Quiz 3 Notes

Question 1

Monsoons

Answer 1

Seasonal reversals of wind. Driven by differential heating of land and water. During the day, land warms faster than water, with hot air rising and cool air sinking, creating lake breezes. At night, land cools faster than water, creating land breezes. Air carried from the ocean over the land during summer is very moist and thus precipitates. In the winter, winds blow precipitation away from the land. Also affected by the swirl induced to the winds by the Coriolis effect

Question 2

Mechanisms of the global conveyor belt

Answer 2

Differences in water density: warm water less dense than cold water; salty water denser than freshwater; cold and salty water the densest and so tends to sink. Less dense water tends to rise.
Winds on surface of northern Atlantic Ocean flow northward from tropical regions: as northern Atlantic ocean currents flow towards higher latitudes, salinity of ocean water gradually increases because of evaporation and ice formation. Water leaves salt behind in the ocean in evaporation and ice expels salt. So, cold, salty, dense water sinks to the ocean floor in the Arctic region, and begin to flow back south to Antarctica. They then flow into the Pacific, where they gradually warm and rise. Driven by winds, surface ocean currents flow westward and complete the cycle

Question 3

Impact of climate change on the conveyor belt

Answer 3

The Arctic’s warming has resulted in significant reduction of ice cover and increase in presence of freshwater in the region. Surface ocean water thereby becomes warmer and less salty and dense. So, sinking of ocean water is reduced and the conveyor belt is weakened. If the belt slows, absorbs less CO2 and less heat

Question 4

Effects of El Niños

Answer 4

Normally, tropical Pacific winds blow eastward, but El Niños reverse this. Makes US winters warmer than normal and causes flooding in CA and Gulf Coast states. Makes hurricanes quieter. Floods Peru and Ecuador and causes droughts in western tropical Pacific. Have a warming effect on climate and occur every 2-7 years. Made stronger by enhanced GHE

Question 5

Instrumental data

Answer 5

Take real time measurements of climate systems, ocean temperatures, etc. In situ measurements measure the phenomenon exactly when and where it occurs; include thermometers, barometers, etc. Remote sensing makes use of satellite radars to examine phenomenon from a distance. Include Argo floats

Question 6

Proxy data

Answer 6

Reflects, but does not directly measure, climate. Used in study of paleoclimatology. Includes tree rings, pollen, and sea sediments like ice cores and coral

Question 7

Oxygen isotopes

Answer 7

99.8% of Earth’s oxygen is 16O, which is lighter. 0.2% is 18O, which is heavier. Lighter water molecules evaporate more readily, meaning that tropical areas are high in O18. As heavier water molecules condense more readily, cold regions are high in O16. The 18O/16O ratio is relatively low in rain and ice and relatively high in ocean water.

Question 8

Delta 18O

Answer 8

Compares ratio of the isotopes to a standard value. Changes directly in response to temperature fluctuations and so provides a very good record of climate. In warmer climates, ice melts and so delta 18O values will decrease in the ocean and increase in glaciers. In colder climates, ice grows and so delta 18O values in the ocean increase and decrease in glaciers. Negative correlation between temperature and delta 18O values in the ocean. Positive correletion between temperature and delta 18O in glaciers. Can be applied in studying coral and ice cores for their records of climate change