Multi-Sensor Estimation of Mixing Heights Over a Coastal City

Journal Article · Tue Jan 01 04:00:00 EST 2008 · Journal of Applied Meteorology and Climatology, 47(1):27-43

DOI:https://doi.org/10.1175/2007JAMC1503.1· OSTI ID:924666

Nielsen-Gammon, John W; Powell, Christina L; Mahoney, Michael J; Angevine, Wayne M; Senff, Christoph; White, Allen B; Berkowitz, Carl M; Doran, J C; Knupp, Kevin

An airborne Microwave Temperature Profiler (MTP) was deployed during the An airborne Microwave Temperature Profiler (MTP) was deployed during the Texas 2000 Air Quality Study (TexAQS-2000) to make measurements of boundary layer thermal structure. An objective technique is developed and tested for estimating the mixed layer (ML) height from the MTP vertical temperature profiles. The technique identifies the ML height as a threshold increase of potential temperature from its minimum value within the boundary layer. In order to calibrate the technique and evaluate the usefulness of this approach, coincident estimates from radiosondes, radar wind profilers, an aerosol backscatter lidar, and in situ aircraft measurements were compared with each other and with the MTP. Relative biases among all instruments were generally less than 50 m, and the agreement between MTP ML height estimates and other estimates was at least as good as the agreement among the other estimates. The ML height estimates from the MTP and other instruments are utilized to determine the spatial and temporal evolution of ML height in the Houston area on 1 Sept. 2000. An elevated temperature inversion was present, so ML growth was inhibited until early afternoon. In the afternoon, large spatial variations in ML height developed across the Houston area. The highest ML heights, well over 2 km, were observed to the north of Houston, while downwind of Galveston Bay and within the late afternoon sea breeze ML heights were much lower. The spatial variations that were found away from the immediate influence of coastal circulations were unexpected, and multiple independent ML height estimates were essential for documenting this feature.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 924666
• Report Number(s): PNNL-SA-50014; KP1205030
• Journal Information: Journal of Applied Meteorology and Climatology, 47(1):27-43, Journal Name: Journal of Applied Meteorology and Climatology, 47(1):27-43 Journal Issue: 1 Vol. 47
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AEROSOLS
AIR QUALITY
AIRCRAFT
BOUNDARY LAYERS
GALVESTON BAY
OPTICAL RADAR
RADAR
SEAS
TEMPERATURE INVERSIONS