21. The surface pressure turned out to be. 22. The resulting mean surface pressure is only 0.6 % of that of Earth ( 101.3 kPa ). 23. Because these are dry-air mole fractions, these measurements do not change with water content or surface pressure . 24. While drilling the oil well, surface pressure control is provided by a blowout preventer ( BOP ). 25. The surface pressure will suddenly drop and the frac engineer will know that the fracture has started. 26. A sudden adjustment in the jet stream can lead to rapid rises and drops in surface pressure . 27. On Monday afternoon, reconnaissance aircraft investigating Roxanne found sustained winds of 60 mph and rapidly falling surface pressures . 28. Surface pressures varied diurnally over a 0.2 millibar range, but showed 2 daily minima and two daily maxima.29. Rising surface pressure over the Northeast is associated with an expanding fair weather system moving southeast from Quebec. 30. But the planet exhibits a dense cloud layer miles above the surface, suggesting the surface pressure is pretty high.
