1. Race to the Pole
The amount of heat transported from the tropics to the Peies by the atmospheres circulation depends on the speed of the circulation, as well as the air's ability to carry heat (i.e. its heat capacity). If the amount of transported heat is significant, the time it Mk. to transport the heat determines a time scale over which a climate change can permeate the climate system.
Similarly, the western boundary currents of the wind-driven ocean circulation transport heat stored in the oceans from the tropics to high latitudes, and the amount of transported heat depends on the speed of the currents as well as the water's heat capacity. Again, the time it takes to transport this heat determines a time scale over which the dentate system can change.
In this problem, wo will estimate the time scales of climate change associated with atmospheric versus oceanic heat transport, the latter es represented by the North Atlantic gyre. Use the following approximate velocities and dimensions of atmospheric and oceanic circulation:
ATMOSPHERE:
horizontal winds (at the surface) - 20 mph' horizontal winds (upper troposphere)- 60 mph (30 Mose)* vertical flow (ascending & descending)- 10 mph (5 mtsoc)' north-south extent of each cell - 30° (note 1.= 111 km) east-west distance between ascent and descent - 7000 km (?)
OCEAN GYRE:
Gulf Stream current - 2 m/sec
other conenh in gyre - 10 cm/sec
range of Gulf Stream - 25°N to 55°N
width of N. Atlantic basin - approx. 3500 km
a. Follow a volume of air . it rises above the equator and moves through the 3-cell circulation, ending up at the pole. (1) Estimate the distance traveled horizontally by this volume, and also the distance it rises and fells (it may help if you sketch the situation). (ii) Using the time-honored relation "distance equals rate times time', find how long it will take for the volume to travel from equator to pole.
b. Ina similar manner, estimate the time it takes a volume of seawater to (i) travel northward with the Gulf Stream; and (ii) move around the rest of the N. Atlantic gyro.
c. How do the total travel times for the atmospheric and ocean circulation (equator to pole to equator for the atmosphere, once around the gyres for the ocean) compare?