Local and transported pollution over San Diego, California (original) (raw)
Related papers
Journal of Geophysical Research, 1998
The cause and extent of elevated ozone levels which are often found during summer in the southeastern United States were the focus of the intensive Southern Oxidants Study (SOS) 1995 Nashville/Middle Tennessee Ozone Study. Six aircraft were extensively instrumented and were deployed in concert during the summer of 1995 from the Nashville Metropolitan Airport. This overview describes the capabilities of the deployed assets, and how their use was managed. Results from the measurements on individual aircraft and their interpretation are contained in the individual papers that follow. 1. Introduction Elevated ozone concentrations have been observed at many locations in the southeastern United States [cf. Meagher et aI., this issue]. Understanding the atmospheric processes that determine these events is the focus of the Southern Oxidants Study (SOS). In order to gain this understanding, a comprehensive set of measurements, detailing the chemical and meteorological conditions for ozone photochemistry in the Southeast, were made at the surface and from airborne platforms during the summer of 1995. These measurements constituted the 1995 Nashville/Middle Tennessee Ozone study intensive. The study intensive was designed to address several science questions that still remain open even after extensive efforts in air quality research [cf. Cowling et aI., this issue].
FIELD SURVEY OF TRANSBOUNDARY AIR POLLUTION WITH
An intensive field survey, with 6-h measurement intervals, of concentrations of chemical species in particulate matter and gaseous compounds was carried out at coastal sites on the Sea of Japan during winter. The concentration variation of SO 2 (g) and HNO 3 (g) were well correlated, whereas the NH 3 (g) concentration variation had no correlation with those of SO 2 (g) and HNO 3 (g). The NH 4 + (p)/non-sea-salt-(nss-)SO 4 2− (p) ratio in particulate matter was mainly affected by the location of the sampling site. One or more concentration peaks of nss-Ca 2+ for survey period were observed. Backward trajectories analyses for the highest nss-Ca 2+ concentration peaks showed some inconsistency in pathways. We consider that insufficient mixing of the atmosphere and/or insufficient time for the transported air pollutants to react with those discharged locally are the most likely explanations for the discrepancies between the measured products [HNO 3 ][NH 3 ] and the calculated values.
Primary Particulate Matter from Ocean-Going Engines in the Southern California Air Basin
Environmental Science & Technology, 2009
The impact of primary fine particulate matter (PM 2.5 ) from ship emissions within the Southern California Air Basin is quantified by comparing in-stack vanadium (V) and nickel (Ni) measurements fromin-useocean-goingvessels(OGVs)withambientmeasurements made at 10 monitoring stations throughout Southern California. V and Ni are demonstrated as robust markers for the combustion of heavy fuel oil in OGVs, and ambient measurements of fine particulateVandNiwithinSouthernCaliforniaareshowntodecrease inversely with increased distance from the ports of Los Angeles and Long Beach (ports). High levels of V and Ni were observed from in-stack emission measurements conducted on the propulsion engines of two different in-use OGVs. The in-stack V and Ni emission rates (g/h) normalized by the V and Ni contents in the fuel tested correlates with the stack total PM emission rates (g/h). The normalized emission rates are used to estimate the primary PM 2.5 contributions from OGVs at 10 monitoring locations within Southern California. Primary PM 2.5 contributions from OGVs were found to range from 8.8% of the total PM 2.5 at the monitoring location closest to the port (West Long Beach) to 1.4% of the total PM 2.5 at the monitoring location 80 km inland (Rubidoux). The calculated OGV contributions to ambient PM 2.5 measurements at the 10 monitoring sites agree well with estimates developed using an emission inventory based regional model. Results of this analysis will be useful in determining the impacts of primary particulate emissions from OGVs upon worldwide communities downwind of port operations.
Atmospheric Chemistry and Physics, 2011
Chronic high surface ozone (O 3 ) levels and the increasing sulfur oxides (SO x = SO 2 +SO 4 ) ambient concentrations over South Coast (SC) and other areas of California (CA) are affected by both local emissions and long-range transport. In this paper, multi-scale tracer, full-chemistry and adjoint simulations using the STEM atmospheric chemistry model are conducted to assess the contribution of local emission sourcesto SC O 3 and to evaluate the impacts of transported sulfur and local emissions on the SC sulfur budgetduring the ARCTAS-CARB experiment period in 2008. Sensitivity simulations quantify contributions of biogenic and fire emissions to SC O 3 levels. California biogenic and fire emissions contribute 3-4 ppb to near-surface O 3 over SC, with larger contributions to other regions in CA. During a longrange transport event from Asia starting from 22 June, high
Aerosol and Air Quality Research, 2012
This study investigated the ozone formation mechanism and air mass trajectory via simultaneous air quality sampling around the coastal region of urban Kaohsiung. Vertical concentration profiles of O 3 and its precursors (NO x and VOCs) were sampled and measured at inland and offshore sites during eight intensive sampling periods. The intensive sampling periods were divided into three categories based on meteorological condition: the sea-land breeze period, the northeastern monsoon period, and the mixed period. Vertical profile results showed that the stratification of O 3 was commonly observed at 40 out of 64 sampling sites accounting for 62.5% of the total O 3 measurement. The results obtained from VOCs measurement indicated that the major species of VOCs was acetone, which accounted for 16.25-64.05% of total TVOCs-C 2 in the offshore region, while the major species of VOCs in the inland region was toluene, which accounted for 6.41-43.77 % of total TVOCs-C 2. Backward trajectories showed that air pollutants emitted from land sources could transport to the offshore region, resulting in a high concentration of oversea NO x and VOCs. Major species of VOCs with high O 3 formation potential were found to be aromatics in the low atmosphere around the coastal region of metro Kaohsiung.
Journal of Geophysical Research, 1996
Measurements of the concentrations of 0 3, CO, NO, NOy, condensation nuclei, and aerosols in 12 size bins ranging from 0.1 to 3.1 gm as well as a variety of meteorological parameters were collected aboard the NCAR King Air in August 1993 during 16 flights over or near the Gulf of Maine. The purpose of this measurement campaign was to describe the sources and variation of ozone and its precursors in the western NARE region during the summer season. Correlations between 03 and CO, 03 and NOy, and other chemical and aerosol measurements are examined. Several features in the altitude profiles are investigated using principal component analysis. The results of the trace gas analyses indicate that anthropogenically influenced ozone production dominated ozone throughout the experimental region at altitudes below 1500 m. Other factors identified include a distinct signature from fresh emissions below 1500 m. Above 1500 m the sources of ozone were determined by transport from a variety of sources.
J. Geophys. …, 2006
From 1997 to 2003, airborne measurements of O 3 , CO, SO 2 , and aerosol properties were made during summertime air pollution episodes over the mid-Atlantic United States (34.7-44.6°N, 68.4-81.6°W) as part of the Regional Atmospheric Measurement, Modeling, and Prediction Program (RAMMPP). Little diurnal variation was identified in the CO, SO 2 , and Å ngström exponent profiles, although the Å ngström exponent profiles decreased with altitude. Boundary layer O 3 was greater in the afternoon, while lower free tropospheric O 3 was invariant at 55ppbv.Thesinglescatteringalbedoincreasedfrommorningtoafternoon(0.93±0.01Aˋ0.94±0.01);however,bothprofilesdecreasedwithaltitude.Aclusteranalysisofbacktrajectoriesinconjunctionwiththeverticalprofiledatawasusedtoidentifysourceregionsandcharacteristictransportpatternsduringsummertimepollutionepisodes.WhenthegreatesttrajectorydensitylayoverthenorthernOhioRiverValley,theresultwaslargeO3values,largeSO2/COratios,highlyscatteringparticles,andlargeaerosolopticaldepths.MaximumtrajectorydensityoverthesouthernOhioRiverValleyresultedinlittlepollution.ThegreatestafternoonO3valuesoccurredduringperiodsofstagnation.North−northwesterlyandnortherlyflowbroughttheleastpollutionoverall.ThecontributionofregionaltransporttoafternoonboundarylayerO3wasquantified.WhenthegreatestclustertrajectorydensitylayovertheOhioRiverValley(55 ppbv. The single scattering albedo increased from morning to afternoon (0.93 ± 0.01À0.94 ± 0.01); however, both profiles decreased with altitude. A cluster analysis of back trajectories in conjunction with the vertical profile data was used to identify source regions and characteristic transport patterns during summertime pollution episodes. When the greatest trajectory density lay over the northern Ohio River Valley, the result was large O 3 values, large SO 2 /CO ratios, highly scattering particles, and large aerosol optical depths. Maximum trajectory density over the southern Ohio River Valley resulted in little pollution. The greatest afternoon O 3 values occurred during periods of stagnation. North-northwesterly and northerly flow brought the least pollution overall. The contribution of regional transport to afternoon boundary layer O 3 was quantified. When the greatest cluster trajectory density lay over the Ohio River Valley (55ppbv.Thesinglescatteringalbedoincreasedfrommorningtoafternoon(0.93±0.01Aˋ0.94±0.01);however,bothprofilesdecreasedwithaltitude.Aclusteranalysisofbacktrajectoriesinconjunctionwiththeverticalprofiledatawasusedtoidentifysourceregionsandcharacteristictransportpatternsduringsummertimepollutionepisodes.WhenthegreatesttrajectorydensitylayoverthenorthernOhioRiverValley,theresultwaslargeO3values,largeSO2/COratios,highlyscatteringparticles,andlargeaerosolopticaldepths.MaximumtrajectorydensityoverthesouthernOhioRiverValleyresultedinlittlepollution.ThegreatestafternoonO3valuesoccurredduringperiodsofstagnation.North−northwesterlyandnortherlyflowbroughttheleastpollutionoverall.ThecontributionofregionaltransporttoafternoonboundarylayerO3wasquantified.WhenthegreatestclustertrajectorydensitylayovertheOhioRiverValley(59% of the profiles), transport accounted for 69-82% of the afternoon boundary layer O 3. Under stagnant conditions ($27% of the profiles), transport only accounted for 58% of the afternoon boundary layer O 3. The results from this study provide a description of regional chemical and transport processes that will be valuable to investigators from the Baltimore, New York, and Pittsburgh EPA Supersites.
Atmospheric Environment, 2003
An air quality screening study was performed to assess the impacts of emissions from the offshore operations of the oil and gas exploration and production by Mexican industry in the Campeche Sound, which includes the states of Tabasco and Campeche in southeast Mexico. The major goal of this study was the compilation of an emission inventory (EI) for elevated, boom and ground level flares, processes, internal combustion engines and fugitive emissions. This inventory is so far the most comprehensive emission register that has ever been developed for the Mexican petroleum industry in this area. The EI considered 174 offshore platforms, the compression station at Atasta, and the Maritime Ports at Dos Bocas and Cayo Arcas. The offshore facilities identified as potential emitters in the area were the following: (1) trans-shipment stations, (2) a maritime floating port terminal, (3) drilling platforms, (4) crude oil recovering platforms, (5) crude oil production platforms, (6) linking platforms, (7) water injection platforms, (8) pumping platforms, (9) shelter platforms, (10) telecommunication platforms, (11) crude oil measurement platforms, and (12) flaring platforms. Crude oil storage tanks, helicopters and marine ship tankers were also considered to have an EI accurate enough for air quality regulations and mesoscale modeling of atmospheric pollutants. Historical ambient data measure at two onshore petroleum facilities were analyzed to measure air quality impacts on nearby inhabited coastal areas, and a source-receptor relationship for flares at the Ixtoc marine complex was performed to investigate healthbased standards for offshore workers. A preliminary air quality model simulation was performed to observe the transport and dispersion patterns of SO 2 , which is the main pollutant emitted from the offshore platforms. The meteorological wind and temperature fields were generated with CALMET, a diagnostic meteorological model that used surface observations and upper air soundings from a 4-day field campaign conducted in February of 1999. The CALMET meteorological output and the generated EI drove the transport and dispersion model, CALPUFF. Model results were compared with SO 2 measurements taken from the monitoring network at Dos Bocas. r