Eco 8_27 Q and A PDF
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This document discusses the differences between climate and weather, and examines the forces that cause short- and long-term variations in climate. It explains concepts like solar radiation, atmospheric circulation, and the Coriolis effect.
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1. What is the difference between climate and weather? Climate is the long-term pattern of weather patterns Weather is the short-term conditions 2. What forces cause short- and long-term variation in climate? Short term Solar Radiation and Earth's Tilt: The tilt of the Earth'...
1. What is the difference between climate and weather? Climate is the long-term pattern of weather patterns Weather is the short-term conditions 2. What forces cause short- and long-term variation in climate? Short term Solar Radiation and Earth's Tilt: The tilt of the Earth's axis (23.5 degrees) affects the intensity and distribution of solar radiation. This causes predictable seasonal variations in climate (e.g., summer and winter) as different parts of the Earth receive varying amounts of sunlight throughout the year. Atmospheric Circulation: The uneven heating of the Earth's surface by the sun creates large-scale circulation patterns like Hadley Cells, Ferrel Cells, and Polar Cells. These cells are responsible for the distribution of heat and moisture, leading to different weather patterns such as heavy rainfall near the equator and deserts around 30° latitude. Coriolis Effect: The rotation of the Earth causes the Coriolis effect, which deflects winds and ocean currents, influencing the Earth's wind patterns. This effect contributes to east-west circulation and affects regional weather patterns. Oceanic and Continental Effects: Large bodies of water (like oceans) have a high specific heat capacity, which means they absorb and release heat slowly, moderating coastal climates. Conversely, land heats and cools more rapidly, leading to more extreme temperature variations inland. Long term Earth's Axial Tilt and Orbital Changes: Changes in the Earth's axial tilt and orbital patterns over millions of years can cause long- term climate shifts, such as ice ages. These variations affect the distribution of solar radiation on the Earth's surface, influencing global temperatures. Global Atmospheric and Ocean Circulation: Long-term changes in atmospheric and ocean circulation patterns can lead to shifts in global and regional climates. For example, changes in the strength and position of wind and ocean currents can impact precipitation and temperature patterns over decades to centuries. 3. How do solar radiation and the Coriolis effect cause the Earth’s wind patterns? Solar Radiation: The uneven heating of the Earth's surface by solar radiation is the primary driver of atmospheric circulation. Solar radiation heats the Earth's surface more at the equator than at the poles. This difference creates convection cells: Hot air rises at the equator, creating low-pressure zones. As the air rises, it cools and spreads towards the poles. At around 30°N and 30°S, the cooled air descends, creating high-pressure zones and leading to the formation of Hadley Cells. This descending air warms and creates dry conditions, resulting in deserts around these latitudes. Coriolis Effect: The Coriolis effect is caused by the Earth's rotation, which makes moving air (wind) appear to be deflected. This effect: Deflects winds to the right in the Northern Hemisphere (clockwise) and to the left in the Southern Hemisphere (counterclockwise). This deflection creates the east-west circulation patterns of the trade winds (Hadley Cells), westerlies (Ferrel Cells), and polar easterlies (Polar Cells). Combined Effect: Together, solar radiation (which drives the vertical movement of air) and the Coriolis effect (which causes the horizontal deflection of wind) shape the global wind patterns, resulting in the complex atmospheric circulation that influences weather and climate around the world. 4. What are Hadley, Ferrel, and Polar Cells? 1. Hadley Cells: Location: Between the equator (0°) and 30° latitude (both North and South). How They Work: Warm air rises at the equator due to intense solar heating. As the air rises, it cools, condenses, and causes heavy rainfall near the equator. The cooled air moves poleward at high altitudes and descends around 30° latitude, creating high-pressure zones and dry conditions, resulting in deserts. The descending air moves back toward the equator along the surface, forming Trade Winds (easterly winds). Key Features: Creates tropical rainforests near the equator and deserts around 30° latitude. 2. Ferrel Cells: Location: Between 30° and 60° latitude (both North and South). How They Work: Air descends from the Hadley Cell around 30° latitude and moves poleward along the surface. This warm, moist air rises again around 60° latitude as it meets colder air from the Polar Cell, leading to stormy and wet weather. At higher altitudes, air moves back toward 30° latitude, completing the cell and creating Westerly Winds (winds blowing from west to east). Key Features: Dominates the mid-latitudes, contributing to temperate climates and westerly winds. 3. Polar Cells: Location: Between 60° latitude and the poles (90°). How They Work: Cold air descends at the poles, creating high-pressure zones. The cold, dense air flows toward the equator along the surface. At around 60° latitude, it meets warmer air from the Ferrel Cell, causing it to rise and creating low-pressure zones. Rising air moves poleward at high altitudes and descends again, completing the cycle and forming Polar Easterlies (winds blowing from east to west). Key Features: Controls the climate near the poles, characterized by cold and dry conditions. 7. Which general types of biomes are found in Texas? Biomes in Texas: Forests, Shrubland, Deserts, Grasslands, Savanna. 8. How do mountains impact the climate near them? Mountains impact the climate through the rain shadow effect: Adiabatic cooling occurs as moist air rises over a mountain. The pressure is reduced, causing the air to expand and cool. As it cools, moisture condenses, leading to precipitation on the windward side of the mountain After the air loses moisture and passes over the peak, it descends on the leeward side, becoming drier and warmer due to compression. This creates a dry, arid climate on the leeward side, known as the "rain shadow" area. (side of mountain with water gets rain and side without water gets dry cool air) Additionally, the temperature generally decreases by 5–8°C for every 1000 meters of elevation, leading to cooler temperatures at higher altitudes. Low elevation (higher temperatures/ lower precipitation), elevation, higher elevation (lower temperatures/ higher precipitation) 9. Does a mountain range’s orientation (N-S or E-W) change the impacts on nearby climates? Yes, a mountain range's orientation affects its impact on climate: North-South (N-S) orientation (e.g., mountain ranges in North and South America) typically blocks prevailing westerly winds and creates distinct wet and dry regions on either side of the range. Moist air from the oceans is forced upward on the windward side, causing precipitation, while the leeward side remains dry. East-West (E-W) orientation (e.g., mountain ranges in Europe and Asia) can impact the flow of air masses differently, potentially affecting seasonal monsoons or other weather patterns that travel from the west to the east or vice versa. In summary, mountain orientation influences how air flows, moisture is distributed, and climatic conditions develop on either side of the range. Notes: 1. Uneven Heating of the Earth's Surface: Because the Earth is a sphere, sunlight hits different parts of the Earth at different angles. Near the equator, sunlight is more direct, providing more energy and warmth. Near the poles, sunlight strikes at a more oblique angle, spreading the energy over a larger area, resulting in less warming. 2. Tilt of the Earth's Axis: The Earth's axis is tilted at about 23.5 degrees. As the Earth orbits the sun, different parts of the Earth tilt toward or away from the sun at different times of the year. This tilt causes seasonal variation: When the Northern Hemisphere is tilted toward the sun, it experiences summer, while the Southern Hemisphere, tilted away, experiences winter. When the Northern Hemisphere is tilted away from the sun, it experiences winter, while the Southern Hemisphere experiences summer. These two factors—uneven heating and the axial tilt—create predictable patterns of latitudinal (from the equator to the poles) and seasonal (changes throughout the year) climate variation. 3. Tropic of Cancer (23.5° North Latitude): Located in the Northern Hemisphere, it marks the point where the sun is directly overhead at noon during the summer solstice (around June 21). This event marks the longest day of the year for the Northern Hemisphere. The region between the Tropic of Cancer and the Tropic of Capricorn is known as the tropics and generally experiences a warm climate year-round. 4. Tropic of Capricorn (23.5° South Latitude): Located in the Southern Hemisphere, it marks the point where the sun is directly overhead at noon during the winter solstice (around December 21). This event marks the longest day of the year for the Southern Hemisphere. These lines are important for understanding the Earth's solar patterns, seasonal changes, and the distribution of different climates across the globe. The area between these two lines experiences the most direct sunlight and is typically characterized by a tropical climate with minimal seasonal temperature variation. 5. Large Variation at the Poles: The poles experience extreme seasonality in both day length and temperature. This is because, due to the Earth's tilt, the poles receive very different amounts of sunlight throughout the year. During summer, the poles can have continuous daylight (24 hours of sun), while in winter, they may experience continuous darkness (24 hours of night). This results in significant temperature fluctuations between summer and winter. 6. Small Variation in the Tropics: The tropics (between the Tropic of Cancer at 23.5°N and the Tropic of Capricorn at 23.5°S) experience small variations in day length and temperature throughout the year. This is because the sun's rays hit this region more directly year-round, resulting in a relatively constant amount of solar energy. Therefore, tropical regions do not have the extreme seasonal changes in day length and temperature that the poles do. The direct solar radiation primarily falls between 23.5°N (Tropic of Cancer) and 23.5°S (Tropic of Capricorn), which coincides with the tilt of the Earth's axis at 23.5 degrees. Question: What if the tilt of earch was larger that 23.5? Answer: more extreme summer and winters 7. Earth’s Tilt: The Earth is tilted at an angle of 23.5 degrees relative to its orbit around the sun. This tilt remains constant as the Earth orbits the sun, meaning the axis always points in the same direction (toward the North Star). 8. Tilt Towards or Away from the Sun: When the Northern Hemisphere is tilted toward the sun (around June), it experiences summer. During this time, the sun’s rays hit this hemisphere more directly, leading to longer days and shorter nights. Conversely, when the Northern Hemisphere is tilted away from the sun (around December), it experiences winter. The sun’s rays strike it at a lower angle, resulting in shorter days and longer nights. The opposite is true for the Southern Hemisphere. When the Northern Hemisphere has summer, the Southern Hemisphere has winter, and vice versa. 9. Equinoxes: During the spring equinox (around March) and the autumn equinox (around September), the Earth's tilt is such that both hemispheres receive equal sunlight. This results in nearly equal day and night lengths everywhere on Earth. At these times, the equator faces the sun directly, and neither hemisphere is tilted toward or away from the sun. 10. Milankovitch Cycles (eccentricity, tilt, and precession) cause variations in the Earth's climate over long timescales by changing the amount and distribution of solar radiation received. These changes have led to periodic ice ages and other long-term climate fluctuations over the past 1-2 million years. 11. The Coriolis Effect is the apparent deflection of moving objects (such as air or water) when viewed from a rotating reference frame, like the Earth. This effect is caused by the Earth's rotation and significantly impacts global wind and ocean current patterns. How the Coriolis Effect Works: Rotation of the Earth: The Earth rotates from west to east. Points on the equator move faster than points closer to the poles because the Earth's circumference is largest at the equator. Deflection of Moving Air: As air moves from high to low-pressure areas, the Earth's rotation causes it to deflect: ▪ Northern Hemisphere: Moving air is deflected to the right. ▪ Southern Hemisphere: Moving air is deflected to the left. This deflection affects the direction of winds and ocean currents. Effects on Wind Patterns: Trade Winds (Hadley Cells): Air moving toward the equator is deflected westward, creating the Trade Winds (easterly winds) that blow from east to west in both hemispheres. Westerlies (Ferrel Cells): Air moving poleward from 30° latitude is deflected eastward, creating the Westerlies that blow from west to east in mid-latitudes. Polar Easterlies (Polar Cells): Air moving from the poles toward 60° latitude is deflected westward, creating the Polar Easterlies. Key Points: The Coriolis Effect does not cause the wind; it only alters the direction of moving air due to Earth's rotation. The effect is strongest at the poles and weakest at the equator. It influences major atmospheric and oceanic circulation patterns, impacting weather systems, storm paths, and ocean currents globally. Importance of the Coriolis Effect: The Coriolis Effect is critical for understanding: Global Wind Patterns: It shapes the direction of Trade Winds, Westerlies, and Polar Easterlies, which affect global climate and weather. Ocean Currents: It influences oceanic circulation, which helps regulate climate by redistributing heat around the planet. Weather Systems: The Coriolis Effect impacts the movement of cyclones and anticyclones, affecting local and regional weather conditions. By deflecting winds and currents, the Coriolis Effect plays a crucial role in creating and maintaining the dynamic atmospheric and oceanic systems that regulate Earth's climate. 12. Seasonality Temperate zones have four seasons with significant temperature changes. Tropical zones experience minimal temperature change but have distinct wet and dry periods. 13. Equatorial Rainy seasons Solar Equator Movement: The solar equator is the area on Earth receiving the most direct sunlight. It shifts throughout the year between the Tropic of Capricorn (23.5°S) and the Tropic of Cancer (23.5°N). This shift occurs due to the tilt of the Earth's axis (23.5 degrees) and its orbit around the sun. Passes Over the Equator Twice: As the solar equator moves northward and southward, it passes over the actual geographic equator twice a year — around the March (Spring) and September (Autumn) equinoxes. One rainy season occurs when the Intertropical Convergence Zone moves over the Tropic of Cancer or Tropic of Capricorn. Two rainy seasons occur at the Equator as the Intertropical Convergence Zone passes over it twice (once while moving northward and once while moving southward) 14. Specific Heat: The amount of heat energy required to raise the temperature of a unit mass of a substance by 1 degree Celsius. Water has a high specific heat (4.19 J/g°C), meaning it requires more energy to change its temperature. Land (soil) has a lower specific heat (0.79 J/g°C), so it heats up and cools down much faster than water. What This is Getting At: Water's high specific heat makes it slower to heat up or cool down, moderating temperatures near oceans or lakes. Land heats and cools faster due to its lower specific heat, leading to more extreme temperature changes on continents compared to coastal areas. This concept helps explain why coastal regions often have milder climates, while inland areas experience more significant temperature variations. Terrestrial Biomes: Note: climate, soils + nutrients, and fire frequency make up a biome 1. Tropical Rainforests: most with 10 degrees of equator / tropics Above freezing year round Temps around 80 year round Precipitation high, around 200 mm per month Characteristics: dense canopy, competition for light, lush forest, epiphytes (plants grow on plants), covers less that 5% earth, but 50 % of its species (high biodiversity) 2. Tropical dry: 0-25 degrees from equator Above freezing year round Note opposite rainy season in Northern and Southern hemisphere (seen in India vs Australia) May be dry for up to 8 months Wet and dry biome because the peak rainy season Characteristics: long dry season, grasslands, bit more trees than savanna, deciduous trees (shed leaves during dry seasons to conserve moisture), high rate of photosynthesis during wet seasons because dry season is long 3. Tropical Savanna: 10-20 N or S of tropical dry forests Short rainy season, during warm months Wet and dry biome Long dry seasons Grasslands with scattered trees, subsoil conditions limit deeper rooted vegetation, deciduous trees (shed leaves during dry seasons to conserve moisture), grass adapted to resprout quickly, high rate of photosynthesis during wet seasons because dry season is long 4. Desert Deserts are located around 30° north and south latitude. Cover about 20% of the Earth's land surface. Have a climate where water loss (through evaporation and transpiration) typically exceeds precipitation. Deserts are not necessarily hot or low in precipitation but are characterized by conditions that cause drought stress, like high temperatures and low moisture. Characteristics: Vegetation is sparse due to the lack of water. Plants that do exist in deserts have unique adaptations to conserve water, such as: Reduced or No Leaves: To minimize water loss through transpiration... Thick Cuticles: On stems or leaves to reduce water loss...Deep Roots: To reach underground water sources...Ephemeral Plants: These plants have a rapid lifecycle, growing only during brief periods of rainfall and remaining dormant as seeds during droughts...Succulents: Plants like cacti store water in their stems or leaves. Desert soils are typically sandy or rocky, low in organic matter, and have a high mineral content. They often have poor water retention, making it difficult for many plants to survive. Sandgrouse are birds that have special adaptations to collect and store water, which they then carry back to their nests to provide hydration for their young. 5. Mediterranean Woodland and Shrubland: 30 to 40 degrees from equator Hot/ dry summers and wet/ mild winters (distinct seasons) Fires are common in this biome in dry summers Adaptations for fire and drought: many tress have fire resistant bark Wine production Plants drought resistant, reduce water loss such as thick/ waxy leaves, shrubs, low trees highly adapted to survive dry and periodic fires Growing season: rainfall and cooler temperatures 6. Temperate Grasslands 30 to 55 degrees from equator Temperate grasslands are mostly gone (97% lost) due to agricultural use Mild precipitation in summer and cold winters/ dry Growing season will be when it is warmer 7. Temperate forest 30 to 50 degrees from equator Warm summer, cold winters but not extreme, NO extreme dry season, consistent rainfall throughout year More rainfall than grassland Songbird migration 8. Boreal Forest (Taiga) 50 to 70 degrees North of equator Just below arctic circle Covers 11% of earths global land area Extreme weather variation, mild summers, extreme cold winters Mostly below freezing most of year Growing season only few months in summer Lower precipitation, bit higher in the summer Only Northern Hemisphere because... The boreal forest is located exclusively in the Northern Hemisphere because it is situated between the tundra to the north and temperate forests to the south. The Southern Hemisphere lacks equivalent landmasses at these latitudes, which is why there is no corresponding boreal forest region. Frogs with anti-freeze like proteins in blood 9. Tundra 60 to 75 degrees North of Equator & north of artic circle Extremely cold and long winters/ summers warm a bit for short time and this is when precipitation can happen and growing season Typically low precipitation Extreme short growing season Only Northern Hemisphere because... Landmass Distribution: The tundra is exclusive to the Northern Hemisphere because of the distribution of landmasses. The Southern Hemisphere does not have equivalent land areas at these high latitudes. The Antarctic is mostly covered by ice, with no large expanses of tundra-like land...Climate Conditions: The cold temperatures necessary for the tundra biome, with its permafrost and short growing seasons, are primarily found in the Northern Hemisphere's polar and sub-polar regions. In the Southern Hemisphere, there are no significant land areas at the latitudes where tundra conditions would naturally occur.