Which of the following statements with reference to surface inversion of…

Surface (or radiation) temperature inversion is a departure from the normal environmental lapse rate, in which temperature usually decreases with height. On clear, calm nights the ground loses heat rapidly through outgoing longwave radiation, cooling the air in immediate contact with it faster than the air just above — leaving a thin layer near the surface where temperature actually increases with height.

Applying this to the two statements:

• Statement 1: in a surface inversion the coldest, densest air sits at the bottom beneath progressively warmer air above. This layering suppresses convection and vertical mixing rather than promoting it, so the near-surface atmosphere becomes more stable, not less. Statement 1 is therefore incorrect.

• Statement 2: because the inversion is driven by nighttime radiative cooling of the ground, it breaks down once sunrise begins warming the surface again, and the resulting convective mixing typically erases it within a few hours of sunrise. Statement 2 is therefore correct.

As a cross-check, contrast this with a subsidence (upper-air) inversion, produced by sinking, compressionally warmed air in an anticyclone:

That short, sunrise-linked lifespan is the signature that distinguishes a surface inversion from such longer-lived inversions, and it is exactly what Statement 2 describes; the stable, convection-suppressing layering set out earlier contradicts Statement 1's instability claim. Since only Statement 2 holds, the correct option is "2 Only".