scholarly journals An assessment of marine atmospheric boundary layer roll detection using Sentinel-1 SAR data

2020 ◽  
Vol 250 ◽  
pp. 112031
Author(s):  
Chen Wang ◽  
Douglas Vandemark ◽  
Alexis Mouche ◽  
Bertrand Chapron ◽  
Huimin Li ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
Marine Atmospheric Boundary Layer ◽  
Sar Data

scholarly journals Inference of Marine Atmospheric Boundary Layer Moisture and Temperature Structure Using Airborne Lidar and Infrared Radiometer Data

1998 ◽  
Vol 37 (3) ◽  
pp. 308-324 ◽  
Author(s):  
Stephen P. Palm ◽  
Denise Hagan ◽  
Geary Schwemmer ◽  
S. H. Melfi
Keyword(s):  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
Potential Temperature ◽  
Airborne Lidar ◽  
Temperature Structure ◽  
Marine Atmospheric Boundary Layer ◽  
Space Technology ◽  
Near Surface ◽  
Surface Moisture ◽  
Infrared Radiometer

Abstract A new technique for retrieving near-surface moisture and profiles of mixing ratio and potential temperature through the depth of the marine atmospheric boundary layer (MABL) using airborne lidar and multichannel infrared radiometer data is presented. Data gathered during an extended field campaign over the Atlantic Ocean in support of the Lidar In-space Technology Experiment are used to generate 16 moisture and temperature retrievals that are then compared with dropsonde measurements. The technique utilizes lidar-derived statistics on the height of cumulus clouds that frequently cap the MABL to estimate the lifting condensation level. Combining this information with radiometer-derived sea surface temperature measurements, an estimate of the near-surface moisture can be obtained to an accuracy of about 0.8 g kg−1. Lidar-derived statistics on convective plume height and coverage within the MABL are then used to infer the profiles of potential temperature and moisture with a vertical resolution of 20 m. The rms accuracy of derived MABL average moisture and potential temperature is better than 1 g kg−1 and 1°C, respectively. The method relies on the presence of a cumulus-capped MABL, and it was found that the conditions necessary for use of the technique occurred roughly 75% of the time. The synergy of simple aerosol backscatter lidar and infrared radiometer data also shows promise for the retrieval of MABL moisture and temperature from space.

How is the marine atmospheric boundary layer turbulence organized in the trades ?

2021 ◽  
Author(s):  
Pierre-Etienne Brilouet ◽  
Marie Lothon ◽  
Sandrine Bony
Keyword(s):  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
Vertical Velocity ◽  
Large Scale ◽  
Layer Structure ◽  
Potential Temperature ◽  
Surface Wind ◽  
Cloud Amount ◽  
Velocity Spectrum ◽  
Marine Atmospheric Boundary Layer

<p>Tradewind clouds can exhibit a wide diversity of mesoscale organizations, and the turbulence of marine atmospheric boundary layer (MABL) can exhibit coherent structures and mesoscale circulations. One of the objectives of the EUREC4A (Elucidating the role of cloud-circulation coupling in climate) field experiment was to better understand the tight interplay between the mesoscale organization of clouds, boundary-layer processes, and the large-scale environment.</p><p>During the experiment, that took place East of Barbados over the Western Tropical Atlantic Ocean in Jan-Feb 2020, the French ATR-42 research aircraft was devoted to the characterization of the cloud amount and of the subcoud layer structure. <span>During its 17 research flights, </span><span>it</span> <span>sampled a </span><span>large diversity of large scale conditions and </span><span>cloud patterns</span><span>. </span>Multiple sensors onboard t<span>he aircraft measure</span><span>d</span> <span>high-frequency </span><span>fluctuations of potential temperature, water vapour mixing ratio and wind , allowing </span><span>for </span><span>an extensive characterization </span><span> of</span><span> the turbulence </span><span>within</span><span> the subcloud layer. </span> <span>A </span><span>quality-controled and calibrated turbulence data</span><span>set</span><span> was produced </span><span>on the basis of these measurements</span><span>, which is now </span><span> available on the EUREC4A AERIS data portal.</span></p><p><span>The </span><span>MABL </span><span>turbulent </span><span>structure i</span><span>s</span><span> studied </span><span>using this dataset, </span><span>through a spectral analysis </span><span>of the vertical velocity</span><span>. Vertical profiles of characteristic length scales reveal a non-isotropic structure with a stretching of the eddies along the mean wind. The organization strength of the turbulent field is also explored </span><span>by defining</span><span> a diagnostic based on the shape of the vertical velocity spectrum. </span><span>The </span><span>structure and the degree of organization of the </span><span>subcloud layer </span><span>are</span><span> characterized for </span><span> different type</span><span>s</span><span> of mesoscale </span><span>convective </span><span>pattern </span><span>and </span><span>as a function of</span><span> the large-scale environment, </span><span>including</span> <span>near-</span><span>surface wind </span><span>and</span> <span>lower-</span><span>tropospheric</span><span> stability conditions.</span></p><p> </p>

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