SRI STORE Lessons: Question and Answer Key - Updated 1-18-13
Lesson
Question #
Question
Answer
Basic
Lesson 1
1
What is the relationship between air
temperature, saturated H20 content, and
relative humidity? Provide a short
answer. Hint*: look at the equation for
relative humidity and Figure 2.
Ambient air temperature↑: saturated H20 content↑: relative humidity↓. At higher air temperatures, the
saturated moisture content of the air is higher, resulting in lower relative humidity (assuming no
moisture is added to the air).
2
What is the relationship between
elevation, pressure and temperature?
Provide a short answer.
Elevation↑: pressure↓: temperature↓. At higher elevation both pressure and air temperature are typically
lower.
3
The relative humidity is 70% at a noontime temperature of 75°F (297°K). How
much must the air cool for dew to form
that night?
Td = (70/100)1/8 (112 + 0.9 (297)) + 0.1(297) – 112
Td = (0.956)(379.3) + 29.7 – 112
Td = 362.8 + 29.7 – 112
Td = 280.5°K = 7.3°C = 45.2°F
In Fahrenheit, 75° - 45.2° = 29.8° (i.e., the air must cool 29.8° that night for dew to form)
The relative humidity is 90% at a noontime temperature of 75°F (297°K). At
what temperature will dew form that
night?
Td = (90/100)1/8 (112+0.9 (297)) + 0.1(297) – 112
5
If Td = T, what is relative humidity?
Relative humidity = 100 %
6
As shown in Figure 3, the NWS
meteorological balloon released from
Edwards AFB , CA on August 4, 2010
measured a temperature lapse rate from
the surface to an elevation of 9,000 m of
6.1°C/1,000 m. During initial release of
the balloon, the temperature and relative
To answer this, we calculate the dew point temperature using Equation 3:
4
Td = 292.0°K = 18.9°C = 66.0°F
Td = (r/100)1/8 (112+0.9T) + 0.1T – 112
Td = (70.4/100)1/8 (112+0.9 (292)) + 0.1(292) – 112
Td = (.957) (374.8) + 29.2 – 112
Lesson
Basic
Lesson 2
Basic
Lesson 3
Question #
Question
Answer
humidity at the ground surface (i.e., sea
level) was recorded as 18.8°C and
70.4% respectively. At what elevation
will the air become saturated? Hint*:
first calculate the dew point.
Td = 275.9°K = 2.7°C
7
Why is relative humidity important?
Higher relative humidity increases the likelihood that water vapor will condense and cause precipitation
1
Compare values among the stations.
Which station recorded the most annual
precipitation? How does elevation at this
weather station compare with the
elevation of the other weather stations?
According to your answers to the above
questions, do precipitation and elevation
appear to be closely aligned?
The Twin Lakes weather station has highest recorded annual precipitation and the highest elevation
compared with the other weather stations.
2
As you move your eye along the terrain
path, what pattern do you see in
precipitation in relation to elevation?
Based on your understanding of
orographic rainfall (first introduced in
Basic Lesson 1), provide a simple
explanation as to why this pattern
occurs.
As elevation increases precipitation increases. As air rises and climbs in elevation and is forced over
mountains, air moisture condenses and rain falls.
1
How does the lapse rate from
temperature recordings by the
radiosonde balloon compare to the lapse
rate from temperature recordings from
the ground stations? Which lapse rate is
faster and why?
A decrease in air temperature from 18.8°C to 2.7°C will cause saturation of the air. The required
decrease is 16.1°C. The elevation at which this decrease will occur is:
16.1°C ÷ 6.1°C/1,000m = 2,515 m
Yes, precipitation and elevation appear to be closely aligned.
The temperature lapse rate within the atmosphere recorded by the radiosonde balloon is greater than the
lapse rate recorded at the ground stations on the surface. This occurs because the Earth is a source of
heat and warms the air near the ground station. Calculations:
2438m (Twin Lakes elevation) -20.40m (San Jose elevation) =241m;
21.61°C (San Jose July Ave Temp)-14.00°C (Twin Lakes July Ave Temp)=7.61°C
7.61°C (temp difference)/2418m (elevation difference) = x°C /1000m
7610=2418x
x=3.14°C (i.e., a 3.14°C change in temperature for every 1000 meter change in elevation)
Lesson
Basic
Lesson 4
Question #
Question
Answer
2
How do the temperature lapse rates for
summer (e.g., August) and winter (e.g.,
February) compare? Which lapse rate
would you expect to be faster and why?
The February lapse rate is 7.2°C while the August lapse rate is 7.3°C. The lapse rate in February is
slightly slower than the August lapse rate. Saturated air will cool more slowly than dry air because of
condensation (adds heat to air), therefore we would expect to see a slower temperature lapse rate in the
winter compared to summer months.
1
Based on what you now know about the
elevation ranges of these four types of
vegetation communities, identify a type
that is likely to have a shrinking habitat
in the California Study Area if global
warming predictions come true, and
explain why. Hint: Think about what
elevation ranges support the different
vegetation types and about the
topography of the Study Area.
As learned in Basic Lesson 1 and 3, elevation influences temperature. At higher elevations climates tend
to be colder but these climates may get warmer with climate change. Given that the topography of
California limits how high in elevation different vegetation communities can go to if the lower
elevations get too warm for them, it is appropriate to argue that vegetation types that live within
mountain ranges that peak at lower elevations are the ones most likely to experience the biggest
proportional shrinkages of their habitats.
2
What range of precipitation totals is
associated with high concentration of
deciduous forests and how does this
compare to the range of precipitation
totals associated with high
concentrations of evergreen forests?
3
Which do you think would be worse for
most plants, an intolerably high monthly
peak temperature or a sustained yet
slightly lower high temperature? Why?
(NOTE: there is not a simple correct
answer for this question.
Deciduous Forests precipitation range: ~20-50 inches
Evergreen Forests precipitation range: ~20-70 inches
NOTE: There is not a simple correct answer to this question. Scientists continue researching which
forms of temperature stress exert the most damage on different plants. Mediating factors may include
time of day in which the intolerably extreme temperature is reached, or the specific plant’s metabolic
structure. For more on this topic, see Wahid, A. Gelani, S, , Ashraf, M, Foolad. M.R. (2007). Heat
tolerance in plants: An overview. Environmental and Experimental Botany 61. 199–223. The article can
be retrieved at http://startinternational.org/library/archive/files/heat-tolerance=eeb2007_fc9bd2df67.pdf. As stated in that article, “Heat stress is often defined as the rise in temperature
beyond a threshold level for a period of time sufficient to cause irreversible damage to plant growth and
development. In general, a transient elevation in temperature, usually 10–15 ◦C above ambient, is
Lesson
Question #
Question
Answer
considered heat shock or heat stress. However, heat stress is a complex function of intensity
(temperature in degrees), duration and rate of increase in temperature” (p. 200).
Advanced
Lesson 1
4
Think of a place in the world where the
extremes in July and January would be
the opposite. Why?
Any place in the Southern Hemisphere
5
Now that you understand more about the
STORE temperature data, study the
relationship between that data and the
ranges of evergreen and deciduous
forests. Which of the two types of trees
seem to be more tolerant of temperature
extremes, evergreens or deciduous?
Justify your answer with evidence from
the data.
Evergreen Forests:
Deciduous Forests:
0.1 degrees F average January daily lowest
temperature
25.1 degrees F average January daily lowest
temperature
100 degrees F July average daily highest
temperature
100 degrees F average July daily highest
temperature
-20 degrees F average January lowest temperature
10.1 degrees F average January lowest temperature
110 degrees F average July highest temperature
110 degrees F average July highest temperature
1
Based on Basic Lessons 2 and 4, would
you expect the change in precipitation to
be uniform across the California Study
Area? Why or why not?
No, precipitation is greater at higher elevations on the western side of a mountain range.
2
How does projected year 2050
precipitation within the California Study
Area compare to recent precipitation?
Does precipitation increase or decrease,
and is the change in precipitation
uniform across the California Study
Area?
Precipitation is projected to increase slightly near the Mount Hamilton weather station and decrease at
the other weather stations.
3
You should notice that the range of
deciduous forest will decrease. Will the
range move eastward or westward? Why
Move eastward up the Sierra Mountains, because generally there is greater precipitation at higher
elevations.
Lesson
Question #
Question
Answer
might it move in this direction?
4
Advanced
Lesson 2
You should notice that the range of
evergreen forests will decrease slightly.
Will the range move eastward or
westward? Why?
Move eastward up the Sierra Mountains, because generally there is greater precipitation at higher
elevations.
1
To try to predict the fate of different
plant species in 2050, why study
projected highest temperatures rather
than projected lowest temperatures?
As part of global warming, temperatures are projected to increase, so occasional extreme low
temperatures that may currently stress various plants in the California Study Area are likely to occur
less, whereas stress-inducing highs are likely to occur more.
2
Study the legends showing the recent
average daily highest July temperatures
and the average daily highest July
temperatures projected for 2050? How
do they compare? (Note: the average
daily highest temperature is the average
of all the highest temperatures reached
daily over the course of the month.)
The daily highest temperature in the California Study Area is projected to shift from a recent average of
100 degrees Fahrenheit to 114 in 2050.
3
How are the ranges of deciduous and
evergreen forests projected to move
within the California Study Area
between now and 2050?
Move eastward up the Sierra Mountains, because the temperatures are generally projected to warm less
at higher elevations.
4
Comparing your analysis in Advanced
Lesson 1, what do you predict will have
a greater influence on vegetation:
changing temperatures or precipitation?
[Hint: Which ranges move and shrink
most, those based on projected
precipitation or those based on projected
Temperature.
Lesson
Question #
5
Question
temperature?]
Conduct some research about what it
takes for a plant species to successfully
adapt to a changing environment.
Broadly speaking, what factors could
make one species adapt more
successfully than another. From your
research, can you identify individual
species within the different vegetation
communities that are likely to adapt
more successfully to the warming
California climate than others?
Answer
Examples of possible factors include (1) reproduction rate, (2) how the seeds are spread, or (3) whether
they are more susceptible to threats from naturally occurring pests or diseases that would thrive in
longer warm seasons or longer dry seasons. For more on this subject, see these professional scientific
research articles:
Climate Change and the Future of California's Endemic Flora
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2481286/
Modeled regional climate change and California endemic oak ranges
http://www.pnas.org/content/102/45/16281.full.pdf+html
(Note: these articles would be challenging reading for your students. Consider assigning them excerpts
and offer assistance such as definitions of difficult vocabulary.)