Meteorology, Meteorology, Weather, ClimateWeather, Climate

So, what’s So, what’s meteorology?meteorology?

No, it’s not the study of objects No, it’s not the study of objects from space that strike Earth.from space that strike Earth.

MeteorologyMeteorology• The study of the atmosphere and the

phenomena usually referred to as weather.

• One of the Earth sciences– Sciences that seek to understand our planet– In the study of meteorology, these sciences

often overlap and include aspects of• Astronomy• Biology• Chemistry• Physics

Why is the study of the atmosphere Why is the study of the atmosphere called “meteorology”?called “meteorology”?

• The origin of the word "meteorology" dates back to ancient Greece.

• In 340 B.C., Aristotle, a philosopher of the day, wrote a treatise called "Meteorologica" about “meteors,” then defined as any object in the sky.

• These airborne items included clouds, snow, and rain--aspects of the atmosphere that fascinated him.

• Add “ology” for “ study of” and you get “meteorology.”

What is the difference between climate and weather?

ClimateClimate A composite of a region’s average conditions

ClimateClimate

• Applies to long-term changes • Measured in terms of:

– Temperature– Precipitation– Snow and ice cover– Winds

• Can refer to– The entire planet– Specific regions (continents or oceans)

What is Weather?What is Weather?

WeatherWeather

• Weather is the state of the atmosphere at a given time and place.

• Shorter fluctuations atmospheric conditions lasting– Hours– Days– Weeks

Typical Newspaper Weather Map

Synoptic Weather MapSynoptic Weather Map

Studying the Atmosphere –Studying the Atmosphere –The Scientific MethodThe Scientific Method

• Hypothesis– An informal idea that has not been widely

tested by the scientific community– Most are discarded.

• Theory– When a hypothesis is capable of explaining a

wide array of observations.– Additional observations support the theory

• New techniques for data analysis• Devise models

Theories can be discardedTheories can be discarded

Ongoing work may disprove the predictions of a current theory

An Historical Example . . .An Historical Example . . .The Geocentric Model of the Solar SystemThe Geocentric Model of the Solar System

• Devised by Ptolemy (Claudius Ptolemaeus) in the second century AD

• Accepted until 1543

The Heliocentric Model replaced the Geocentric Model

Pluto is no longer considered a planet!

Pluto’s Been Demoted!Pluto’s Been Demoted!

• On August 24, 2006 the International Astronomical Union redefined the definition of a planet as:– “a celestial body that is in orbit around the sun– has sufficient mass for its self-gravity to

overcome rigid body forces so that it assumes a nearly round shape,

– and has cleared the neighborhood around its orbit.”

Pluto is now considered Pluto is now considered a “Dwarf Planet”a “Dwarf Planet”

• Pluto lost its status as a planet because it’s highly eccentric orbit crosses over the orbit of Neptune.– As such it hasn’t “cleared the

neighborhood around its orbit.

• A dwarf planet like Pluto is– Any other round object that

• Has not “cleared the neighborhood around its orbit• Is not a satellite

A A LawLaw or or UnifyingUnifying Theory Theory

• If a theory has survived the test of time– Years or decades

• It’s the closest approximation to “the truth” as possible.

• It’s impossible to prove a theory as being true.

• We can only prove it’s untrue.

A View of EarthA View of Earth

• Earth is a “water planet.”

• The most conspicuous features seen from space are– Oceans– Clouds

A closer view shows . . .A closer view shows . . .

• The three major parts of Earth’s physical environment – The solid Earth (land)– The water portion– Atmosphere

InterfacesInterfaces

• Our environment is highly integrated– It’s not dominated by

land, water, or air alone.

• It’s characterized by continuous interactions as– Air comes in contact

with rock– Rock comes in contact

with water– Water comes in contact

with air.

Earth’s Four SpheresEarth’s Four Spheres

• Earth is divided into four independent parts• Each loosely occupies a shell around Earth

– This why they’re called spheres

The GeosphereThe Geosphere

• The solid Earth• The largest sphere

– Extends from the surface to the center of the planet

• Three principle regions based on compositional differences– Crust– Mantle– Core

The AtmosphereThe Atmosphere• A very shallow layer of

gases• 99% is within 30 km (20

mi) of Earth’s surface• An integral part of our

planet– Provides the air we breath– Protects us from harmful

short-wave solar radiation• Energy exchanges

between Earth’s surface and the atmosphere and space produce weather.

The HydrosphereThe Hydrosphere

• The collective mass of water found on, under, and above Earth’s surface

• The hydrosphere includes . . .

OceansOceans

• Cover nearly 71% of Earth’s surface• Average depth is 3,800 meters (12,500 ft.)• Accounts for 97% of Earth’s water

StreamsStreams

LakesLakes

GlaciersGlaciers

Ground WaterGround Water

CloudsClouds

Volume ComparisonsVolume ComparisonsVolume of the

Entire HydrosphereVolume of the

Entire Atmosphere

The BiosphereThe Biosphere• Includes all life on Earth• Most is concentrated near

Earth’s surface

Distribution of Earth’s WaterDistribution of Earth’s Water

Earth System ScienceEarth System Science

• The four spheres can be studied separately

• However . . .– The parts are not isolated.– Each is related in some way to the others– A complex and interacting whole results that

is called• The Earth System

An Interdisciplinary Approach to An Interdisciplinary Approach to Studying EarthStudying Earth

• The way in which individual components of land, water, air, and life forms are connected must be understood.

• A system is– Any size group of interacting parts that form a

complex whole to serve a function– Most natural systems are driven by sources of

energy that move mater and/or energy from one place to another.

Open SystemsOpen Systems

• In most natural systems energy flows into and out of the system.

• Weather systems are open systems.– In storms the amount of water vapor available

changes, flow of air into and out changes, etc.

Course OutcomesCourse Outcomes

• Understand how various types of energy transfer affect the atmosphere and weather

Course OutcomesCourse Outcomes

• Understand weather variables – Temperature– Air pressure– Wind– Moisture

• In terms of– Causes– How they’re measured and recorded– Patterns associated with various types of weather– How they’re used in weather prediction

Course OutcomesCourse Outcomes• Understand how the

interaction of air masses produces a storm– Cyclogenesis– Types of fronts

• The role of upper air conditions

Course OutcomesCourse Outcomes

• Plot and interpret weather maps– Surface maps– Upper air maps

Surface Synoptic Map Upper air map

Course OutcomesCourse Outcomes• Identify Types of Severe Weather

Know what precautions to take . . .

Course OutcomesCourse Outcomes• Forecast weather

using– Synoptic maps– Weather data trends– Numerical Data