Monitoring Arctic Aerosols

Transcription

1 Monitoring Arctic Aerosols Dave Hofmann with contributions from Russ Schnell, Bob Stone and John Ogren NOAA Earth System Research Laboratory Boulder, Colorado, USA Presented at the Hemispheric Transport of Atmospheric Pollution Workshop, St. Petersburg, Russian Federation, April 2, 2009

2 Source regions of aerosol transported into the Arctic haze dust smoke volcanoes Courtesy of Bob Stone, NOAA/ESRL

3 ARCTIC HAZE HAS BEEN STUDIED FOR AT LEAST THE PAST 25 YEARS AGASP- Arctic Gas & Aerosol Sampling Program Six Distinct Arctic Haze Layers Upwind of Barrow, Alaska. Nearest Possible Sources are 10,000 km distant. Courtesy of Russ Schnell, NOAA/ESRL

4 Black Carbon Profile Upwind of Barrow, Alaska March 11,1983 Black Carbon (ng m -3 ) Courtesy of Russ Schnell, NOAA/ESRL

5 Black Carbon is usually accompanied by carbon dioxide and methane CH 4 BC Hourly Average CO 2, CH 4 and BC, Surface, Barrow, Alaska, April 15-16, 1986 CO 2 Courtesy of Russ Schnell, NOAA/ESRL

6 NOAA-federated Long-term Aerosol Network ALT BRW SUM TIK BRM WHI EGB KPS SPL THD BND ARN SGP WLG AMY CSJ LLN MLO SMO SPO CPT Legend NOAA affiliate future sites Courtesy of John Ogren, NOAA/ESRL

7 LONG-TERM ARCTIC AEROSOL MEASUREMENTS Implementation status Barrow Tiksi Summit Radiative properties 100% 10% 10% Chemical composition 50% 0% 0% Size distribution 100% (2007) 100% (Finland) 0% Cloud condensation nuclei 100% 0% 0% Light absorbing particles in snow 0% 0% 0%

8 light absorption (Mm -1 ) estimated black carbon (ug/m 3 ) NOAA observatory - Barrow, Alaska Aerosol Light Absorption at Barrow Proportional to black carbon Measured by NOAA since 1988 Seasonal - peak in winter from Arctic haze Date YEAR Courtesy of John Ogren, NOAA/ESRL

9 Springtime Arctic Atmospheric Pollution Monthly averaged concentrations for March of a) light scattering and b) light absorption at 550 nm for sub-10 micron aerosol at Barrow, and c) black carbon (ng m -3 ) for Alert. Trend lines are not shown for significance < 90%. Data made available for Barrow by NOAA ESRL and for Alert by the Canadian National Atmospheric Chemistry (NAtChem) Database and Analysis System. From Quinn et al., Tellus 59B, , x x BC, ng m -3 Absorption, Mm -1 Scattering, Mm a) Barrow scattering b) Barrow absorption March averages trend ( = 0.01) trend ( = 0.05) Trend ( = 0.1) Trend ( = 0.001) Trend ( = 0.1) c) Alert black carbon

10 a) Alert 82N Canada SULFATE e) Karasjok 69.5N Norway 1.0 g S m b) Nord 81N Greenland f) Svanvik 69.5N Norway c) Zeppelin 79N Svalbard g) Janiskoski 69N Russia April SO 4 = March SO 4 = LT April Trend ST April Trend LT March Trend ST March Trend d) Barrow 71N Alaska h) Oulanka 66N Finland Monthly averaged concentrations in g S m-3 of sulfate for March and April. Trend lines are not shown if the significance for the trend is < 90%. Data made available for Alert by the Canadian National Atmospheric Chemistry (NAtChem) Database and Analysis System, for Barrow by NOAA PMEL ( and for the other stations by EMEP ( From Quinn et al., Tellus 59B, , 2007.

11 AOD Anomaly AOD Anomaly AEROSOL OPTICAL DEPTH March El Chichón Pinatubo April 1/78 1/80 1/82 1/84 1/86 1/88 1/90 1/92 1/94 1/96 1/98 1/00 1/02 Monthly averaged AOD anomalies at Barrow, Alaska for March and April. The anomalies are relative to a base of non-volcanic years. Data from 1982 and 1983 and from 1992 and 1993 were removed due to stratospheric aerosol from the major El Chichón and Pinatubo volcanic eruptions, respectively. Vertical lines represent the 1 standard deviation of the monthly mean. Data made available by NOAA ESRL. From Quinn et al., Tellus 59B, , 2007.

12 FOREST FIRE SMOKE 30 June 2004 Barrow Brooks Range Courtesy of Bob Stone, NOAA/ESRL

13 ( 3-hour time steps) Alert BRW CO mg m -2 FLEXPART Tracer Simulation (A. Stohl 2006) Courtesy of Bob Stone, NOAA/ESRL

14 Desert Dust SeaWiFs Courtesy of Russ Schnell, NOAA/ESRL

15 3 April April 2002 Asian Dust (brownish yellow plumes) being blown from the Gobi Desert over the Sea of Japan in early April Dust/haze was observed at Barrow, Alaska about 7 days later following each event. Images courtesy of NASA SeaWiFs and ORBIMAGE. Courtesy of Russ Schnell, NOAA/ESRL

16 REDOUBT (60.5 N) ERUPTION IN ALASKA MARCH 23, 2009

17 CONCLUSIONS The scattering component of Arctic Haze began to decline about 1980 although the decline appears to have stopped about 1998 and may have increased since that time. Arctic black carbon has also declined since measurements began about Black carbon from forest fire smoke is a long-range transport threat in the Arctic. Desert dust likewise will continue to affect Arctic air quality. Volcanic eruptions are sporadic sources of Arctic pollution, critical for aviation. Long-term monitoring at an increased number of Arctic sites is necessary in order to determine trends in specific components in the future.

18 PAM-ARCNIP Bob Stone, who is responsible for a large part of ESRL s Arctic aerosol work, is currently on the PAM-ARCNIP mission, on the twin turbo-prop Polar 5 (AWI-Polar Institute) from Bremerhaven, Germany to the USA by way of the North Pole, and will be at the Russian Station North Pole 36 April 3-5.

19 13OSH Polar-5 Flight ~ April TRO 1BRE 4N36 3LGY 5SND # ID Name Dates 10FAI 11BRW 9SHB 12INU 7EUR 8RES 6ALT 1. BRE Bremerhaven dep. 30 Mar 2. TRO Tromso LGY Longyearbyen (base) N36 N. Pole 36 (ice is.) SND Station Nord ALT Alert EUR Eureka RES Resolute SHB Sachs Harbor FAI Fairbanks BRW Barrow INU Inuvik OSH Oshawa, CAS arr. 27 Apr

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21 WMO/GAW Recommended Aerosol Parameters Core Variables Continuous Measurements AOD - multiwavelength σ sp - multiwavelength σ ap - multiwavelength Chemistry 2 size ranges Mass 2 size ranges Comprehensive Variables σ bsp hemispheric backscatter coefficient CNC number concentration CCN cloud condensation nuclei Intermittent Measurements Size distribution Chemical composition size fractionated f (RH) scattering dependence on humidity CCN spectra several supersaturations Vertical distribution lidar, aircraft profiles