The temperature gradient is defined as the change in temperature over the change in distance, dT/dx. The pressure gradient is defined as the change is pressure over the change in distance, dP/dx. Here are some examples of finding these gradients.
a) The temperature at point A is 10 C, the temperature at point B is 20 C, and point A is 100 km from point B. What is the temperature gradient?
dT = 20 C - 10 C = 10 C, dx = 100 km; dT/dx = 10 C / 100 km = 0.1 C/km
b) The pressure at point A is 1020 mb, the pressure at point B is 995 mb, and point A is 400 km from point B. What is the pressure gradient?
dP = 1020 mb - 995 mb = 25 mb, dx= 400 km, dP/dx = 25 mb / 400 km = 0.0625 mb/km, or 6.25 mb per 100 km