Assessment of global navigation satellite system (GNSS) radio occultation refractivity under heavy precipitation

Autor: R. Padullés, E. Cardellach, K.-N. Wang, C. O. Ao, F. J. Turk, M. de la Torre-Juárez
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: Atmospheric Chemistry and Physics, Vol 18, Pp 11697-11708 (2018)
Druh dokumentu: article
ISSN: 1680-7316
1680-7324
DOI: 10.5194/acp-18-11697-2018
Popis: A positive bias at heights between 3 and 8 km has been observed when comparing the radio-occultation (RO)-retrieved refractivity with that of meteorological analyses and reanalyses 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 ray paths to calculate the excess phase induced by precipitation. The study consisted of 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 reanalyses show a disagreement under high specific-humidity conditions and, in consequence, heavy precipitation.
Databáze: Directory of Open Access Journals