-Absolute humidity is the water mass per unit volume, (mg/m3). Water vapor pressure(hPa),is a partial pressure, which equals to the pressure of the air parcel where the dry air were not there but the water vapor. Saturated water vapor pressure,(hPa),is the water vapor pressure at saturation of the same temperature. Relative humidity refers to the ratio of water vapor pressure to saturated water vapor pressure,(% Dew point temperature(K)is the temperature when the air parcel is cooled to condensation under constant pressure – Absolute humidity is the water mass per unit volume, (mg/m3). – Water vapor pressure (hPa), is a partial pressure, which equals to the pressure of the air parcel where the dry air were not there but the water vapor. Saturated water vapor pressure, (hPa), is the water vapor pressure at saturation of the same temperature. – Relative humidity refers to the ratio of water vapor pressure to saturated water vapor pressure, (%) – Dew point temperature (K) is the temperature when the air parcel is cooled to condensation under constant pressure