Open AccessImpact of Asian emissions on observations at Trinidad Head, California, during ITCT 2K2
Author(s) -
Goldstein Allen H.,
Millet Dylan B.,
McKay Megan,
Jaeglé Lyatt,
Horowitz Larry,
Cooper Owen,
Hudman Rynda,
Jacob Daniel J.,
Oltmans Sam,
Clarke Andrew
Publication year - 2004
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2003jd004406
Subject(s) - environmental science , atmospheric sciences , ozone , chemical transport model , range (aeronautics) , climatology , deposition (geology) , trace gas , air pollution , pollution , mixing ratio , meteorology , troposphere , geography , geology , structural basin , chemistry , paleontology , materials science , organic chemistry , composite material , ecology , biology
Field measurements of a wide suite of trace gases and aerosols were carried out during April and May 2002, along with extensive chemical transport modeling, as part of the NOAA Intercontinental Transport and Chemical Transformation study. Here, we use a combination of in‐situ ground‐based measurements from Trinidad Head, CA, chemical transport modeling, and backward trajectory analysis to examine the impact of long‐range transport from Asia on the composition of air masses arriving at the California coast at the surface. The impact of Asian emissions is explored in terms of both episodic enhancements and contribution to background concentrations. We find that variability in CO concentrations at the ground site was largely driven by North American emissions, and that individual Asian plumes did not cause any observable pollution enhancement episodes at Trinidad Head. Despite this, model simulations suggest that Asian emissions were responsible for 33% of the CO observed at Trinidad Head, providing a larger mean contribution than direct emissions from any other region of the globe. Surface ozone levels were found to depend primarily on local atmospheric mixing, with surface deposition leading to low concentrations under stagnant conditions. Model simulations suggested that on average 4 ± 1 ppb of ozone (10% of observed) at Trinidad Head was transported from Asia.