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Title: Multi-Sensor Estimation of Mixing Heights Over a Coastal City

Abstract

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 heightmore » 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.« less

Authors:
; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
924666
Report Number(s):
PNNL-SA-50014
KP1205030; TRN: US200809%%411
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Meteorology and Climatology, 47(1):27-43; Journal Volume: 47; Journal Issue: 1
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; AEROSOLS; AIR QUALITY; AIRCRAFT; BOUNDARY LAYERS; GALVESTON BAY; OPTICAL RADAR; RADAR; SEAS; TEMPERATURE INVERSIONS

Citation Formats

Nielsen-Gammon, John W., Powell, Christina L., Mahoney, Michael J., Angevine, Wayne M., Senff, Christoph, White, Allen B., Berkowitz, Carl M., Doran, J. C., and Knupp, Kevin. Multi-Sensor Estimation of Mixing Heights Over a Coastal City. United States: N. p., 2008. Web. doi:10.1175/2007JAMC1503.1.
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. Multi-Sensor Estimation of Mixing Heights Over a Coastal City. United States. doi:10.1175/2007JAMC1503.1.
Nielsen-Gammon, John W., Powell, Christina L., Mahoney, Michael J., Angevine, Wayne M., Senff, Christoph, White, Allen B., Berkowitz, Carl M., Doran, J. C., and Knupp, Kevin. 2008. "Multi-Sensor Estimation of Mixing Heights Over a Coastal City". United States. doi:10.1175/2007JAMC1503.1.
@article{osti_924666,
title = {Multi-Sensor Estimation of Mixing Heights Over a Coastal City},
author = {Nielsen-Gammon, John W. and Powell, Christina L. and Mahoney, Michael J. and Angevine, Wayne M. and Senff, Christoph and White, Allen B. and Berkowitz, Carl M. and Doran, J. C. and Knupp, Kevin},
abstractNote = {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.},
doi = {10.1175/2007JAMC1503.1},
journal = {Journal of Applied Meteorology and Climatology, 47(1):27-43},
number = 1,
volume = 47,
place = {United States},
year = 2008,
month = 1
}
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