Answer to Question 1
Fog is a cloud layer on the ground with visibility restricted to less than 1 km (3,300 ft). Radiation fog results when radiative cooling of the surface chills the air directly above the surface to the dew-point temperature. Advection fog occurs when air in one place migrates to another place where the conditions are right for saturation. For instance, when warm, moist air moves over a cooler ocean current. Valley fog is a type of advection fog, which results from cooler, denser air settling in low-lying areas. Similarly, upslope fog forms as moist air is lifted due to topography and, as a result, adiabatically cools. Evaporation fog forms when cold air lies over a warm water body and water molecules evaporate from the water surface into the cold, overlying air.
Answer to Question 2
The normal lapse rate is the average decrease in temperature with increasing altitude, a value of 6.4 C/1000 m (3.5 F/1000 ft). However, the actual rate can vary greatly in space and time. The environmental lapse rate (ELR) is the actual lapse rate at a particular place at a particular time. The rate at which dry (i.e. not saturated) air cools by expansion as it rises, an average value of 10 C/1000 m (5.5 F/1000 ft). The moist adiabatic rate, the rate at which a saturated air parcel cools as it rises, has an average value of 6 C/1000 m (3.3 F/1000 ft). These adiabatic rates also apply to the warming of descending air.