Long-Term Tropospheric Ozone Variation Over Western Pacific Ocean

EPA Grant Number: FP916325
Title: Long-Term Tropospheric Ozone Variation Over Western Pacific Ocean
Investigators: Deviatova, Elena A.
Institution: University of Maryland - College Park
EPA Project Officer: Boddie, Georgette
Project Period: January 1, 2004 through December 31, 2006
Project Amount: $110,627
RFA: STAR Graduate Fellowships (2004) RFA Text |  Recipients Lists
Research Category: Academic Fellowships , Air Quality and Air Toxics , Fellowship - Atmospheric Sciences


Ozone is a critical trace constituent of the atmosphere and an important indicator of changing global pollution levels. Transport of Asian emissions to the Pacific Ocean and consequentially eastward towards North America is becoming a growing concern. In tropical Asia, ozone monitoring has been rare and irregular until recent decades. Analysis of unpublished aircraft ozone measurements from the 1978-1979 Winter Monsoon Experiment (MONEX) in Malaysia will be of great interest to the global scientific community. The objective of this research is to analyze MONEX data to quantify the rate of ozone increase in the developing East Asia. This information will give grounds for future ozone emission projections and environmental policies. My hypothesis, which forms the basis of the proposed research, is that analysis of MONEX data will reveal an ozone mixing ratio increase on the order of 5-10 parts per billion by volume in tropical Asia in the past 2 decades.


Data from existing ozonesonde stations and recent field campaigns will be used for comparison with Winter MONEX ozone data. Because ozone behavior in the tropics differs from region to region, long-term observations from various sites, such as Java and Hong Kong, will be useful in assessing the seasonal variation of ozone within MONEX flight tracks in the South China Sea. MONEX missions around Peninsular Malaysia encountered air masses from the Northern Hemisphere, rich in ozone precursor gases as a result of movement of the Intertropical Convergence Zone (ITCZ) toward Southern Hemisphere. Because ITCZ can be displaced by as much as 10 degrees from the equator and the upper-level wind pattern and origin of air monitored at each of the ozonesonde stations can vary, not all suitable profiles can be considered in this study. Furthermore, variation in ozone profiles with respect to El Niño/Southern Oscillation (ENSO) will determine whether a single neutral ENSO year will be used for comparison or an average of all available years. Field campaigns in the Western Pacific also will provide valuable data for comparison with MONEX measurements. Recent studies such as the west Pacific Exploratory Mission (PEM-WEST A) in fall 1991, will be considered. Yet the challenging task is to find a data set for comparison that was collected in the same part of the Pacific Ocean, on the same side of the ITCZ, during the same ENSO year, and during the same season. The goal is to formulate an unbiased analysis of ozonesonde vertical distributions of ozone and MONEX aircraft data, mainly available for an altitude of 6 km. In addition, back-trajectories will be used to analyze the origins of air masses during the MONEX missions and during the recent studies so that differences in ozone measurements will be supplemented by air mass origin data. Likewise, forward-trajectories can be used to compare the transport events of air parcels eastward toward North America.

Supplemental Keywords:

fellowship, ozone, Asia, Pacific Ocean, air pollution, Winter Monsoon Experiment, MONEX, air masses, Intertropical Convergence Zone,, RFA, Scientific Discipline, Air, Environmental Monitoring, tropospheric ozone, Atmospheric Sciences, Ecology and Ecosystems, fate and transport, ozonesonde stations, ozone, air sampling, air quality model, atmospheric monitoring