Comparison of ground-based millimeter-wave observations in the arctic winter

During the Radiative Heating in Underexplored Bands Campaign (RHUBC), held in February-March 2007, three millimeter-wave radiometers were operated at the Atmospheric Radiation Measurement (ARM) Programpsilas site in Barrow, Alaska. These radiometers operate several channels located around the strong 183 GHz water vapor line, which is crucial for ground-based water vapor measurements in very dry conditions, typical of the Arctic. Simultaneous radiosonde observations were carried out during conditions with very low water vapor content (les 2 mm). Observations from the three instruments are presented, together with the adjustments made to account for different design characteristics. The overall agreement during RHUBC among the three instruments and between instruments and forward model is discussed quantitatively.