Realms of Earth: The Four Great Realms: The natural systems encountered in physical geography operate within the four great realms, or spheres, of the Earth. These are the atmosphere; the lithosphere, the hydrosphere, and the biosphere. Lithosphere - All processes associated with the solid earth Hydrosphere - All processes associated with water Atmosphere - All processes associated with the gases that envelope the earth Biosphere - All processes that involve living organisms

Four great Realms

Biosphere The biosphere is the global sum of all ecosystems. The biosphere is the global ecological system integrating all living beings and their relationships, including their interaction with the elements of the lithosphere, geosphere, hydrosphere, and atmosphere. The biosphere is postulated to have evolved, beginning with a process of biopoiesis (life created naturally from non-living matter such as simple organic compounds) or biogenesis (life created from living matter), at least some 3.5 billion years ago. On land, the life layer is the zone of interactions among the biosphere, lithosphere, and atmosphere

BioSphere and Four Realms of Earth.

Hydrosphere The hydrosphere describes the combined mass of water found on, under, and over the surface of a planet.

Lithosphere A lithosphere is the rigid outermost shell of a rocky planet, and can be identified on the basis of its mechanical properties. It comprises the crust and the portion of the upper mantle that behaves elastically on time scales of thousands of years or greater This outermost solid layer of the Earth provides a platform for most life-forms. The solid bedrock bears a shallow layer of soil in which nutrient elements become available to organisms. The surface of the lithosphere is sculpted into landforms which provide varied habitats for plants, animals, and humans.

Lithosphere Different Layers

Inside the Earth

Rock Formation

Atmosphere Thin Gaseous envelope The gaseous layer that surrounds the Earth. It receives heat and moisture from the surface and redistributes them, returning some heat and all of the moisture to the surface. It supplies vital elements needed to sustain life forms. Thin Gaseous envelope

ATMOSPHERIC TEMPERATURE Greenhouse gases This diagram shows the average global temperature of air at altitude. Temperature tends to decrease with altitude Temperature inversions (when it increases with altitude) occur where various gases cause varying rates absorption of radiation ENVIRONMENTAL LAPSE RATE

Atmospheric Layers Troposphere – Temp decrease w/ height So far, we have seen that both air pressure and air density decrease with height above the earth Air temperature has a more complicated vertical profile. Look at this diagram, notice that air temp normally decreases from the surface up to about 11 km (36,000 ft) or 7 mi. This decrease in air temp with increasing height is due mainly to the fact that the sunlight warms the earth’s surface and the surface then warms the air above it. The rate at which air temp decreases with height is called Lapse Rate. The standard lapse rate is about 3.6F per 1000 ft of rise. Note this is only an average and is not always the case. There are times when air temperature actually increases with height. This condition is known as a temperature inversion. We use radiosondes to measure the day to day changes in the lapse rate. Troposphere – Temp decrease w/ height Most of our weather occurs in this layer Varies in height around the globe, but Averages about 11 km in height. Figure 1.7

Atmospheric Layers Stratosphere Temperature inversion in stratosphere Ozone plays a major part in heating the air at this altitude So far, we have seen that both air pressure and air density decrease with height above the earth Air temperature has a more complicated vertical profile. Look at this diagram, notice that air temp normally decreases from the surface up to about 11 km (36,000 ft) or 7 mi. This decrease in air temp with increasing height is due mainly to the fact that the sunlight warms the earth’s surface and the surface then warms the air above it. The rate at which air temp decreases with height is called Lapse Rate. The standard lapse rate is about 3.6F per 1000 ft of rise. Note this is only an average and is not always the case. There are times when air temperature actually increases with height. This condition is known as a temperature inversion. We use radiosondes to measure the day to day changes in the lapse rate. Figure 1.7

Atmospheric Layers Mesosphere Middle atmosphere – Air thin, pressure low, Need oxygen to live in this region. Air quite Cold -90°C (-130°F) near the top of mesosphere So far, we have seen that both air pressure and air density decrease with height above the earth Air temperature has a more complicated vertical profile. Look at this diagram, notice that air temp normally decreases from the surface up to about 11 km (36,000 ft) or 7 mi. This decrease in air temp with increasing height is due mainly to the fact that the sunlight warms the earth’s surface and the surface then warms the air above it. The rate at which air temp decreases with height is called Lapse Rate. The standard lapse rate is about 3.6F per 1000 ft of rise. Note this is only an average and is not always the case. There are times when air temperature actually increases with height. This condition is known as a temperature inversion. We use radiosondes to measure the day to day changes in the lapse rate. Figure 1.7

Atmospheric Layers Thermosphere “Hot layer” – oxygen molecules absorb energy from solar Rays warming the air. Very few atoms and molecules in this region. So far, we have seen that both air pressure and air density decrease with height above the earth Air temperature has a more complicated vertical profile. Look at this diagram, notice that air temp normally decreases from the surface up to about 11 km (36,000 ft) or 7 mi. This decrease in air temp with increasing height is due mainly to the fact that the sunlight warms the earth’s surface and the surface then warms the air above it. The rate at which air temp decreases with height is called Lapse Rate. The standard lapse rate is about 3.6F per 1000 ft of rise. Note this is only an average and is not always the case. There are times when air temperature actually increases with height. This condition is known as a temperature inversion. We use radiosondes to measure the day to day changes in the lapse rate. Figure 1.7