GEOG 1114 1st Edition Lecture 16 Outline of Last Lecture Atmospheric Disturbances continued Cyclones Anticyclones Low Latitudes Minor Atmospheric Disturbances Outline of Current Lecture Measuring climates according to climate controls Circulation patterns Air masses Ocean currents Location Classifying Climates Climatic Zones Climographs Major Climate types their groupings Current Lecture Measuring Climates According to Climate Controls General Circulation Patterns These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Sources of air masses pressure systems wind patterns 7 components Subtropical highs trade winds ITCZ Westerlies Easterlies Air masses Secondary circulation patterns in mid latitudes characterized by distinct air masses Identified by their source regions A P T E c m Latitude Location Length of day Intensity of solar radiation affects temperature and rates of evaporation Seasons Ocean Currents Warm and cold tied to latitude and insolation Currents result of winds tides Coriolis force Proximity to Oceans Land near oceans less temperature range Topography Local elevation mountainous regions change in temperature pressure and moisture with altitude slope aspect Water Balance Balance between plants need for evapotranspiration and actual precipitation Indicates moisture surplus deficit and recharge situations Evaporation precipitation deficit Dry conditions Precipitation Evaporation Surplus Wet Conditions Continentality Land V Water Differential heating of land and water Continental Land Masses alter circulation Distance from Water Latitude position Effects precipitation and temperature ranges Classifying Climates Numerous climate classifications have been developed Each uses a different index or a combination of indices to describe global climate classes Range from very general to extremely complex Modified Koppen System General Description Developed by Wladimir Koppen a German Climatologist in 1918 Most widely used Average Temperature and PPTN data for each location is used to determine the classification of that place Vegetation patterns are used to determine zone boundaries Each classification is given A descriptive name and Letter code based on 2 or 3 letters Six Major Climatic Zones A Tropical B Dry C Mild Mid Latitude D Severe Mid Latitude E Polar H Highland Letter Codes First Letters capitals shown above indicate major climate groups Second Letters refers to precipitation characteristics A C D Climates Only f Wet all year m Monsoon precipitation pattern w Winter dry season s Summer dry season W Desert S Steppe B climates only E climates only T Tundra F Ice Caps a Hot summers b Warm summers c Cool summers d Very cold winters h Hot desert or steppe k Cold dessert or steppe Third Letters refers to temperature C D Climates only B Climates only Climographs Tool Used in the study of climates to classify the climate of a place Graphic representation of monthly temperature and precipitation Months of year are indicated along the bottom of a climograph chart by 1st letter of each month Average monthly temp is plotted with a solid line and indicated by the scale on the left side of the chart Average monthly PPTN is indicated by bars with the scale in inches found along the right side of the chart Global Distribution of Climates 15 Major Climate types Group A Tropical Humid Climates Molded by tropical latitudinal regions Winterless climates little temperature change Moisture is prevalent Precipitation influenced by ITCZ Three subtypes Tropical Wet Af Equatorial Monotonous Climate Daily temperature range exceeds annual range High Humidity Tropical Monsoonal Am Regions with prominent monsoonal wind pattern Extensive rainfall during high sun season Cherrapunji India averages 425 inches Tropical Savanna Aw Lies north and south of Af climates Seasonal alteration of wet dry periods due to position of ITCZ Smallest rainfall amounts of tropical regions Group B Dry Climates Cover about 30 of land area worldwide Lack of uplift or lack of moisture Typical in subtropics Marine deserts Two main types W Desert S Steppe Two subtypes h hot deserts or steppe k cold Subtropical Desert BWh Lie near subtropical highs Precipitation is scarce Precipitation that does form is short lived and very intense Hot temperatures Subtropical Steppe BSh Typically surrounds BWh climates Separate desert climate from humid climate Extremes are muted in steppe regions Cooler temperature More rainfall Seasonal concentration of rainfall Midlatitude Desert BWk Far removed from oceanic influence Meager and erratic rainfall Midlatitude Steppe BSk Occupies transitions between desert and humid climates Greater precipitation than midlatitudes deserts Less temperature extremes