A research probe is lowered into an ultra-deep vertical borehole from sea level to a depth of several kilometers. Which statement correctly explains the changes in atmospheric pressure and density experienced by the probe as it descends?
The pressure increases because the local gravitational field strength ggg increases rapidly as the probe approaches the Earth's dense metallic core, drawing more air molecules to the bottom.
Both the pressure and density of the air increase because the increased height of the air column above the probe increases the weight of air pressing down, compressing the air below.
The pressure increases because of the greater weight of the air column above, but the density of the air decreases because the air becomes warmer at greater depths.
The pressure decreases because the mass of the Earth's crust above the probe exerts an upward gravitational pull, reducing the effective weight of the air column.