Climate: Rain, Temp
Geology: Surface
Soils, Plants
Subsurface
Climate: Rain, Temp
Geology: Surface
Soils, Plants
Subsurface
Langley = 1
cal/cm2
CD > AB means more
light absorbed by atm,
less to surface
Great Lakes = 105 Langleys/day Dec
500 langleys/day summer
Reflection is measured by “albedo”
Absorption
by surface
Reflection by
atmosphere
Reflection
by surface
Absorption by atm.
Month
Dec.
Summer
Langley
105
500
Albedo
80-90% (snow)
Wind from south and west
Prairie!!
Forest locations
Soil deposits
Wind from North, sometimes east
Bending direction of air mass (dishpan) leads to thermals: thunderstorms,
rapid temperature change (40-50 degrees). 1/2 Chicago moisture = Tstorm
Shifting wind directions, give rise to thermals, which give rise to thunderstorms
Prairies!!
Chicago not really part of this classificaton : cold winters, no dry season, cool
summer
Lake effect: Material flow within the lake.
Movement of sand south, also movement of pollutants north
“Whiting” of the Lake occurs in the warmer months. CO2 rises due to
Biological activity. The high calcium content of the lake (Silurian reef!)
Results in CaCO3 precipitation. The amount of Ca depends upon
Particulate matter stirring of the lake bed and sides.
Particulate matter as
Measured by satellite
Reflection measurements
Program Goal to create an integrated observational and numerical modeling
program for the winter-spring resuspension event(s) and to assess their
impact on the transport and transformation of biogeochemically important
materials and on lake ecology. Three fundamental hypotheses focus this
program:
Hypothesis 1: The plume is a result of the first winter-spring storm after
ice-out and represents the resuspension of particulate materials (and
associated constituents have been stored in the lake as surface sediment
"floc" for a distribution of times, during which they have undergone
differential diagenesis.
Hypothesis 2: The forced, two-gyre vorticity wave response of the lake to
episodic wind events, occasionally modified by stratification, is a major
mechanism for nearshore-offshore transport of particulate matter and
associated constituents in the Great Lakes.
Hypothesis 3 : Physical processes, (e.g. resuspension, turbulence) associated
with the plume event are important in determining the nutrient and light
climate, and in structuring the biological communities throughout the spring
isothermal period, and in setting the conditions for the critical 'spring bloom'
period.
Lake Effect
1. Wind direction
2. Microclimate
3. Regional climate
4. Currents
5. Surface deposits and
Erosion (bluffs and sand)
No ice means more evaporative loss of water
Water levels important in determining water temp and bacteria counts
Beach closings
No scientific basis, but rise and fall used to be on an ~11 year cycle
Lake Levels – Predicting the Effect of Global Warming
Drier climate
Means soil
And plants
Will adsorb
More water
Less runoff
Into the lake
Predicted Effects of Lake level fall
1.
2.
3.
4.
5.
Broader beaches
Boaters will have less access to docks and marinas
Commercial navigation crippled – have to carry lighter loads
Completely unknown effect on lake biology (invasive species etc.)
Alteration of water withdrawals policies for NE Illinois
Troubles discussed in this
Article are primarily related
To marina access
N
Average wind
Directions (average
Over OHare/Midway
High thermals rising = Bird migrations
Shore breeze – temperature gradients in flora along lake front
Shore breeze – effects on pollutants
Shore breeze – effects on placement of sand dunes, bluffs
Wave action
depends on distance
traveled.
Wave breaks when water
depth = 4/3 wave height.
Lake effect: precipitation and microclimates
Fetch = distance that waves can build as well as clouds.
For non-snow determines wave height and surges. A big wind
can mass transport water at 5% speed of wind = Lake Shore Drive
closings.
Lake effect on frost free days!!! Should have fewer frost free period, frost
free days variable in Chicago area = microclimates
Plant hardiness zones
Variable rainfall within Chicago area results indifferent microclimates
Large diversity of ecological niches. Chicago average 34 inches. S. Dunes, 36
Rainfall variation nationally
Restricts prairie to west.
Pennisula survives: thunderstorms
Does not extend further east (rain)
Rain
Bedrock
Surface deposits
South moving
sand
Wetlands
Geology
Weather
West Nile Virus!
Habitat Diversity = Species Diversity
From: Species Diversity in Space and Time, Michael L. Rosenzweig
Summary
1. Winds are generally from west during the hot summer
Means blowing soil from west, deposits to east
Means, fire blows east, stops on western side of rivers
Means, forests used to lie to the eastern side
2. Jet stream shifts = thunderstorms, = survival of prairie outside of
current climatic range
3. Lake effect
1. Lake breezes, wave action – sand and bluffs
2. Lake breezes, thermals – bird migrations
3. microclimates along lake, large variations in ppt and temp
= very high biological diversity!
Last time: we finally set up an experiment worthy of an
An air pollution expert
NE
NNE
N
ENE
61
46
E
30
15
0
-15
-30
-46
-61
0
15
30
46
61
SE
Incinerator 1994, 1995, 1998
Backtrajectories
July 5, 2000
July 27, 2000
July 17, 2000
[ng/m3]
10000
1000
ng/m3
TXRF
Martina Schmeling
LUC
Spectrochim. Acta B
In Press
100
10
Pb
1
0.1
0.01
S
K
Ca
Ti
V
5-Jul-00
Cr
Mn Fe
17-Jul-00
Ni
Cu
27-Jul-00
Zn
Br
Sr
Pb