PS215/CLOUD 2010 Progress Report SPSC open session, CERN, 4Apr11 Douglas Worsnop, Aerodyne Research/University of Helsinki On behalf of the CLOUD Collaboration Austria: University of Innsbruck, Institute for Ion and Applied Physics, Innsbruck University of Vienna, Faculty of Physics, Vienna Finland: University of Helsinki, Department of Physics and Helsinki Institute of Physics, Helsinki Finnish Meteorological Institute, Helsinki University of Eastern Finland, Kuopio Germany: Johann Wolfgang Goethe-University of Frankfurt, Institute for Atmospheric and Environmental Sciences, Frankfurt am Main Leibniz Institute for Tropospheric Research (IfT), Leipzig Portugal: SIM, University of Lisbon and University of Beira Interior, Lisbon Russia: Lebedev Physical Institute, Solar and Cosmic Ray Research Laboratory, Moscow Switzerland: CERN, PH Department, Geneva Paul Scherrer Institut (PSI), Laboratory of Atmospheric Chemistry, Villigen Tofwerk/Aerodyne, Thun United Kingdom: University of Leeds, School of Earth and Environment, Leeds University of Manchester, School of Earth, Atmospheric and Environmental Sciences, Manchester United States: California Institute of Technology, Division of Chemistry and Chemical Engineering, Pasadena, CA

Aerosols in the Atmosphere Acid C.E. Kolb, Nature, 2002

Aerosols are “saving us” from global warming Direct Aerosol Scattering Indirect Cloud Effects Aerosols are “saving us” from global warming

Thermal structure and clouds of the atmosphere Height (km) Noctilucent clouds (NLCs) 100 80 60 40 20 Mesopause Polar stratospheric clouds (PSCs) Mesosphere Ice Clouds (Cirrus) Stratopause Mixed-phase clouds Introduction to a more microphysical classification of clouds, based on temperature regimes (warm, mixed-phase, cirrus, …) Stratosphere Warm clouds Tropopause Troposphere -150 -100 -50 50 Temperature (°C) Prof. Dr. Max Mustermann | Musterfakultät

 ~ 0.5 m  sunlight Why, in fact, are aerosols so important? Why, in fact, are aerosols so DIFFICULT? Anthropogenic perturbation: CO2 increase 100 – 200 ppm other Green House Gases 1-2 ppm Aerosol Increase 1- 2 ppb  ~ 0.5 m  sunlight Mie scattering theory Atmoospheric pressure Kelvin Effect Direct optical Scattering efficiency Stokes diameter CCN (indirect cloud effect)

< 2nm

Cosmic Rays new particles more cloud droplets ??? Mainly highly energetic protons and alpha-particles stemming from Super Nova explosions. The cosmic rays produce showers of secondary particles (pions, muons, etc.), and create ions and radicals in the atmosphere. Main source of ions in the free atmosphere, At ground: decay of radon gas is also a major source of ions. Hess found increasing ionisation of air with altitude (1912, up to 5 km, Nobel- prize 1936). new particles more cloud droplets ??? 8

CLOUD chamber in CERN ”East Hall” in July 2010 “laboratory cosmic rays” Jasper Kirkby, Joachim Curtius et al submitted, 2010

CLOUD FACILITY UPGRADES PLANNED FOR 2011 Thermal housing: Improvements in the thermal system to allow operation at low temperatures, down to near 183K. Gas system: Various improvements to the gas system and control software, including new operation for adiabatic chamber expansions of up to -200 mbar. Chamber cleanliness: Improvements in the purity of the water used for the humidifier, by generating synthetic water from pure hydrogen combustion in pure oxygen. Installation of a quartz tube containing a high-intensity UV source for chemically breaking down and cleaning organic backgrounds in the chamber under high O3 conditions. Replacement of the ozone generator by a design involving only quartz and stainless steel components in contact with the air flow. Field cage: Installation of zirconia HV feedthroughs to allow operation up to 50 kV without surface charge buildup. Replacement of the gold-coated Cu-Be springs for electrical contacts with stainless steel springs. Manhole covers: Construction of the final upper and lower manhole covers with all ports, windows, UV feedthroughs, and fans. Addition of nozzles (hoods) to both fans to improve efficiency at reduced fan speeds. Sampling probes: Design and installation of custom sampling probes to optimise the performance of individual analysing instruments. Beam counter: Installation of a new scintillator plate for the first beam counter.

< 2nm

CLOUD analysing instruments Aerosol particles: CPC battery (2.5-10 nm cut-off) PSM (1-3 nm, scanning cut-off) DEG-CPC (2 nm cut-off) Nano-DMA (1-10 nm) SMPS (4-80 nm) Ions/charged aerosol particles: AIS (+/- size spectra 0.3-40 nm) Gerdien (+/- small ions) Mass spectrometers CIMS (H2SO4) PTRMS (organics, NH3…) APi-ToF (ions < 2500 amu @0.02 amu) Gas analysers: NH3, O3, SO2 Chamber conditions: Pt 100 array (0.01°C), pressure, dew point (RH @0.1%) Aerosol particles: CPC battery (2.5-10 nm cut-off) PSM (1-3 nm, scanning cut-off) DEG-CPC (2 nm cut-off) Nano-DMA (1-10 nm) SMPS (4-80 nm) Ions/charged aerosol particles: AIS (+/- size spectra 0.3-40 nm) Gerdien (+/- small ions) Mass spectrometers CIMS (H2SO4) PTRMS (organics, NH3…) APi-ToF (ions < 2500 amu @0.02 amu) Gas analysers: NH3, O3, SO2 Chamber conditions: Pt 100 array (0.01°C), pressure, dew point (RH @0.1%)

CLOUD experiments at the CERN PS in 2010 represent the most rigorous laboratory evaluation yet accomplished of binary, ternary and ion-induced nucleation of sulphuric acid particles under atmospheric conditions. Results include first measurements of: Ion-induced vs neutral nucleation, Molecular composition of the critical clusters, Binary nucleation of H2SO4-H2O at mid-tropospheric temperatures Ternary nucleation mechanism of NH3-H2SO4-H20 at planetary boundary layer temperatures. A manuscript on the main findings from the 2010 runs has been submitted for publication.

PUBLICATIONS CLOUD results from November 2009 and June 2010 runs were presented at: International Aerosol Conference, IAC2010, Helsinki, 29 August – 3 September 2010, The CLOUD abstracts comprised 7 oral presentations and 6 posters. One poster (Kupc, on the CLOUD UV system) won a best poster award at the meeting. Invited presentations of CLOUD results were made at other conferences, including: International Accelerator Conference, Kyoto, May 2010 (Kirkby) American Geophysical Union, San Francisco, December 2010 (Curtius) ASPERA InterdisciplinaryWorkshop, December 2010 (Baltensperger). European Aerosol Conference, EAC2011, Manchester, September 2011, Twelve abstracts have submitted, inclduing keynote plenary talk Following publication of the recently-submitted CLOUD manuscript, planning to about 10 additional manuscripts are planned for submission to peer-reviewed journals during 2011.

COLLABORATION ASPECTS During 2010, CLOUD Collaboration meeting were held at PSI, 25–28 January (Data Workshop) and at CERN, 12–16 April (Data Workshop) and 14–15 October. A one-week CLOUD/CLOUD-ITN workshop was held at the University of Vienna in early 2011 comprising a Data Workshop, 14–16 February, and an Open Workshop, 16-18 February. The Open Workshop included around 25 invited external scientists from Europe and the United States to hear and discuss the CLOUD results. Several new partners joined the CLOUD collaboration during 2010: University of Manchester, UK: world experts in ice particles and atmospheric electricity Aerodyne Research, Inc., Massachusetts, USA: world leader for aerosol mass spectrometers. Tofwerk AG, Thun, Switzerland: world leader for time-of-flight mass spectrometers. The current FP7 Marie Curie Network, CLOUD-ITN, was selected as an example of an “ideal MC network” for presentation (Duplissy) at “Marie Curie Actions for an Innovative Europe”, Brussels, 9–10 December, 2010, attended by high-level EU and European research policy-makers <http://mariecurieactions2010.teamwork.fr/en/programme>. A proposal for a new FP7 Marie Curie network, CLOUD-TRAIN, was submitted (January 2011) for 13 MC CLOUD Fellows for the period 2012–2014. (J. Curtius, Coordinator, Goethe-University of Frankfurt)

PHYSICS AIMS AND BEAM REQUEST 2011 2011: one data-taking period, a single 6-week run, is planned: 13 June - 24 July 2011: Ion-induced and neutral nucleation studies of sulphuric acid particles in association with added trace organic vapours: 1. Amines ( e.g. (CH3)2NH ). 2. Volatile organic compounds (e.g. -pinene, emitted by pine trees). This run will investigate the role of organic species and their low-volatility oxidised products in a) nucleation and b) growth of atmospheric aerosols. Three spills per supercycle are requested. Fall 2011: After the June/July run, CLOUD will have collected the world’s foremost laboratory data on atmospheric nucleation and growth. Physics priority during the second half of 2011 will be data analysis rather than collection of more experimental data. Following thorough analysis of the CLOUD in second half of 2011, scientific goals will be chosen for the 2012 data taking period. In parallel, there will be important technical developments on the CLOUD facility in the second half of 2011. The rapid adiabatic expansion system will be installed and comissioned. Technical runs (without beam) will test CLOUD in a classical Wilson expansion chamber mode for generation of liquid and ice clouds. Runs (with beam) to test new instrument designs/configurations – e.g. IMS-APi-ToF Thermal performance of the chamber will be tested down to near 183K, using upgraded thermal housing and new precision thermo-regulator.

First “clean” measurement of H2SO4-H20-NH3 nulceation, ion and neutral CLOUD SUMMARY 3 experimental runs: 12/2009, 6/2010, 11/2010 Nucleation: Binary H2SO4 + H2O Ternary H2SO4 + H2O + NH3, DMA [ (CH3)2NH ] T: -25C, 5C, 20C [H2SO4] ~ 5e6 to 5e9 mol/cm3, note: atmosphere 1-10e6 (< 0.5 ppt) [NH3] 35 – 1000 ppt atmosphere 1-10000 ppt June 2011: add DMA + oxidized organics (a-pinene) Demonstrate lower T operation (down to -60C<) Fall 2011: Demonstrate Cloud expansion chamber mode First “clean” measurement of H2SO4-H20-NH3 nulceation, ion and neutral [ all previous experiments heavily contaminated ] Organics necessary to explain actual “impure” atmosphere CERN Beam + Low T = Cosmic Rays at top of lower atmosphere “where the clouds are”

Cosmic Rays new particles more cloud droplets ??? Mainly highly energetic protons and alpha-particles stemming from Super Nova explosions. The cosmic rays produce showers of secondary particles (pions, muons, etc.), and create ions and radicals in the atmosphere. Main source of ions in the free atmosphere, At ground: decay of radon gas is also a major source of ions. Hess found increasing ionisation of air with altitude (1912, up to 5 km, Nobel- prize 1936). new particles more cloud droplets ??? 24

Many thanks to: the ITN fellows and all the co-workers of CLOUD, CERN staff and especially Jasper Kirkby. the EC for funding the Marie Curie Initial Training Network „CLOUD-ITN“. the German BMBF for funding of the „CLOUD-09“ project. CERN, the Swiss National Science Foundation and the Academy of Finland Center of Excellence for funding support.

CLOUD collaboration Cosmics Leaving OUtdoor Droplets 15 institutes: CERN involvement: PH-SME-CL PH-DT: EN-MME EN-MEF EN-CV TE-VSC CLOUD, DT ST Tea 12May2010, A.Onnela & J. Duplissy 26