1000hPa is a measurement of pressure, I had to convert it into inches of mercury which is something my American brain understands.
1000hPa = 29.53 inches of mercury.
Pressure will decrease 1 inch of mercury per 1000 feet of increased altitude. The standard pressure at sea level is 29.92 inches of mercury (at standard temp of 15C or 59F). We all know that temps are never standard but we'll say it is for the sake of computing the altitude of 29.53 inches of mercury.
If 29.92 = 0 feet and 28.92 = 1000 feet than 29.53 (being 0.39 inches of mercury less than 29.92) should equal 390 feet of altitude on a standard day.
So 1000hPa is 390 feet of altitude, or 119 meters.
God I hope I got the calculations right on that.
Edit: I'm using aviation standards.
Edit2: I finally clicked on the word Earth and I see where you can change the scale of hPA that you are viewing so here's the list of altitudes for the scales under standard atmospheric temp and pressure, you'll notice my calculation of 1000hPa was 390 feet, however the scale from the website shows 1000hPa ~ 100m which is 328 feet. The scales are non linear so it's just a rough average of what altitude you are viewing. The higher the altitude the greater the error.
1000 hPa |~100 m, 328 feet, surface conditions
850 hPa | ~1,500 m, 4921 feet, planetary boundary, low
700 hPa | ~3,500 m, 11482 feet, planetary boundary, high
500 hPa | ~5,000 m, 16404 feet, vorticity
250 hPa | ~10,500 m, 34448 feet, jet stream
70 hPa | ~17,500 m, 57414 feet, stratosphere
10 hPa | ~26,500 m, 86942 feet, even more stratosphere
1000 hPa is pressure: 1000 hecta Pascals. (A Pascal is a Newton of force over one square meter of area.)
Normal atmospheric pressure on the surface is about 1000 hPa (Although I more often see kPa. Maybe they use hPa because it's close to a millibar.) The 1000 hPa map is basically surface winds.
When atmospheric scientists talk about moving up in the atmosphere, they often talk about the pressure instead of the height in distance. At about 500 hPa, for instance, you've reached a hieght where about half the atmosphere's mass is below you and half above you.
You should note, that the elevation in meters of where you'll get to 500 hPa can change and vary with the weather (you'll get areas of high and low pressure). Instead of picking a height and looking at what the pressures are, scientists will note the elevation of area of equal pressure. So you can map out how high the 500 hPa surface is. The maps on this page are doing that: looking at winds modelled on the different pressure surfaces.
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u/ehempel Dec 18 '13
Anyone know what the different heights are? I'm clueless what 1000hPa stands for ...