) winter and (b) summer.
Make specific reference to the urban heat island effect and the influence of Lake Ontario. You should
back up your arguments with statistical evidence. (10)
2. You live in a detached home in Lethbridge. You notice on your gas bill that your total gas
consumption so far this year is 800 m3. You estimate that your gas consumption by non-furnace
appliances was about 200 m3. (Note: Gas has an energy content of 37.5 MJm-3, and your furnace has an
efficiency of 92 per cent. Heat loss can be converted from MJh-1 to kW as follows: 3.6 MJ/h = 1 kW).
(10)
(i)
(ii)
(iii)
(iv)
(v)
(vi)
Calculate your furnace’s gas consumption per heating degree day.
Calculate your furnace’s gas consumption on January 13th and January 24th.
What is your home’s total heat loss (MJd-1) on these dates ?
How much gas would your furnace have consumed for an identical house in (a) Regina or (b)
Toronto, so far this year (assume a linear relationship between HDD and gas consumption)?
In terms of output (kW), how powerful a furnace would you recommend in each of these
three cities for this home? Justify your answer. (Typically, you should recommend a furnace
40% more powerful than that needed on the coldest day of the year.)
Imagine that you moved from an identical house in Regina to your current one in Lethbridge
on December 31, 2004. Assume a cost of $0.75/m3 for gas. How much cheaper was it to
heat the Lethbridge home?
3. Examine the data in the files entitled NORTH FACING.xls, NORTH FACING ONE METRE.xls,
SOUTH FACING.xls and SOUTH FACING ONE METRE.xls. How does temperature vary between
south and north facing slopes (i) at 10cm and (ii) at 1m, during the daytime and night-time periods? (6)
PART B: Storm Development and Upper Air Analysis (Mar 14)
1. Examine a tephigram taken at a site where precipitation is occurring. Mark on your tephigram (from
http://twister.sbs.ohio-state.edu/upperair.html or weather.unisys.com) the unstable portion of the
atmosphere from which the precipitation is falling. (2)
2. Keep track of storm systems in North America during the next seven days. Find an example of (i) a
strengthening storm and (ii) a mature, weakening, occluded storm system. The same system can be used
at different times for (i) and (ii), if necessary. Show a surface pressure map, a 500 mbar height map and
any other relevant information for each system (this can be pasted from a weather site such as
weather.unisys.com or weatheroffice.ec.gc.ca). Making reference to both maps, consider surface and
upper air conditions to explain why system (i) strengthened and system (ii) weakened.(10)
3. For the strengthening system (above) or another strengthening system, draw a vertical cross section of
the atmosphere around the surface low pressure sytem, denoting the zones of low surface pressure, high
surface pressure, upper air divergence, upper air convergence, positive vorticity and negative vorticity.
(10)