Atmosphere Modelling Group

Transcription

1 Atmosphere Modelling Group (with a strong focus on new particle formation) University of Helsinki Department of Physics Division of Atmospheric Sciences cm meters kilometers PENCIL- COUD UHMA MALTE SCADIS SOSA ECHAM5- HAM seconds days months years

2 cm meters kilometers Natalia Babkovskaia PENCIL CLOUD Henri Vuollekoski UHMA Michael Boy (group leader) Rosa Gierens Johanna Lauros MALTE Chatriya Watcharapaskorn Sampo Smolander K.V. Gopalkrishnan SCADIS Anton Rusanen Ditte Mogensen Luxi Zhou SOSA Risto Makkonen ECHAM5- HAM Sanna-Liisa Sihto He Qingyang seconds days months years The UHMA box model nucleation coagulation cloud droplet activation condensation Figure: Miikka Dal Maso

3 UHMA University of Helsinki Multi- component Aerosol model MECCO a method to estimate concentrations of condensing organics Vuollekoski, H., et al. Journal of Aerosol Science,41, , What is growing the particles?

4 Basic idea of Markov chain Monte Carlo methods 0 probability 1 MECCO a method to estimate concentrations of condensing organics UHMA

5 Testing MECCO--UHMA: create perfect data UHMA MECCO UHMA is working

6 Field data needs to be smoothened Preliminary testing of with field data

7 MALTE / SOSA / SCADIS 3000 m METEOROLOGY Aerosol SCADIS EMISSIONS UHMA CHEMISTRY MEGAN 15 m KPP MCM 0 m MALTE Model to predict new Aerosol formation in the Lower Tropospher Particle concentration and flux dynamics in the atmospheric boundary layer as the indicator of formation mechanism Lauros et al., Atmos. Chem. Phys. Discuss. 10, , 2010

8 MALTE (Hyytiälä,, March 2006) Measurements: DMPS J = K * [H 2 SO 4 ] 2 (K = 5*10-13 cm 3 s -1 ) J = K org1 * * [H 2 SO 4 ] * {[Mont.][O 3 ]} J = K org2 * * [H 2 SO 4 ] * {[Mont.] [OH]} Vertical profile of particles with D p > 10 nm Observation Kinetic nucleation (H 2 SO 4 ) Organic induced nucleation

9 SOSA Model to calculate the concentrations of Organic vapours and Sulphuric Acid Long term statistical comparison of different compounds

10 dark green: green: light green: Long-term data analyses: days > 75 % of the yearly mean value between 9 am and 3 pm days > 60 & < 75 % of the yearly mean value between 9 am and 3 pm days > 50 & < 60 % of the yearly mean value between 9 am and 3 pm H 2SO4 Rp1 CS

11 Modelling Atmospheric OH- Reactivity in a Boreal Forest OH-reactivity = loss rate of OH R OH = k OH+X [X] Unit of OH-reactivity, R OH is [s -1 ] k OH+X is the rate coefficient [cm 3 mol -1 s -1 ] [X] is the concentration of chemical compound X Measured and Modeled OHreactivity for August 2008 Modeled (blue) and 30 minute resolution, measured OH-reactivity (black) from the 13 th to the 27 th of August, 2008 at 14 meters.

12 Modeled, Measured, and Missing OH- Reactivity 13-27Aug 13-18Aug 19-27Aug Modeled 2.5 s s s -1 Measured 6.5 s s s -1 Missing 4s -1 / 61% 6.2 s -1 / 73% 2.5 s -1 / 49% We seem to be able to predict 30-50% of the OH-reactivity! Vertical profile of OH-reactivity [s -1 ] peak near ground during night night deposition and suppression of boundary layer

13 Seasonally variation for 2008 Contributions from inorganic compounds, isoprene, methane, monoterpenes, and other VOCs. Fighting fire with fire: Could NO x emission be used to remove methane in a catastrophic clathrate release scenario?

14 Clathrate gun hypothesis Methane clathrate is crystalline solid which looks like ice, and in which a large amount of methane is trapped within a crystal structure of water Temperature rise Clathrates naturally occur in permafrost and seabed. Total reservoirs on earth ranges from 10 3 to 10 4 GtC. Clathrate destablize Methane release [Kennet et al. 2000] Large methane emission at ESAS Greater than 80% of East Siberian Arctic Shelf (ESAS) bottom waters and greater than 50% of surface waters are supersaturated with methane regarding to the atmosphere. The amount of methane currently coming out of ESAS is comparable to the amount coming out of the entire world's oceans. [Shakhova et al., Science 5 March 2010]

15 RCP database: By 2100, total methane emission may increase 300%. Osasto / Henkilön nimi / Esityksen nimi How is methane oxidized in atmosphere? CH 3 O NO O 2 OH CH 4 CH 3 O 2 O 2 OH hv HO 2 CH 3 OOH OH HCHO OH hv OH CO CO 2 Deposition

16 Adding NO x decrease methane... CH 4 + OH + O 2 CH 3 O 2 + H 2 O CH 3 O 2 + NO NO 2 + CH 3 O CH 3 O + O 2 HCHO + HO 2 HO 2 + NO NO 2 + OH CH 4 +2O 2 +2NO HCHO+H 2 O+2NO 2 2(NO 2 + hv NO + O) 2(O + O 2 +M O 3 +M) Net: CH 4 +4O 2 +2hv HCHO+2O 3 +H 2 O R. P. Wayne, Chemistry of Atmosphere, 3rd edition, Oxford University Press, New York, 2000 Adding NO x has both cooling and warming effects

17 A set of models were used to assess the effects of adding NO x RF in CH 4 Radiative forcing (RF) is the change in net irradiance at the tropopause/top of atmosphere. CH 4 and NO x concentration were fixed at different values Baseline scenario: Unperturbed methane and NO x concentration level. 10M/100M, 1N scenario: 10/100 times present day methane concentration level ; Unperturbed NO x concentration level. 10M, 2N scenario: 10 times present day methane concentration level; 2 times present day NO x concentration level.

18 After double NO x emission methane life time change is small RF change due to ozone and aerosol indirect effect are comparable Scenario O 3 radiative forcing (W/m 2 ) CDNC-albedo related radiative forcing (W/m 2 ) CH 4 lifetime (years) 1M,1N M, 1N M, 2N Increase the methane by 10 in the atmosphere would result in a radiative forcing change of W/m 2. How big are the heating and cooling effects? Scenario with CH 4 increased 10-fold concentration EFFECT Magnitude (J/m 2 ) Doubling of the NO X concentration for a year CH 4 removal O 3 increase CDNC increase Net We do get a net cooling effect!!! But...

19 Cooling effect insignificant Net cooling effect: J/m W/m 2 *year It is too small compared to the initial warming due to methane increase ( 2.51 W/m 2 ) as well as associated ozone warming (0.76 W/m 2 ) and aerosol indirect effects (2.06W/m 2 ) W/m 2 << ( ) W/m 2 Not an effctive way to save us! Elevated methane level leads to strong CDNC reduction

20 CDNC reduction leads to positive aerosol indirect effects CDNC reduction leads to positive aerosol indirect effects

21 PENCIL-Cloud Cloud Pencil code as a powerful tool for calculation of the turbulence coupled with an aerosol dynamic module to study cloud processes Scientific objectives studying the influence of turbulence on the aerosol dynamics and vice versa inside a cloud investigating the activation of particles at the cloud boundary quantifying the effect of particle production at the outflow of a cloud

22 2D aerosol + fluid dynamics model SCADIS (SCALAR DISTRIBUTION) SCADIS is a high-resolution 3D model capable of computing the physical processes with both plant canopy and atmospheric boundary layer simultaneously Horizontal and Vertical Resolution As per specific requirement

23 TKE OVER HYYTIÄLÄ FOR ONE DAY ECHAM5-Ham Ham an aerosol-climate modelling system Past, present and future new particle formation

24 Past Present Future #/cm 3 Condensation nuclei (diameter > 3 nm) Cloud condensation nuclei (diameter > 70 nm)

25 Aerosol indirect effect (W/m 2 (anthropogenic effect: present-day/future compared to pre-industrial)

26 Aerosol indirect effect (W/m 2 ) (anthropogenic effect: present-day/future compared to pre-industrial)