Publication Date:
2018-03-08
Description:
A positive bias at heights between 3 and 8km has been observed when comparing the radio occultation retrieved refractivity with that of meteorological analyses and re-analyses, in cases where heavy precipitation is present. The effect of precipitation in RO retrievals has been investigated as a potential cause of the bias, using precipitation measurements interpolated into the actual three dimensional RO raypaths to calculate the excess phase induced by precipitation. The study consisted in comparing the retrievals when such extra delay is removed from the actual measurement and when it is not. The results show how precipitation itself is not the cause of the positive bias. Instead, we show that the positive bias is linked to high specific humidity conditions regardless of precipitation. This study also shows a regional dependence of the bias. Furthermore, different analyses and re-analyses show a disagreement under high specific humidity conditions and in consequence, heavy precipitation.
Electronic ISSN:
1680-7375
Topics:
Geosciences