Stephan Borrmann Kathy Law (Univ. Paris-Jussieu) Daniel Kunkel, Joachim Curtius (Univ. of Mainz and MPIC) Ralf Weigel(Univ. Clermont-Ferrand)Silvia Viciani (INOA, Florence) G. Shur, A. Ulanovsky (CAO, Moscow, Russia) Ultrafine particles in the West African UT/LS: In-situ measurements in August 2006 during the AMMA monsoon period2007 EGU General Assembly, AS 1.14 1 FR4O-001

(1) Instrument: COPAS on Russian high altitude research aircracft M-55 Geophysica

heated channel (250C)Condensable liquid: Fluorinert - 1 Hz data

- 10%- isokinetic inlet < 1m Specialized CPC type COndensation PArticle counting Systemunheated channel

1 Hz time series/vertical profiles up to 20 km of particle # / cm

* for sizes > 6 nm* for size diam. > 10 nm* for size diam. > 14 nm* above 10 nm after heating to 250 C => non volatile residue * derived: Fraction f of non volatile to total # for > 10 nmCOPAS Deliverables

2 Modified FSSP-SPP100 1 Cloud Imaging Probe CIP2 COPAS unitsUMAINZ/MPIC instrumentation on Geophysica COPAS ICOPAS II

Russian M-55 Geophysica (20 km ceiling)

(2) Results:Global background aerosol between potential temperatures of 367 K and 460 K

TROCCINOX, SCOUT-O3, AMMA transfer flightsLatitude range: 55 N to 20 S , Jan 2005 until Aug 2006, no major volcano eruption Marrakesh MaroccoOuagadougou Burina FasoAccra GhanaVerona Italy

Marrakech-OuagadougouHeated 10 nm channel Cold 10 nm channelPressure hPa]

-- n6 TROCCINOXTransfer Germany - Brazil-- n6 SCOUT Transfer Germany - Australia, altitude range 367 K to 460 K 12 km to 17 km AMMA transfer

(3) Results: Vertical profiles Mid-latitudes, Brazil, Australia, West-Africa

-- EUPLEX- Test, Forli, 2002 CN, Laramie, USA, Deshler et al. 2003 Marshal Test flight, OPH 2005 SCOUT-Transfer, OPH - Larnaca, 2005 SCOUT-Transfer, Larnaca - OPH, 2005-- AMMA 2006, mid-latitude flightsMid latitude vertical profiles 2002 to 20061999, 41N20052005 35N2002,44N2005, 48NJuly 2006Remar-kably konstant from 1999 until 2006

04.11.2005 OPH - Larnaca 04.11.2005 Larnaca - Dubai 07.11.2005 Dubai Hyderabad 09.11.2005 Hyderabad U-Tapao 11.11.2005 U-Tapao - Brunei 12.11.2005 Brunei Darwin

09.12.2005 Darwin - Brunei 10.12.2005 Brunei U-Tapao 13.12.2005 U-Tapao Hyderabad 14.12.2005 Hyderabad - Dubai 16.12.2005 Dubai - Larnaca 17.12.2005 Larnaca - OPHCOPAS-data vs altitudeparticle sizes > 6 nm 1 mSCOUT-O3 transfer flights Germany AustraliaNov. and Dec. 2005Tropospheric variabilityStratospheric compactness

SCOUT-O3 local flights Darwin, Australia 16.11.2005 19.11.2005 23.11.2005 25.11.2005 29.11.2005 30.11.2005 A 30.11.2005 B 05.12.2005Contrail crossing ?COPAS-data vs altitudeparticle sizes > 6 nm 1 m

n10 non-volatile n10 total n14 n6-- median n10COPAS-data vs altitudeparticle sizes > 6 nm 1 mAMMA local flights Ouagadougou:

* Unusual increase above 450 K * Compact data with very little scatter * No nucleation particlesParticle number concentration [cm]Potential Temperature [K]

AmmaDarwinBrazilBrock, 1995Potential temperature [K]Particle mixing ratio [#/mg]Context of other tropical data from Geophysica: Vertical profiles Tropical Brazil, Australia,West-Africa

=> W. African profile IS unusual.

All AMMA flights:Red: = 500 K Blue: = 350 KAnomaly also in N2O space

Except AMMA all data from Chuck Wilson, Denver University, ER-2 and WB-57 tropical measurements from 1996 onwardUltrafine particle mixing ratio [#/mg of air]Potential temperature [K]Context with other tropical data

(4) Results: nonvolatile ultrafine particles ( > 10 nm and 1 m )(nonvolatile) particle number above 10 nm per cm of air (250 C)total particle number density > 10 nm (ambient temperature)f = nonvolatile residuesambient particles =

Mid latitudes Brock et al. (1995) outside tropics-- COPAS n10 median (2002)

Arctic Latitudes-- COPAS n10 inside polar vortex (2003)-- COPAS n10 outside polar vortex (2003)

Tropics Brock et al. (1995) inside tropics-- COPAS n10 Brasil (2005) -- COPAS n10 Australia (2005)

EXAMPLE:

Arctic data 2003

high fraction of non-volatile particles inside Arctic vortex (~70 %)Curtius et al., ACP, 2005EUPLEX 2003Ratio of non-volatile particle numberto total particle number > 10nm, < 1 m=> subsidence of meteoritic material from mesosphere

Mid latitudes Brock et al. (1995) outside tropics-- COPAS n10 median (2002)

Arctic Latitudes-- COPAS n10 inside polar vortex (2003)-- COPAS n10 outside polar vortex (2003)

Tropics Brock et al. (1995) inside tropics-- COPAS n10 Brasil (2005) -- COPAS n10 Australia (2005)

TROPICAL BRASIL Non-volatile particlesconstant at 20-30% in LS

More variable, but typically ~10% in TTL and below.Ratio of non-volatile particle numberto total particle number > 10nm, < 1 m2005 0123 - 0227

AUSTRALIA 2005 Slightly higher level (10%) of non-volatile particlesover the continent thanabove the seaRatio of non-volatile particle numberto total particle number > 10nm,

AMMA: Ouaga ratio of non volatileparticles to total number

* Values above 360K are at 50%. * Tropical Brazil was 20%. * Tropical Australia 60% but higher up. 4.8.2006 8.8.2006 11.8.2006

n10 non-volatile n10 total n14 n6-- median n10AMMA summary:COPAS-data vs altitude

particle sizes > 6 nm 1 m

Ouagadougou local flightsParticle number concentration [cm]Potential Temperature [K]

(5) Results from specific cases:

Biomass burning particles

High CO for biomass burning is correlated with high ultrafine particle Number densities

AMMA flight August 8, 2006High CO for biomass burning is correlated with high non-volatileultrafine particle componentTheta:Blue 370 KGrey 385 KYellow 400 KRed 430 K

Biomass burning: Vertical profiles over Accra, August 13, 2006Difference between n6 and n14 is zero. Thus:no new particle formation in bmb plume above Accra

Direct evidence for homogeneous nucleation in the tropics n6 n15 altitudeFlight altitude in kmParticle number density in cm-3Only ultrafine particles 6 nm size 14 nmUTC flight time [hours]TROCCINOX,BRAZIL, 24.2.2005

Biomass burning:Vertical profiles over Accra, August 4, 2006

Large latitudinal data sets on non-volcanic background ultrafine particles within 2005 through TROCCINOX, SCOUT-O3, AMMA mid-lat. transfer, survey, test flights. For AMMA unexpected increase above 420 K => No explanation sofar.

Non-volatility vs. total aerosol number ratios between 20% and 80%, maximum near 400 K => No explanation for this profile sofar.

Above 400 K ultrafine particle numbers constant since 1999 at mid-latitudesSummary

Thanks for your interest.

Heater efficiency of COPAS I at 250C with pure H2O- H2SO4- particlesBoiling point of H2O- H2SO4particles under pressure conditions at 10 20 km: ~ 150C

(Rosen, 1971) not heated channel heated channel at 250C 300 hPa 150 hPa 70 hPaparticle diameter in nmparticle number concentration in cm-3 (log)particle number density in cm-3 (linear)H2SO4/H2O 150nm particles with 0.5% by volume nonvolatile component will be detected as non-volatile.

Hector Cb-cloud flights vs. continental Australia flight Hector flight, 25.11.2005 Hector flight, 30.11.2005 A Hector flight, 30.11.2005 B ENVISAT flight, 05.12.2005SCOUT-O3 Australia 2005

Red : Darwin Dec. 2005Green: Aracatuba, Brazil Feb 2005Black: mid-lat blue: arcticCOPAS n > 10 nm

Import of ultrafine nuclei from high altitudes inside polar vortexParticle number mixing ratio in [ # / mg ] N2O mixing ratio in [ ppbv ] EXAMPLE: Arctic data 2003

Correlation of ultrafine particles with long lived tracer N2OCurtius et al., ACP, 2005

n10 non-volatile n10 total -- median n10 VeronaMarrakechMarrakechAre data ok ? Mid-latitude partsof AMMA transferconsistent with other profiles.

Only cloud free air parcels are seen here.The right set of curves, i.e. everything except the red points, shows the vertical profiles of alllocal flights as number concentration of particles larger than 6 nm (purple), larger than 10 nm(black), larger than 14 nm (green). The red curve shows the the number concentration ofParticles larger than 10 nm AFTER the sample air was heated to 250 Celsius. Thus, red is The number of NON-volatile residual particles. The idea is that if stratospheric aerosol particlesconsist of sulfuric acid water then this counter should show zeroes because all particles evaporate.The nonzero values near the troopuase show that a significant fraction of these nanometerparticles contain NON-H2SO4 material. This could be soot, mineral material, biomass burningresidues etc. The fact that the volatile fraction in this profile decreases with altitude shows thatthe aerosol becomes more sufuric acid like with altitude. From the profiles in ppt file sheet nr. 2you see what the profiles look like elsewhere. The BIG surprise in AMMA was that the number densities INCREASE with altitude over Ouaga. We have seen such increases in the Arctic as youcan see in sheet 4 encircled blue. BUT THERE the aerosol in high altitudes was 80 % NON-volatile, i.e. not much sufuric acid. We could very nicely show that this non volatile stuff was METEORITIC ablationmaterial which was sucked down from the mesosphere inside the polar vortex. The American ER-2 peopleHad previously interreted this increase as result of local homogeneous nucleation of H2SO4-H2O particles occurring aloft, and a number few theoreticians quickly proved that this was possible.They did not have such a non-volatile residue channel on board and did not know that the particescant be sulfuric acud ;-) In AMMA we saw such an increase but now it IS sulfuric acid. I have no clue.And THAT is exciting. Terry and I exchanged thoughts and we both are sceptic of volcanic eruption ascause for a number of reasons. Remove cloud data Make a plot from data only above cloudsBeim 1205 Flug gab es wolken am anfang, spaeter nicht. Fix hat den Plot des LIDAR dazu.The right set of curves, i.e. everything except the red points, shows the vertical profiles of alllocal flights as number concentration of particles larger than 6 nm (purple), larger than 10 nm(black), larger than 14 nm (green). The red curve shows the the number concentration ofParticles larger than 10 nm AFTER the sample air was heated to 250 Celsius. Thus, red is The number of NON-volatile residual particles. The idea is that if stratospheric aerosol particlesconsist of sulfuric acid water then this counter should show zeroes because all particles evaporate.The nonzero values near the troopuase show that a significant fraction of these nanometerparticles contain NON-H2SO4 material. This could be soot, mineral material, biomass burningresidues etc. The fact that the volatile fraction in this profile decreases with altitude shows thatthe aerosol becomes more sufuric acid like with altitude. From the profiles in ppt file sheet nr. 2you see what the profiles look like elsewhere. The BIG surprise in AMMA was that the number densities INCREASE with altitude over Ouaga. We have seen such increases in the Arctic as youcan see in sheet 4 encircled blue. BUT THERE the aerosol in high altitudes was 80 % NON-volatile, i.e. not much sufuric acid. We could very nicely show that this non volatile stuff was METEORITIC ablationmaterial which was sucked down from the mesosphere inside the polar vortex. The American ER-2 peopleHad previously interreted this increase as result of local homogeneous nucleation of H2SO4-H2O particles occurring aloft, and a number few theoreticians quickly proved that this was possible.They did not have such a non-volatile residue channel on board and did not know that the particescant be sulfuric acud ;-) In AMMA we saw such an increase but now it IS sulfuric acid. I have no clue.And THAT is exciting. Terry and I exchanged thoughts and we both are sceptic of volcanic eruption ascause for a number of reasons. Heater 1 m long, 12 mm id stainless steel with heating wires wrapped around.Careful laboratory calibrations were performed with the homogeneously nucleated H2SO4/H2O droplets after Middlebrook et al., 1995. 10 to 200 nm droplets were completely evaporated.Already small contamination with ammonia already produced non volatile residues that were detected.A 150 nm diameter particle of 99.5% BSD with 0.5% non volatile residue by volume gives a 26 nm particle, which is above the 10 nm detection cutoff.