1. By Joshua Tobias
MEA 514
12/4/13

2. • Considers the presence of
aerosols disrupting the riming
process of ice particles within
a mix phase cloud.
• A larger concentration of
aerosols within a mixed phase
cloud will delay or suppress
snowfall.
• If this occurs on the windward
side of a geographic barrier,
then ice particles may be
advected and precipitate
further downstream.

3. Lynn, B., A. Khain, D. Rosenfeld, and W. L. Woodley (2007), Effects of
aerosols on precipitation from orographic clouds, J. Geophys. Res., 112.
• Modeled a snowfall event under two separate environmental conditions:
1) Continental Polluted Conditions Caused Snowfall Spillover to occur.
2) Maritime Pristine Conditions Caused snowfall to remain primarily on the
windward side of the orographic barrier
Question to ask…
What would happen in a real life scenario, with a land locked, maritime
influenced event? (i.e. Lake-Effect Event)
How can aerosols affect lake-effect snow distribution?

4. • Focused on three
sequential Lake Effect
Storms within the Tug
Hill Plateau region of
Upstate NY
• Lake Storm Dalmatian
( Jan. 19-21 2008)
• Lake Storm English
Setter
(Jan 23-24, 2008)
• Lake Storm Fox Hound
(Jan. 25, 2008)
QUALITATIVE ANALYSIS!
• Level 3 Modis Optical Depth Maps (Giovanni)
• AirNow Fine Particle Concentration (EPA/Giovanni)
• Reanalysis Maps from National Operational
Hydrologic Remote Sensing Center’s Interactive
Snow Mapping Service: Temperature, Average
Wind, Snowfall Accumulation during 24 hour period
of maximum snowfall.

5. • First and strongest
storm of the
three, with
accumulations of
up to 3 feet in
some locations.
• Highest snowfall
confined to lake
shore, with some
blow over beyond
the plateau. • Defined by a single band that developed from a westerly
flow, with the strongest winds along the southern shore 10
to 15 mph.
• Note: Winds averaged for the 24 hour period of highest snowfall.

6. • MODIS displayed optical
depths between .125 and .155
• Very LOW Maritime
Concentration
• AirNow Concentrations
reaching 10.3 μg/ m^3
• Also low by EPA standards
• Good Air Quality

7. • Low concentrations of aerosols confine the bulk the major
snowfall to the windward side of the Tug Hill Plateau
• Any spillover displayed may be attributed to the stronger
surface winds over the lake.

8. • Quickly followed Lake Storm Dalmatian, after the passage of a frontal
system. Arctic air reestablished itself over the Tug Hill Region.
• The flow is similar to that of Dalmation, but the winds were much
weaker, at 5 to 10 mph.

9. • Aerosol optical depth over
Lake Ontario proved to be
even lower or mixed out after
the frontal passage
• However, AirNow fine
particle concentration were
much higher along the
Southern Lake shore during
English Setter.
Concentrations ranged
between 10.4 and 13.1 μg/m^3

10. • The narrow band that developed during English Setter can clearly be
seen in the 24 hour snowfall map.
• However, unlike in Lake Storm Dalmation, the extension of snowfall
is much further inland. Snowfall appears to occur further into the
Adirondacks, despite lower average winds off the lake.

11. • Represents the weakest of the three storms, with only a narrow band of
heavy snow developing over Jefferson and Oswego County (close to the lake
shore).
• Winds and temperature were comparable to Lake Storm English Setter.

12. • Aerosol concentrations prove
to low both over Lake Ontario
and New York during Fox
Hound.

13. • Despite lower aerosol concentrations during Fox Hound, an extension
of snowfall accumulation inland still occurred.
• Unlike in English Setter though, a slight Northwest shift in the
prevailing flow occurred. This could have caused the further
distribution of snow inward.

14. • All three storms displayed snowfall redistribution that extended
inland to some extent. The general accumulations that occurred
within these locations ranged between 3 to 7 inches.
• Lake Storm English Setter displayed the highest aerosol
concentrations of the three storms. It also displayed the largest
area of displaced accumulations of the three. Possible spillover?
• The snowfall redistribution that occurred within Dalmatian and
English Setter could be attributed to more to the changes within
the prevailing flow at the time.
• Final Conclusion: The impact of aerosols on these three storms is
still ambiguous, but worth further investigation.
• Despite generally low concentrations, it is still possible that
aerosols could be playing some role in snowfall distribution 
English Setter

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