Spurious pressure and geopotential height fluctuations in the North American Regional Reanalysis

Analyses by the North American Regional Reanalysis (NARR) occasionally exhibit spurious and physically unrealistic fluctuations in geopotential height, surface pressure, and sea level pressure. The fluctuations are not evident in surface observations, typically extend through a greater part of the troposphere, and are not necessarily accompanied by dynamically consistent thermodynamic and kinematic changes. Our poster will present examples of the fluctuations, illustrate their frequency of occurrence, and provide explanations as to their causes.