susannah burrows 1,2 w ith contributions from : c. hoose 3 , u. pöschl 2 , m. g. lawrence 2,4
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The potential influence of marine biological activity on ice nuclei concentrations over the Southern Ocean . Susannah Burrows 1,2 w ith contributions from : C. Hoose 3 , U. Pöschl 2 , M. G. Lawrence 2,4. 1 – Pacific Northwest National Laboratory 2 – Max Planck Institute for Chemistry - PowerPoint PPT PresentationTRANSCRIPT
The potential influence of marine biological activity on ice nuclei concentrations over the Southern Ocean Susannah Burrows1,2
with contributions from: C. Hoose3, U. Pöschl2, M. G. Lawrence2,4
1 – Pacific Northwest National Laboratory2 – Max Planck Institute for Chemistry3 – Karlsruhe Institute of Technology4 – Institute for Advanced Sustainability Studies
Burrows, S. M., Hoose, C., Pöschl, U., and Lawrence, M. G.: Ice nuclei in marine air: biogenic particles or dust?, Atmos. Chem. Phys., 13, 245-267, doi:10.5194/acp-13-245-2013, 2013.
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Do biological / biogenic particles matter for ice nuclei (IN) populations?
Globally, the most-important and best-studied ice nuclei are dust (and soot), BUT:
Some biological / biogenic particles are more efficient IN than dust, particularly at warmer temperatures.Might induce freezing earlier, changing cloud development
Emerging picture: a possible role for biological / biogenic particles as IN under certain conditions:
Possible role of organic / biological material in enhancing IN activity of dust (Schnell and Vali, 1972; Pratt et al., 2009; Conen et al., 2011, others)
Pristine, biologically active continental environments in absence of dust (“green ocean”) (Prenni et al., 2009)
Warm, low-altitude mixed-phase clouds (Spracklen and Heald, 2013)
Marine environments? (Bigg, 1973; Schnell and Vali, 1976; Burrows et al., ACP, 2013, Knopf et al., 2012, others)
Measurements of IN concentrations in marine air
IN concentrations compared to Chl-a distribution
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In situ data: Bigg, 1973; Chlorophyll: MODIS climatology
Chl-a in µg m-3
B73 IN counts(different color scale)
Schnell and Vali (1976): Possible marine biological source of IN?
Burrows et al., ACP, 2013
Marine biological IN estimate
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Satellite data: proxies for marine biological activity
(POC, Chl-a)
Model parameterization:
Sea spray emissions
Intermediate result from simulations:
Particulate organic matter in sea spray
In situ data: IN concentration in marine plankton
bloom
Result: IN estimate in sea spray
Comparison with filter measurements and estimated
dust IN concentrations
Satellite: POC
Burrows et al., ACP, 2013
Comparison at -15°C (from B73)
Simulated POM concentrations
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Burrows et al. (2013)
Vignati et al. (2010)
Particulate organic matter (POM), μg m-3
Burrows et al., ACP, 2013
Comparison of proposed marine biological IN distribution with estimated dust IN distribution
Burrows et al., ACP, 2013
Upper bound:BIO-IN ∙ 10
{or dust IN ∕ 10 }
Marine biological IN: percent contribution to total simulated IN(total = dust + marine biological)
- compared at -15°C- in MBL- annual mean
8 Burrows et al., ACP, 2013
UPPER
BEST
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Moving sea spray chemistry forwardEmpirical parameterizations semi-mechanistic
Chl-a (correlated) surfactants (causal)
Extrapolate from blooms Account for different chemistry in gyres
Burrows et al., ACPD, 2014
Gantt et al., 2011Burrows et al., ACPD, 2014