Atmosphere Modelling GroupAtmosphere Modelling Group(with a strong focus on new particle formation)(with a strong focus on new particle formation)

University of HelsinkiUniversity of HelsinkiDepartment of PhysicsDepartment of Physics

Division of Atmospheric SciencesDivision of Atmospheric Sciences

MALTE SOSA

SCADIS

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ECHAM5-HAM

UHMA

PENCIL-COUD

MALTE SOSA

SCADIS

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ECHAM5-HAM

UHMA

Luxi Zhou

Ditte Mogensen

Risto Makkonen

HenriVuollekoski

Rosa Gierens

Johanna Lauros

K.V. Gopalkrishnan

Sampo Smolander

Anton Rusanen

Sanna-LiisaSihto

He QingyangChatriya Watcharapaskorn

PENCILCLOUD

Natalia Babkovskaia

Michael Boy(group leader)

The UHMA box model

coagulation

cloud dropletactivation

nucleation

condensation

Figure: Miikka Dal Maso

UHMAUHMA –– University of Helsinki MultiUniversity of Helsinki Multi--component Aerosol modelcomponent Aerosol model

MECCO – a method to estimateconcentrations ofcondensing organics

Vuollekoski, H., et al. Journal of Aerosol Science,41, 1080-1089, 2010.

What is growing the particles?

0 probability 1

Basic idea of Markov chain Monte Carlo methods

MECCO – a method toestimate concentrationsof condensing organics

UHMA

Testing MECCO--UHMA: create perfect data

UHMA

MECCO—UHMAis working

Field data needs to be smoothened

Preliminary testing of with field data

MALTE / SOSA / SCADISMALTE / SOSA / SCADIS

0 m

15 m

3000 m

METEOROLOGY

EMISSIONSCHEMISTRY

KPP

MCM

MEGAN

SCADIS

Aerosol

UHMA

MALTEMALTE –– Model to predict new AerosolModel to predict new Aerosolformation in the Lowerformation in the Lower TropospherTropospher

Particle concentration and fluxdynamics in the atmospheric boundarylayer as the indicator of formationmechanism

Lauros et al., Atmos. Chem. Phys. Discuss. 10, 20005-20033, 2010

Measurements: DMPS

J = K * [H2SO4]2 (K = 5*10-13 cm3 s-1)

J = Korg1 * * [H2SO4] * {[Mont.][O3]}

J = Korg2 * * [H2SO4] * {[Mont.] [OH]}

MALTE (HyytiMALTE (Hyytiäällää, March 2006), March 2006)

Vertical profile of particles withVertical profile of particles withDDpp > 10 nm> 10 nm

Observation

Organic inducednucleation

Kinetic nucleation (H2SO4)

SOSASOSA –– Model to calculate theModel to calculate theconcentrations of Organicconcentrations of Organic vapoursvapours andand

SulphuricSulphuric AcidAcid

Long term statistical comparison ofdifferent compounds

dark green: days > 75 % of the yearly mean value between 9 am and 3 pmgreen: days > 60 & < 75 % of the yearly mean value between 9 am and 3 pmlight green: days > 50 & < 60 % of the yearly mean value between 9 am and 3 pm

Long-term data analyses: 2003-2008

CSSOHRp 421

Modelling Atmospheric OHModelling Atmospheric OH--Reactivity in a Boreal ForestReactivity in a Boreal Forest

OH-reactivity = loss rate of OH

ROH = kOH+X [X]

Unit of OH-reactivity, ROH is [s-1]

kOH+X is the rate coefficient [cm3mol-1s-1]

[X] is the concentration of chemical compound X

Measured and Modeled OH-reactivity for August 2008

Modeled (blue) and 30 minute resolution, measured OH-reactivity

(black) from the 13th to the 27th of August, 2008 at 14 meters.

Modeled, Measured, and Missing OH-Reactivity

We seem to be able to predict 30-50% of the OH-reactivity!

13-27Aug 13-18Aug 19-27Aug

Modeled 2.5 s-1 2.3 s-1 2.6 s-1

Measured 6.5 s-1 8.6 s-1 5.1 s-1

Missing 4s-1 / 61% 6.2 s-1 / 73% 2.5 s-1 / 49%

peak near ground during nightnight deposition and suppression of boundary layer

Vertical profile of OH-reactivity [s-1]

Seasonally variation for 2008

Contributions from inorganic compounds, isoprene,methane, monoterpenes, and other VOCs.

Fighting fire with fire:

Could NOx emission be used toremove methane in a catastrophicclathrate release scenario?

Clathrate gun hypothesis

Clathratedestablize

Methanerelease

Temperature rise

[Kennet et al. 2000]

Methane clathrate is crystallinesolid which looks like ice, and inwhich a large amount of methaneis trapped within a crystalstructure of water

Clathrates naturally occur inpermafrost and seabed.

Total reservoirs on earth rangesfrom 103 to 104 GtC.

• Greater than 80% of East Siberian Arctic Shelf(ESAS) bottom waters and greater than 50% of surfacewaters are supersaturated with methane regarding to theatmosphere.

• The amount of methane currently coming out ofESAS is comparable to the amount coming out of theentire world's oceans.

•[Shakhova et al., Science 5 March 2010]

Large methane emission at ESAS

7.12.2010 29Osasto / Henkilön nimi / Esityksen nimi

RCP database: By 2100, total methane emission mayincrease 300%.

How is methane oxidized in atmosphere?

15.09.2010 30

CH4 CH3O2OHO2

CH3OOH

HO2

HCHO

NOCH3O

CO CO2hv

Deposition

O2

OH OH

OHOH

hv

CH4 + OH + O2 CH3O2 + H2OCH3 O2 + NO NO2 + CH3OCH3O + O2 HCHO + HO2

HO2 + NO NO2 + OH

CH4+2O2+2NO HCHO+H2O+2NO2

2(NO2 + hv NO + O)2(O + O2 +M O3 +M)

Net: CH4+4O2+2hv HCHO+2O3+H2O

Adding NOx decrease methane.....

R. P. Wayne, Chemistry of Atmosphere, 3rd edition,Oxford University Press, New York, 2000

Adding NOx has both cooling andwarming effects

RF inCH4

A set of models were used to assess the effects of adding NOx

Radiative forcing (RF) is thechange in net irradiance at thetropopause/top of atmosphere.

Baseline scenario:• Unperturbed methane and NOx concentration level.

10M/100M, 1N scenario:• 10/100 times present day methane concentration level ;• Unperturbed NOx concentration level.

10M, 2N scenario:• 10 times present day methane concentration level;• 2 times present day NOx concentration level.

CH4 and NOx concentration were fixedat different values

Increase the methane by 10 in the atmosphere would result in a radiativeforcing change of 2.514 W/m2.

Scenario O3 radiativeforcing (W/m2)

CDNC-albedo relatedradiative forcing (W/m2) CH4 lifetime (years)

1M,1N 0.0 0.0 12

10M, 1N 0.76 2.06 22.2

10M, 2N 1.10 1.70 19.8-0.36+0.34

After double NOx emission …

methane life time change is small

RF change due to ozone and aerosol indirect effect are comparable

EFFECT Magnitude (J/m2)

CH4 removal - 5.95×106

O3 increase + 10.72×106

CDNCincrease

- 11.35×106

Net - 6.58×106

Scenario with CH4 concentrationincreased 10-fold

Doubling of the NOX concentrationfor a year

We do get a net cooling effect!!! But....

How big are the heating and cooling effects?

Cooling effect insignificant

Net cooling effect: -6.58 J/m2 -0.21 W/m2*year

It is too small compared to the initial warming due to methane increase( 2.51 W/m2) as well as associated ozone warming (0.76 W/m2) and aerosolindirect effects (2.06W/m2).

0.21 W/m2 << (2.51 + 0.76 + 2.06) W/m2

Not an effctive way to save us!

Elevated methane level leads to strong CDNC reduction

CDNC reduction leads to positive aerosol indirect effects

CDNC reduction leads to positive aerosol indirect effects

PENCILPENCIL--CloudCloud

Pencil code as a powerful tool forcalculation of the turbulence coupledwith an aerosol dynamic module tostudy cloud processes

Scientific objectivesScientific objectives

• studying the influence of turbulence on theaerosol dynamics and vice versa inside acloud

• investigating the activation of particles atthe cloud boundary

• quantifying the effect of particle productionat the outflow of a cloud

2D aerosol + fluid dynamics model2D aerosol + fluid dynamics model

SCADISSCADIS((SCASCALARLAR DISDISTRIBUTION)TRIBUTION)

SCADIS is a high-resolution 3D model capable ofcomputing the physical processes with bothplant canopy and atmospheric boundary layersimultaneously

Horizontal and Vertical Resolution – As perspecific requirement

TKE OVER HYYTIÄLÄ FOR ONE DAY

ECHAM5ECHAM5--HamHaman aerosolan aerosol--climate modelling systemclimate modelling system

Past, present and futurenew particle formation

Past Present Future

Condensation nuclei(diam

eter > 3 nm)

Cloud condensation nuclei

(diameter > 70 nm

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#/cm3

Aerosol indirect effect (W/m2

(anthropogenic effect: present-day/future compared topre-industrial)

Aerosol indirect effect (W/m2)(anthropogenic effect: present-day/future compared to

pre-industrial)