Inversion variability in the Hawaiian trade wind regime

Abstract

Using 1979-2003 radiosonde data at Hilo and Līhu'e, Hawaii, the trade wind inversion (TWI) is found to occur approximately 82% of the time at each station, with average base heights of 2225 m (781.9 hPa) for Hilo and 2076 m (798.8 hPa) for Līhu'e. A diurnal pattern in base height of nighttime high and afternoon low is consistently found during summer at Hilo. Inversion base height has a September maximum and a secondary maximum in April. Frequency of inversion occurrence was found to be higher during winters and lower during summers of El Niño years than non-El Niño years. Significant upward trends were found for inversion frequency at Hilo for March-May (MAM), June-August (JJA), and September-November (SON) seasons, and at Līhu'e for all seasons and for annual values. © 2007 American Meteorological Society.