Explain what key sociocultural (human) and physical characteristics define this as a region.

Charles's law states that at a constant pressure, the volume of a given amount of gas is directly proportional to its absolute temperature. Charle's law is also derived from the ideal gas law which states that:

PV = nRT

As you can see, V and T are already directly proportional with each other. The only difference with Charles Law is that pressure was held constant, cancelling out the moles and gas constant.