Buildup of the Surface Based Temperature Inversions during ALPACA-PBL. - INSU - Institut national des sciences de l'Univers Access content directly
Conference Papers Year : 2023

Buildup of the Surface Based Temperature Inversions during ALPACA-PBL.

Natalie Brett
  • Function : Author
  • PersonId : 1155290
Kathy S. Law
Slimane Bekki
David E. Atkinson
  • Function : Author

Abstract

During winters in high latitudes, when an anticyclone feature establishes in the region, an outstanding surface radiative cooling initiates giving origin to the formation of a surface based temperature inversion layer (SBI), also known as a stably-stratified planetary boundary layer (PBL). This often shallow temperature inversion layer modulates the surface cooling regime and isolates the surface from the rest of the troposphere. Mixing and dispersion of pollutants and particulate matter within stratified layers are severely constrained, and therefore, the SBI is a key player in urban air pollution. Similarly, the presence of SBIs have a climate feedback effect on continental and ocean surfaces. A detailed analysis of the buildup of SBIs was conducted based on high resolution vertical temperature profiles obtained by a microwave radiometer, combined with dynamic observations of the PBL flow based on a Doppler Wind Lidar and surface observations of turbulent and radiative fluxes. Four cases of SBI buildup were captured from Feb. 11th to 18th, 2022 during the ALPACA field experiment. These cases show a mixture of columnar cooling and surface cooling forced by surface net radiation deficits in clear sky conditions. Above the SBI, the presence of a warming layer ~ 250 m AGL was noted and initially attributed to the adiabatic compression experienced by the anticyclonic air mass under quasi-quiescent regional flows. A detailed synoptic and dynamic analysis will be presented.
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Dates and versions

insu-04218973 , version 1 (26-09-2023)

Identifiers

  • HAL Id : insu-04218973 , version 1

Cite

Douglas Keller, Gilberto Javier Fochesatto, Elsa Dieudonné, Natalie Brett, Kathy S. Law, et al.. Buildup of the Surface Based Temperature Inversions during ALPACA-PBL.. The 103rd AMS Annual Meeting, Jan 2023, Denver (Colorado), United States. ⟨insu-04218973⟩
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