Arctic Troposphere Transport and Air Quality Theme

Jim Sloan

University of Waterloo

CANDAC Workshop Toronto 24 October 2007

Arctic Troposphere Transport and Air Quality  Participants:  CANDAC: A. Manson, B. McArthur, N. O’Neill, J. Sloan, K. Strong  Collaborators: J. McConnell, T. Uttal  Scientific Interests (focus on aerosols)  Arctic Pollutants and deposition.

   Arctic Haze Chemical Contaminants – Persistent Organic Pollutants, heavy metals, etc.

Polar sunrise chemistry  Meteorology and modelling  Transport and chemistry of PM – Source identification – Size distributions, compositions, etc.

ATTAQ at PEARL   Current activities:   In situ PM monitoring by Aerosol Mass Spectrometer   Size distributions: 0 to ~700 nm Chemical composition Sun, star photometers  Aerosol Optical Depth measurements Wish list:  Addition of conventional aerosol measurements   Size distribution: SMPS Total local aerosol loading (CPC/TEOM… ?)

Primary Arctic Pollutants

 Found in surface snowpack measurements  Transported from lower latitudes and deposited to surface – no local sources Hg and heavy metals POPs

Secondary Pollutants

 Found in lower troposphere  Atmospheric reactions at source or in transit Arctic Haze, Barrow

Transport & General Circulation

(long term transport) Westerlies transport mid-latitude air towards poles Polar front dynamics and polar cells contribute

Mechanisms for Arctic Transport

High latitude averaged transport “Grasshopper” mechanism (Semi-volatile gas phase) AMAP 2002

Transport of Anthropogenic Pollutants

 Anthropogenic contaminants atmospherically transported thousands of kilometres from mid and low-latitude sources to the Arctic troposphere  SOx, heavy metals, POPs  Sulphur aerosols, cause acid rain; climate change  Heavy metals and POPs are biomagnified, causing Arctic predators such as seals, cetacea, and polar bears to have high levels of contamination,, affecting the health of Northern indigenous communities Bard, S. M., “Global transport of anthropogenic contaminants and the consequences for the Arctic marine ecosystem”, Marine Pollution Bulletin, 38,

356-379, 1999.

Ozone transport into the Arctic

Trajectory study of ozone transport after polar sunrise surface depletions. April 1992 –2000. The maps link specific regions in the Arctic with the observed O 3 mole fractions (nmol mol -1 ) at Alert. The colours show the calculated average mole fractions in air that traversed the area. Contour lines indicate the average travel distance in days to the measurement location.

Jan W. Bottenheim and Elton Chan “A trajectory study into the origin of spring time Arctic boundary layer ozone depletion” JGR (D111), D19301, doi:10.1029/2006JD007055, 2006

Transport from European Sources

 CTM study of export pathways of pollution from Europe from 1987 to 1997    Winter pathways are advection to the (1) middle/high latitudes of the North Atlantic Ocean, (2) Russia and the Russian Arctic, Summer export occurs by both advection and convection; advection predominantly to Russia Two major regions of convection in summer that loft European pollution into the free troposphere, one centered over Germany and the other over the Ural Mountains in Russia.

Duncan, B. N. and I. Bey, A modeling study of the export pathways of pollution from Europe: Seasonal and interannual variations (1987-1997),

Journal of Geophysical Research-Atmospheres, 109, 2004..

Identification of source regions

(Flexpart footprints for BC sources) Importance of different locations as sources for anthropogenic BC that appears at latitudes north of 70 emission at that location) Integrated for 30 days o (= time spent in a specific location x A . Stohl, “Characteristics of atmospheric transport into the Arctic troposphere” JGR (D) 111, D11306, doi:10.1029/2005JD006888, (2006)

Cross-Tropopause Transport

 Lagrangian analyses of upward troposphere to stratosphere exchange (TSE) and downward stratosphere to troposphere exchange (STE) in the extratropical Northern Hemisphere from May 1995 to April 1996    Chemical implications of extratropical cross-tropopause transport The meridional distribution of the net flux is upward in subtropics, downward in mid-latitudes and weakly upward in the Arctic region.

The localized source regions for deep TSE indicate that pollutants emitted in eastern North America and Asia have an enhanced potential for being rapidly transported into the lowermost stratosphere Wernli, H. and M. Bourqui, A Lagrangian "1-year climatology'' of (deep) cross tropopause exchange in the extratropical Northern Hemisphere, Journal of

Geophysical Research-Atmospheres, 107, 2002.

Dynamics and transport

NAO and transport from Europe.

(a) Residual NO 2 columns [10 observations for (NAO + 14 molecules cm −2 ] retrieved from GOME satellite - NAO − ) composites during (1996–2002) winters.

(b) Simulated NO 2 columns [mg m -2 ] for a European emission tracer with a 1-day lifetime.

White lines: correlation coefficients with the NAO index.

S. Eckhardt, et al., “The North Atlantic Oscillation controls air pollution transport to the Arctic” Atmos. Chem. Phys., 3, 1769-1778, 2003.

AMS Report

Arrival August 2006

AMS at PEARL

Instrument location Inlet and calibration system

Aerosol Mass Spectrometer Components

Inlet 1ATM ~10 -3 Torr 1Torr Aerodynamic Lens TOF Chopper 10 -5 Torr 10 -7 Torr QMS Ionizer 10 -8 Torr Heater

CFD to design sampling from cold source

e.g. -40C to 20 C Cylindrically-symmetric heater gives turbulence due to differential expansion Localized heating gives recirculation

Installation of External Inlet

The worker The supervisors

Survival of External Inlet

After Installation (2006) At Polar Sunrise (2007) Survived the winter but modifications are needed to provide better temperature control

Example Results: Four 1-Week Time Series Measurements of Sulfate & Organics 29 Aug – 5 Sept Sulfate 5 – 12 Sept.

Organic 13 – 20 Sept.

6 – 13 Oct.

0.8

0.2

-0.2

0.0

-0.4

-0.2

0.6

0.8

0.4

0.6

0.2

0.4

0.0

-0.4

8/11/2006 8/11/2006 8/21/2006 8/21/2006 0.8

0.6

0.4

0.2

0.0

8/31/2006 Date and Time 9/10/2006 -0.2

9/20/2006

Aerodynamic Radii

Water Ammonium Nitrate Sulphate Chloride Organics Water Ammonium Nitrate Sulphate Chloride Organics Water Ammonium Nitrate Sulphate Chloride Organics Approx. lens transmission limit 0.5

0.4

Water Ammonium Nitrate Sulphate Chloride Organics Water Ammonium Nitrate Sulphate Chloride Organics 8/31/2006 Date and Time -0.4

9/10/2006 8/21/2006 -0.1

10 Date and Time 2 3 4 9/10/2006 5 6 7 8 9 100 2 3 Vacuum Aerodynamic Diameter (nm) 4 5 6 7 8 9 1000  -0.2

2 3 4 5 4 5 6 10 6 7 8 9 100 2 3 Vacuum Aerodynamic Diameter (nm) Only small particles are observed 7 8 9 1000 2 2

AOD Measurements with Sun Photometers In operation at 0PAL and PEARL 0PAL – CIMEL 327 PEARL – CIMEL 401

Early AOD Results

2 April 2007: 0PAL – Fine and coarse; PEARL mostly fine

Resolute Bay optical depths, June 29 fine mode smoke June 29 cloud

PEARL optical depths 0.1

0.08

0.06

fine mode OD coarse mode OD smoke total OD June 29, 30 0.04

0.02

0 180.5

180.6

Cloud & smoke 180.7

180.8

180.9

181 181.1

181.2

181.3

181.4

181.5

181.6

181.7

181.8

181.9

182 182.1

182.2

182.3

cloud

Smoke layer