environmental heterogeneity

Climate

long term pattern of weather on a local, regional or global scale.

weather

the combination of temperature humidity , precipitation, and cloudiness at a specific place and time

Solar radiation

all of the differences in climate around the earth are driven by solar radiation, the ability to sustain life on earth is due to the suns radiation

About the Sun

• main source of energy

• only 51 % reaches the earth and is absorbed and remitted as heat

• the greenhouse effect is crucial to maintain surface temperature

• The amount of energy from it intercepted by the earth varies with latitude ( poles <, equator>)

atmospheric circulation

In summary, atmospheric circulation encompasses the large-scale movement of air in the Earth's atmosphere, driven by solar heating and influenced by the Coriolis effect due to the planet's rotation. It is a fundamental driver of global climate and weather patterns.

uplift

• In summary, atmospheric circulation uplift is the vertical movement of air in the atmosphere, driven by solar heating, convection, and the Coriolis effect. It creates pressure systems, wind patterns, and the overall climate and weather patterns we experience on Earth.

• warm air rising from the tropics, condences and precipitates, leading to cool air being forced north and south

subsidence

• In summary, subsidence in atmospheric circulation involves the downward movement of air in regions of high atmospheric pressure. It leads to stable, clear weather conditions and plays a significant role in the creation of deserts, wind patterns, and climate zones around the world. Subsidence is an essential component of Earth's atmospheric circulation system, working in conjunction with uplift to drive global weather and climate patterns.

• air moves back to earth’s surface when temperature gradient equalizes.

distinct cell formation

Distinct cell formation in Earth's atmospheric circulation refers to the creation of three primary circulation cells: the Hadley Cell, the Ferrel Cell, and the Polar Cell.

Hadley cell

• The Hadley Cell is located in the tropical regions, roughly between the equator (0⁰) and 30⁰ latitude.

• It is formed from the uplift of warm, moist air at the equator. As the Sun's intense heat warms the surface near the equator, air rises, creating a low-pressure area.( uplift of the equator)

Ferrel cell

• The Ferrel Cell is situated in the mid-latitudes, between 30⁰ and 60⁰ latitude.

• It forms as a result of the circulation between the Hadley Cell and the Polar Cell. It closes off the other cells in the mid-latitudes.

Polar cell

• The Polar Cell is located in the polar regions, roughly between 60⁰ and 90⁰ latitude.

• formed from subsidence of air at the poles.

• It is formed from the subsidence (sinking) of cold, dense air at the poles. As air near the poles cools, it becomes denser and sinks, creating a high-pressure area.

Wind currents

• The Coriolis effect, caused by the Earth's rotation, influences the direction of wind movement. In the Northern Hemisphere, winds tend to curve to the right, while in the Southern Hemisphere, they curve to the left. This effect results in the formation of large-scale wind patterns, such as the trade winds, westerlies, and polar easterlies.

• viewed from space, wind move directly north- south

Ocean currents

• created by global winds create ocean currents and continents act as obstructions to the water currents

• clockwise in the northern hemisphere

• anticlockwise in the southern hemisphere

• warm currents move from the tropics outwards, while cooler currents originate from the poles

• main thermal conveyers of the planet

Other factors

1. distribution of land and water

2. elevation

3. earth orbit around the sun

Distribution of land and water

The distribution of land and water on Earth significantly affects climate and weather patterns. Water, being a superior heat absorber, retains heat longer than land. The type of vegetation on land influences its heat absorption capacity, and the albedo, or reflectivity, of surfaces impacts how much solar radiation they reflect.

Internal continental areas are less influenced by ocean currents' heating and cooling effects. The southern hemisphere generally experiences higher precipitation levels compared to the northern hemisphere, partly due to its larger water surface area.

Mountainous topography can create rain shadows, leading to dry areas on the leeward side. Deep continental regions, far from water bodies, tend to be very dry. These factors collectively contribute to the planet's diverse climate and weather patterns.

elevation

Elevation has a significant impact on climate and temperature patterns. As elevation increases, air temperature tends to decrease, as the warming effect of the Earth's surface diminishes. This is because greater air pressure at the surface causes molecules to move faster, resulting in warmer temperatures.

Earth orbit and axial tilt

The Earth's axial tilt also plays a crucial role in seasonal temperature variations. During May to August in the Northern Hemisphere (NH), it is tilted toward the sun, leading to increased solar radiation and summer. From November to February, the NH tilts away from the sun, causing decreased solar radiation and winter. The Southern Hemisphere experiences reversed seasons.

Seasonal changes are most pronounced in temperate zones, while polar regions have extreme day-night cycles. Tropical areas experience shifts in the Intertropical Convergence Zone (ITCZ), leading to wet and dry seasons. These elevation and seasonal factors collectively contribute to Earth's diverse climate patterns.

weather patterns differe at different spacial scales

• global, regional, local and micro

• 
  Global and regional climate patterns determine the large-scale distribution of plants and animals • Local climatic conditions do not match the general climate profiles of the larger region • Because local patterns of microclimate are the actual environmental conditions experienced by organisms → our focus