unit 6: atmosphere interactions and weather

Unit 6: Atmosphere Interactions and Weather

At the end of this unit you will be able to

Calculate: Dewpoint and Relative Humidity

Read and Interpret Charts in Reference Tables

Determine the height of a cloud base using a graph

Read and create station models

List the characteristics of Pressure zones, and fronts

Create synoptic maps

Laboratory Activities for this unit:

Measuring Dewpoint and Relative Humidity

Dewpoint and Cloud Formation

Hurricane Floyd

Station models

Climactic factors: Mountains and Rainfall

Coastal Vs. Continental

Prevailing wind: Winds that usually blow from a certain direction all year

Wind: horizontal movement of air in the atmosphere

Isobar: A line that connects equal air pressure

Barometer: instrument used to measure air pressure

Air pressure/ Barometric pressure: weight of the air above you

Jet Stream: Winds at the top of the troposphere

Anemometer: instrument used to measure wind speed

Evaporation: change of a liquid to a gas, water into the atmosphere

Evapotranspiration: evaporation of water from plants, water into the atmosphere

Visibility: the farthest distance you can see

Precipitation: water coming out of the atmosphere in the form of liquid or solid

Condensation: water vapor turning to liquid water to form clouds

Dewpoint: temperature at which dew (condensation) forms

Relative Humidity: what percent of the air is water

Psychrometer: instrument used to measure relative humidity and dewpoint

Air mass: body of air in the troposphere with the same temperature and humidity

Cyclone: Low pressure system, counterclockwise and towards the center, aka, a Low pressure center

Front: an interface between two different air masses

Isotherm: a line that connects equal temperatures

Climate: overall conditions of a regions weather

Insolation: Incoming Solar Radiation , sunlight

Coriolis Effect: deflection of winds and ocean currents based on the rotation of the earth.

Storm: a violent disturbance in the atmosphere

Hurricane/Typhoon: a large Low pressure that forms over warm water, with winds over 74 miles per hour

I. Interactions in our atmosphere

A. Density of air

1. As temp , it takes up more space (expands) volume , density

Analogy:

Dancing, as you dance you get hotter so you move away from each other and take up more space.


B. Wind

1. caused by density differences (different air pressure)

a. unequal heating of the earth’s surface

1. poles = low temperature

2. equator = higher temperature

The equator gets direct

light and that makes it warmer

The poles get less direct light and that makes them cooler

Wind is caused by differences in pressure

because land and water do

not heat up at the same

rate

During the day land heats up

faster causing a low pressure over the land

and high pressure over

the water

At night the water is warmer and a low pressure is found over it where the land is cooler and has a high pressure

REMEMBER:

EVERYTHING FLOWS FROM HIGHS TO

LOWS

INCLUDING PRESSURE


Wind Analogy You go to Sea Breeze during the day


3. (p 14), ESRT, Wind pattern chart

The purple arrows indicate cold air sinking a high pressure zone an area of

convergence

The light green arrows indicate

warm air rising a low pressure zone of

divergence

On your ESRT draw in the Highs and Lows and label with blue the areas of high pressure and in red the areas of low pressure


C. Water into our atmosphere

1. evaporation rates


Analogy: Surface area- wadded up towel versus a towel hanging on the rack

Analogy: Windspeed- A blow dryer on low or on high

Analogy: Temperature: a blow dryer on hot or cool


D. Water out of the atmosphere 1. Condensation: process by which water vapor is turned into a liquid.

a. energy is released, heat is given off


D. Water out of the atmosphere 2. Precipitation: clouds fill with water droplets (saturated) and cannot hold anymore and they fall to earth.

a. Types: rain, hail, snow, freezing rain, sleet

5. Dewpoint (F): point at which clouds (dew) forms

a. p. 12, ESRT

b. Dry bulb = air temp

AS air rises it cools and when the air condenses a cloud forms, we say that the dewpoint has been reached

Wet bulb.. Has a sock over the end of the thermometer

Dry bulb… just a regular thermometer

6. Relative humidity:

a. amount of moisture

(water vapor )

in the air,

b. Measured in %.

c. Use a sling psychrometer

3 things you need to have

clouds:1. Water vapor

2. Condensation Nuclei

3. Temperature to cool off & hit the DEW POINT!

Cloud types

Alto Cumulus

Fair weather Cumulus

Big and puffy

Cirrostratus

Cirrus

Cloud types

Cloud types

These clouds cover the entire sky

In Syracuse

we typically

have these clouds all

winter long

Cloud types

These are thunderstorm clouds, notice the anviling

This is caused by high winds that pull the top of the cloud

Nimbus means: RAIN

As you go up

there is less air

so the cloud expands

Practice:

1. Dry bulb = 12°C

Wet bulb = 10°C

DP = ?

Cloud height= ?

Practice:

1. Dry bulb = 12°C

Wet bulb = 10°C

DP = 8°C

Cloud height= ?

Practice:

1. Dry bulb = 12°C

Wet bulb = 10°C

DP = 8°C

Cloud height=0.5 km

2. Dry bulb = 22°C

Wet bulb = 17°C

DP = ?

Cloud height = ?

2. Dry bulb = 22°C

Wet bulb = 17°C

DP = 14°C

Cloud height = ?

2. Dry bulb = 22°C

Wet bulb = 17°C

DP = 14°C

Cloud height = 1.0 km

3. Dry bulb = 30°C

Wet bulb = 24 °C

DP = ?

Cloud height = ?

3. Dry bulb = 30°C

Wet bulb = 24 °C

DP = 21°C

Cloud height = ?

3. Dry bulb = 30°C

Wet bulb = 24°C

DP = 21°C

Cloud height = 1.1 km

Weather 3

II. Weather and Our Atmosphere

A. Weather: observations based on air temperature, dewpoint, humidity, cloud cover, wind, etc… at a certain time and location.

B. Page 13, ESRT Station Models

Station model map

NY State Station model map

II. Weather and Our atmosphere

B. Page 13, ESRT Station Models

1. Temperature

F C use thermometers above.


1. Wind direction, the place where the tail is pointing (named by where it comes from)


2. Wind speed: how many feathers are on the tail

a. whole = 10 knots b. half = 5 knots (always in 5’s)


c. Knots to MPH

1. 20 knots x 1.15 mph = ___________

2. 15 Knots = _______mph

3.______ knots = 51.75 mph


4. Barometric Pressure (air pressure)

a.Decoding adds a 10 or a 9 in front and places a decimal in between the last 2 numbers.

b. 9 in front if the value are more than 500, 10 in front if the value is less than 500


c.Examples

1. 825 = ________

2. 426 = ________

3. 922 = ________


4. Barometric Pressure

(air pressure)

d. Millibars Inches

1. Use the chart on page 13, ESRT

2. 1000.0 mb =______inches

3. ______ mb = 29.96 inches


4. Barometric Pressure

(air pressure)

e. Isobars: lines that show equal barometric pressure

1. When the lines are close together = fast wind, lines are far apart = slow wind.


Isobaric contour map


f. Measure pressure with a barometer

1. pressure above 1013.2 is considered HIGH pressure

a. Dry, cold air



1. Pressure below 1013.2 is considered LOW pressure.

a. moist, warm air


5. Dewpoint (F): point at which clouds (dew)

forms

a. p. 12, ESRT

b. Dry bulb = air temp

AS air rises it cools and when the air condenses a cloud forms, we say that the dewpoint has been reached

6. Relative humidity:

a. amount of moisture

(water vapor )

in the air,

b. Measured in %.

c. Use a sling psychrometer

7. Precipitation

a. 3 things you need to have

1. Water vapor

2. Condensation nuclei, something to form on

3.Cooling air


C. Air Masses

1.Humidity (lower case letter)

a.over water = moist and maritime

b.over land = dry and continental


C. Air Masses

2. Temperature ( Capital letter)

a.Polar = cold, near polar areas

b. Tropical = warm/ hot, near the equator, tropical areas


Air mass animation

D. Air masses and Pressure Zones

1. Warm air, rises, low pressure,

counter clockwise,moist,

below 1013.2 mb.


Pressure animation


2. Cold air, sinks, high pressure,

clockwise, dry,above 1013.2 mb.


Pressure animation

Remember

Clocks are always high on the wall , so….High rotates clockwise

Or Left hand rule!


3. Low pressure air goes into the center

4. High-pressure air goes out away from the center.


E. Air Masses and Boundaries

1. Front is an edge of an on coming air mass



2. 4 types

a.Cold, air sinks, High Pressure, FAST, close to the ground, narrow band of rain.


cold front animation


2. 4 types

b. Warm; air rises, Low pressure, slow, wide band of rain.


warm front animation


2. 4 types

c. Stationary, warm and cold fronts battling, both travelling in opposite directions


Stationary front animation


2. 4 types

d. Occluded, warm front caught between 2 cold fronts.


occluded front animation

National Weather Map Current



3. water vapor , less dense

DEMO ___________________

unit 6: atmosphere interactions and weather

Documents

liquid water

low pressure system

large low pressure

low pressure centerfront

cold air

body of air

evaporation of water

water vapor