Measuring Atmospheric Composition at PEARL: An Overview of the First Two Years

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Measuring Atmospheric Composition at PEARL: An Overview of the First Two Years Kimberly Strong Department of Physics, University of Toronto C. Adams 1, R. Batchelor 1, J.R. Drummond 2, W. Daffer 3, P.

1 Measuring Atmospheric Composition at PEARL: An Overview of the First Two Years Kimberly Strong Department of Physics, University of Toronto C. Adams 1, R. Batchelor 1, J.R. Drummond 2, W. Daffer 3, P.F. Fogal 1, A. Fraser 1, F. Kolonjari 1, R. Lindenmaier 1, G. Manney 3, K.A. Walker 1, and M.A. Wolff 1 (1) Dept. of Physics, University of Toronto, Toronto, ON, M5S 1A7 (2) Dept. of Physics & Atmospheric Science, Dalhousie University, Halifax, NS, B3H 1Z9 (3) Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA International Arctic Change 2008 Conference Quebec City, 9-12 December 2008

2 Overview Arctic Stratospheric Ozone The PEARL at Eureka The Arctic Middle Atmosphere Chemistry Theme Instruments The First Two Years of Measurements Outlook Tobias Kerzenmacher

km) Ozone is also a greenhouse gas, absorbing IR radiation

3 Ozone in the Atmosphere Ozone absorbs harmful solar UV-B radiation ( nm) This warms the stratosphere (~10-50 km) Ozone is also a greenhouse gas, absorbing IR radiation and heating the troposphere (0-10 km) WMO Ozone Assessment 2006

4 Polar Total Ozone Trends WMO Ozone Assessment 2006

5 Causes of Ozone Depletion Emission and transport of ozone-depleting gases containing chlorine and bromine CFCs, halons, CH 3 Cl, CCl 4, CH 3 Br, Conversion to reactive halogen (Cl, Br) gases Global chemical depletion of ozone (~3%) Severe polar springtime depletion due to formation of polar stratospheric clouds and subsequent chemical reactions Montreal Protocol on Substances that Deplete the Ozone Layer Entered into force in 1989 Established controls on halogen source gases Later strengthened by a series of Amendments

6 Recovery of Ozone Recovery due to: Reductions in halogen source gases Cooling of stratosphere, hence slower ozone-destroying reactions Changes in total ozone from 60 S to 60 N IPCC/TEAP SROC 2005

7 Need for Arctic Measurements the frequency of measurements deep in the Arctic vortex remains low. The situation is unsatisfactory given the highly non-linear sensitivity of Arctic stratospheric ozone to cold winters. Chemical and dynamical perturbations caused by strong volcanic eruptions make it impossible to derive a linear trend [in total ozone], which highlights the importance of continuous measurements throughout the expected recovery of the ozone layer during the coming decades. IGOS 2004 Atmospheric Chemistry Report

Atmospheric Change (CANDAC) since August 2005 Three facilities: PEARL ridge lab, ØPAL, and

8 The PEARL at Eureka Polar Environment Atmospheric Research Laboratory Formerly Env. Canada s Arctic Stratospheric Ozone Observatory Run by the Canadian Network for Detection of Atmospheric Change (CANDAC) since August 2005 Three facilities: PEARL ridge lab, ØPAL, and SAFIRE Located on Ellesmere Island, Nunavut (80 N, 86 W) 15 km from Eureka Weather Station 1100 km from North Pole

9 Arctic Middle Atmosphere Chemistry Science Questions What is the chemical composition of the Arctic stratosphere above PEARL? How and why is it changing with time? How is it coupled to dynamics, microphysics, and radiation? What is the polar stratospheric bromine budget? Significant source of uncertainty BrO + ClO cycle estimated to contribute up to half chemical loss How will the polar stratosphere respond to climate perturbations? Particularly while Cl and Br loading is high How will changes in atmospheric circulation affect polar ozone? Cooling (more ozone depletion) or warming (less)?

10 Arctic Middle Atmosphere Chemistry Primary Composition Instruments Bruker 125HR Fourier transform infrared spectrometer (FTS) Direct solar (and lunar) absorption, cm -1 at high resolution UV-visible grating spectrometer (GBS) Zenith-scattered (and direct) solar absorption, nm Stratospheric ozone lidar Differential Absorption Lidar (DIAL) Brewer spectrophotometer Ozone total columns Polar Atmospheric Emitted Radiance Interferometer (P-AERI) Emission, cm -1 (3-25 µm) at low spectral resolution See four T22 posters by R. Batchelor, C. Adams, A. Moss, and M. Wolff Measurements Reactive species, source gases, reservoirs, dynamical tracers O 3, NO, NO 2, HNO 3, ClONO 2, HCl, OClO, BrO, HF, N 2 O, CFCs, CO, CH 4, C 2 H 6, HCN, OCS,...

11 UV-Visible Spectrometer New PEARL-GBS instrument installed in August 2006 Side-by-side with UT-GBS instrument (10 th Arctic campaign) Recently installed sun-tracker for multi-axis scanning and direct solar observations greater tropospheric sensitivity Daily automated zenith-sky measurements O 3, NO 2, BrO, OClO columns retrieved Clive Midwinter

12 First Year of O 3 & NO 2 at PEARL Vortex over Eureka Annemarie Fraser

13 First Year of O 3 & NO 2 at PEARL Vortex over Eureka NO 2 decreases in Fall as sunlight decreases. NO 2 recovers in Spring (complicated by vortex dynamics). Annemarie Fraser

14 Two Years of O 3 and NO 2 C. Adams, A. Fraser Day 2006 Day 2007 Day 2008

15 Spring 2007 O 3 and NO 2 vortex Inside Outside vortex Scaled potential vorticity (spv): allows definition of thresholds for inside and outside the vortex Provided by G. Manney and W. Daffer spv at 490K (lower stratosphere), indicates that Eureka is inside the vortex for large part of the campaign Annemarie Fraser, Cristen Adams

16 Understanding Spring Results AM PM vortex Fraser et al., ACP, 2008 PV plots from Andreas Dornbrack (DLR) and ECMWF Annemarie Fraser, Cristen Adams

PEARL Bruker FTS New PEARL Bruker IFS 125HR

solar infrared absorption measurements Need

Solar tracker High spectral resolution (up to

beamsplitter Vertical profiles and columns of

17 PEARL Bruker FTS New PEARL Bruker IFS 125HR FTS installed July 2006 Daily semi-automated solar infrared absorption measurements Need direct sun - late February to late October Solar tracker High spectral resolution (up to cm -1 ) InSb and MCT detectors, KBr beamsplitter Vertical profiles and columns of many species retrieved using optimal estimation (SFIT2 v3.92c)

18 The First Two Years of FTS Data O 3 Rebecca Batchelor, Rodica Lindenmaier HCl chlorine reservoir HF a tracer HNO 3 nitrogen reservoir ClONO 2 chlorine reservoir

19 Spring 2007 FTS Data O 3 HCl chlorine reservoir 2007: Recall - the vortex was above Eureka for a large part of the campaign. HF a tracer HNO 3 nitrogen reservoir ClONO 2 chlorine reservoir spv Rebecca Batchelor, Rodica Lindenmaier; spv data - G. Manney & W. Daffer; PV plot - A. Dornbrack & ECMWF

HNO 3 nitrogen reservoir ClONO 2 chlorine reservoir spv Mar 13 Mar.

20 Spring 2008 FTS Data O 3 HCl chlorine reservoir 2008: Sudden stratospheric warming in mid-february and very little vortex activity above Eureka during March HF a tracer HNO 3 nitrogen reservoir ClONO 2 chlorine reservoir spv Mar 13 Mar. 13 Rebecca Batchelor, Rodica Lindenmaier; spv data - G. Manney & W. Daffer; PV plot - A. Dornbrack & ECMWF

21 Outlook Will climate change enhance or reduce ozone depletion? Remains uncertain, particularly in the Arctic Long-term measurements are essential to understanding the chemical state of Arctic stratosphere and future changes Focus of the Arctic Middle Atmosphere Chemistry theme at PEARL PEARL site is now well established at Eureka Large suite of instruments (<20) operating successfully Have first two years of data from UV-visible and FTS instruments Clearly see impact of springtime vortex dynamics and chemistry Future plans include Integration with complementary measurements at PEARL Contributions to IPY atmospheric science, e.g., through IASOA Comparisons with models: CMAM-DA, GEM-BACH, SLIMCAT,...

22 CANDAC/PEARL Co-Investigators Principal Investigator Prof. James R. Drummond, Dalhousie University / University of Toronto CANDAC Manager of Operations Dr. Pierre Fogal, University of Toronto Theme Leaders Prof. Tom Duck, Dalhousie University, The Arctic Radiative Environment: Impacts of Clouds, Aerosols, and Diamond Dust Prof. Jim Sloan, University of Waterloo, Arctic Tropospheric Transport and Air Quality, Prof. Kimberly Strong, University of Toronto, Arctic Middle Atmospheric Chemistry Prof. William Ward, University of New Brunswick, Waves and Coupling Processes Co-Investigators Dr. Stephen Argall, University of Western Ontario Dr. Hans Fast, Environment Canada Dr. David Hudak, Environment Canada Prof. Alan Manson, University of Saskatchewan Dr. Bruce McArthur, Environment Canada Dr. Tom McElroy, Environment Canada Prof. Norman O'Neill, Université de Sherbrooke Prof. Marianna Shepherd, York University Prof. Gordon Shepherd, York University Prof. Robert Sica, University of Western Ontario Dr. Kevin Strawbridge, Environment Canada Prof. Kaley Walker, University of Toronto Prof. Jim Whiteway, York University The following organizations are involved in supporting CANDAC and PEARL: AIF/NSIRT, CFCAS, CFI, CGCS, CSA, EC, GOC-IPY, MRI, MSC, NSERC, NSTP, OIT, PCSP, SEARCH

In 2002, a group of university researchers joined together under the title of the Canadian Network for the Detection of Atmospheric Change (CANDAC)

1 In 2002, a group of university researchers joined together under the title of the Canadian Network for the Detection of Atmospheric Change (CANDAC) with the objective of improving the state of observational