GEOG 1300, Sec 001, Spring 2010

Weather & Climate

M-W 12:00-13:50, Brewster B-102

Tropical Storm Eugene

Hurricane Emily

July 19, 2005

Dr. Hong-Bing Su

Department of

Geography

(1) Student Survey

(2) Course Overview

(3) Introduction to Weather & Climate

Lecture #01

January 11, 2010, Monday

(1) 1300. Weather and Climate (4) (F,S,SS) (FC:SC)

(2) Introductory survey of meteorology including

weather and climate principles, processes, and

patterns, at a variety of scales from local to global.

(3) It is the first course in atmospheric sciences.

(4) Emphasis on North America.

Course Descriptions

(1) The first course in Atmospheric Science.

(2) A prerequisite for core courses of the undergraduate

Certificate in Atmospheric Science offered by the

Department of Geography at ECU.

(3) Currently being reviewed at NC GA: a B.Sc. degree

in Applied Atmospheric Sciences.

More about this Course

(1) GEOG 3510 Physical Meteorology

(2) GEOG 3520 Dynamic Meteorology

(3) GEOG 3550 Principles of Synoptic Meteorology

(4) GEOG 4510 Meteorological Instruments & Observations

Four Core courses required for the

Certificate in Atmospheric Science

(1) M-W 12:0013:50

(2) Office hours: TuTh, 11:0013:00

or by appointment

(3) 14 Mondays, 14 Wednesdays

(4) These schedules are subject to cancellations

announced by the university (e.g., adverse weather)

Course Schedule

(1) Total 3 exams: 2 mid-term exams (20% each)

Final exam (30%).

(2) In-class and take-home exercises count for 30%.

(3) Exams are generally non-cumulative, but none of

the exams can be dropped.

(4) All exams are close-book, no paper nor electronic

notes will be allowed.

(5) A make-up exam may be offered ONLY if a

verifiable and university allowed excuse, such as a

doctor’s note, is provided to the instructor.

Exams

(1) A: 85% and higher

(2) B: 70% and higher

(3) C: 55% and higher

(4) D: 50% and higher

(5) F: Below 50%

Grade

Each exam of the entire class may be adjusted (curved)

based on all scores.

(1) Attendance is required.

(2) Students need to sign the attendance sheet in each

class.

(3) For each missing class that is not excused, 1-point

will be deducted from your final course grade.

Today is exempted as the first day of class.

(4) Same excuses allowed for make-up exams apply.

Attendance Policy

Course Webpage

http://core.ecu.edu/geog/suh/Courses/Courses.html

Password: Weather2010Su/index

Global

Circulation

Hurricane Floyd September 15, 1999

What is this?

Extratropical cyclones, sometimes called

mid-latitude cyclones or wave cyclones

Mid-latitude Cyclones

Typical winter mid-latitude cyclone paths

Tornado

Thunderstorm

Lightning

Conversion between Temperature Scales

oF = 9 / 5 oC + 32

oC = 5 / 9 ( oF – 32 )

K = oC + 273.16

oC = K – 273.16

Old formula (1945): Twc = 0.0817(3.71V0.5 + 5.81 – 0.25V)(T-91.4)+91.4

New

formula:

The smaller the solar angle, the greater area of beam spreading

Beam Spreading

A

C

B

BC

AB= sin ( = solar angle)

Stefan-Boltzmann Law:

The radiation intensity ( I ) in unit of W m-2 from a body with an absolute temperature T (in unit of K) is proportional to the 4th power of T:

Radiation Properties & Principles

I = ε σ T4

σ = the Stefan-Boltzmann constant in W m-2 K-4

ε = emissivity

Blackbodies (perfect emitters, ε = 1), Graybodies (ε < 1)

Indices of Water Vapor Content in the Atmosphere

mv

mq = =

Specific humidity q (g kg-1)

Mixing ratio of water vapor r (g kg-1)

mv = mass of water vapor

md = mass of dry air

m = mass of atmosphere

mv

mv + md

mv

md

r =

Relative humidity (RH) is the percentage of actual water vapor content in the air relative to that (maximum water vapor content) in saturated air.

Indices of Water Vapor Content in the Atmosphere

e

es

RH =

x 100%

q

qs

r

rs

x 100%

x 100%

RH =

RH =

Atmospheric pressure

= gravity

x density of mercury

x height of mercury

Weight = gravity

x density

x volume

volume = height x area

pressure = weight / area

Measurement of

Atmospheric

Pressure

Mercury

Barometer:

Basic Definitions: Atmosphere

A gaseous envelope gravitationally bound to a celestial

body (e.g., a planet and its satellite in the solar system).

Different atmosphere have very different properties.

The atmosphere of Venus is very thick and cloudy, and

is responsible for its very high surface temperature by

virtue of the greenhouse effect. On the other hand, the

Martian atmosphere is very sparse.

Earth’s atmosphere is intermediate between the above

two extremes, distinguishing from all other atmospheres

by its very active hydrologic cycle. Water plays a very

important energetic role and a crucial factor to the

existence of severe storms in the Earth’s atmosphere.

Basic Definitions: Weather

The state of the atmosphere, mainly with respect to its

effects upon life and human activities.

As distinguished from climate, weather consist of the

short-term (minutes to days) variations in the

atmosphere.

Popularly, weather is thought of in terms of elements

like temperature, humidity, precipitation, cloudiness,

visibility, and wind, at a given time and locations.

As used in the taking of surface weather observations,

a category of individual and combined atmospheric

phenomena that must be drawn upon to describe the

local atmospheric activity at the time of observation.

Basic Definitions: Climate

The slowly varying aspects of the atmosphere-

hydrosphere-land surface system.

It is typically characterized in terms of suitable averages

of the climate-system over periods of a month or more,

taking into considerations the variation in time of these

averaged quantities. Climate classifications include the

spatial variation of these time-averaged variables.

Beginning with the view of local climate as little more

than the annual course of long-term averages of surface

temperature and precipitation, the concept of climate has

broadened and evolved in recent decades in response to

the increased understanding of the underlying processes

that determine climate and its variability.

Basic Definitions: Climate System

The system, consisting of the atmosphere,

hydrosphere, lithosphere, and biosphere,

determining the Earth’s climate as the result of

mutual interactions and responses to external

influences (forcing).

Physical, chemical, and biological processes

are involved in the interactions among the

components of the climate system.

Basic Definitions: Meteorology

The study of the physics, chemistry, and dynamics

of the Earth’s atmosphere, including the related

effects at the air-earth boundary over both land and

the oceans.

Fundamental topics include the composition,

structure, and motion of the atmosphere.

The goals ascribed to meteorology are the complete

understanding and accurate prediction of

atmospheric phenomena.

In popular usage, the underlying science of weather

and weather forecasting.

Basic Definitions: Climatology

The description and scientific study of climate.

Descriptive climatology deals with geographic and temporal

distributions of meteorological observations over a specific

period of time.

Scientific climatology addresses the nature and controls of

the Earth’s climate and causes of climate variability and

climate change on all time scales.

Modern treatment of the nature and theory of climate must

deal with the dynamics of the entire atmosphere-ocean-land

surface climate system, in terms of its internal interactions

and its responses to external factors.

Applied climatology addresses the climate factors involved

in a broad range of problems relating to the planning, design,

operations, and other decision-making activities of climate

sensitive sectors of the modern society.

Basic Definitions:

Atmospheric Science

The comprehensive study of the physics,

chemistry, and dynamics of the Earth’s

atmosphere, from the Earth’s surface to

altitudes of several hundred kilometers, this

usually include atmospheric chemistry,

aeronomy (physics and chemistry of the upper

atmosphere), magnetospheric (plasma)

physics, and solar influences on the entire

region.

Meteorology vs. Climatology

What are the main differences?

Meteorology– weather

– instantaneous state of

the atmosphere

– Forecast of changes

over short time period

– For example, daily, 3-5

day weather forecast

Climatology– climate

– statistical properties of

the atmosphere (mean,

variance, extremes)

– Long term characteristics

of a place

– For example, monthly

average or more.

IPCC 2007Components in Climate Change Modeling

http://lwf.ncdc.noaa.gov/oa/reports/billionz.html

(1) What are the differences between weather and

climate?

(2) What are the differences between meteorology,

climatology, and atmospheric sciences?

(3) True or False:

Floods are the most deadly weather events.

Questions

(4) Multiple Choice:

Which of the following weather events costs the

most financial loss?

A) Tornado

B) Hurricane

C) Lightning

D) Extreme Heat

Questions