Earth’s topography is responsible for rain shadows and temperature inversions, producing variation in temperature and precipitation. In the oceans, topographical variability produces differences in water depth, which affects light penetration, water temperature, water pressure, and water movement. Vegetation, especially forests, affects climate through the process of evapotranspiration. Humans have transformed urban climate; cities are on average hotter than rural areas.
learning outcomes
You should be able to:
Explain and compare the causes and effects of rain shadows and temperature inversions.
Explain why ocean-
Describe and contrast ways in which agriculture and human infrastructure (such as urbanization) may transform local and regional climates.
What are some of the major ways that Earth’s topography affects land and ocean physical conditions?
Mountain ranges and valleys can create local and regional differences in temperature and precipitation due to their effects on atmospheric circulation. They also influence the flow of fresh water in rivers and lakes. The topography of the seafloor creates variations in water depth, which affects light penetration, water temperature, water pressure, and water movement (i.e., currents, waves, and tides). These changes in physical conditions create different zones containing characteristic biota, which are similar to terrestrial biomes on land.
Why are cities warmer than rural areas, and what are country breezes? How and why could the temperature within a city be changed with the establishment of a large forested park?
Cities are warmer because concrete, asphalt, and the dark roofs of buildings absorb heat from solar radiation and radiate that heat in the evening hours. Cities also produce more heat through the burning of fossil fuels from cars, factories, and buildings. The temperature differential between cities and the surrounding countryside can create “country breezes,” air movement generated as rising warm air from the city is replaced by cold surface air from surrounding rural areas. Parks can serve to cool the surrounding air through the evapotranspiration of trees and other vegetation.
With an understanding of how Earth’s physical environment, including climate, is determined at a variety of spatial scales, we turn next to biogeography: how the physical environment and other geographic and historical processes determine the global distribution of organisms on Earth.