Obtaining a diurnal climatology of the boundary layer along the California coast using ACARS
Especially at busy airports, the high frequency of soundings from ACARS since 2001 provides an opportunity to produce a climatological record of the diurnal cycle of the lower atmosphere including wind patterns, boundary layer height, and inversion strength which has not been done at this resolution over such a long time period. This study explores both the difficulties associated with using ACARS to produce a robust climatology and also the benefits of using ACARS to characterize the lower atmosphere. One key example is at Los Angeles International Airport (LAX). Since large horizontal gradients exist at the coast, a clear and significant difference in the characteristics of the boundary layer was found between the flight paths occurring east of the airport (offshore) and those to the west of the airport (inland). Thus, flight path must be considered when constructing the climatology or even when ingesting the data into model analysis fields. When applying ACARS data to depict the diurnal cycle of events such as the Catalina eddy, these issues must be considered or the results will be distorted.