Transcript Welcome to aos 101: weather and climate

TA: Courtney Obergfell
 TA
: Courtney Obergfell
 Discussion: Wednesdays 12:05-12:55 PM,
Room 823 AO & SS
 Office: AO & SS Room 1311
 Email: [email protected]
 Office Hours: Mondays 11:00 AM-12:15 PM,
Tuesdays 2:40-3:40 PM, or by appointment
 Discussion Website:
http://www.aos.wisc.edu/~aos101co
 On
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Name
Email
Year
Intended Major
 On
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Front
Back
Why you signed up for a discussion section
Topics you’d like covered
 Hand
in HW
 Short quiz
 Weather/Map Discussion
 Review of last week – questions?
 New lecture topic

Atmospheric Science: the comprehensive study
of the physics, chemistry, and dynamics of the
earth's atmosphere, from the earth's surface to
several hundred kilometers.

Oceanography: The scientific study of oceans,
the life that inhabits them, and their physical
characteristics, including the depth and extent
of ocean waters, their movement and chemical
makeup, and the topography and composition of
the ocean floors.
 Government
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National Weather Service: issues forecasts, warnings,
fire weather, etc.
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Military
Research: develops forecast models, research hurricanes,
tornadoes, climate, develop satellites, etc.
 Private
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Industry
commodity trading (agriculture, oil), energy
companies (oil, wind farms), insurance/risk
management, forecasting firms (transportation,
construction, radio stations, etc.), air quality
 Academia
 Television
 Daily
concerns – What to wear, flight delays,
etc
 Agriculture and Food concerns
 Safety
 Insurance and property damage
 Future
 Observations
allow meteorologists to assess
the current state of the atmosphere
 Usually
taken at the same time using the
same standardization across the country to
be consistent
 Taken
by people or automated sensors
 Temperature
 Dewpoint
 Barometric
Pressure
 Wind Speed and Direction
 Cloud Cover
 Present Weather
 Cloud Type
 Etc…
 Ships
 Buoys
 Commercial
Aircraft (ACARS)
 Satellite
 All
of this data goes into forecast models
Both are measured with a hygrothermometer
which is shielded from the effects of direct
sunlight.
 Dewpoint is the temperature at which the water
vapor in the atmosphere condenses into liquid
water.
 Dewpoint is not the same as Relative Humidity.
 Scientists and most of the world uses the Kelvin
or Celsius scale, while the U.S. still uses the
Fahrenheit scale.
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Tk  Tc  273.15
Tf  9  (Tc  32)
5
Tc  (Tf  32) * 5
9
Measured with
barometer
 Units of hectopascals
(hPa), millibars (mb) or
inches of mercury (in
Hg)
 Reported values are
adjusted to sea level -otherwise pressure
maps would simply
reflect topography
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 Anemometer
measures
speed
 Weather vane tells us wind
direction
 Speed measured in knots:
1 knot = 1.151 mph
 1 knot = 0.514 m/s
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 Weak
hurricane has winds
over 65 knots (75mph)!
http://www.spl.org/images/branc
h/BAL_art/anemometer.jpg
 Amount
and height
 Cloud type is done by sight only

Balloons with
“radiosondes” attached
are released twice per
day at 72 stations in the
U.S. (~900 worldwide)
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Measures temperature,
dewpoint, wind speed
and direction and
pressure as it rapidly
rises throughout the
atmosphere
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Atmospheric
“soundings” are created
from these observations.
These help
meteorologists
understand the vertical
profiles of temperature,
dewpoint, etc
A
very large amount of weather data can
be retrieved from a given weather station
Temperature – In U.S., expressed in degrees
Fahrenheit. Most other countries, in degrees
Celsius.
 Dewpoint – Expressed in same units as
temperature.
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Wind Direction – The line drawn represents the direction
from which the wind is blowing.
Wind Speed – Represented as barbs on the line. Wind
speed is measured in knots
 Short barb = 5 kts
 Long barb = 10 kts
 Triangle = 50 kts
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Surface Pressure – Adjusted to sea level. Units are in mb.
 - If reported value is greater than 500, the initial 9 is
missing. Place it on the left and divide by 10. I.e.: 827 =
982.7mb
 - If reported value is less than 500, the initial 10 is missing.
Place it on the left and divide by 10. I.e.: 027 =
1002.7mb.
Pressure Tendency – Change in pressure over last three hours.
Change in pressure is represented by a value and line
indicating how the pressure was changing.
 Total
cloud amount represents the
fraction of the sky covered
Visibility – How far we can see from the
observing point, expressed in units of miles.
 Present weather conditions – Symbols are used to
convey this information (rain, snow, ice, etc.).
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