TA: Courtney Obergfell. TA : Courtney Obergfell Discussion: Thursdays 2:25-3:15 PM, Room 823 AOS ...

TA: Courtney Obergfell

TA : Courtney Obergfell Discussion: Thursdays 2:25-3:15 PM,

Room 823 AOS Office: AOS Room 1311 Email: obergfell@wisc.edu Office Hours: Mondays 1:30-2:45PM,

Tuesdays 2:45-3:45 PM, or by appointment

Discussion Website: http://www.aos.wisc.edu/~aos101co

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Attendance Hand in HW Weather 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.

Meteorology: day-to-day weather, study of weather systems (snowstorms, tornadoes, etc.), forecasting

Climatology: study of long term trends, large-scale phenomena (El Nino), climate change

Atm. Chemistry: pollution, ozone layer

Atm. Physics: how clouds/rain forms, using satellites to observe planet

Oceanography: ocean currents, carbon cycle, effect on atmosphere

Government: National Weather Service: issues forecasts,

warnings, fire weather, etc.Research: develops forecast models, research

hurricanes, tornadoes, climate, develop satellites, etc.

Military

Private industry: commodity trading (agriculture, oil),

energy companies (oil, wind farms), insurance/risk management, forecasting firms (transportation, construction, radio stations, etc.), air quality

Academic: Teaching, research

Broadcast: Television and radio forecasts

Daily concerns – What to wear, flight delays, etc

Agriculture and Food concerns Safety Insurance and property damage Future

January 28, 2010

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

Ships Buoys Commercial Aircraft (ACARS) Satellite

All of this data goes into forecast models

Temperature Dewpoint Barometric Pressure Wind Speed and Direction Cloud Cover Present Weather Cloud Type Etc…

Both are measured with a thermometer which is shielded from direct sunlight.

DewpointDewpoint 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.

Tk Tc 273.15

Tf 95 (Tc 32)

Tc (Tf 32)* 59

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

Anemometer measures speed

Weather vane tells us wind direction

Speed measured in knots:1 knot = 1.151 mph1 knot = 0.514 m/s

Weak hurricane has winds over 65 knots (75mph)!

http://www.spl.org/images/branch/BAL_art/anemometer.jpg

Amount and height Cloud type is done by sight only

Balloons with “radiosondes” attached are released twice per day at 92 stations in the U.S. (~900 worldwide)

Measures: temperature dewpoint wind speed and direction pressureas it rapidly rises

throughoutthe atmosphere

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.

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

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.).

February 4 – Sam & Danielle February 11 – Jordan & Alaura February 18 – Daniel & Brady March 4 – Will & Alexandra March 11 – Nicole & Alex M. March 18 – Kaela, Becky, & Madison March 25- Shane & Teryn April 8 – Kelly April 15- Ye Jin & Changmin April 22 – Nick O. & Sarah April 29 – Megan & Melissa May 6 – Jackson