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 Effects of Global Warming on the Poleward Heat Transport by Non-Stationary Large-Scale Atmospheric Eddies, and Feedbacks Affecting the Formation of the Arctic Climate

2021 ◽  
Vol 9 (8) ◽  
pp. 867
Author(s):  
Sergei Soldatenko
Keyword(s):  
Global Warming ◽  
Heat Transport ◽  
Large Scale ◽  
Arctic Sea Ice ◽  
Arctic Climate ◽  
The Arctic ◽  
Arctic Amplification ◽  
Near Surface ◽  
Feedback Mechanisms ◽  
Arctic Sea

It is a well-known fact that the observed rise in the Arctic near-surface temperature is more than double the increase in global mean temperature. However, the entire scientific picture of the formation of the Arctic amplification has not yet taken final shape and the causes of this phenomenon are still being discussed within the scientific community. Some recent studies suggest that the atmospheric equator-to-pole transport of heat and moisture, and also radiative feedbacks, are among the possible reasons for the Arctic amplification. In this paper, we highlight and summarize some of our research related to assessing the response of climate in the Arctic to global warming and vice versa. Since extratropical transient eddies dominate the meridional transport of sensible and latent heat from low to high latitudes, we estimated the effect of climate change on meridional heat transport by means of the β-plane model of baroclinic instability. It has been shown that the heat transport from low and middle latitudes to the Arctic by large scale transient eddies increases by about 9% due to global warming, contributing to the polar amplification—and thereby a decrease in the extent—of the Arctic sea, which, in turn, is an important factor in the formation of the Arctic climate. The main radiative feedback mechanisms affecting the formation of the Arctic climate are also considered and discussed. It was emphasized that the influence of feedbacks depends on a season since the total feedback in the winter season is negative, while in the summer season, it is positive. Thus, further research is required to diminish the uncertainty regarding the character of various feedback mechanisms in the shaping of the Artic climate and, through that, in predicting the extent of Arctic sea ice.

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...

First insight into thermodynamic profiles, IWV and LWP from ground-based microwave radiometers during MOSAiC

2021 ◽  
Author(s):  
Andreas Walbröl ◽  
Patrick Konjari ◽  
Ronny Engelmann ◽  
Hannes Griesche ◽  
Martin Radenz ◽  
...  
Keyword(s):  
Water Vapour ◽  
Collaborative Research ◽  
Surface Processes ◽  
Arctic Climate ◽  
The Arctic ◽  
Arctic Amplification ◽  
Feedback Mechanisms ◽  
Integrated Water Vapour ◽  
Microwave Radiometers ◽  
Insight Into

<p>The Arctic is currently experiencing a more rapid warming compared to the rest of the<br>world. This phenomenon, known as Arctic Amplification, is the result of several processes.<br>Within the Collaborative Research Centre on Arctic Amplification: Climate Relevant Atmospheric<br>and Surface Processes and Feedback Mechanisms (AC)3, our research focuses<br>on the influence of water vapour, the strongest greenhouse gas. The collection of data<br>about water vapour is essential to understand its impact on Arctic Amplification. Over<br>the past decades, a positive trend in integrated water vapour in the Arctic has been<br>identified using radiosondes and reanalyses for certain regions and seasons. However, inconsistent<br>magnitudes of the moistening trend in the reanalyses cause the need of a more<br>thorough investigation. While radiosondes offer precise measurements of thermodynamic<br>(temperature and humidity) profiles, they fail to capture the variability of water vapour<br>because of the low sampling rate (two to four sondes per day) and spatial coverage. To<br>obtain a more complete picture of water vapour variability, remote sensing instruments<br>(satellite- and ground-based) are used. Microwave radiometers (MWRs) onboard polar<br>orbiting satellites allow the coverage of the entire Arctic but suffer from uncertainties<br>related to surface emission. Observations at the surface gathered during the Multidisciplinary<br>drifting Observatory for the Study of Arctic Climate (MOSAiC) campaign can<br>serve as reference measurements in the central Arctic for the assessment of water vapour<br>products from reanalyses, models and satellite retrievals.<br><br>In this study, we give a first insight into the variability of integrated water vapour (IWV),<br>liquid water path (LWP) and thermodynamic profiles retrieved from two ground-based<br>MWRs onboard the research vessel Polarstern throughout the MOSAiC campaign. The<br>first radiometer is a standard low frequency HATPRO system and the other one is the<br>high-frequency MiRAC-P, which is particularly suited for low water vapour contents. The<br>retrieved quantities are compared with radiosonde measurements. A first analysis reveals<br>that the IWV is very well captured by the MWR measurements. Over the observation<br>period (October 2019 - October 2020), a large variety of meteorological conditions occurred.<br>Besides the considerable seasonal cycle, which is especially interesting because of<br>the contrast between polar night and polar day, several synoptic events contribute to the<br>variety of conditions, which will be highlighted as well.</p><p><br>We gratefully acknowledge the funding by the Deutsche Forschungsgemeinschaft (DFG, German Research<br>Foundation) — Project 268020496 — TRR 172, within the Transregional Collaborative Research Center<br>"Arctic Amplification: Climate Relevant Atmospheric and Surface Processes, and Feedback Mechanisms<br>(AC)3". Data used in this manuscript was produced as part of the international Multidisciplinary drifting<br>Observatory for the Study of the Arctic Climate (MOSAiC) with the tag MOSAiC20192020 and the<br>Polarstern expedition AWI_PS122_00.</p>

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 Process drivers, inter-model spread, and the path forward: A review of amplified Arctic warming

2021 ◽  
Author(s):  
Patrick Taylor ◽  
Robyn Boeke ◽  
Linette Boisvert ◽  
Nicole Feldl ◽  
Matthew Henry ◽  
...  
Keyword(s):  
Conceptual Model ◽  
Current Knowledge ◽  
Stable Stratification ◽  
Surface Energy Budget ◽  
Arctic Climate ◽  
Climate Feedback ◽  
Future Research ◽  
Climate Projections ◽  
Driving Mechanisms ◽  
Near Term

Arctic amplification (AA) is a coupled atmosphere-sea ice-ocean process. This understanding has evolved from the early concept of AA, as a consequence of snow-ice line progressions, through more than a century of research that has clarified the relevant processes and driving mechanisms of AA. The predictions made by early modeling studies, namely the fall/winter maximum, bottom-heavy structure, the prominence of surface albedo feedback, and the importance of stable stratification have withstood the scrutiny of multi-decadal observations and more complex models. Yet, the uncertainty in Arctic climate projections is larger than in any other region of the planet, making assessment of high-impact, near-term regional changes difficult or impossible. Reducing this large spread in Arctic climate projections requires a quantitative process understanding. This manuscript aims to build such understanding by synthesizing current knowledge of AA and to produce a set of recommendations to guide future research. It briefly reviews the history of AA science, summarizes observed Arctic changes, discusses modeling approaches and feedback diagnostics, and assesses the current understanding of the most relevant feedbacks to AA. These sections culminate in a conceptual model of the fundamental physical mechanisms causing AA and a collection of recommendations to accelerate progress towards reduced uncertainty in Arctic climate projections. Our conceptual model highlights the need to account for local feedback and remote process interactions, specifically the water vapor triple effect, within the context of the annual cycle to constrain projected AA. We recommend raising the priority of Arctic climate sensitivity research, improving the accuracy of Arctic surface energy budget observations, rethinking climate feedback definitions, coordinating new model experiments and intercomparisons, and pursuing the role of episodic variability in AA as a research focus area.

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.

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