Meteorology, Weather, Climate

So, what’s meteorology?

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

Meteorology 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 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?

Climate Climate A composite of a region’s average conditions

Climate 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?

Weather Weather is the state of the atmosphere at a given time and place. Shorter fluctuations atmospheric conditions lasting –Hours –Days –Weeks Climate vs. Weather – You Tube 0imOLw&feature=youtu.be

Typical Newspaper Weather Map

Synoptic Weather Map

Studying the Atmosphere – The 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 discarded Ongoing work may disprove the predictions of a current theory

An Historical Example... The 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! 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 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 Law or Unifying 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 Earth Earth is a “water planet.” The most conspicuous features seen from space are –Oceans –Clouds

A closer view shows... The three major parts of Earth’s physical environment –The solid Earth (land) –The water portion –Atmosphere

Interfaces 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 Spheres Earth is divided into four independent parts Each loosely occupies a shell around Earth –This why they’re called spheres

The 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 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 Hydrosphere The collective mass of water found on, under, and above Earth’s surface The hydrosphere includes...

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

Streams

Lakes

Glaciers

Ground Water

Clouds

Volume Comparisons Volume of the Entire Hydrosphere Volume of the Entire Atmosphere

The Biosphere Includes all life on Earth Most is concentrated near Earth’s surface

Distribution of Earth’s Water

Earth 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 Studying 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 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.

Feedback Mechanisms Processes that alter changes already underway Most systems have a variety of positive and negative feedback mechanisms, particularly the climate system.

Positive Feedback Produces additional climate beyond that caused by the original factor Amplifies change underway Not to be interpreted as a “good” change. Example: –Decrease in solar energy could result in glaciers at high latitudes –Increase in ice and snow cover could further result in lower temperatures.

Positive Feedback Positive Feedback As climate becomes wetter –Forests replace grasslands –Increased transpiration –Rainfall increases due to increased water vapor Positive Feedback

Negative Feedback Climate change is muted. Not to be considered a “bad” change. After initial climate change is triggered, some components of the climate system reduce it. Example –Effect of clouds on warming effects of increasing CO 2 in the atmosphere.

Negative Feedback Chemical weathering of certain rocks removes carbon dioxide (CO 2 )from the atmosphere CO 2 is a greenhouse gas –It absorbs long-wave radiation emitted by Earth’s surface

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

Course 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 Outcomes Understand how the interaction of air masses produces a storm –Cyclogenesis –Types of fronts The role of upper air conditions

Course Outcomes Plot and interpret weather maps –Surface maps –Upper air maps Surface Synoptic Map Upper air map

Course Outcomes Identify Types of Severe Weather Know what precautions to take...

Course Outcomes Forecast weather using –Synoptic maps –Weather data trends –Numerical Data