J.R. S. answered 09/19/17
Tutor
5.0
(145)
Ph.D. University Professor with 10+ years Tutoring Experience
Pressure. The solubility of a gas (Oxygen in this case) increases as the pressure increases. The pressure at the equator will be greater than the pressure at higher altitudes. Because of this, more oxygen gas is dissolved in the water at the equator than at higher altitudes.