TA: Courtney Obergfell

TA : Courtney Obergfell Discussion: Wednesdays 12:05-12:55

PM, Room 823 AO & SS Office: AO & SS Room 1311 Email: obergfell@wisc.edu 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 FrontNameEmailYear Intended Major

On BackWhy you signed up for a discussion sectionTopics 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.

GovernmentNational Weather Service: issues forecasts,

warnings, fire weather, etc.

MilitaryResearch: develops forecast models, research

hurricanes, tornadoes, climate, develop satellites, etc.

Private 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.

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 72 stations in the U.S. (~900 worldwide)

Measures temperature, dewpoint, wind speed and direction and pressure as it rapidly rises throughout the 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.).