Transpacific Transport of Ozone Pollution and the Effect of Recent Asian Emission Increases on Air Quality in North America: An Integrated Analysis Using Satellite, Aircraft, Ozonesonde, and Surface Observations

We use an ensemble of aircraft, satellite, sonde, and surface observations for April–May 2006 (NASA/INTEX-B aircraft campaign) to better understand the mechanisms for transpacific ozone pollution and its implications for North American air quality. The observations are interpreted with a global 3-D chemical transport model (GEOS-Chem). OMI NO2 satellite observations constrain Asian anthropogenic NOx emissions and indicate a factor of 2 increase from 2000 to 2006 in China. Satellite observations of CO from AIRS and TES indicate two major events of Asian transpacific pollution during INTEX-B. Correlation between TES CO and ozone observations shows evidence for transpacific ozone pollution. The semi-permanent Pacific High and Aleutian Low cause splitting of transpacific pollution plumes over the Northeast Pacific. The northern branch circulates around the Aleutian Low and has little impact on North America. The southern branch circulates around the Pacific High and some of that air impacts western North America. Both aircraft measurements and model results show sustained ozone production driven by peroxyacetylnitrate (PAN) decomposition in the southern branch, roughly doubling the transpacific influence from ozone produced in the Asian boundary layer. Model simulation of ozone observations at Mt. Bachelor Observatory in Oregon (2.7 km altitude) indicates a mean Asian ozone pollution contribution of 9±3 ppbv to the mean observed concentration of 54 ppbv, reflecting mostly an enhancement in background ozone rather than episodic Asian plumes. Asian pollution enhanced surface ozone concentrations by 5–7 ppbv over western North America in spring 2006. The 2000–2006 rise in Asian anthropogenic emissions increased this influence by 1–2 ppbv.Earth and Planetary SciencesEngineering and Applied Science

University-industry relationships and open innovation: Towards a research agenda

Accepted versio

The PHENIX Experiment at RHIC

The physics emphases of the PHENIX collaboration and the design and current status of the PHENIX detector are discussed. The plan of the collaboration for making the most effective use of the available luminosity in the first years of RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program available at http://www.rhic.bnl.gov/phenix

Global AIRS and MOPITT CO measurements: Validation, comparison, and links to biomass burning variations and carbon cycle

New results of CO global total column measurements using the Atmospheric Infrared Sounder (AIRS) aboard the Aqua satellite in comparison with Measurements of Pollution in the Troposphere (MOPITT) sensor aboard the Terra satellite are presented. Both data sets are validated using ground-based total column measurements in Russia and Australia. A quality parameter based on the Profile Percent A Priori values from the standard MOPITT product is introduced. AIRS data (version 4) for biomass burning events are in agreement or lower than both MOPITT and ground measurements, but CO bursts can be seen by AIRS in most cases. For the cases of low CO amounts in the Southern Hemisphere AIRS has a positive bias of ∼30-40% compared to MOPITT and ground truth. MOPITT data were used to estimate interannual variations of CO sources assuming a standard seasonal cycle for the main CO remover OH. A positive trend of CO global emissions for the second half of the year between 2000 and 2006 was found with no visible trend for the first half of the year. CO annual emission in 2006 was 184 ± 40 Tg higher that that in 2000-2001. The monthly emission anomalies correlate well with an independently calculated Global Fire Emission Database (GFED2). Total carbon contribution from biomass burning in 1997, 1998 (both estimated by GFED2), and 2006 (according to MOPITT) were as high as (0.6-1) Pg C/year larger than in 2000, suggesting that fires can explain a substantial fraction of the interannual variability of CO2. Copyright 2008 by the American Geophysical Union

Variabilidade Espaço-Temporal do Monóxido de Carbono Sobre a América do Sul a Partir de Dados de Satélite de 2003 A 2012

Using the information of the Earth Observation System/AQUA (EOS/AQUA) satellite during the 2003-2012 period, the present work investigates the tropospheric carbon monoxide (CO) behavior over the central South American region, and its spatiotemporal variability. The results show a well-defined seasonal behavior of the CO concentration, with decrease during the wet season and increase during dry season, due to the biomass burning increase during this period. Since the biomass burning is directly associated with the climate variability, through the rainfall decrease/increase in the central and eastern South American sector, the CO possesses high variability in central Brazil, the region with the largest number of burning focus. The results also show that the CO variability in the interanual time scale is related to the El Niño/Southern Oscillation (ENSO) phenomenon, such that rainfall reduction (increase) in the central and eastern part of South America during the La Niña (El Niño) onset phase contributes to increase (reduce) the biomass burning and in consequence the CO emission in this region. On the other hand, during the ENSO mature stage, the great rainfall and CO concentration variabilities occur in the northern and northeastern South American regions. The results presented in this paper might be useful for monitoring activities. © 2017, Sociedade Brasileira de Meteorologia. All rights reserved