mark g. lawrence max planck institute for chemistry, mainz, germany

Cloud Processing of Trace Gases and Aerosols:

What are we missing / what should we do in the

future?

Mark G. Lawrence

Max Planck Institute for Chemistry, Mainz, Germany

Chemistry-Climate Interactions WorkshopSanta Fe, 10 February 2003

“At the Cleaners with Mark”

Mark G. Lawrence

Max Planck Institute for Chemistry, Mainz, Germany

Chemistry-Climate Interactions WorkshopSanta Fe, 10 February 2003

“Doing the Laundry with Mark”

Mark G. Lawrence

Max Planck Institute for Chemistry, Mainz, Germany

Chemistry-Climate Interactions WorkshopSanta Fe, 10 February 2003

Objectives

• Importance of clouds for atmospheric chemistry?

•Major outstanding issues?

• (Chemistry climate?)

Organized Picture of thewide range and complexity of

issues

TopicsBreak down into 2x2 different topics:

• Cloud type

– Shallow: • Stratiform, fair weather cumulus, and non-Cb

cirrus– Deep:

• Vertical motions exceeding 2-3 km: Cumulus convection (cu-congestus to MCSs and Hurricanes) and deep cirrus anvils (e.g., squall line)

• Chemical phase– Gases– Aerosols

Outline

• Shallow Clouds– Introduction/Effects– Issues

• Deep Clouds– Introduction/Effects– Issues

• Assessment of Priorities

Illustrations/Exampleslargely with MATCH results

Current studies often not explicitly listed

 ISSUE

Importance (O3, AOT)

Difficulty (80-90% job)

G A G A

 SHALLOW CLOUDS

Parameterization: Microphysics        

Parameterization: Cloud Fraction        

Liquid water chemistry: Role of internal/external mix        

Liquid water chemistry: Uptake kinetics/amount      

…        

 DEEP CLOUDS

Parameterization: Thermo/Location/Intensity        

Vertical Transport: Entrainment        

Vertical Transport: Detrainment        

Vertical Transport: Downdrafts        

…        

Fill in withL/M/H

Fill in withL/M/H

Shallow Clouds

StratocumulusNorth

Atlantic

(From the Karlsruher Wolkenatlas)

StratocumulusGermany

(From the Karlsruher Wolkenatlas)

Fair Weather CumulusKarlsruhe

(From the Karlsruher Wolkenatlas)

Altocumulus LenticularisUtah

(From the Karlsruher Wolkenatlas)

Processing air

Cirrus

New Mexico

(From the Karlsruher Wolkenatlas)

New Mexico

Bolivia

Shallow Cloud Issues

• Parameterization

• Liquid Water Chemistry

• Ice Surface Chemistry

• Precipitation Scavenging

• Radiative Transfer / Photolysis Rates

Issues: Parameterization

• Microphysics– Currently mainly bulk schemes– Global models: mostly prognostic only for

total condensate, diagnostic for the rest – Cloud resolving models: typically bulk

schemes but prognostic for all condensate types

Large-ScaleProcesses

Cloud-ScaleProcesses

Control

Feedback

Issues: Parameterization

• Cloud cover– Diagnostic threshold (Slingo) schemes in

widest use– Often decoupled from microphysics,

though recent improvements…?– Always decoupled from advection (so far…)

Large-ScaleProcesses

Cloud-ScaleProcesses

Control

Feedback

Issues: Parameterization• Cloud cover – resolving cloud systems

<2% of rain cells (and <5% of clouds) exceed T42 (~105 km2), however…

From Wilcox, Thesis, 2002

Issues: Parameterization• Cloud cover – resolving cloud systems

…rain cells > T42 produce 70% of the total precipitationHouze/Mapes (Pacific):1% of clouds > 105 km2, but are 25% of total cloud cover

No coupling of clouds in one grid cell

with th

ose in the neighborin

g cells!

From Wilcox, Thesis, 2002

Issues: Liquid Water Chemistry

• Aerosols– Crucial for processing of all aerosol types

– Importance of internal/external mixtures (type, age, and size) and coating for determining hygroscopicity, nucleation, and optics?

– Collection/uptake of existing aerosols by droplets?

– Form of aerosols after evaporation (and evaporation process)?

– Coupling with gas phase chem (e.g., interaction of S and N cycles, halogen release, etc.)?

Issues: Liquid Water Chemistry

• Gases– Effects on O3 and HOx still under debate:

locally strong, globally moderate to weak

– Halogen and NMVOC reactions?

– Coupling with aerosol chem (e.g., SO2 oxidation, N2O5 hydrolysis)?

Issues: Ice Surface Chemistry

• Aerosols– Uptake/ageing of aerosols on ice?

Dependence on type/mixture?

• Gases– Halogen activation?

– HO2 + O3 (and other O3- or HOx-related reactions?)

– NMVOC reactions?

Issues: Precipitation Scavenging

• Aerosols– Major loss for all aerosol types

(some after processing)– Importance of aerosol type/mixture for

nucleation and collection?

Issues: Precipitation Scavenging

• Gases– Major loss process for reactive nitrogen, odd hydrogen, VOCs,

and halogens– Water solubilities generally known (except VOCs)– Ice uptake/retention very poorly characterized– Kinetic uptake limitations difficult to model (generally

neglected)

Issues: Precipitation Scavenging

• Example: Effect on soluble gases with a surface source

Based on Crutzen and Lawrence, J. Atmos. Chem., 2000

Hx in M/atm:

Hx = 0Hx = 103

Hx = 104

Hx = 105

Hx = 106

Issues: Precipitation Scavenging

• Example: Effect on soluble gases with a surface source

Based on Crutzen and Lawrence, J. Atmos. Chem., 2000

Hx in M/atm:

Hx = 103

Hx = 104

Hx = 105

Hx = 106

Hx = 1010

Issues: Precipitation Scavenging

• General– Precipitating fraction and stratiform/convective split– Preservation of information on scavenged areas– Slower sedimentation of smaller hydrometeors

Issues: Precipitation Scavenging

• Precipitating fraction

From Wilcox, Thesis, 2002

Issues: Precipitation Scavenging

• Preservation of Information / Artificial Mixing

t0 t0 + scav t0 + scav + adv t0 + t

Shorter t => worse artificial mixing!

Issues: Precipitation Scavenging

• Slower sedimentation of smaller hydrometeors

From Lawrence and Crutzen, Tellus, 2000

Issues: Radiative Transfer

• Effects on Photolysis Rates (and heating rates…)

– Effect on OH and CH4 small to moderate (~10%)

– Already simulated rather accurately (Landgraf/Crutzen)

From Landgraf, Thesis, 1998

MATCH-MPICsimulation

Deep Clouds

Organized

Convection

Cumulus CongestusMiam

i

Karlsruhe(From the Karlsruher

Wolkenatlas)

Near Karlsruhe

Cumulonimbus with and without Anvil

(From the NOAA Gallery)

Supercell Cumulonimbus

(From Houze‘s Cloud Atlas)

Squall Line

Hurricane Floyd

Mass-Balance

Subsidence

Downdrafts

Deep Convection: Characteristics

Updrafts

Eigenschaften der Eigenschaften der KonvektionKonvektion

Precipitation and Precipitation and slower slower

SedimentationSedimentation

PrecipitatiPrecipitationon

Anvils Anvils (Ice)(Ice)

LightniLightningng

Deep Convection: Characteristics

Deep Cloud Issues

• Parameterization

• Vertical (dry) Transport

• Precipitation Scavenging

• Lightning NOx

• Several components to deal with:– Thermodynamics (T/t, Q/t, Q1, Q2)– Microphysics– Cloud Cover / Precipitation Swath– Mass Fluxes / Tracer Transport– Proper treatment in offline models

(pre-stabilized thermodynamic profiles)

Issues: Parameterization

Large-ScaleProcesses

Moist-ConvectiveProcesses

Control

Feedback

Issues: Parameterization

• Wide range of philosophies and closures

• Focus of testing on thermodynamics; Tracers (e.g., CO, CH3I) may provide powerful tests

• Mesoscale organization rarely considered– CEMs: delays in response to large-scale forcing– First attempts by Donner, others? – Relevance for tracer transport unknown, likely substantial

Large-ScaleProcesses

Moist-ConvectiveProcesses

Control

Feedback

Issues: Vertical (dry) Transport

• Updraft Effects – Transport to the UT:– O3 and O3-precursors– HOx reservoirs– Stratosphere-relevant gases (halogenated gases, COS)– Aerosols – esp. Dust, BC, OC, and Sulfate precursors– Clean air masses

Example:

Southern Asian CO

from MATCH-MPIC

Issues: Vertical Transport

?Entrainment intothe Ensemble

?

Tropopause

Mu

Z

Issues: Vertical Transport

?Entrainment intothe Ensemble

Detrainment fromthe Ensemble

?

Mu

Z

?

Tropopause

Issues: Vertical Transport

?Entrainment intothe Ensemble

Detrainment fromthe Ensemble

?

Mu

Z

??

Tropopause

??

Issues: Vertical Transport

• Updraft Effects – Importance of Detrainment Region:

MATCH-MPIC O3:

Detrain-top----------

Base run

Issues: Vertical Transport

?

Downdrafts

• Strength

• Feeder Regions

( Organization)

• Entrainment

• Detrainment

?

Significance of downdrafts?

Issues: Vertical Transport

Mass-Balance Subsidence

• In same model column?

• As part of circ. cells (Hadley, Walker)?

Issues: Vertical Transport• Role of Subsidence, Balance with Updrafts:

From Lelieveld and Crutzen, Science, 1994

Issues: Vertical Transport• Role of Subsidence, Balance with Updrafts:

MATCH-MPIC O3:

Base run----------

No Conv Transp

Issues: Vertical Transport• Role of Subsidence, Balance with Updrafts:

Trop. Total Ozone (Tg)Run MATCH-MPIC1 MOGUNTIA2

No Convection 293 315

With Convection 328 (+12%) 253 (-20%)(Base Run)

1 This Study (when conv. precip is also turned off => 297 Tg)2 Lelieveld & Crutzen, Science, 1994 (only conv. transport turned off)

Cause for difference??

Issues: Vertical Transport

Degree/Amount ofPenetration into the TTL

(tropical tropopause layer)?

Issues: Vertical Transport

Penetration into the Stratosphere?• Tropical?• Extratropical?• Induced STF?

Issues: Precipitation Scavenging

• Scavenging Effects:– Major loss process for all aerosol types (some after processing)

– Major loss process for reactive nitrogen, odd hydrogen, and VOCs

– Important for stratosphere-relevant gases (soluble halogenates)

Issues: Precipitation Scavenging

Amount/Distribution?

Based on a MATCH simulation with NCEP reanalysis data

Issues: Precipitation Scavenging

Precipitation Swath?

Core/Anvil, Intensity?

Origin of scavenged air?

} }}

Issues: Precipitation Scavenging

Kinetic Uptake Limitations

Issues: Precipitation Scavenging

• Uptake in/on ice

• Retention in supercooled droplets upon freezing

Issues: Precipitation Scavenging• Importance of retention in ice and kinetic uptake limits

Based on Crutzen and Lawrence, J. Atmos. Chem., 2000

Hx in M/atm:

Hx = 103

Hx = 104

Hx = 105

Hx = 106

Hx = 1010

Ice

Issues: Precipitation Scavenging• Importance of retention in ice and kinetic uptake limits

Based on Crutzen and Lawrence, J. Atmos. Chem., 2000

Hx in M/atm:

Hx = 103

Hx = 104

Hx = 105

Hx = 106

Hx = 1010

Ice

Issues: Precipitation Scavenging• Importance of retention in ice

30 min 45 min 60 min

WRF - (Preliminary!)

Insoluble

Soluble

Degassed

Issues: Precipitation Scavenging• Importance of retention in ice WRF -

(Preliminary!)

Issues: Precipitation Scavenging

Artificial Mixing(preservation of info)

Issues: Lightning NOx

Issues: Lightning NOx

Influence on NOx and O3

(MATCHResults)

O3 Ratio:with/withoutLightning

NOx Ratio:with/withoutLightning

Issues: Lightning NOx

• Global Amount

• Regional Distribution

• Vertical Distribution

• Charge Separation

• NOx Production Mechanism

Issues: Lightning NOx

Global Amou

nt

REFERENCE(type of estimate)

P(NO)(1016 molecules

J-1)

P(NO)(1025

Molecules flash-1)

F(102 flashes s-1)

G(NO)(Tg (N) year-1)

Lawrence et al. (1995)(review)

- 2.3 (1-7) 1 (0.7-1.5) 2 (1-8)

Kumar et al. (1995)(observations)

  0.5 1 2

Ridley et al. (1996)(observations)

  - 1 2-5

Levy et al. (1996)(theoretical)

- - - 3-5

Price et al. (1997)(observations)

10 - 0.7-1 12.2 (5-20)

Price et al. (1997)(theoretical)

10 - - 13.2 (5-25)

Wang et al (1998)(laboratory)

- 3.1 0.3-1 2.5-8.3

Nesbitt et al. (2000)(observations)

- 0.87-6.2 0.57 0.9

Issues: Lightning NOx• Regional Distribution

MATCH-MPICOTD

Extratropics - underestimated

Tropics - overestimated

Flashes/km2/Month

Overarching Issues

Major Overarching Issues

• Do we need to unify/combine stratiform and convective cloud parameterizations?

• Do we need to keep separate cloudy and cloud-free variables for each grid cell?

• How do we include the effects of mesoscale organization?

• How do we properly compare CEM studies with 1D versions from global models?

• Which geographical regions need the most attention?

Priorities

 ISSUE

Importance (O3, AOT)

Difficulty (80-90% job)

G A G A

 SHALLOW CLOUDS

Parameterization: Microphysics L/M H H H

Parameterization: Cloud Fraction M H L/M L/M

Liquid water chemistry: Role of internal/external mix

- H - H

Liquid water chemistry: Uptake kinetics/amount L/M L/M L L/M

Liquid water chemistry: Aerosol processing details - H - H

Liquid water chemistry: Effects on O3/HOx L/M - M -

Liquid water chemistry: Halogens / NMVOCs L/M - H -

Liquid water chemistry: Gas-aerosol coupling L/M H H H

Ice surface chemistry L/M ? H H

Precipitation scavenging: Amount/Fraction M H M/H M/H

Precipitation scavenging: Ice uptake/retention M M(?) H H

Precipitation scavenging: (Liquid) kinetic limitations M M M M

Precipitation scavenging: Artificial mixing M H M/H M/H

Photolysis rates L L L L

 DEEP CLOUDS

 ISSUE

Importance (O3, AOT)

Difficulty (80-90% job)

G A G A

 DEEP CLOUDS

Parameterization: Thermo/Location/Intensity H H M/H M/H

Vertical Transport: Entrainment M/H M M/H M/H

Vertical Transport: Detrainment M/H M M/H M/H

Vertical Transport: Downdrafts L L M M

Vertical Transport: Subsidence – connection to LS circ

M/H M H H

Vertical Transport: Penetration into the TTL M/H L/M M/H M/H

Vertical Transport: Penetration into the Strat / STE L/M L M/H M/H

Precipitation scavenging: Amount/Distribution /Swath M H M/H M/H

Precipitation scavenging: Ice uptake/retention M M(?) H H

Precipitation scavenging: (Liquid) kinetic limitations M M/H H H

Precipitation scavenging: Artificial mixing M H H H

Lightning NOx: Amount M - M -

Lightning NOx: Distribution M - L/M -

Extras

(type of estimate)

REFERENCEP(NO)

(1016 molecules J-1)P(NO)

(1025 Molecules flash-1)

F(102 flashes s-1)

G(NO)(Tg (N) year-1)

Tuck (1976) (theoretical)

- 1.1 5 4

Chameides et al.(1976) (theoretical)

3-17 6-14 4 18-41

Noxon (1976)(field observations)

- 10 5 37

Chameides (1979) (theoretical)

8-17 16-34 4 47-100

Dawson (1980) (theoretical)

- 0.8 5 3

Hill et al. (1980) (theoretical)

- 1.2 1 0.9

Levine et al.(1981)(laboratory )

5 ± 2 0.5 5 1.8 ± 0.7

Kowalczyk (1981) - - - 5.7

Peyrous and Lapeyre (1982)(laboratory)

1.6 3.2 4 9.4

Drapcho et al. (1983)(field observations)

- 40 1 30

Franzbau et al. (1989)(field observations)

- 300 1 220

Sisterson (1990)(theoretical)

- 8.2 2 12

Liaw et al. (1990) - - - 81

Issues: Precipitation Scavenging

• Precipitation Swath

• Core/Anvil fraction

• Uptake in/on ice

• Retention in supercooled water upon freezing

• Kinetic uptake limitations

• Preservation of information (artificial mixing)

(From the NOAA Gallery)

Tornadoes

Hail

Lightning

Issues: Parameterization

• Distribution/Intensity of deep convection

Based on a MATCH simulation with NCEP reanalysis data

From Lawrence and Crutzen, Tellus, 2000

Issues: Lightning NOxInfluence on NOx and O3

O3 Ratio:with/withoutLightning

NOx Ratio:with/withoutLightning

500 hPa

MATCH-MPIC

Einfluss der vertikale Verteilung von Blitzen

Verhältnisder Stickoxide:Amboss/gesamt Wolke

Verhältnisdes Ozons:Amboss/gesamt Wolke

Dru

ck (

hP

a)D

ruck

(h

Pa)

Vertical distribution: Implications for tropospheric chemistry.

Ratios of zonal averages for NOx, and O3 for July 1997.

NOx O3

Pick/base Pick/base