Browsing by Author "Owen, Robert"
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- Aerosol Measurements in the Free Troposphere at the North Atlantic Pico Mountain Observatory in the Azores.Publication . Mazzoleni, Claudio; Fialho, Paulo; Gorkowski, Kyle; Owen, Robert; Dziobak, Michael P.; Hueber, Jacques; Dzepina, Katja; Kramer, Louisa; Olsen, Seth C.; Kumar, Sumit; Helmig, DetlevPico is a small island (447 km2) in the archipelago of the Azores, Portugal, in the North Atlantic Ocean. The island has a very steep inactive volcano. An atmospheric monitoring station (Pico Mountain Observatory) was established close to the summit of the volcano by the late Dr. Richard Honrath and colleagues in 2001. The station, far from persistent local sources, is located near the northern cliff of the summit caldera at an altitude of 2225 meters. The station altitude is typically well above the boundary layer during summertime, when average marine boundary-layer heights are below 1200 meters and rarely exceed 1300 meters. Air masses reaching the station are often transported from North America and seldom from Europe or North Africa. The station’s uniqueness and significance lie in its location that allows study of the transport and evolution of gases and aerosols from North America in the free troposphere. Until recently, the focus was on the measurement and analysis of trace gases (ozone, carbon monoxide, non-methane hydrocarbons, nitrogen oxides) and light-absorbing aerosol (black carbon and iron oxide). Aerosol light attenuation has been measured at the site since 2001 using a seven-wavelengths aethalometer. An optical particle sizer was installed at the site in 2010 and has been running in parallel to the aethalometer for two seasons. A three-wavelength nephelometer, to measure the aerosol total- and back-scattering, and aerosol samplers for morphological and chemical analysis will be installed at the site in 2012. Our goal is to enhance the observatory monitoring capabilities for aerosol research. The objectives of this new research program are to: (a) assess background as well as specific event tropospheric aerosol properties, (b) compare aerosol and gases measurements with model outputs, and (c) use the data collected to provide satellite validation. This research is anticipated to enhance our understanding of the interactions between tropospheric aerosols, clouds, and climate by allowing, for example, the analysis of North American outflows and seasonal changes, the assessment of different source regions, the estimation of aerosol radiative forcing above marine clouds and in clear sky, and the study of the relative contribution of anthropogenic versus biomass burning emissions. In this poster we present a preliminary analysis of the black carbon and aerosol size data in conjunction with retroplume model analysis.
- Climatology and Atmospheric Chemistry of Non-Methane Hydrocarbon Emissions over the North Atlantic.Publication . Muñoz, Mauricio; Helmig, Detlev; Hueber, Jacques; Mazzoleni, Claudio; Mazzoleni, Lynn R.; Owen, Robert; Val Martin, Maria; Fialho, Paulo; Plass-Duelmer, ChristianNon-methane hydrocarbons (NMHC) covering the C2 to C7 volatility range have been monitored at the Pico Mountain Observatory, Pico Island, Azores, Portugal, since 2004. The Observatory is located at 2225 m a.s.l. in the caldera of the Pico Mountain volcano, and during most times receives lower free tropospheric air that has been transported across the North Atlantic. The 7-year NMHC record has been analyzed for seasonal behavior of photochemical processing, atmospheric transport time, and source region using ratios of NMHC species as indicators of photochemical aging and HYSPLIT model outputs. Transport conditions resulting in elevated and low NMHC conditions were specifically studied to investigate seasonal pollution transport in the North Atlantic region.
- Free Tropospheric Aerosol Measurements at the Pico Mountain Observatory, Azores (2225m asl).Publication . Mazzoleni, Claudio; Mazzoleni, Lynn R.; Fialho, Paulo; Kumar, Sumit; Dzepina, Katja; Dziobak, Michael P.; Kramer, Louisa; Olsen, Seth C.; Owen, Robert; Helmig, Detlev; Hueber, Jacques; China, SwarupIn this poster we discuss a limited subset of the aerosol measurements performed at the Pico Mountain Observatory. The Black Carbon (BC) mass shows a clear seasonal pattern over a ten-years period. The 2012 scattering measurements show highly variable signals with events with high scattering and periods of very low aerosol loading. Dust events are clearly captured by the aethalometer, as well the nephelometer Ångström exponents. Particles have various shapes, and mixing states, and soot particles typically are very compacted.
- Impacts of anthropogenic and boreal fire emissions in the central North Atlantic lower free troposphere: summertime observations at the PICO-NARE observatory.Publication . Val Martin, Maria; Honrath, Richard; Kleissl, J.; Owen, Robert; Lapina, K.; Fialho, Paulo; Helmig, Detlev; Tanner, D. M.We present measurements of CO, O3, aerosol Black Carbon (BC) made over the central North Atlantic lower Free Troposphere (FT) during the summers of 2001-2004 along with measurements of nitrogen oxides (NOx and NOy) made during the summer of 2004 (ICARTT period) and non-methane hydrocarbons (NMHCs) made during the winter 2004-spring 2005.
- Large-scale impacts of anthropogenic and boreal fire emissions apparent in multi-year free tropospheric observations in the Azores.Publication . Honrath, Richard; Val Martin, Maria; Kleissl, J.; Owen, Robert; Lapina, K.; Fialho, Paulo; Helmig, Detlev; Tanner, D. M.Pico Mountain in the Azores Islands provides an ideal location for studies of the central N. Atlantic lower free troposphere. The PICO-NARE station has operated there since summer 2001. Here, we present key findings from summertime measurements, during 2001-2004. Main Findings: Anthropogenic and boreal wildfire emissions dominate variations in CO and have major impacts on O3, nitrogen oxides, non-methane hydrocarbons (NMHCs) and black carbon.
- North American Boreal Wildfire and Anthropogenic Emissin Impacts in the Lower Free Troposphere over the North Atlantic Region: observations at the PICO-NARE stationPublication . Fialho, Paulo; Val Martin, Maria; Honrath, Richard; Owen, Robert; Pfister, Gabriele; Lapina, K.; Barata, FilipeWe present analyses of CO, O3, nitrogen oxides (NOx and NOy) and aerosol black carbon (BC) measurements made in the lower free troposphere (FT) over the North Atlantic region during summers 2004 (ICARTT period) and 2005.
- A permanent free tropospheric observatory at Pico summit in the Azores Islands? Past measurements (2001–2005) and future plans.Publication . Honrath, Richard; Fialho, Paulo; Helmig, Detlev; Val Martin, Maria; Owen, Robert; Kleissl, J.; Strane, J. M.; Dziobak, Michael P.; Tanner, D. M.; Barata, Filipe; Lapina, K.Pico mountain in the Azores Islands provides a base for continuous, free tropospheric measurements that is unique in the central North Atlantic region. The PICO-NARE station was installed there in 2001 as a temporary observatory. However, the location proved ideal for studies of aged emissions from anthropogenic (N. American) and boreal fire (N. American and Russian) emissions, as well as for less frequent interception of European and African plumes. As a result, station operation was continued through summer 2005, and we are planning for continuing operation and conversion into a permanent Portuguese GAW station in the future. This poster will provide an overview of the station, the measurements made there, typical transport pathways to the station and interannual variability in transport, and an overview of the full suite of multi-season observations and key findings from measurements to date. In addition, data availability and near-term and long-term plans for the station's future will be discussed.
- Photochemical evolution of continental outflow to Pico Mountain (Azores): Integrating observations with CTM simulations in lowerFT outflow.Publication . Honrath, Richard; Owen, Robert; Li, Q. B.; Helmig, Detlev; Fialho, PauloAn analysis of the consistency of lower-FT observations with chemical transport model (CTM) simulations in aged U.S. export.
- Properties of Aerosol in the North Atlantic Free Troposphere at the Pico Mountain Observatory, Azores.Publication . Mazzoleni, Claudio; Mazzoleni, Lynn R.; Fialho, Paulo; Kumar, Sumit; Dzepina, Katja; Dziobak, Michael P.; Kramer, Louisa; Olsen, Seth C.; Owen, Robert; Helmig, Detlev; Hueber, Jacques; Wrigth, Kendra; Zhang, Bo; China, SwarupThe Pico Mountain Observatory is located at an altitude of 2225 meters above sea level in the summit caldera of the Pico volcano in the Azores, Portugal (38.47°N, 28.40°W). The scientific value of the station stems from the fact that this is the only permanent free-tropospheric monitoring station in the central North Atlantic, with negligible influence from local sources and that frequently samples air from the North American continent. Thus, it is an ideal site for studying long-range transported pollution. The station started operating in 2001 with a focus on gaseous species (e.g., ozone, carbon monoxide, nitrogen oxides, and non-methane hydrocarbons) and aerosol particles that absorb light (black carbon [BC] and aerosol dust). The absorbing aerosol mass concentrations, in units of equivalent black carbon mass concentrations, have been monitored using a seven-wavelength aethalometer (Magee scientific model AE31). Ancillary measurements at the station include meteorological parameters such as temperature, relative humidity, pressure, wind direction, and speed. Due to the harsh environmental conditions at the site, most measurements have been performed during the summer seasons. In the summer of 2012, new aerosol instrumentation and samplers were installed at the station. The new equipment includes a three-wavelength nephelometer (Ecotech model Aurora 3000) that measure aerosol scattering and backscattering fraction, a set of four high-volume samplers for the collection and chemical analysis of aerosol, a sequential sampler to collect aerosols on membranes and grids, and an optical particle counter. Membranes and grids are analysed offline with scanning and transmission electron microscopy to study morphological properties and elemental composition of the aged aerosols. In this poster we will discuss some of the analysis of the decadal BC mass concentration data, as well as some analysis of the new aerosol data with a focus on aerosol optical properties and morphology. Analysis of these properties is important for a better understanding of aerosol’s life cycle and ageing during their transport over the Atlantic, with implications on aerosol radiative properties and climate science.