Geography 1001: Climate & Vegetation. Agenda for Lecture 11: T Oct 2 nd. Hydrologic Cycle Model. Review Lecture 9. Global Water Scarcity

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1 Geography 1001: Climate & Vegetation Agenda for Lecture 11: T Oct 2 nd Logistics 1 st Exam in 9 days! Take advantage of my office hours Students with documented excuses, please me this week Review Lecture 10 Lecture 11 Instructor: Andrés Holz Review Lecture 9 Hydrologic Cycle Model Water Resources: The Hydrologic Cycle Our Water Supply Water in the West Figure 9.1 Water Withdrawal by Sector Global Water Scarcity Figure 9.21 Figure

2 Total water use (2000) Figure 9.11 Total water use (2000) Drought throughout this last summer Chapter 10: Global Climate Systems Climate components & relationships Köppen Climate Classification Criteria Benefits & Drawbacks Köppen-Geiger Climate System Earth s Climate Classification Climate Climate is weather over time & space (i.e. > 30 days) Climatology is the study of climate Climatic regions are areas with similar weather statistics 2

3 Insolation Climate Components (5) Climate Components: Insolation, Latitude, and daily & seasonal variations Temperature Pressure Air Masses Precipitation Climate Components: Temperature, latitude Climate Components: Pressure, Variation in pressure winds patterns (spatial & temporal) differences in Temps Cloud cover altitude Land/water heating differences Climate Components: Air Masses, Climate Components: Precipitation Spatial/ temporal patterns 3

4 Precipitation in North America Seasonal Pressure and Precipitation Patterns Figure 9.6 Climate Relationships Generalized Climate Regions Figure 10.3 Figure 10.4 Köppen Climate Classification Empirical (data) system Began with heat zones in 1884 Published first wall map in 1928 Köppen Classification: hierarchical criteria 1. Average monthly temperatures 2. Average monthly precipitation 3. Total annual precipitation Do you think that boundaries of this classification are perfect? There are not perfect. Think of the scale the whole planet!. Thus, the trend is more important than the exact location of the boundaries. 4

5 Köppen Classification: benefits & drawbacks Benefits of this classification It correlates reasonably with actual world Standard worldwide and readily available data Köppen-Geiger Climate System Drawbacks (doesn t include) Winds, temps extremes, precipitation intensity, amount of sunshine, cloud cover, or net radiation The causes of precipitation or temperature patterns Figure 10.5 Classification Categories (based purely on temperature criteria) (A) Tropical equatorial and tropical latitudes (C) Mesothermal mid-latitudes, mild winters (D) Microthermal mid- and highlatitudes, cold winters Classification Categories (based purely on temperature criteria) (E) Polar high latitudes and polar regions (H) Highland compares to lowlands at the same latitude, highlands have lower temperatures (B) Desert permanent moisture deficits* Köppen-Geiger Climate System Figure

6 Sub-climates Within each climates, the subtypes are based on precipitation gradients Tropical Climates (A) Consistent day length and insolation input produce consistently warm temperatures Inter Tropical Convergence Zone (ITZC) brings rain as it shifts seasonally with the high sun Warm ocean temperatures and unstable maritime air masses Precipitation Gradient Tropical Climates Equatorial and tropical latitudes Tropical Rain Forest Climates rainy all year Tropical Monsoon Climates 6 to 12 months rainy Tropical Savanna Climates less than 6 months rainy Tropical Climates (A) ~36% of the earth s surface the most extensive climate category. Tropical Rain Forest Tropical Monsoon Figure 10.7 Figure

7 Tropical Savanna Mesothermal Climates C Shifting air masses of maritime and continental origin Migrating cyclonic and anti-cyclonic systems bring changeable weather conditions and air mass conflicts Summers transition from hot to warm as you move away from tropics Figure 10.9 Precipitation Gradient (seasonality) Mesothermal Climates Midlatitudes, mild winters Humid Subtropical hot-summer climates Marine West Coast warm to cool summers Mediterranean dry-summer climates Mesothermal Climates (C) 2 nd largest % of earth s surface (landocean) ~27%. Area alone is considered only fourth. Together, A & C climate dominate more than half of earth oceans and about one third of the land area. ~ 55% of people around the world lives in C s climates Meso-thermal middleheat, or middle temps Mesothermal Climates (C) Mesothermal Humid Subtropical Figure

8 Mesothermal Marine West coast Mesothermal Mediterranean Figure Average Annual Temperature Gradient Microthermal Climates D Increasing seasonality (daylenght and Sun altitude) Mid and high latitudes, cold winters Humid Continental hot to warm summers Subarctic cool summers Microthermal Climates (D) Humid microthermal long winters & some summer warmth. ~ 21% of earth s land surface is influenced by these climates = about 7% of earth s total surface. These climate experience great temperature ranges, related to continentality and air mass conflicts. Given the lack of land mass in the S- hemisphere, this climate can only be found in the N-Hemisphere. Microthermal Climates (D) Subarctic Cool Summer Figure

9 Polar and Highland Climates Extremes of day length between winter and summer determine the amount of insolation received Low Sun altitude even during the long summer days is the principal climatic factor Light-colored surfaces of ice and snow reflect substantial energy away from the ground surface, thus reducing net radiation Polar and Highland Climates High latitudes and polar regions Tundra high latitude and high altitude Ice Cap and Ice Sheet permanently frozen Polar Marine oceanic association ~19% of earth s total surface This climate have no true summer average monthly temps never rises over above 50F Polar Climates (E) Arid and Semiarid Climates B Dry air in subtropical high-pressure systems dominates Sometimes form in the rain shadow of mountains Continental interiors, particularly central Asia, are far from moisture bearing air masses Dry, Arid, and Semiarid Climates Permanent moisture deficits Arid desert - less that about 35 cm (14 in.) precipitation per year Semiarid steppe - less than about 60 cm (23.6 in) precipitation per year They occupy ~35% of earth s; the most extensive climate over land. 9

10 Dry, Arid, and Semiarid Climates (B) Desert Landscape Figure Low-Latitude Hot Desert Mid-Latitude Cold Desert Figure Figure Generalized Climate Regions Figure