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Statement of environmental problem for ATMS 320_ Fall 2004


									             Statement of environmental problem for ATMS 320, Fall 2004
        The J.P. Mulligan Company is seeking to hire a contractor to help with placing
weather instrumentation in the vicinity of a bridge (see Figure 1) that they own
connecting a local highway to the J.P. Ski Resort. The bridge is susceptible to freezing
rain and was the scene of a terrible traffic accident during the previous ski season. This
project is a call for proposals to private companies to produce a solution that will help to
avoid another traffic accident by providing information so that road conditions will be
safe for the passage of J.P. Ski Resort customers.

         A typical temperature profile that produces freezing rain events is shown in
Figure 2. The profile shows an upper and lower freezing level, the latter of which
represents the top of the sub-freezing layer next to the surface (the bridge surface at 500
meters above sea level). When the sub-freezing layer (SFL) has a depth that exceeds a
critical value, dZc, the precipitation reaches the bridge surface as sleet. When the SFL
has a depth less than dZc and greater than 500 meters, the precipitation reaches the bridge
surface as freezing rain. A SFL depth of less than 500 meters indicates that the
precipitation will reach the surface as warm rain. Freezing rain is the most dangerous
precipitation type as it falls as supercooled liquid water and freezes on the bridge surface
on contact. Sleet is less of a problem as it can be removed in a similar fashion as snow.
The critical depth, dZc, is a linear function of wind speed at the bridge surface. Under
calm wind conditions (wind speed is zero), dZc has a value of 1300 meters. Under the
conditions of a wind speed of 20 m s-1, dZc has a value of 1100 meters. Precipitation will
NOT reach the ground in any form if the average dewpoint depression within the SFL is
greater than 5oC.
         The particular weather scenario for your proposal is pictured in Figure 1 where
the valid time is 11:00pm Local Time (LT) on Thursday, 24 February. At this time, a
station (GRT) directly north of the bridge (dark shaded rectangle) is observing four-dot
(heavy) rain at an elevation of 3300 meters above sea level. This position represents the
leading edge of a southward moving storm that, if it continues at the same advection
speed as the current GRT wind observation (20 m s-1), will reach the bridge in 18 hours.
You can assume that the storm propagation speed will not exceed 20 m s-1, however, it
may decrease so that the storm actually reaches the bridge later than 18 hours into the
future. In your proposal, you will need to provide weather information that will keep the
bridge clear during the peak travel period from noon LT on Friday (25 Feb) through noon
LT on Saturday (26 Feb). You can assume that the storm will have cleared the area after
noon LT on Saturday.

                J.P. Mulligan has invested in five trucks, each requiring a crew of two, for
snow removal and ice prevention. The quickest mobilizing time is 15 hours before the
crews are on the bridge ready to clear it; 12 hours to get the crews into the garage and
three hours to equip the trucks with the proper road-clearing gear. Once the five trucks
are on scene, it takes one hour for five trucks to effectively clear an impassable bridge.

      Statement of environmental problem for ATMS 320, Fall 2004 (continued)
A single truck would take five hours to clear the bridge. Once the bridge is initially
cleared, it takes one hour for the bridge to reach impassable conditions as frozen
precipitation is falling if no preventive maintenance is done by any trucks. Each truck
crew person costs the equivalent of $50.00 per hour during the time period 9:00am-
5:00pm Mon-Fri and costs $150.00 per hour for time worked outside of this period
(overtime). These rates include both pay and benefits.
                An incorrect report as to the type of pending frozen precipitation will
require a period of four hours for the trucks to return to the garage to be re-equipped with
the proper road-clearing gear. Sleet and snow require similar road-clearing gear. Freezing
rain requires different road-clearing gear from sleet or snow.

        Weather Instruments
                Your company will propose to deploy an observing system that consists of
any instruments listed in Table 1. The information obtained from the observing system
will serve as guidance for the J.P. Mulligan Company in a strategy to effectively keep the
bridge clear so that customers (and revenue) can flow into the J.P. Ski Resort. Each hour
of bridge closure costs the J.P. Mulligan Company $100,000.00 in revenue.
                Each instrument consists of an initial start-up cost (purchase price +
installation price) and a daily maintenance cost. The installation price is $2000.00 per
instrument site. The purchase price and daily/”one shot” cost of each instrument is given
in Table 1. You can deploy observing platforms at any location outside of the “private
land” boundary as marked in Figure 1 by the 1500 meter above sea level height contour.
You can assume that the riverbank is at an elevation of 300 meters above sea level.

The winning proposal:
         Sure, money talks. But the cheapest solution will not necessarily win. Your
proposed observing network will be put to the test by advecting the storm southward with
a fixed vertical wind, temperature, and dewpoint profile. In other words, you know from
Figure 1 that the winds at 3300 meters above sea level are always blowing from the north
at 20 m s-1 and that the temperature and dewpoint temperature are always 33oF at this
elevation. You can think of the atmosphere as being “frozen” (pun not intended) such that
its vertical profiles are everywhere the same and constant as the storm moves southward.

       Your group must list all potential resource costs related to both Personnel and
Weather Instruments for the given 37 hour weather scenario. Each group can submit only
one solution as a part of your proposal. Good luck!!

 Written report of at least four pages (double-spaced) containing a description of your
solution including your projected overall total costs to the J.P. Mulligan Company, to be
written by the non-presenting member of your group.

 A 15 minute Powerpoint presentation describing your solution (“making the pitch!”).
Two members of each group participate in the presentation. A part of every winning
“pitch” is to directly address the cost of buying into your solution vice the cost of doing


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