mixing ratio
Quick Summary
In meteorology, the mixing ratio (r) is a measure of atmospheric humidity. It is defined as the ratio of the mass of water vapor (mv) to the mass of dry air (ma) in a given parcel of air: r = mv / ma. This dimensionless ratio is typically expressed in grams per kilogram (g/kg).1
Another related humidity index is specific humidity (q), which is the ratio of the mass of water vapor to the total mass of moist air (ma + mv): q = mv / (ma + mv). At normal atmospheric pressures and temperatures below 30°C, the mass of water vapor is a small fraction of the total air mass, making the mixing ratio and specific humidity values practically equal. These humidity indexes are crucial for understanding weather patterns, as water vapor influences temperature regulation and precipitation.12
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