Unit Three – The Atmosphere and Climate

Taken from Earth Science written by Lutgens & Tarbucks

Created by: S. Koziol6/3/2013 – ?/?/2013

Chapter 16 - Weather

The major element of weather and climate are air temperature, air pressure, wind speed , precipitation, humidity.

Troposphere

Earth’s Surface

Stratosphere

Mesosphere

Thermosphere

Tropopause

Stratopause

MesopauseThe four layers

of the atmosphere from the top down are:

Structure of the Atmosphere

Troposphere

Earth’s Surface

Stratosphere

Mesosphere

Thermosphere

Tropopause

Stratopause

MesopauseHow is the structure

determined?

Structure of the Atmosphere

Based on Temperature

Troposphere

Earth’s Surface

Stratosphere

Mesosphere

Thermosphere

Tropopause

Stratopause

Mesopause

The bottom layer of atmosphere in which we live is called the troposphere:

•most weather

•Most of the pollution

•greatest % mass of the atmosphere

Structure of the Atmosphere

Chapter 16 – The Atmosphere (continued)

Most weather occurs in the Troposphere.Even though strong thunderstorms sometimes

reach the stratosphere (or tropopause).

Chapter 16 – The Atmosphere (continued)

The value of the normal lapse rate is 6.5 C degrees per kilometer

Chapter 16 – Weather vs. Climate

Weather is a word used to denote the state of the atmosphere at a particular place over a short period of time.

The generalization of atmospheric conditions over a long period of time is referred to as climate.

Climate

Climate is:– a historical agglomeration of weather data– dependent on daily observations– a statistical rendering of the earth's atmosphere

Climate (continued )

Climate consists of all of the following:– expected atmospheric conditions– statistical properties of the atmosphere– long-term behavior of the atmosphere

Climate (continued )

Chapter 16 – Please remember.

Regarding meteorological conditions , climate is what you expect, and weather is what you get.

Sunrise 10/17/2006 off Rt. 21

Photograph taken by S. Koziol

Chapter 17 Moisture , Clouds & Precipitation

Sunrise 10/17/2006 off Rt. 21

Photograph taken by S. Koziol

Chapter 17 Moisture , Clouds &

Precipitation

A cloud is best described a visible aggregates of minute water droplets or tiny crystals of ice suspended in the air.

Chapter 17 - CloudsClouds are classified on the basis of their form and height.

Cirrus (high)

Cumulus

(middle)

Stratus

(low)

Cloud Forms (3 main classes)

Cirrus are thin and wispy clouds, they are high and are always composed entirely of ice crystals.

Cloud Forms (high)

Altocumulus

(shown here in early stages of development)

Cloud Forms (middle)

Cumulous or (middle clouds) are composed of liquid droplets.

Stratus clouds are best described as sheets or layers that cover much or all of the sky

Cloud Forms (low)

Stratocumulus clouds are considered low clouds.

Nimbostratus

Cloud Forms (cumulonimbus)

Cumulonimbus clouds which can span nearly the entire troposphere

This is the cloud type most associated with hail.

Chapter 17 Clouds (continued)

The term nimbus means “rainy cloud.”

Cloud Forms

High – cirrus, cirrostratus, cirrocumulus

Middle – altostratus, altocumulus

Low – stratus, stratocumulus, nimbostratus

Clouds with extensive vertical development – cumulous & cumulonimbus

Chapter 17 - Humidity

The general term for the amount of water vapor in air is humidity

Chapter 17 Pressure and Temperature Changes

When air expands, it will cool

Chapter 17 – Air PressureThe force exerted by the weight of the air above is called air pressure.

Chapter 17 – Standard Air Pressure

Standard sea-level pressure (1 atm) is: 29.92 inches of Hg760 mm Hg101.325 kPa

Chapter 18 – Air Pressure & Wind

Chapter 18 - WindAir that flows horizontally with respect to Earth’s surface is referred to as wind.

Variations in air pressure from place to place are the principal cause of wind.

Chapter 18 High-pressure

Centers of high pressure are called anticyclones

Chapter 18 – Low-pressureA low-pressure system often brings cloudiness and precipitation.

Chapter 18 – General MovementThe general movement of low-pressure centers across the United States is from west to east.

Chapter 18 - Coriolis

The deflective force of Earth’s rotation on all free-moving objects is called the Coriolis effect.

Chapter 19 - Air MassAn immense body of air characterized by a similarity of temperature and moisture at any given altitude is referred to as an air mass.

The area in which an air mass acquires its characteristic properties of temperature and moisture is called its source region.

Chapter 19 - FrontsThe boundary that separates

different air masses is called a front.

Chapter 19 – Fronts (continued)

Warmer , less dense air is always forced aloft along a front.

Chapter 19 – Cold Fronts When cold air is actively advancing into a region

occupied by warmer air, the boundary is called cold front.

When cold air is actively advancing into a region occupied by warmer air, the boundary is called cold front.

Chapter 19 – Cold Fronts (continued)

Cold fronts advance more rapidly than warm fronts

Chapter 19 – Warm Fronts

When the surface position of a front moves so that warm air occupies territory formerly covered by cooler air, it is called a warm front.

Chapter 20 – Climate & Weather

Chapter 20 – Climate & WeatherThe description of aggregate weather conditions of a place or region is termed climate.

Chapter 20 – Climate (continued)

Earth’s Climate systems consists of the atmosphere, hydrosphere, solid Earth, biosphere and cryosphere and involves the exchanges of energy and moisture that occurs among the five parts.

Chapter 20 – Climate – (continued) The two most important elements in climate description are temperature and precipitation.

Chapter 20 – Mean Surface Temperature

If CO2 (carbon dioxide) levels reach projected levels, models predict that by the year 2100 mean global surface temperatures will increase by 1.1 to 6.4°C

Chapter 20 – Earth’s ResponseModels indicate that the temperature response in polar regions due to global warming triggered by carbon dioxide and trace gasses could be as much as two to three times greater than the global average.

Chapter 20 – Earth’s Response

Greenhouse warming could cause a rise in sea level.

Chapter 20 – Earth’s ResponsePossible consequence of greenhouse

warming:

more frequent and intense hurricanesrising sea levels shifts in the paths of large scale

cyclonic stormsincrease of heat waves and droughts

Chapter 20 – Climate Change Myths ?

Climate Myth What the science says . . .

“Climate’s changed before”

Natural climate change proves that climate is sensitive to an energy imbalance. As Earth accumulates heat, global temperatures will go up. CO2 is imposing an energy imbalance. Past climate change actually provides evidence for our climate's sensitivity to CO2.

“It’s the Sun.” In the last 35 years the sun has shown a slight cooling trend. Sun and climate have been going in opposite directions.

“Its not that bad.” The negative impacts of global warming on agriculture, health, economy and environment far outweigh any positives.

“There is no consensus”

95% of active climate researchers actively publishing climate papers endorse that humans are causing global warming.

“It’s cooling” All the indicators show that global warming is still happening.

Chapter 20 - HomeostasisHomeostasis is the property of a system that regulates its internal

environment and tends to maintain a stable, relatively constant condition of properties such as temperature.