Use the provided figures on to explore ocean circulation by looking at the chloroflourocarbon (CFC) content of the water.
Note that the only source of CFCs into the atmosphere is humans. Release of CFCs into the atmosphere increased after the 1960s but started decreasing in the late 1990-2015. Answer the following, keeping in mind that these measurements were taken in 1998-1999.
Hint: think about how the water in the ocean circulates and when it does/does not interact with the atmosphere due to thermohaline circulation.
Notes for interpreting the figures:
· The figures show a transect from North to South, one in the Pacific and one in the Atlantic.
· White spots indicate no data
· The grey areas show where the bottom of the ocean is at that location (aka the bathymetry)
· The color shows the concentration of CFCs in the ocean (NOT the temperature!)
1. In what areas of the Atlantic and Pacific is the CFC concentration zero? Why is that?
2. Identify how and explain why the Atlantic and Pacific CFC concentrations are different.
3. If we took another cross-section in the Atlantic today, how would you expect it to look different from the 1998-1999 cross-section? Why? Hint: Think about what is happening with CFCs in the atmosphere since 1998-1999.
CFC Concentrations in the Ocean
RED – HIGH concentration
PURPLE – LOW concentration
ATLANTIC
SOUTH NORTH
PACIFIC:
SOUTH NORTH