Regional climatesVariety of different scales of climatic investigations

•macroclimate- largest area of study, area extends for 4 x 108 m2, up to 6000 m vertically

•(continental in scale)•mesoclimate- 103 m2 up to 4 x 108 m2 in area

•(sub continental in scale)•Local climate - a group of microclimates that characterize a specific region; 103 to 108 m2 in size•Microclimate - the smallest category 1 to 104 m2 in area

•An individual field or park

Regional climatesVariety of different scales of climatic investigations

•macroclimate- largest area of study, area extends for 4 x 108 m2, up to 6000 m vertically

•(continental in scale)•mesoclimate- 103 m2 up to 4 x 108 m2 in area

•(sub continental in scale)•Local climate - a group of microclimates that characterize a specific region; 103 to 108 m2 in size•Microclimate - the smallest category 1 to 104 m2 in area

•An individual field or park

Schematic of climatic scales of studySchematic of climatic scales of study

Climate classification: What, Why and How?

What:Organize regions with similar climates

Why:Understand what causes the climate to be what it is and when to worry about departures

How:Look at moisture, temperature, evaporation, transpiration, vegetation, altitude, latitude, etc. and decide on some value that sets the boundary (threshold)- commonly related to plants

Climate classification: What, Why and How?

What:Organize regions with similar climates

Why:Understand what causes the climate to be what it is and when to worry about departures

How:Look at moisture, temperature, evaporation, transpiration, vegetation, altitude, latitude, etc. and decide on some value that sets the boundary (threshold)- commonly related to plants

Köppen climate classification scheme

Uses Monthly mean temps, monthly mean precipitation, and annual mean temps to establish major climatic zones

•designated with capital letters

Widely used but frequently criticized

•no agreement between plants and climate

•variability in the factors that set boundary

= climate classification changes constantly

Köppen climate classification scheme

Uses Monthly mean temps, monthly mean precipitation, and annual mean temps to establish major climatic zones

•designated with capital letters

Widely used but frequently criticized

•no agreement between plants and climate

•variability in the factors that set boundary

= climate classification changes constantly

ClassClass Class nameClass name SubcategorySubcategorySubcategory nameSubcategory nameKey characteristic for Key characteristic for sub categorizationsub categorization

AA Tropical humid Tropical humid Af Af Tropical wet Tropical wet No dry season No dry season

Am Am Tropical monsoonal Tropical monsoonal

Short dry season; heavy Short dry season; heavy monsoonal rains in other monsoonal rains in other

months months Aw Aw Tropical savanna Tropical savanna Winter dry season Winter dry season

BB Dry Dry BWh BWh Subtropical desert Subtropical desert Low-latitude desert Low-latitude desert BSh BSh Subtropical steppe Subtropical steppe Low-latitude dry Low-latitude dry BWk BWk Mid-latitude desert Mid-latitude desert Mid-latitude desert Mid-latitude desert BSk BSk Mid-latitude steppe Mid-latitude steppe Mid-latitude dry Mid-latitude dry

CC Mild Mid-Latitude Mild Mid-Latitude Csa Csa Mediterranean Mediterranean Mild with dry, hot summer Mild with dry, hot summer

Csb Csb Mediterranean Mediterranean Mild with dry, warmMild with dry, warm

Cfa Cfa Humid subtropical Humid subtropical Mild with no dry season, Mild with no dry season, hot summer hot summer

Cwa Cwa Humid subtropical Humid subtropical Mild with dry winter, hot Mild with dry winter, hot summer summer

Cfb Cfb Marine west coast Marine west coast Mild with no dry season, Mild with no dry season, warm summer warm summer

Cfc Cfc Marine west coast Marine west coast Mild with no dry season, Mild with no dry season, cool summer cool summer

Köppen Climate tableKöppen Climate table

summersummer

DD

Severe Mid-Latitude Severe Mid-Latitude Dfa Dfa

Humid continental Humid continental

Humid with severe Humid with severe winter, no dry winter, no dry season, hot summer season, hot summer

Dfb Dfb

Humid continental Humid continental

Humid with severe Humid with severe winter, no dry winter, no dry season, warm season, warm summer summer

Dwa Dwa

Humidcontinental Humidcontinental

Humid with severe, Humid with severe, dry winter, hot dry winter, hot summer summer

Dwb Dwb

Humid continental Humid continental

Humid with severe, Humid with severe, dry winter, warm dry winter, warm summer summer

Dfc Dfc Subarctic Subarctic

Severe winter, no Severe winter, no dry season, cool dry season, cool summer summer

Dfd Dfd Subarctic Subarctic

Severe, very cold Severe, very cold winter, no dry winter, no dry season, cool summer season, cool summer

Dwc Dwc Subarctic Subarctic Severe, dry winter, Severe, dry winter, cool summer cool summer

Dwd Dwd Subarctic Subarctic

Severe, very cold Severe, very cold and dry winter, cool and dry winter, cool summer summer

EE Polar Polar ET ET Tundra Tundra Polar tundra, no true Polar tundra, no true summer summer

EF EF Ice Cap Ice Cap Perennial ice Perennial ice HH Highland Highland

Climate zones of the worldDivided into alphabetic categories

A, B, C, D, E, H zones

Climate zones of the worldDivided into alphabetic categories

A, B, C, D, E, H zones

KÖPPEN Climate classificationTropical climates designated with a capital “A”Based in part on vegetation zones that are sensitive to moisture and temperature

KÖPPEN Climate classificationTropical climates designated with a capital “A”Based in part on vegetation zones that are sensitive to moisture and temperature

Tropical (A) Climates - All tropical climates are warmthe subdivisions are based on differences in rain Tropical Rainforest (Af) Climates located 0-15° N/S Lat. Diurnal temperature range is greater than the difference between the warmest and coolest months (annual range). Every month has precipitation and no month is deficient in rainfall. This high amount of rainfall keeps the soil moisture at capacity. EVT occurs at potential rate

Tropical (A) Climates - All tropical climates are warmthe subdivisions are based on differences in rain Tropical Rainforest (Af) Climates located 0-15° N/S Lat. Diurnal temperature range is greater than the difference between the warmest and coolest months (annual range). Every month has precipitation and no month is deficient in rainfall. This high amount of rainfall keeps the soil moisture at capacity. EVT occurs at potential rate

Am- Tropical monsoonal climateDiurnal temperature range is greater than the difference between the warmest and coolest months (annual range). seasonal precipitation surplus and deficit Distinctive dry and wet season related to wind reversal

Aw- Tropical savanna climateDiurnal temperature range is greater than the difference between the warmest and coolest months (annual range). precipitation deficit much of the yearDistinctive dry and wet season

Am- Tropical monsoonal climateDiurnal temperature range is greater than the difference between the warmest and coolest months (annual range). seasonal precipitation surplus and deficit Distinctive dry and wet season related to wind reversal

Aw- Tropical savanna climateDiurnal temperature range is greater than the difference between the warmest and coolest months (annual range). precipitation deficit much of the yearDistinctive dry and wet season

B climates - semi-arid to arid

Several sub categories

B climates - semi-arid to arid

Several sub categories

All B-climates have less than 30” of annual precipitation

BW climates are arid (less than 10”) and can be divided further based on latitude (temperature)

BWh- low latitude hot and dry

BWk- mid latitude cool and dry

BWh is a function of Hadley cell circulation; occur between 18 and 32° N-S Latitude

All B-climates have less than 30” of annual precipitation

BW climates are arid (less than 10”) and can be divided further based on latitude (temperature)

BWh- low latitude hot and dry

BWk- mid latitude cool and dry

BWh is a function of Hadley cell circulation; occur between 18 and 32° N-S Latitude

BS climates are semi-arid (more than 10” but less than 30” of rain) and can be divided further based on latitude (temps)

BSh- low latitude hot and dry

BSk- mid latitude cool and dry

A gradational change from A climates on either side of the B climates

BS climates are semi-arid (more than 10” but less than 30” of rain) and can be divided further based on latitude (temps)

BSh- low latitude hot and dry

BSk- mid latitude cool and dry

A gradational change from A climates on either side of the B climates

C climates- Mesothermal temperate

Warm summers (<10°C); Mild Winters (between -3 to 18°C)

Annual moisture distribution determines subcategories

C climates- Mesothermal temperate

Warm summers (<10°C); Mild Winters (between -3 to 18°C)

Annual moisture distribution determines subcategories

C-subcategories

Cf = moisture evenly distributed throughout the year

Cw = 10x the amount of moisture in the summer as compared to the driest winter month

Cs = 3x as much moisture in the winter as compared to the driest summer month; at least 1 month with less than 3 cm of precipitation

C-subcategories

Cf = moisture evenly distributed throughout the year

Cw = 10x the amount of moisture in the summer as compared to the driest winter month

Cs = 3x as much moisture in the winter as compared to the driest summer month; at least 1 month with less than 3 cm of precipitation

Csa= called Mediterranean climate•western edge of mid-latitude continents

Cfa= called a Humid subtropical climate•Southeastern edge of mid latitude continents

Cfb= called Marine west coast•Western edge of continents at higher latitudes

Csa= called Mediterranean climate•western edge of mid-latitude continents

Cfa= called a Humid subtropical climate•Southeastern edge of mid latitude continents

Cfb= called Marine west coast•Western edge of continents at higher latitudes

D climates- Severe Mid-latitude

All have severe winters; short summers that range form hot in the south to cool to the north

D climates- Severe Mid-latitude

All have severe winters; short summers that range form hot in the south to cool to the north

E climates - Polar No true summer

Cold all year long

E climates - Polar No true summer

Cold all year long

Köppen climate regions of North AmericaKöppen climate regions of North America

Köppen climate regions of the USKöppen climate regions of the US

Trewartha climate classification scheme - a modified version of the Köppen system. Attempts to redefine the broad climatic groups in such a way as to be closer to vegetational zoning. Group A - this is the tropical climate group, defined as places which do not receive annual winter frosts (in maritime regions this corresponds closely to the Köppen boundary). Climates with no more than 2 dry months are classified Ar , while others are classified Aw . There is no specific monsoon climate identifier.Group B - this is identical to the Köppen scheme. Group C - in the Trewartha scheme this category includes subtropical climates only (8 or more months above 10 °C). The identifiers are the same as the first two letters of the Köppen identifier - the Mediterranean climate is denoted Cs and the humid subtropical climate, Cf or Cw .

Trewartha climate classification scheme - a modified version of the Köppen system. Attempts to redefine the broad climatic groups in such a way as to be closer to vegetational zoning. Group A - this is the tropical climate group, defined as places which do not receive annual winter frosts (in maritime regions this corresponds closely to the Köppen boundary). Climates with no more than 2 dry months are classified Ar , while others are classified Aw . There is no specific monsoon climate identifier.Group B - this is identical to the Köppen scheme. Group C - in the Trewartha scheme this category includes subtropical climates only (8 or more months above 10 °C). The identifiers are the same as the first two letters of the Köppen identifier - the Mediterranean climate is denoted Cs and the humid subtropical climate, Cf or Cw .

Trewartha Climate scheme (Continued)Group D - this group represents temperate climates. Continental climates are represented as Dca (Köppen Dfa, Dwa, Dsa ) and Dcb (Köppen Dfb ,Dwb ,Dsb ). Maritime temperate climates (Köppen Cfb ,Cwb ,Csb ,Cfc ) are denoted Do in the Trewartha classification. The dividing point between maritime and continental climates is 0 °C in the coldest month, rather than the usual Köppen value of -3 °C.

Group E - this group is undivided and contains the continental subarctic climates (Köppen Dfc ,Dwc ,Dfd )

Group F - this is the polar climate group, split into Ft (Köppen ET ) and Fi (Köppen EF ).

Group H - Highland climates - in which altitude is the most important factor determining climate.

Trewartha Climate scheme (Continued)Group D - this group represents temperate climates. Continental climates are represented as Dca (Köppen Dfa, Dwa, Dsa ) and Dcb (Köppen Dfb ,Dwb ,Dsb ). Maritime temperate climates (Köppen Cfb ,Cwb ,Csb ,Cfc ) are denoted Do in the Trewartha classification. The dividing point between maritime and continental climates is 0 °C in the coldest month, rather than the usual Köppen value of -3 °C.

Group E - this group is undivided and contains the continental subarctic climates (Köppen Dfc ,Dwc ,Dfd )

Group F - this is the polar climate group, split into Ft (Köppen ET ) and Fi (Köppen EF ).

Group H - Highland climates - in which altitude is the most important factor determining climate.

Other climate classification schemes

Thornthwaite-based his scheme on moisture effectiveness and temperature efficiency

•mathematical relationships easy to identify from available meteorological data

•Also uses info on season when rain or snow falls

Other climate classification schemes

Thornthwaite-based his scheme on moisture effectiveness and temperature efficiency

•mathematical relationships easy to identify from available meteorological data

•Also uses info on season when rain or snow falls

Genetic classification

Identifies the “Why” of climates first and uses that information to establish each climatic zone

-which air mass dominates

Genetic classification

Identifies the “Why” of climates first and uses that information to establish each climatic zone

-which air mass dominates

Tropical Tropical wetwet

Tropical Tropical wet and wet and drydry

Tropical Tropical dry dry (desert)(desert)

Grp Grp II

mid mid latitude latitude wetwet

Mid Mid latitude latitude summer or summer or winter drywinter dry

mid mid latitude latitude dry dry (desert)(desert)

Grp Grp IIII

Polar wetPolar wet Polar wet Polar wet and dryand dry

Polar dry Polar dry (desert)(desert)

GrpGrpIIIIII

WetWet DryDryWarmWarm

ColdCold

Air masses and climatic types

Climate zones determined by air mass

VegetationClosely linked to climate

Often used as PROXY data for lack of climate data5 distinct veggie zones

•Forests = trees; many different types of forests

•e.g., hardwood, conifer, rainforest•Deserts = discontinuous veggies; scrub brush; cactus, etc.•Grasslands = grasses•Taiga = cold; climate evergreen conifer forests•Tundra = cold; grasses sedges mosses and lichens

VegetationClosely linked to climate

Often used as PROXY data for lack of climate data5 distinct veggie zones

•Forests = trees; many different types of forests

•e.g., hardwood, conifer, rainforest•Deserts = discontinuous veggies; scrub brush; cactus, etc.•Grasslands = grasses•Taiga = cold; climate evergreen conifer forests•Tundra = cold; grasses sedges mosses and lichens