Observation of nucleation mode particles in the UT LS: From dedicated field studies to routine observations by instrumented in service aircraft

Transcription

1 Observation of nucleation mode particles in the UT LS: From dedicated field studies to routine observations by instrumented in service aircraft Andreas Petzold Andreas Minikin Markus Hermann IEK 8, FZ Jülich; DLR Oberpfaffenhofen DLR Oberpfaffenhofen IfT, Leipzig CLOUD-ITN Final Conference Königstein i. Taunus May 2012

2 Rationale Particle nucleation in the background UT LS at low temperatures is a frequently observed process The contribution of UT LS particle nucleation to the global aerosol budget is not well known Observations on a global scale are scarce Observation of particle nucleation by remote sensing (ground based/space borne) is not possible So far, dedicated field studies provide the bulk of observation data Instrumented in service aircraft will permit routine observation of particle nucleation on a global scale CLOUD-ITN Final Conference Königstein i. Taunus May

3 Outline Observation of particle nucleation in the UT LS from field studies using the DLR Falcon research aircraft UT LS aerosol climatology based on observations from the monthly deployment of CARIBIC container aboard Lufthansa D AIHE Expected gain of knowledge from IAGOS which will operate 20 long haul aircraft equipped with scientific instruments CLOUD-ITN Final Conference Königstein i. Taunus May

4 Background UT LS Size Distribution Atmospheric Lifetime dn/dlog 10 D p [particle/cm ³STP] nucleation Aitken accumulation coarse Particle Diameter D p [µm] Typical aerosol particle size distribution in the upper troposphere and lowermost stratosphere (UT LS) de Reus et al., JGR, 2001 Nucleation mode particles: Detection by CPC D p = 5 20 nm hours Jaenicke, J. Aerosol Sci.1980 CLOUD-ITN Final Conference Königstein i. Taunus May

5 Background Scatter plot of FT aerosol over central Europe in (30 flight h) accumulation mode particles SCA activation scavenging ACC MED particle nucleation condensation coagulation NUCL nucleation mode particles both figures: Schröder et al., JGR 2002 No option for banana plots in airborne observation statistical approach Schematic illustrating the map of likely states of tropospheric aerosols: NUCL: fresh, nucleated state, ACC: aged, accumulated state, SCA: cloudprocessed state. The state MED represents the typical background aerosol. CLOUD-ITN Final Conference Königstein i. Taunus May

6 Observation Platforms for the UT LS CARIBIC A LH D AIHE DLR Falcon 20 max. ceiling 12 km OPC 3 CPC instrumented container 1.5 t weight monthly deployment inlet CLOUD-ITN Final Conference Königstein i. Taunus May

7 Overview of DLR Falcon aerosol campaigns Jul/Aug 1988 LACE 11 flights 31.3 h SCAVEX 1a 8 flights 21.7 h spring Sep/Oct 2000 INCA NH 12 flights 34.1 h SCAVEX 2a 4 flights 13.5 h spring Jul/Aug 2000 UES 13 flights 40.1 h autumn Northern mid-latitudes (western/central Europe) Apr/May 2001 Apr 2002 Nov 2002 SCAVEX 2b 5 flights 16.6 h late autumn Jul/Aug 2004 ITOP 15 flights 43.6 h / cont. Mar/Apr 2000 INCA SH 12 flights 39.0 h autumn May/Jun 2004 ASTAR 14 flights 36.7 h arctic spring/ CLOUD-ITN Final Conference Königstein i. Taunus May

8 Overview of DLR Falcon aerosol campaigns Jul/Aug 1988 LACE 11 flights 31.3 h Sep/Oct 2000 INCA NH 12 flights 34.1 h autumn Jul/Aug 2000 UES 13 flights 40.1 h Apr/May 2001 SCAVEX 1a 8 flights 21.7 h spring Apr 2002 SCAVEX 2a Nov 2002 SCAVEX 2b 4 flights 5 flights 13.5 h 16.6 h Southern mid-latitudes & Arctic clean air spring late autumn Jul/Aug 2004 ITOP 15 flights 43.6 h / cont. Mar/Apr 2000 INCA SH 12 flights 39.0 h autumn May/Jun 2004 ASTAR 14 flights 36.7 h arctic spring/ CLOUD-ITN Final Conference Königstein i. Taunus May

9 Overview of DLR Falcon aerosol campaigns Jul/Aug 1988 LACE 11 flights 31.3 h Apr/May 2001 SCAVEX 1a 8 flights 21.7 h spring Sep/Oct 2000 INCA NH 12 flights 34.1 h autumn Apr 2002 SCAVEX 2a 4 flights 13.5 h spring Jul/Aug 2000 UES 13 flights 40.1 h Nov 2002 SCAVEX 2b 5 flights 16.6 h late autumn Jul/Aug 2004 ITOP 15 flights 43.6 h / cont. Mar/Apr 2000 May/Jun 2004 INCA SH ASTAR 12 flights 14 flights 39.0 h 36.7 h arctic autumn spring/ CLOUD-ITN Final Conference Königstein i. Taunus May

10 Overview of DLR Falcon aerosol campaigns Jul/Aug 1988 LACE 11 flights 31.3 h Apr/May 2001 SCAVEX 1a 8 flights 21.7 h spring Sep/Oct 2000 INCA NH 12 flights 34.1 h autumn Apr 2002 SCAVEX 2a 4 flights 13.5 h spring Jul/Aug 2000 UES 13 flights 40.1 h Nov 2002 SCAVEX 2b 5 flights 16.6 h late autumn Jul/Aug 2004 ITOP 15 flights 43.6 h / cont. Mar/Apr 2000 INCA SH 12 flights 39.0 h autumn May/Jun 2004 ASTAR 14 flights 36.7 h arctic spring/ CLOUD-ITN Final Conference Königstein i. Taunus May

11 Mid latitude aerosol vertical profiles pressure altitude (km) Aitken mode ~ nm number conc. (cm -3 stp) Nucleation mode ~5-14 nm number conc. (cm -3 stp) Accum. mode ~0.1-1 μm number conc. (cm -3 stp) Refractory part. non-volatile 250 C ~10 nm -1 μm number conc. (cm -3 stp) number concentration (cm -3 stp) Profiles: Median, 10-, 25-, 75-, 90-percentiles per 800 m height interval Logarithmic concentration scale (except NUCL), concentrations corrected to standard conditions (stp) In-cloud data excluded from data set CLOUD-ITN Final Conference Königstein i. Taunus May

12 Mid latitude aerosol vertical profiles () AITK NUCL ACC NON-V UES continent. pressure altitude (km) LACE continent. pressure altitude (km) number concentration (cm -3 stp) CLOUD-ITN Final Conference Königstein i. Taunus May

13 Mid latitude autumn aerosol vertical profiles: southern & northern hemisphere INCA NH autumn pressure altitude (km) AITK NUCL ACC NON-V INCA SH autumn pressure altitude (km) number concentration (cm -3 stp) CLOUD-ITN Final Conference Königstein i. Taunus May

14 Mid latitude aerosol vertical profiles (spring) AITK NUCL ACC NON-V SVX 2001a continent. spring pressure altitude (km) SVX 2002a continent. spring pressure altitude (km) number concentration (cm -3 stp) CLOUD-ITN Final Conference Königstein i. Taunus May

15 Frequency of occurrence in the UT Vertical lines: P10, P25, median, P75, P90 INCA NH autumn INCA SH autumn normalized frequency of occurence (%) Aitken accum. mode refractory NUCL + AITK ACC NON-V particle number concentration (cm -3 stp) CLOUD-ITN Final Conference Königstein i. Taunus May

16 Mid latitude UT Statistics box : from 25- to 75 percentiles, including median whiskers: 5- to 95-percentiles x : 1- to 99-percentile : arithmetic mean Properties of NUCL mode: UT background level large seasonal and spatial variability altitude = 8 10 km T = K p = hpa AITK Aitken Ultrafine Accum. mode SH - INCA (SH) fall NH - INCA (NH) fall SCAVEX spring 2001 SCAVEX spring 2002a SCAVEX 2002b fall UFA/EXPORT LACE98 MINOS NUCL ACC NON-V Non-volatile SH - INCA (SH) fall NH - INCA (NH) fall SCAVEX spring 2001 SCAVEX spring 2002a SCAVEX 2002b fall UFA/EXPORT LACE98 MINOS particle number concentration (cm -3 stp) CLOUD-ITN Final Conference Königstein i. Taunus May

17 UT LS aerosol distribution from CARIBIC tropic of Cancer Aitk + Acc tropic of Cancer Nucl profile data profile data Probability distribution on the route from Germany to India (Hermann et al, 2001) CLOUD-ITN Final Conference Königstein i. Taunus May

18 UT LS aerosol distribution from CARIBIC Annual map of measured and along trajectories extrapolated number concentrations of nucleation mode particles (between 4 and 12 nm diameter, particles cm 3 STP). Plotted is the 50 percentile in 15 x 15 degree geo cells (Heintzenberg et al., 2011). CLOUD-ITN Final Conference Königstein i. Taunus May

19 Ion measurements in the UT Measurements conducted during EUCAARI LONGREX in May 2008 using the Neutral Cluster Air Ion Spectrometer NAIS on board of the DLR Falcon. Mirme et al., ACP 2010 Number concentration for small positive (red) and negative (blue) ions as a function of altitude shown as median, 25% and 75% percentile. Part of the negative ions are not detected above 4 km due to a shift of the measurement range of the instrument CLOUD-ITN Final Conference Königstein i. Taunus May

20 Ion measurements in the UT No significant gradient in ion concentration NUCL observed in BL and UT but not in the mid FT Strong gradient of ACC Mirme et al., ACP 2010 NUCL ACC CPC data: Hamburger et al., in prep. red: stable atmospheric conditions blue: frequent frontal passages CLOUD-ITN Final Conference Königstein i. Taunus May

21 Extending the Database by Deploying Instrumented In Service Aircraft Installation aboard A340/A330 First flight of LH D-AIGT on 8 July 2011 CLOUD-ITN Final Conference Königstein i. Taunus May

22 IAGOS Aerosol Package designed by DLR/FZJ, enviscope, IfT, and Grimm Aerosol Technik Robust instrument for routine measurements from in service aircraft particle size distribution (> 250 nm) integral number of particles (> 5 nm) non volatile particle cores (> 5 nm) OPC (> 250 nm) and two CPC (> 5 nm): particles available for the formation of water and ice clouds; volcanic ash & mineral dust particles Thermodenuder: information on non volatile particles, e.g.: soot particles emitted by aircraft volcanic ash, mineral dust, BB products Information on gas to particle conversion and nucleation Special inlet for particle sampling: Rosemount inlet footprint Installation scheduled for 2013 CLOUD-ITN Final Conference Königstein i. Taunus May

23 Conclusions and Visions Particle Nucleation in the UT LS Frequent observation Large variability (temporal and spatial) Global models cannot fully reproduce observations GLOMAP Underlying processes and involved species are not fully understood Value of Routine Aircraft Observations Provide vertical profiles in the troposphere (e.g., O 3, CO, CO 2, CH 4, NO x, VOC, aerosol,..) Sample tropopause region at high spatial resolution Study long term trends in the UT and LS Visions for IAGOS instrumentation Extensions SO 2 Mass Spectrometer Aerosol Mass Spectrometer Aerosol Extinction CLOUD-ITN Final Conference Königstein i. Taunus May

24 Questions to CLOUD Observations suggest nucleation in the UT (and BL) but not in the FT Is there a preference for nucleation in the UT? OR Is frequent nucleation occurring across the entire tropospheric column, but further cluster growth is quenched in the FT, e.g. by accumulation mode aerosol serving as condensation sink? What are the key precursor gases? Ternary H 2 SO 4 /NH 3 /H 2 O nuc. Which role do ions play? Neutral dominates Does the nucleation rate depend on pressure? No pressure dep. What are the atmospheric processes triggering nucleation? CLOUD-ITN Final Conference Königstein i. Taunus May