(2009? Nanning) Xiaoming made his own barometer as shown in the figure with a glass bottle, a thin glass tube with openings at both ends and a rubber stopper, and blew air from the upper end of the tu

(2009? Nanning) Xiaoming made his own barometer as shown in the figure with a glass bottle, a thin glass tube with openings at both ends and a rubber stopper, and blew air from the upper end of the tube. Only when the pressure of the gas in the bottle is greater than the external atmospheric pressure can the water column be pressed above the bottle mouth; When you go upstairs, the height is rising, the atmospheric pressure will decrease with the increase of the height, the external atmospheric pressure will become smaller, and the atmospheric pressure in the bottle will be greater than the external atmospheric pressure, which will further press the water column outward, so the water column will increase.

So the answer is: increase, decrease.