Lecture on climate and weather ppt .pptx

WEATHER AND CLIMATE

1. NATS 101
Lecture 3
Climate and Weather

2. Climate and Weather
“Climate is what you expect.
Weather is what you get.”
-Robert A. Heinlein

3. Weather
Weather – The state
of the atmosphere:
for a specific place
at a particular time
Weather Elements
1) Temperature
2) Pressure
3) Humidity
4) Wind
5) Visibility
6) Clouds
7) Significant Weather

4. Surface Station Model
Temperatures
Plotted F in U.S.
Sea Level Pressure
Leading 10 or 9 is
not plotted
Examples:
1013.8 plotted as 138
998.7 plotted as 987
1036.0 plotted as 360Ahrens, p 431
Responsible for boxed parameters

5. Sky Cover and Weather
Symbols
Ahrens, p 431
Ahrens, p 431

6. Wind Barbs
Direction
Wind is going towards
WesterlyWesterly  from the West
Speed (accumulated)
Each flag is 50 knots
Each full barb is 10 knots
Each half barb is 5 knots
Ahrens, p 432
65 kts from west

7. temperature
dew point
SLP pressure
wind
cloud cover
Ohio State website

8. Practice Surface Station
Temperate (
o
F)
Pressure (mb) Last
Three Digits (tens,
ones, tenths)
Dew Point (later)
Moisture
Wind Barb
Direction and Speed
Cloud Cover Tenths
total coverage
Ahrens, p 431
72
58
111
Decimal point
What are Temp, Dew Point,
SLP, Cloud Cover, Wind
Speed and Direction?

9. Practice Surface Station
Sea Level Pressure
Leading 10 or 9 is
not plotted
Examples:
1013.8 plotted as 138
998.7 plotted as 987
1036.0 plotted as 360
Ahrens, p 431
42
18
998
Decimal point
What are Temp, Dew Point,
SLP, Cloud Cover, Wind
Speed and Direction?

10. Surface Map Symbols
•Fronts
Mark the boundary
between different
air masses…later
Significant weather
occurs near fronts
Current US Map
Ahrens, p 432

12. Radiosonde
Weather balloons, or
radiosondes, sample
atmospheric to 10 mb.
They measure
temperaturemoisture
pressure
They are tracked to get
winds
Ahrens, Fig. 1

13. Radiosonde Distribution
Radiosondes released at
0000 and at 1200 GMT for a
global network of stations.
Large gaps in network over
oceans and in less affluent
nations.
Stations ~400 km apart over
North America

14. Radiosonde for Tucson
Example of data taken by
weather balloon released
over Tucson
Temperature (red)
Moisture (green)
Winds (white)
Note variations of all fields
with height
UA Tucson 1200 RAOB
troposphere
stratosphere
tropopause
temperature
profile
moisture
profile
wind
profile

15. Climate
Climate - Average weather and range of
weather, computed over many years.
Whole year (mean annual precipitation for
Tucson, 1970-present)
Season (Winter: Dec-Jan-Feb)
Month (January rainfall in Tucson)
Date (Average, record high and low
temperatures for Jan 1 in Tucson)

18. Climate of Tucson
Monthly Averages
Individual months can show significant
deviations from long-term, monthly means.

19. Average and Record
MAX and MIN
Temperatures for Date

20. Climate of Tucson
Probability of Last Freeze
Cool Site: Western Region Climate Center

21. Climate of Tucson
Probability of Rain
Cool Site: Western Region Climate Center

22. Climate of Tucson
Extreme Rainfall
Cool Site: Western Region Climate Center

23. Climate of Tucson
Snow!
Cool Site: Western Region Climate Center

24. Summary
•Weather - atmospheric conditions at
specific time and place
Weather Maps  Instantaneous Values
•Climate - average weather and the range
of extremes compiled over many years
Statistical Quantities  Expected Values

25. Reading Assignment
•Ahrens
Pages 25-30
Problems 2.1-2.4
(2.1  Chapter 2, Problem 1)
•Don’t Forgot the 4”x 6” Index
Cards…