Introduction: Mount Pinatubo as a test of climate feedback mechanisms

2003 ◽  
pp. 1-8 ◽  
Author(s):  
Alan Robock
Keyword(s):  
Climate Feedback ◽  
Feedback Mechanisms ◽  
Mount Pinatubo

scholarly journals Discussions of Arctic climate feedback mechanisms

Eos ◽  
2004 ◽  
Vol 85 (15) ◽  
pp. 147
Author(s):  
Sebastian Gerland ◽  
Birgit Njåstad ◽  
Elisabeth Isaksson ◽  
Vladimir Pavlov ◽  
Jens H. Christensen ◽  
...  
Keyword(s):  
Arctic Climate ◽  
Climate Feedback ◽  
Feedback Mechanisms

scholarly journals Ice nucleating particles in the Canadian High Arctic during the fall with implications for climate feedback mechanisms in the region

2022 ◽  
Author(s):  
Jingwei Yun ◽  
Erin Evoy ◽  
Soleil Worthy ◽  
Melody Fraser ◽  
Daniel Veber ◽  
...  
Keyword(s):  
High Arctic ◽  
Atmospheric Particles ◽  
Mixed Phase ◽  
Climate Feedback ◽  
Small Subset ◽  
Canadian High Arctic ◽  
Feedback Mechanisms ◽  
Mixed Phase Clouds

Ice nucleating particles (INPs) are a small subset of atmospheric particles that can initiate the formation of ice in mixed-phase clouds. Here we report concentrations of INPs during October and...

scholarly journals BVOC–aerosol–climate feedbacks investigated using NorESM

2019 ◽  
Vol 19 (7) ◽  
pp. 4763-4782 ◽  
Author(s):  
Moa K. Sporre ◽  
Sara M. Blichner ◽  
Inger H. H. Karset ◽  
Risto Makkonen ◽  
Terje K. Berntsen
Keyword(s):  
Gross Primary Production ◽  
Diffuse Radiation ◽  
Global Scale ◽  
Climate Feedback ◽  
Anthropogenic Aerosol ◽  
Feedback Mechanisms ◽  
Aerosol Forcing ◽  
Cloud Properties ◽  
Aerosol Scattering ◽  
Set Up

Abstract. Both higher temperatures and increased CO2 concentrations are (separately) expected to increase the emissions of biogenic volatile organic compounds (BVOCs). This has been proposed to initiate negative climate feedback mechanisms through increased formation of secondary organic aerosol (SOA). More SOA can make the clouds more reflective, which can provide a cooling. Furthermore, the increase in SOA formation has also been proposed to lead to increased aerosol scattering, resulting in an increase in diffuse radiation. This could boost gross primary production (GPP) and further increase BVOC emissions. In this study, we have used the Norwegian Earth System Model (NorESM) to investigate both these feedback mechanisms. Three sets of experiments were set up to quantify the feedback with respect to (1) doubling the CO2, (2) increasing temperatures corresponding to a doubling of CO2 and (3) the combined effect of both doubling CO2 and a warmer climate. For each of these experiments, we ran two simulations, with identical setups, except for the BVOC emissions. One simulation was run with interactive BVOC emissions, allowing the BVOC emissions to respond to changes in CO2 and/or climate. In the other simulation, the BVOC emissions were fixed at present-day conditions, essentially turning the feedback off. The comparison of these two simulations enables us to investigate each step along the feedback as well as estimate their overall relevance for the future climate. We find that the BVOC feedback can have a significant impact on the climate. The annual global BVOC emissions are up to 63 % higher when the feedback is turned on compared to when the feedback is turned off, with the largest response when both CO2 and climate are changed. The higher BVOC levels lead to the formation of more SOA mass (max 53 %) and result in more particles through increased new particle formation as well as larger particles through increased condensation. The corresponding changes in the cloud properties lead to a −0.43 W m−2 stronger net cloud forcing. This effect becomes about 50 % stronger when the model is run with reduced anthropogenic aerosol emissions, indicating that the feedback will become even more important as we decrease aerosol and precursor emissions. We do not find a boost in GPP due to increased aerosol scattering on a global scale. Instead, the fate of the GPP seems to be controlled by the BVOC effects on the clouds. However, the higher aerosol scattering associated with the higher BVOC emissions is found to also contribute with a potentially important enhanced negative direct forcing (−0.06 W m−2). The global total aerosol forcing associated with the feedback is −0.49 W m−2, indicating that it has the potential to offset about 13 % of the forcing associated with a doubling of CO2.

scholarly journals BVOC-aerosol-climate feedbacks investigated using NorESM

2018 ◽  
Author(s):  
Moa K. Sporre ◽  
Sara M. Blichner ◽  
Inger H. H. Karset ◽  
Risto Makkonen ◽  
Terje K. Berntsen
Keyword(s):  
Gross Primary Production ◽  
Diffuse Radiation ◽  
Global Scale ◽  
Climate Feedback ◽  
Anthropogenic Aerosol ◽  
Feedback Mechanisms ◽  
Aerosol Forcing ◽  
Cloud Properties ◽  
Aerosol Scattering ◽  
Set Up

Abstract. Both higher temperatures and increased CO2 concentrations are (separately) expected to increase the emissions of biogenic volatile organic compounds (BVOCs). This has been proposed to initiate negative climate feedback mechanisms through increased formation of secondary organic aerosol (SOA). More SOA can make the clouds more reflective, which can provide a cooling. Furthermore, the increase in SOA formation has also been proposed to lead to increased aerosol scattering, resulting in an increase in diffuse radiation. This could boost gross primary production (GPP) and further increase BVOC emissions. In this study, we have used the Norwegian Earth System Model (NorESM) to investigate both these feedback mechanisms. Three sets of experiments were set up to quantify the feedback w.r.t. (1) doubling the CO2, (2) increasing temperatures corresponding to a doubling of CO2 and (3) the combined effect of both doubling CO2 and a warmer climate. For each of these experiments we ran two simulations, with identical set-up, except for the BVOC emissions. One simulation was run with interactive BVOC emissions, allowing the BVOC emissions to respond to changes in CO2 and/or climate. In the other simulation, the BVOC emissions were fixed at present day conditions, essentially turning the feedback off. The comparison of these two simulations enable us to investigate each step along the feedback as well as estimate their overall relevance for the future climate. We find that the BVOC feedback can have a significant impact on the climate. The annual global BVOC emissions are up to 63 % higher when the feedback is turned on compared to when the feedback is turned off, with the largest response when both CO2 and climate are changed. The higher BVOC levels lead to the formation of more SOA mass (max 53 %), and result in more particles through increased new particle formation as well as larger particles through increased condensation. The corresponding changes in the cloud properties lead to a −0.43 W m−2 stronger net cloud forcing. This effect becomes about 50 % stronger when the model is run with reduced anthropogenic aerosol emissions, indicating that the feedback will become even more important as we decrease aerosol and precursor emissions. We do not find boost in GPP due to increased aerosol scattering on a global scale. Instead, the fate of the GPP seem to be controlled by the BVOC effects on the clouds. However, the higher aerosol scattering associated with the higher BVOC emissions is found to also contribute with a potentially important enhanced negative direct forcing (−0.06 W m−2). The global total aerosol forcing associated with the feedback is −0.49 W m−2 indicating that it has the potential to offset about 13 % of the forcing associated with a doubling of CO2.

Physico-chemical measurements to investigate regional cloud-climate feedback mechanisms

1996 ◽  
Vol 30 (10-11) ◽  
pp. 1573-1579 ◽  
Author(s):  
V.K. Saxena ◽  
P.A. Durkee ◽  
S. Menon ◽  
John Anderson ◽  
K.L. Burns ◽  
...  
Keyword(s):  
Climate Feedback ◽  
Feedback Mechanisms ◽  
Chemical Measurements ◽  
Physico Chemical
Sign in / Sign up

Export Citation Format

Share Document