Thursday, March 07, 2013

Aerosols in the Woods

Direct Observations of Atmospheric Aerosol Nucleation

  • Markku Kulmala,
  • Jenni Kontkanen,
  • Heikki Junninen,
  • Katrianne Lehtipalo,
  • Hanna E. Manninen,
  • Tuomo Nieminen,
  • Tuukka Petäjä,
  • Mikko Sipilä,
  • Siegfried Schobesberger,
  • Pekka Rantala,
  • Alessandro Franchin,
  • Tuija Jokinen,
  • Emma Järvinen,
  • Mikko Äijälä,
  • Juha Kangasluoma,
  • Jani Hakala,
  • Pasi P. Aalto,
  • Pauli Paasonen,
  • Jyri Mikkilä,
  • Joonas Vanhanen,
  • Juho Aalto,
  • Hannele Hakola,
  • Ulla Makkonen,
  • Taina Ruuskanen,
  • Roy L. Mauldin III,
  • Jonathan Duplissy,
  • Hanna Vehkamäki,
  • Jaana Bäck,
  • Aki Kortelainen,
  • Ilona Riipinen,
  • Theo Kurtén,
  • Murray V. Johnston,
  • James N. Smith,
  • Mikael Ehn,
  • Thomas F. Mentel,
  • Kari E. J. Lehtinen,
  • Ari Laaksonen,
  • Veli-Matti Kerminen,
  • Douglas R. Worsnop
In case anybunny was wondering how many Finns can dance on the entry port of a mass spectrometer.  But more seriously, this is an important paper.  The authors used a panalopy of  mass spectrometers and other instruments to follow the growth of aerosols at a research station in the woods of southern Finland.  The results are astounding.

First, they found that the number of small clusters (< 1.2 nm) was essentially constant over time with loss from evaporation and reaction balancing growth by accretion and reaction. 

Second, growth up to about 1.9 nm occurs through reactions with sulfuric acid.  Significant growth only occurred on days when sulfuric acid concentrations increases and was synchronous with it.  On the other hand, theory shows that sulfuric acid/water aerosols are not stable by themselves requiring amines to stabilize and measurements with an atmospheric pressure inlet time of flight mass spectrometer showed that the intermediate aerosols did incorporate amines.  This means that sulfuric acid from SOx oxidation can be rate limiting

Third, above this limit, organic addition dominates and growth requires (photo)chemical activation by oxidation

Fourth, neutral clusters dominate as shown in the figure above and for all aerosol sizes.  The purple line shows the relative numbers of neutral (purple), ionic( blue) and ions formed by recombination (red) aerosols.  This is surprising and casts a different light on claims that cosmic ray ionization controls aerosol production.








11 comments:

Oale said...

Part of the reason is that the doctorate in Finland requires at least a couple of publications before the thesis paper...

Magnus Westerstrand said...

Oale... got similar problems in Sweden... stupid system to get money to the specific universities...

EliRabett said...

This calls for disemvowelling

Russell Seitz said...

theory shows that sulfuric acid/water aerosols are not stable by themselves requiring amines to stabilize


Are you suggesting a synergy between amine-based direct atmospheric CO2 capture schemes and sulfuric acid aerosol geoengineering?

EliRabett said...

Theory shows it and measurement confirms it. You need amines or similar organic to stabilize the aerosols. As you point out this has implications for geoengineering, but if you are going to dump a bunch of sulfates a bit of ammonia or methylamine is no biggie.

However, bunnies can torture the geoengineers with this a bit

Russell Seitz said...

Bunnies should wrinkle their noses at the carbon captivators first- The amines in question come in bottles with the charming warning label :

FLAMMABLE STENCH


With a per capita inventory of hundreds of kilos of Essence of Mackeral Guts, amine CO2 capture amounts to an olefactory doomsday machine.

Anonymous said...

"Part of the reason is that the doctorate in Finland requires at least a couple of publications before the thesis paper..."

Not at least in my university, and that requirement is news to me in general. Where did you get that from? (The Helsinki U. requirements are below and none there either http://www.helsinki.fi/tutkinnonuudistus/jatkotutkinto/tohtori.html#3 )

Anonymous said...

This previous article could perhaps be more understandable by the so called ordinary readership:


Toward Direct Measurement of Atmospheric Nucleation
Markku Kulmala et al
Science 5 October 2007: 89-92.
Published online 30 August 2007 [DOI:10.1126/science.1144124]

-F

Oale said...

Dear anonymous, it seems my info was dated (1990s), lovely.

Anonymous said...

Oale, I don't think there ever has been such a requirement here, as I've personally seen quite a few people I know struggle through with their doctoral degrees over the past few decades. I though the Ministry had come up with something startlingly new without telling any one of us...


-F


Magnus Westerstrand said...

No formal requirements ofc... Informal at lots of research groups still