Chemical Engineering in Daily Life – Question 67: In North China during the Spring and Autumn period, does the relative humidity increase or decrease on the day following moderate to heavy rainfall?
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This post was last edited by yjqin1 on 2015-9-6 at 11:35. In North China during spring and autumn, a rainstorm brings great joy to people’s hearts. This solves both the drought problem and the haze issue, with clear skies often prevailing the next day. Question: In such a situation, does the relative humidity of the air on the day after it rains become higher or lower?
This humidity should be higher compared to before it rains.
Haha, you suddenly pulled me into the ditch.
Since it is a sunny day, the relative humidity won’t be very high. It is related to air pressure, so it’s difficult to compare.
This post was last edited by yjqin1 on 2015-9-6 13:30. How is relative humidity defined? The atmospheric pressure at the same location changes very little. Even the centrifugal force generated by the high-speed rotation of the strongest typhoons can only reduce the atmospheric pressure at sea level from 1.0 atm to around 0.91 atm. The relative humidity in a given area can vary between 6% and 100%.
Relative humidity is equal to the partial pressure of water vapor in the air divided by the saturated vapor pressure of water at the same temperature. The air is saturated on rainy days, but it becomes unsaturated after rain, causing the relative humidity to decrease
It has lower humidity than on rainy days, but higher humidity than the day before it rains
This post was last edited by yjqin1 on 2015-9-6 23:26. The lowest relative humidity in Tianjin today was 21%, recorded at 3:00 p.m； The relative humidity at 11:00 a.m. is 32% right now ； It is 11:20 p.m. now, with a relative humidity of 55%.
Relative humidity decreases. According to engineering thermodynamics, relative humidity is equal to the partial pressure of moist air in the air divided by the saturated air pressure at that temperature. Before it rains, the partial pressure of moist air in the air is higher than after it rains; based on the definition of relative humidity, this value therefore decreases.