Advancing Understanding Of Planetary Boundary Layer Height: Insights From Dropsonde And Hsrl2 Lidar Measurements During The Activate Field Campaigns
Presenter: Yike Xu P261
Co-Author(s): Yike Xu, Brandon Mitchell, Lauren Cutler ,Richard Ferrare , Johnathan Hair, Chris Hostetler, Amy Jo Scarino, Taylor Shingler ,Armin Sorooshian, Kenneth Lee Thornhill, Xubin Zeng
Advisor(s): Xubin Zeng
1Hydrology & Atmospheric Sciences
The planetary boundary layer (PBL) is the lowest layer of the atmosphere and controls exchanges of fluxes of energy and diffusion of pollutants. Its height is essential for understanding atmosphere-surface interactions. Over the ocean, understanding the marine boundary layer is limited due to the scarcity of observation. Dropsondes have been widely used to retrieve PBLH over the ocean due to their high precision. NASA’s Aerosol Cloud meTeorology Interactions oVer the western ATlantic Experiment (ACTIVATE) over the Northwest Atlantic Ocean from 2020 to 2022 used various instruments to observe the structure of PBL, including dropsondes. We use thermodynamic profiles to compute PBLH from 760 dropsondes in this study. There are four common ways to retrieve the PBLH from the dropsonde thermodynamic profile: the parcel method, the gradient of potential temperature, the gradient of relative humidity (RH), and the bulk Richardson number method. We evaluate and select the best algorithm for each method. We also assess the performance of these four methods under both stable and unstable PBLs. Besides dropsondes, data from additional observation instruments will be used to provide insights: for instance, cloud fraction from the airborne High-Spectral-Resolution Lidar – Generation 2 (HSRL-2) and the cloud in-situ data collected onboard the Falcon aircraft are used for cloud condition. Furthermore, we use the dropsonde-derived PBLH to evaluate the performance of lidar-retrieved MLH from HSRL-2.