Year-end Sale % OFF 
Abstract
Abstract. Aerosol loading over Interior Alaska displays a strong seasonality, with pristine conditions generally prevailing during winter months. Long term aerosol research from the University of Alaska Fairbanks indicates that the period around April typically marks the beginning of the transition from winter to summer conditions. In April 2008, the NASA-sponsored "Arctic Research of the Composition of the Troposphere from Aircraft and Satellites" (ARCTAS) field campaign was conducted to analyze incursions of aerosols transported over Alaska and the Canadian North. In and around Fairbanks, Alaska, data concerning aerosol characteristics were gathered by polarization (0.693 μm) lidar, DRUM Impactor sampler, and balloon-borne optical particle counter. These data provide information on the vertical distribution and type of aerosol, their size distributions, the chemical nature of aerosol observed at the surface, and timing of aerosol loading. A detailed synoptic analysis placed these observations into their transport and source-region context. Evidence suggests four major aerosol loading periods in the 25 March–30 April 2008 timeframe: a period during which typical Arctic haze conditions prevailed, several days of extremely clear conditions, rapid onset of a period dominated by Asian dust with some smoke, and a period dominated by Siberian wildfire smoke. A focused case study analysis conducted on 19 April 2008 using a balloon-borne optical particle counter suggests that, on this day, the majority of the suspended particulate matter consisted of coarse mode desiccated aerosol having undergone long-range transport. Backtrack trajectory analysis suggests aged Siberian wildfire smoke. In the last week of April, concentrations gradually decreased as synoptic conditions shifted away from favoring transport to Alaska. An important result is a strong suggestion of an Asian dust incursion in mid-April that was not well identified in other ARCTAS measurements. The lidar and OPC-sonde unambiguously discern aerosols height stratification patterns indicative of long range transport. Identification of a dust component is suggested by DRUM sampler results, which indicate crustal species, and supported by synoptic and trajectory analysis, which indicates both a source-region lifting event and appropriate air-mass pathways.
Highlights
Transport of aerosols is of particular concern in the Arctic because transportation from remote locations can be a primary source for contaminants that would not otherwise be observed
This paper focuses on description and analysis of ground- and balloonbased observations gathered over Interior Alaska, and the meteorological context during the observing period, for the first phase of the mission, Aircraft and Satellites” (ARCTAS)-A
Forest fire smoke episodes transported from northern China and eastern Russia are not uncommon at Arctic Facility for Atmospheric Remote Sensing (AFARS) in spring
Summary
Transport of aerosols is of particular concern in the Arctic because transportation from remote locations can be a primary source for contaminants that would not otherwise be observed. Following a distant biomass burning episode, they noted atmospheric contaminants which included ozone, carbon monoxide, and gaseous elemental mercury in the European and Russian Arctic (Stohl et al, 2007). Enhanced deposition can be found on snow surfaces In these cases the surface radiation balance can be altered by a reduction of albedo, which can act to hasten seasonal melt (Stohl et al, 2007; Haywood and Boucher, 2000). In terms of source attribution for observed surface contaminants, several studies have noted a link between the occurrence of atmospheric or surface contaminants and the timing of Arctic Haze events. The contamination noted by Douglas and Sturm (2004) was observed to increase in the late winter, which they found to correspond to atmospheric haze loading
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
