Terence Lee Kubar

and 3 more

Over 18 years of satellite data from Multi-Angle Imaging Spectroradiometer (MISR) and 14 years from Global Navigation Satellite System-radio occultation (GNSS-RO), with ERA5 reanalysis temperature profiles, are used to assess the co-variability of cloud and thermodynamic properties of the Northeast Pacific subtropical marine boundary layer. Low cloud top height (CTH) inferred from MISR and planetary boundary layer height (PBLH) inferred from GNSS-RO are well-correlated spatially for all seasons when seasonally-varying mid-latitude grids (temperature at 700 hPa < 4°C) are removed (r=0.83), or when vertical velocity at 500 hPa (ω500) indicates descent (r=0.74). The temporal correlation of PBLH and CTH is highest in the stratocumulus region (r=0.72), with the CTH versus PBLH slope close to one for heights between 0.8 km and 1.6 km of the time series. Seasonal sea-surface to 700 hPa lapse rate (LR) is spatially related with PBLH and more strongly with CTH, and ω500 modulates seasonal CTH-LR relationships. The impact of El Niño Southern Oscillation (ENSO) through teleconnections on the PBL structure is also characterized, with maximum deseasonalized temperature anomalies near or above PBL top (near the surface) during La Niña (El Niño), with CTH, PBLH, and LR anomalies largest during the strong 2015-2016 El Niño. Temperature anomalies above the PBL lead CTH’ and PBLH’ by 15 and 18 months, respectively, just under half the time scale of the periodicity of an Ocean Niño Index mode (~3.1 years), suggestive of the role of atmosphere-to-ocean exchange manifesting in a deepening PBL during warm ENSO.