1. Summarize Winter Lab Activities
2. Review Weather Maps & Finish Map Exercise
NREM 407/507
February 5
Day 8
3. Begin delineating watersheds on topographic maps
Should now be finished reading through page 75 and begin
pages 76-95 in Reading Material
Winter Lab Assignment Due Tuesday - Feb 17 - Please have one
team member e-mail me the exercise product with written
verification that all other team members have edited the submitted
copy
Francisco
Team Activity
Florida Citrus & Strawberry crops
threatened by hard freeze
4-6 hours of 28 F (-2 C) last night.
Why? – use weather map to explain.
What are wind directions at Ames,
Atlanta, cost of N Carolina – be
prepared to show that on this map.
Explain why irrigating crops might
help
• what is the science behind it
• how long do they have to irrigate to
provide the benefit
• will it protect the crops below 28 F
(-2 C)?
6 am Today
Describe what is Midnight
Today
happening on
these 2 maps
What is snow? – What is needed for snow to
form?
Snow is frozen water crystals that have frozen
around a nuclei – which grow by vapor
diffusion and freezing onto snowflakes.
How do snowflakes move differently than
raindrops, sleet or hail when falling?
How did we compare this? What does it mean
for snow packs & streamflow? What kind of
areas catch snow & produce streamflow?
Very light – influenced by wind, because they
are not liquid they do not infiltrate but can be
further blown once on the ground – can stick
together and deform around objects.
What effect does snow have on the macro- and microclimate?
Albedo – reflects between 40-90% of solar radiation – energy not
absorbed by the surface. This keeps surface air cold
Insulates things below it – high air to water content – air poor
conductor of heat.
How does water storage differ between snow and rain? (How long
has snow been on the ground at Soper’s Mill this winter?) What
happens to snow stored in a snowpack over time?
Snow is stored as interception storage, more in depressions and
areas of calm. Rain is stored briefly in surface depressions before
entering surface water (streams, ponds, lakes) or the soil mantle.
How do animals cope in the winter?
Changing body mass & fat
Changing social structure - herding
Selecting/ creating favorable
microhabitats
Entering dormant state of torpor –
short periods of slow down
Hibernating – up to 9 months of
reduced metabolism
Migrating
What are differences in overwintering strategies of conifers
& deciduous trees &
herbaceous plants?
Why are red cedar the only
true native conifers in Iowa?
Snow Catch in Western
Conifer Forests
Why would reduction in forest cover in
small units result in more snow pack?
Decreased canopy interception & calm
conditions for deposition
Why would reduction in forest cover
result in more stream flow? (Think
winter & summer)
More snow pack to melt &
Less ET in previous year means less
snowmelt needed for soil moisture
recharge – more for stream flow.
Slow grow rate of high elevation
conifers means harvest effect on
stream flow may last up to 60-70 years
Average snow depth in the forest was 12 inches (30.5 cm) & in open field 4
inches (10.1 cm).
If the snow has a 30% density how many inches, cm of water is that?
12 in x 0.3 = 3.6 in (9.1 cm)
4 in x 0.3 = 1.2 in (3 cm)
How many acre-ft, cubic feet, cubic meters, gallons, liters is that?
3.6/12 = 0.3 ac-ft X 43,560 ft2/ac = 13,068 ft3 (365 m3) x 7.48 gal/ft3 = 97,748 gal
(371,445 liters)
1.2/12 = 0.1 ac-ft X 43,560 ft2/ac = 4,356 ft3 (122 m3) X 7.48 gal/ft3 = 3,358 gal
(123,815 liters)
Corn transpires 4,000 gal/acre/day Forest transpires – 6,000 gal/ac/day – how
many days of worth of transpiration is this snow equivalent to?
(Forest – 16 days – cornfield – 0.8 days)
X
Team Activity
Create diagrams to show valley components – side slope, nose slope, head
slope, divide, interfluve
Create a diagram to show slope components – summit, shoulder, backslope,
footslope, toe slope.
Be prepared to explain how these each impact water movment.
Team Activity
Watershed
Concave
Convex
Valley
Components
Slope
Components
Valley and Slope Components
Assignment:
•
•
•
•
•
•
Short piece for a Wikapedia – limited by space
Four topics – each team member writes one section
A section is limited to 225-250 words
Sections need to transition from one to the other
Each member will edit whole paper
One member will e-mail to me
Due one week from Tuesday (Feb 17).
Oriented NE to SW
Cold Front
NE
Slope of Frontal Surface = 1:50
to 1:150 (1 mile vertical for each
mile horizontal)
Move at 10-40 mph
SW
Wind
Speed
Wind shift with
in
passage SW to NW
Cold
Clouds – cumulus (vertical) Air
Rain – short, intense
right at front
Warm Air
Warm Front
Oriented NW to SE
Slope of Frontal Surface =
1:100 to 1:300
Move at 5-20 mph
NW
Wind shift with passage ENE to SW
SE
Clouds –
stratus
Rain – long,
gentle ahead
of front
Development of
Occluded Front
Faster moving cold
front catches up to
warm front lifting
warm air off the
ground
Draw Isobars – Plotting those evenly divisible by 4 mb – Begin with 1004
around L on Wave Cyclone
1020
H
1024
H
1028
1024
1020
1008
1016
1012
Questions a 1-3
L
1004
H
cP
H
H
L
H
1008
L
1004
mT
Questions a 4 & 5
H
Calm &
Dew Point =
Actual Temp
H
Fractostratus
Of Bad Weather
1008
H
L
1004
Wind
off
warmer
water
Questions b 1-4
Cumulonimbus
with anvil shaped top
H
Falling
cP
Steady then falling
H
Steady
H
L
Rising
1008
L
1004
mT
Question b 5
H
Start with c 1-2
H
~170o
H
L
H
~60o
L
1004
500/24 = 21 mph
Question c 1-2
400/24 = 17 mph
H
275/12 = 23 mph
125/12 = 10.5 mph
Counterclockwise
Backing
Veering
Clockwise
Backing
Counterclockwise
12 hrs
Questions c 3-6
New Orelans
7 pm