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Title: A Meteorological Overview of the MILAGRO Field Campaigns

Abstract

We describe the large-scale meteorological conditions that affected atmospheric chemistry over Mexico during March 2006 when several field campaigns were conducted in the region. In-situ and remote-sensing instrumentation was deployed to obtain measurements of wind, temperature, and humidity profiles in the boundary layer and free atmosphere at four primary sampling sites in central Mexico. Several models were run operationally during the field campaign to provide forecasts of the local, regional, and synoptic meteorology as well as the predicted location of the Mexico City pollutant plume for aircraft flight planning purposes. Field campaign measurements and large-scale analyses are used to define three regimes that characterize the overall meteorological conditions: the first regime prior to March 14, the second regime between March 14 and 23, and the third regime after March 23. Mostly sunny and dry conditions with periods of cirrus and marine stratus along the coast occurred during the first regime. The beginning of the second regime was characterized by a sharp increase in humidity over the central plateau and the development of late afternoon convection associated with the passage of a weak cold surge on March 14. Over the next several days, the atmosphere over the central plateau became driermore » so that deep convection gradually diminished. The third regime began with the passage of a strong cold surge that led to humidity, afternoon convection, and precipitation over the central plateau that was higher than during the second regime. The frequency and intensity of fires, as determined by satellite measurements, also diminished significantly after the third cold surge. The synoptic-scale flow patterns that govern the transport of pollutants in the region are described and compared to previous March periods to put the transport into a climatological context. The complex terrain surrounding Mexico City produces local and regional circulations that govern short-range transport; however, the mean synoptic conditions modulate the thermally-driven circulations and on several days the near-surface flow is coupled to the ambient winds aloft.« less

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
908722
Report Number(s):
PNNL-SA-54469
KP1205030; TRN: US200722%%884
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Atmospheric Chemistry and Physics, 7(9):2233-2257; Journal Volume: 7; Journal Issue: 9
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; AIRCRAFT; ATMOSPHERIC CHEMISTRY; BOUNDARY LAYERS; COMPLEX TERRAIN; CONVECTION; HUMIDITY; METEOROLOGY; PLANNING; PLUMES; POLLUTANTS; PRECIPITATION; SAMPLING; SATELLITES; SURGES; TRANSPORT

Citation Formats

Fast, Jerome D., de Foy, B., Rosas, F. A., Caetano, E., Carmichael, Gregory, Emmons, L., McKenna, D., Mena, M., Skamarock, W., Tie, X., Coulter, Richard L., Barnard, James C., Wiedinmyer, Christine, and Madronich, Sasha. A Meteorological Overview of the MILAGRO Field Campaigns. United States: N. p., 2007. Web. doi:10.5194/acp-7-2233-2007.
Fast, Jerome D., de Foy, B., Rosas, F. A., Caetano, E., Carmichael, Gregory, Emmons, L., McKenna, D., Mena, M., Skamarock, W., Tie, X., Coulter, Richard L., Barnard, James C., Wiedinmyer, Christine, & Madronich, Sasha. A Meteorological Overview of the MILAGRO Field Campaigns. United States. doi:10.5194/acp-7-2233-2007.
Fast, Jerome D., de Foy, B., Rosas, F. A., Caetano, E., Carmichael, Gregory, Emmons, L., McKenna, D., Mena, M., Skamarock, W., Tie, X., Coulter, Richard L., Barnard, James C., Wiedinmyer, Christine, and Madronich, Sasha. Thu . "A Meteorological Overview of the MILAGRO Field Campaigns". United States. doi:10.5194/acp-7-2233-2007.
@article{osti_908722,
title = {A Meteorological Overview of the MILAGRO Field Campaigns},
author = {Fast, Jerome D. and de Foy, B. and Rosas, F. A. and Caetano, E. and Carmichael, Gregory and Emmons, L. and McKenna, D. and Mena, M. and Skamarock, W. and Tie, X. and Coulter, Richard L. and Barnard, James C. and Wiedinmyer, Christine and Madronich, Sasha},
abstractNote = {We describe the large-scale meteorological conditions that affected atmospheric chemistry over Mexico during March 2006 when several field campaigns were conducted in the region. In-situ and remote-sensing instrumentation was deployed to obtain measurements of wind, temperature, and humidity profiles in the boundary layer and free atmosphere at four primary sampling sites in central Mexico. Several models were run operationally during the field campaign to provide forecasts of the local, regional, and synoptic meteorology as well as the predicted location of the Mexico City pollutant plume for aircraft flight planning purposes. Field campaign measurements and large-scale analyses are used to define three regimes that characterize the overall meteorological conditions: the first regime prior to March 14, the second regime between March 14 and 23, and the third regime after March 23. Mostly sunny and dry conditions with periods of cirrus and marine stratus along the coast occurred during the first regime. The beginning of the second regime was characterized by a sharp increase in humidity over the central plateau and the development of late afternoon convection associated with the passage of a weak cold surge on March 14. Over the next several days, the atmosphere over the central plateau became drier so that deep convection gradually diminished. The third regime began with the passage of a strong cold surge that led to humidity, afternoon convection, and precipitation over the central plateau that was higher than during the second regime. The frequency and intensity of fires, as determined by satellite measurements, also diminished significantly after the third cold surge. The synoptic-scale flow patterns that govern the transport of pollutants in the region are described and compared to previous March periods to put the transport into a climatological context. The complex terrain surrounding Mexico City produces local and regional circulations that govern short-range transport; however, the mean synoptic conditions modulate the thermally-driven circulations and on several days the near-surface flow is coupled to the ambient winds aloft.},
doi = {10.5194/acp-7-2233-2007},
journal = {Atmospheric Chemistry and Physics, 7(9):2233-2257},
number = 9,
volume = 7,
place = {United States},
year = {Thu May 03 00:00:00 EDT 2007},
month = {Thu May 03 00:00:00 EDT 2007}
}