O2(uM) CO2(uatm) 0 50 100150200250 300 200 400 600 800 1000 1200 1000 1000 人 North Atlantic North 2000 Atlantic 2000 E E North 3000 3000 Pacific 4000 4000 North 5000 Pacific 5000 (a) (b) Seawater dissolved oxygen and carbon dioxide variation with depth. Depth profiles for the North Pacific and North Atlantic Oceans showing concentration of(a)oxygen and (b)carbon dioxide. 00