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Course Syllabus can be found at: http://www.wx4sno.com/portfolio/BSU/spring_2012/
This lecture will be posted AFTER class at: http://www.wx4sno.com/portfolio/BSU/spring_2012/lectures/

Lesson 19

Climographs

Köppen Classification System & Procedures
 Climate Controls

Climographs

Climographs, or climatic diagrams, provide an overview of climate at a certain location

Can span hours, days, months, but usually are a one year average

Months are listed along the bottom

Monthly temperature is shown as a solid line

Temperature scale along the left side

Monthly precipitation shown as bars

Precipitation scale along the right side

Indianapolis, IN, USA (Dfa)

Minsk, Belarus (Dfb)

Yukon Territory, Canada (Dfc)

Climate Classification Purpose

Simplify the complexities that comprise the climate system

Summarize climate information

Schemes minimize the within group variability and maximize the between group variability

All locations within a group are very similar to one another, but different from other groups

Long-term shifts in climate boundaries

Climate variability

Biophysical impacts

Climate Classification Usefulness

Examine the expected weather patterns for climate based forecasting
 What’s the upcoming winter going to be like?
Lots of rain or lots of snow?

Long-term shifts in climate boundaries
 Can we expect the “humid South” to shift north, changing Indiana’s climate over the next century?

Quantitative Classification:
Köppen System

Developed first world
“climate classification” in the 1870s

Hierarchical scheme

15 types (e.g. Dfa )

Based on monthly data:

Temperature

Precipitation

Corresponds with biomes
Wladimer Köppen
(1846-1940)

Köppen System: Modified

Numerous modifications since inception

Most widely used—fairly simplistic

Defined the ecotone (or biome boundaries)
Grassland-forest ecotone: Paraguay

Köppen System: Modified
First-Order Divisions

Temperature-based
 A: Tropical

B: Dry

C: Mesothermal

D: Microthermal
 E: Polar
 H: Highland

Köppen System:
Second-Order Divisions

Precipitation based
 f: year-round rainfall
 m: monsoon rainfall
 s: summer dry season
 w: winter dry season

Köppen System:
Third-Order Divisions

Based on summer temperatures
 a: hot summers
 b: warm summers
 c: cool/mild summer

Arid climate
 h: hot and dry
 k: cold and dry
 Special: fog occurrence (n / n’)

Using the Flow Chart

Using the Flow Chart

Tropical Climates (A)
Climate: Af

Mesothermal or Mild Climates
(C)
Climate: Cfa

Microthermal or Severe
Midlatitude (D)
Climate: Dfb

Polar Climates (E)
Climate: ET

Köppen System: Modified
Major Climate Types

Köppen System: Major World Climates

Climate Controls

Factors that govern local weather and climate

Five major controls of climate

Latitude and season

Water proximity (continentality)

Oceanic circulation

Semi-permanent pressure systems

Topography

Latitude: Insolation Variability

Variation in solar angle striking surface

Attenuation: depletion of solar rays

Latitude: Insolation Variability

Atmospheric path length varies due to the curvature of the earth

Earth-Sun Relationships

Rotation: spin of earth about its axis

Approximately 15 degrees longitude/hr

Daylight length

Water Proximity: Continentality

Influence of large land mass

Variable energy fluxes dependent on surface type and their respective specific heat capacities

Oceanic Circulation: Surface

Oceanic Circulation: Deep Water

Semi-permanent Pressure Systems

NH: Surface/Upper Level Flow

Topography

Normal lapse rate: 6.5° C/km

Large diurnal temperature ranges at higher elevations. Why?

Varying insolation absorption rates

Orographic effects

Homework

For the climographs, please use English units
 °F
 in

Extra Credit #2