Question

Surface ocean currents can occur on local and global scales and are typically wind-driven. Deep ocean currents are density-driven and differ from surface currents in scale, speed, and energy. Water density is affected by the temperature, salinity, and depth. The colder and saltier the ocean water, the denser it is. The greater the density differences between different layers in the water column, the greater the mixing and circulation. Density differences in ocean water contribute to a global-scale circulation system, also called the global conveyor belt. The ocean’s global conveyor belt plays a key role in distributing heat energy and regulating both weather and climate. The driving force behind the global conveyor belt is
Responses
A heating and cooling differences between ocean water and land masses.heating and cooling differences between ocean water and land masses.
B the differences in the heat energy balance at different latitudes on Earth.the differences in the heat energy balance at different latitudes on Earth.
C variations in Earth's orbital distances around the Sun throughout the year.variations in Earth's orbital distances around the Sun throughout the year.
D air circulation in the troposphere due to differences in incoming solar radiation.air circulation in the troposphere due to differences in incoming solar radiation.
Question 2


The Gulf Stream originates near the southern tip of Florida and travels along the east coast of the United States and across the North Atlantic. South of Greenland, the Gulf Stream widens and slows, becoming a vast, slow-moving, warm current known as the North Atlantic Drift that passes over western Europe. Hypothesize about the climates of the two locations indicated in the top map, Newfoundland in Canada (left) and Scotland (right).
Responses
A Because the two locations are found at approximately the same latitude, we would expect them to have similar climates.Because the two locations are found at approximately the same latitude, we would expect them to have similar climates.
B As the Gulf Stream travels north, its warm waters cool and there is no great differences between the climates of the two locations.As the Gulf Stream travels north, its warm waters cool and there is no great differences between the climates of the two locations.
C The warm Gulf Stream and its associated winds keep the climate of Scotland much warmer than Newfoundland even though they are at approximately the same latitude.The warm Gulf Stream and its associated winds keep the climate of Scotland much warmer than Newfoundland even though they are at approximately the same latitude.
D The warm Gulf Stream has cooled considerably by the time it reaches the higher latitudes, causing condensation of evaporated ocean waters. We expect Scotland to have much more snow than Newfoundland.The warm Gulf Stream has cooled considerably by the time it reaches the higher latitudes, causing condensation of evaporated ocean waters. We expect Scotland to have much more snow than Newfoundland.

Answer 1

1) B — the global conveyor belt is driven by differences in the heat-energy balance (temperature) at different latitudes, which create density differences (together with salinity) that drive deep thermohaline circulation.

2) C — Scotland is much milder than Newfoundland at similar latitudes because the warm Gulf Stream/North Atlantic Drift and associated maritime air keep western Europe warmer; Newfoundland is cooled by colder currents (e.g., the Labrador Current) and more continental influences.