Transcript Isobars

Isobars and Air Pressure
Eric Angat
Teacher
Isobars
line of constant pressure
http://clem.mscd.edu/~sng1/MTR2400/LP8.htm
Isobars
line of constant pressure
What is the direction of the wind?
Low pressure means
bad weather. The wind
rotates
High pressure means
COUNTERCLOCKWISE.
good weather. The wind
rotates CLOCKWISE.
http://ww2010.atmos.uiuc.edu/(Gl)/guides/maps/sfcobs/cntr/wind.rxml
Air Pressure Explained!
1. What happens to the density of air as we go
higher up in the atmosphere?
2. When does air contract?
3. When does air expand?
4. What is a barometer?
5. What does it mean by low pressure (L)?
6. What does it mean by high pressure (H)?
Air Pressure Explained!
https://www.youtube.com/watch?v=jmQ8FWnM0fA
http://spot.pcc.edu/~lkidoguc/Aquatics/AqEx/Water.htm
Air Pressure Explained!
1. What happens to the density of air as we go higher up in the atmosphere?
The density of air decreases because of lower air pressure.
2. When does air contract?
Air contracts when it is cooled.
3. When does air expand?
Air expands when it is heated.
4. What is a barometer?
Barometer is an instrument that measures air pressure.
5. What does it mean by low pressure (L)?
Low pressure means bad weather and precipitation.
6. What does it mean by high pressure (H)?
High pressure means good weather.
Isobar Contours
7. What is the average atmospheric pressure?
8. What are low pressures?
9. What are high pressures?
10. What is the interval between isobars?
11.Which states have bad weather?
12. What do you notice about the distances
between isobars in areas of low pressure
compared to the area of high pressure?
http://theweatherwiz.com/school/chpt2a.htm
Isobar Contours
Isobar Contours
7. What is the average atmospheric pressure?
1013 millibars
8.
What are low pressures?
Lower than 1013 millibars is low pressure.
9.
What are high pressures?
Higher than 1013 millibars is high pressure.
10. What is the interval between isobars?
Interval is 4 millibars
11. Which states have bad weather?
Arizona and Tennessee
12. What do you notice about the distances between isobars in areas of low
pressure compared to the area of high pressure?
Isobars in low pressure areas are closer to each other while
isobars of high pressure areas are farther away from each other.
13. How do I draw Isobars
http://facweb.bhc.edu/academics/science/h
arwoodr/GEOL101/Labs/Wind/index.htm
Isobars are lines of constant pressures.
1024
Isobars have
1022 intervals of 4 mb.
1036
1027
1033
1035
1029
992
996
1000
1004
1008
Isobars are lines of constant
pressures.
1024
1036
1027
1033
1035
1029
1022
Find the
lowest air
pressure that
has an
interval of 4.
Isobars have intervals of 4 mb.
1024
1036
Not
windy
1033
1035
Connect the
1022 isobars starting
from 1024 mb.
1027
1024 mb
1029
1028 mb
1032 mb
windy
1036 mb
Isobars are lines of constant
pressures.
13. How do I draw Isobars
Isobar lines are drawn across
equal air pressures with interval
of 4 millibars. When isobars are
close to each other, it is windy.
When isobars are farther away
from each other there is light
wind.
Predict the Weather
14. What are isobars?
15. What kind of wind is present when
isobars are close together?
16. What kind of wind is present when
isobars are wider apart from one
another?
17. Why do we need to know the direction
of the wind when predicting the
weather? Think!
Predict the Weather
http://mrsdlovesscience.com/weathermap.html
Predict the Weather
14. What are isobars?
Isobars are lines of constant pressures.
15. What kind of wind is present when isobars are close
together?
Wind is strong.
16. What kind of wind is present when isobars are wider apart
from one another?
Wind is light.
17. Why do we need to know the direction of the wind when
predicting the weather? Think!
So that we can predict the direction of the front.
18. Using the weather map,
identify the air pressure in the following states.
16
20
16
12
24
H
8
L
KEY:
a. California __1016__________
b. Nevada _____1020______________________
c. Utah, Wyoming, Colorado ______1024______
d. North Carolina _______1012_____________
e. Indiana, Ohio, Kentucky ______1008________
f. Wisconsin _________1012________________
19. Which states are experiencing good weather?
______ Utah, Wyoming, Colorado _________
20. Which states are experiencing bad weather?
____ Indiana, Ohio, Kentucky ______