GHY 104 1st Edition Lecture 22Global Climate SystemsClimate - Climate – is weather averaged over time and over broad geographic areas. - Climatology – is the study of climate over both time and space. - One aspect of climate study is the identification of climate regions, areas with similar weather patterns. - A central goal is to analyze climate variability over time, such as global climate change.- By studying variability over time, we can understand how the climate system works. Earth’s Climate System and Classification- Climate Components:- Insolation- Temperature- Pressure- Air Masses- Precipitation- These help to classify climatic regions- Then used to develop the Koppen Climate Classification System- In turn, the classification system is used to analyze global climate patterns.KoppenClimate Classification - Tropical Climates (A)- Arid/Semiarid Climates (B)- Mesothermal Climates (C) (=warm temperate)- Microthermal Climates (D) (= cool temperate)- Polar Climates (E)- Primary Letters- Tropical Climates (A) Average temperature of every month > 18 ⁰C- Arid/Semiarid Climates (B) Evaporation > precipitation- Mesothermal Climates (C) Average temperature of warmest month > 10 ⁰C but coldest month > -3 ⁰C Seasonal climates - Microthermal Climates (D) Average temperature of warmest month > 10 ⁰C Average temperature of coldest month < -3 ⁰C Extensive range in annual temperatures.- Polar Climates (E) Average temperature of all months < 10 ⁰C Short growing season for plantsSecondary Ltters- These letters are based on seasonal precipitation- f = adequate rainfall all through the year, no distinct dry season- w = winter dry (keep in mind the hemisphere), if 70% or more of annual rainfall occurs in summer- s = summer dry, if 70% or more of annual rainfall occurs in winter- m = monsoon, extremely wet summer (A climate only)- For B climates only:- S = semiarid = steppe- W = arid = dessert- Which results in either BS or BW- E climates only:- T = tundra- F = perpetual frost = permanent ice - Results in either ET or EFTertiary Letters- The third letters are based on seasonal and annual temperature:- a = hot summer, warmest month > 22 ⁰C (C, D only)- b = warm summer, warmest month < 22 ⁰C (C, D only)- c = cool summer, < 4 months over 10 ⁰C (C, D only)- d = very cold winter, coldest month < -38 ⁰C (D only)- h = dry-hot, annual temperature > 18 ⁰C (B only)- k = dry-cold, annual temperature < 18 ⁰C (B only)Examples of Combinations- Af = Tropical Rainforest climate type- Am = Tropical Monsoon climate type- BWh = Low-Latitude Hot Desert climate type- Cfa = Humid Subtropical climate type- Csa = Mediterranean climate type - Dfb = Humid Continental climate type - ET = Tundra climate type - Primary = Latitudinal- Secondary = Precipitation- Tertiary =