1. Aerosol Microphysical Properties (AMP) Measurements for ATom and cloud! 1) Where do particles come from in the remote troposphere? New particle formation Emission sources (sea- salt, dust, anthro) linkage to convection 2) Where do cloud- active particles (CCN & IN) come from? Growth from new particles Emission sources cloud number/phase 3) Support other science Cloud detection Airmass origin/age particle surface area

2. Why do we care about the origin of particles in the remote troposphere?

3. Sensitivity of Cloud Albedo to CCN concentration Moore et al., 2013 using GMI with cloud droplet adjoint Cloud Fraction (MODIS) Cloud Fraction x Sensitivity of Cloud Albedo to CCN number Why do we care about the origin of particles in the remote troposphere?

4. AMP Science Interests Mechanism(s) of new particle formation in the remote troposphere Influence of new particle formation on abundance and distribution of cloud-active particles (CCN) Hemispheric differences in aerosol abundance, properties and effects on clouds Challenge models' simulations of aerosol properties, distribution, abundance and the processes that control these (emissions, processing, removal) in a poorly sampled region of the atmosphere

5. Kazil et al. 2010 simulated neutral, charged, and organic cluster NPF in ECHAM5-HAM model Spatial distribution provides information on NPF mechanism Newly formed particles CCN-sized particles Fraction from ion mechanisms

6. Spatial distribution provides information on NPF mechanism Yu et al. 2010 Similar results from Pierce, Pierce and Adams, Spracklen, Carslaw, Dunne, Erlykin These models are essentially unconstrained (Tony Clarke produced a latitude/height composite, but it is not representative sampling) Challenge models' simulations of aerosol properties, distribution, abundance and the processes that control these (emissions, processing, removal) in a poorly sampled region of the atmosphere

7. AMP Measurements for ATom Nucleation Mode Aerosol Size Spectrometer (NMASS) Five CPCs operated in parallel—condensation technique 4 nm to 60 nm in 5 size classes; 1 s resolution LARGE inlet Ultra-High Sensitivity Aerosol Spectrometer (UHSAS) Size and count particles by laser light scattering 60 nm to 1000 nm in 100 size classes; 1 s resolution LARGE inlet Cloud and Aerosol Spectrometer with Depolarization (CAS-depol) Size and count particles by laser light scattering detect frozen cloud particles 0.5 to 50 µm wing-mounted canister operated by Bernadett Weinzierl, DLR/LMU-Munich

8. Example of AMP data from spring 2015 Difference method + optical particle counter precision? accuracy? how well can we detect low concentrations of newly formed particles? how well can we measure the smaller CCN sizes?

9. Instrument Status Instruments are functional new calibrations new inversion algorithm evaluate precision; difference method preparing spares CAS-depol cloud probe being purchased and flown by Bernadett Weinzierl at DLR Possible spare from LARGE group

10. Logistics Will carry all supplies calibrants, spare components no gases replace NMASS fluid every flight—perfluorotributylamine (3M Fluorinert FC-43) install spare instruments in rack

11. Delivered Datasets Level 1 (24 hrs): Submicron particle number, surface, and volume at 1 Hz Coarse/cloud particle number at 0.1 Hz Level 2 (7 months): Three aerosol modes (nucleation, Aitken, and accumulation) Number concentration, mean diameter, standard deviation Aerosol surface area (dry and ambient RH (w/AMS data)) Calculated extinction (dry and ambient RH (w/AMS data)) Coarse particle number, mean diameter, standard deviation Cloud occurrence (flag) Cloud phase Cloud number, effective radius, liquid water content

13. Aerosol Microphysical Properties (AMP) Measurements for ATom The AMPS team Chuck Brock (NOAA) Dr. Christina Williamson (NOAA and CU) Dr. Agnieszka Kupc (Schrödinger Fellow— NOAA, CU, and U. Vienna) Prof. Bernadett Weinzierl (DLR and LMU-Munich)

16. Size Distribution Measurements: how well can we do? CPC difference method + optical particle counter precision? accuracy? how well can we detect low concentrations of newly formed particles? how well can we measure the smaller CCN sizes?

17. Size Distribution Measurements how well can we do? CPC difference method + optical particle counter precision? accuracy? how well can we detect low concentrations of newly formed particles? how well can we measure the smaller CCN sizes? operate two NMASS instruments (one nominally a spare)?