Natalia Andronova (1953–2014)

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108617/1/eost2014EO390006.pd

An evaluation of the potential radiative forcing and climatic impact of marine organic aerosols as heterogeneous ice nuclei

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99667/1/grl50794.pd

Indirect Effects of Secondary Organic Aerosol on Cirrus Clouds

Secondary organic aerosols (SOA) have been identified as a potential source of depositional ice nucleating particles and thus may have a radiative effect on cirrus clouds. This study develops a global model to examine the radiative effect of SOA on cirrus clouds using different treatments for the size distribution of SOA. The SOA from new particle formation by organics and their subsequent growth has a radiative effect of 0.35 ± 0.06 W m−2, while the radiative effect of SOA calculated by assuming a fixed size distribution is 0.31 ± 0.08 W m−2. This positive radiative effect on cirrus clouds opposes the negative effect of anthropogenic soot on cirrus clouds. In addition, the inclusion of SOA as an ice nucleating particle changes the background ice crystal number concentration, which impacts the calculation of radiative forcing from other aerosols. The radiative forcing of aircraft soot is estimated to be −0.11 ± 0.03 W m−2 when including SOA formed from new particle formation by organics and growth. This is less negative than simulations that do not include ice nucleation from SOA. The change in SOA formed from organic nucleation from the preindustrial period to the present day causes a positive forcing of 0.02 ± 0.04 W m−2. It is important to use a size distribution based on the explicit formation mechanism for SOA to calculate their radiative effects. The simulation using an assumed fixed size distribution incorrectly results in a negative forcing of SOA between the present day and preindustrial atmospheres because it does not correctly calculate the change of SOA in the accumulation mode.Key PointsThe radiative effect of SOA is estimated to be 0.31 to 0.35 W m−2 using assumed and predicted size distributionsThe radiative forcing of aircraft soot is decreased from −0.20 to −0.11 W m−2 when SOA acting as an INP is added to the background atmosphereThe historical radiative forcing of SOA on cirrus clouds is estimated to be 0.02 ± 0.04 W m−2 with the predicted SOA size distributionPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154925/1/jgrd56147_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154925/2/jgrd56147.pd

Global Modeling of Secondary Organic Aerosol With Organic Nucleation

Organic nucleation has been identified as an important way to form secondary organic aerosol (SOA) and change the number concentration of aerosol and thus its climate effect. A global atmospheric chemistry model is developed to include a comprehensive organic nucleation scheme that includes heteromolecular nucleation of sulfuric acid and organics, neutral pure organic nucleation, and ion‐induced pure organic nucleation. Our model simulation shows reasonable agreement with the seasonal as well as spatial pattern of organic carbon concentration in America, while it fails to predict the seasonal pattern of organic carbon in Europe due to the lack of sharp increases in primary organic aerosol emissions in the winter. Including organic nucleation decreases the bias of the annual average particle number concentration at 54% of the available observation sites and increases the temporal correlation coefficients at 58% of the sites. Ion‐induced pure organic nucleation contributes the most to the total organic nucleation rate, which peaks around 400 hPa in the tropics. Heteromolecular nucleation of sulfuric acid and organics dominates the total organic nucleation rate in the summer and mostly occurs in the lower troposphere. The number concentration of particles formed from organic nucleation (newSOA) in the nucleation and Aitken modes is highest in the tropics, while accumulation mode newSOA is highest in the Northern Hemisphere due to growth as a result of the condensation of sulfate. Three sensitivity experiments suggest that more studies are needed to investigate the formation mechanism of newSOA, so that a more accurate simulation of the spatial and size distribution of newSOA can be developed.Key PointsA new version of the CESM/IMPACT atmospheric model is developed to include three organic nucleation schemesIncluding organic nucleation improves the model’s ability to simulate aerosol number concentrationIon‐induced pure organic nucleation is the largest contributor to the global new organic particle formationPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151313/1/jgrd55629_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151313/2/jgrd55629.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151313/3/jgrd55629-sup-0001-Figure_SI-S01.pd

Climate change - The cloud conundrum

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62779/1/432962a.pd

Inverse modeling of biomass burning emissions using Total Ozone Mapping Spectrometer aerosol index for 1997

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95187/1/jgrd12041.pd

A dynamic aerosol module for global chemical transport models: Model description

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94951/1/jgrd11164.pd

Simulation of the global contrail radiative forcing: A sensitivity analysis

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96352/1/grl29839.pd

Precipitation changes in a GCM resulting from the indirect effects of anthropogenic aerosols

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94948/1/grl13844.pd

Effects of cloud overlap in photochemical models

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95365/1/jgrd10939.pd