scholarly journals The observed influence of local anthropogenic pollution on northern Alaskan cloud properties

2017 ◽  
Author(s):  
Maximilian Maahn ◽  
Gijs de Boer ◽  
Jessie M. Creamean ◽  
Graham Feingold ◽  
Greg M. McFarquhar ◽  
...  
Keyword(s):  
Anthropogenic Pollution ◽  
Radiative Properties ◽  
Anthropogenic Sources ◽  
The Arctic ◽  
Industrial Emissions ◽  
Condensation Nuclei ◽  
Cloud Drop ◽  
Near Surface ◽  
Cloud Properties ◽  
The Impact

Abstract. Due to their importance for the radiation budget, liquid-containing clouds are a key component of the Arctic climate system. Depending on season, they can cool or warm the near-surface air. The radiative properties of these clouds depend strongly on cloud drop sizes, which are governed by the availability of cloud condensation nuclei. Here, we investigate how cloud drop sizes are modified in the presence of local emissions from industrial facilities at the North Slope of Alaska. For this, we use aircraft in-situ observations of clouds and aerosols from the 5th Department of Energy Atmospheric Radiation Measurement (DOE ARM) Program’s Airborne Carbon Measurements (ACME-V) campaign obtained in Summer 2015. Comparison of observations from an area with petroleum extraction facilities (Oliktok Point) with data from a reference area relatively free of anthropogenic sources (Utqiaġvik/Barrow) represents an opportunity to quantify the impact of local industrial emissions on cloud properties. In the presence of local industrial emissions, the mean effective radii of cloud droplets are reduced from 12.2 to 9.8 μm, which leads to a suppression of drizzle production and precipitation. At the same time, concentrations of refractory black carbon and condensation nuclei are enhanced below the clouds. These results demonstrate that the effects of anthropogenic pollution on local climate need to be considered when planning Arctic industrial infrastructure in a warming environment.

scholarly journals The observed influence of local anthropogenic pollution on northern Alaskan cloud properties

2017 ◽  
Vol 17 (23) ◽  
pp. 14709-14726 ◽  
Author(s):  
Maximilian Maahn ◽  
Gijs de Boer ◽  
Jessie M. Creamean ◽  
Graham Feingold ◽  
Greg M. McFarquhar ◽  
...  
Keyword(s):  
Anthropogenic Pollution ◽  
Radiative Properties ◽  
Anthropogenic Sources ◽  
The Arctic ◽  
Industrial Emissions ◽  
Condensation Nuclei ◽  
Cloud Drop ◽  
Near Surface ◽  
Cloud Properties ◽  
The Impact

Abstract. Due to their importance for the radiation budget, liquid-containing clouds are a key component of the Arctic climate system. Depending on season, they can cool or warm the near-surface air. The radiative properties of these clouds depend strongly on cloud drop sizes, which are governed in part by the availability of cloud condensation nuclei. Here, we investigate how cloud drop sizes are modified in the presence of local emissions from industrial facilities at the North Slope of Alaska. For this, we use aircraft in situ observations of clouds and aerosols from the 5th Department of Energy Atmospheric Radiation Measurement (DOE ARM) Program's Airborne Carbon Measurements (ACME-V) campaign obtained in summer 2015. Comparison of observations from an area with petroleum extraction facilities (Oliktok Point) with data from a reference area relatively free of anthropogenic sources (Utqiaġvik/Barrow) represents an opportunity to quantify the impact of local industrial emissions on cloud properties. In the presence of local industrial emissions, the mean effective radii of cloud droplets are reduced from 12.2 to 9.4 µm, which leads to suppressed drizzle production and precipitation. At the same time, concentrations of refractory black carbon and condensation nuclei are enhanced below the clouds. These results demonstrate that the effects of anthropogenic pollution on local climate need to be considered when planning Arctic industrial infrastructure in a warming environment.

scholarly journals Nitrogen Oxides (NOx) in the Arctic Troposphere at Ny-Ålesund (Svalbard Islands): Effects of Anthropogenic Pollution Sources

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 901
Author(s):  
Antonietta Ianniello ◽  
Roberto Salzano ◽  
Rosamaria Salvatori ◽  
Giulio Esposito ◽  
Francesca Spataro ◽  
...  
Keyword(s):  
Nitrogen Oxides ◽  
Ozone Depletion ◽  
Atmospheric Stability ◽  
Anthropogenic Pollution ◽  
Anthropogenic Sources ◽  
The Arctic ◽  
Source Tracking ◽  
Atmospheric Measurements ◽  
North West ◽  
The Impact

Atmospheric measurements of nitrogen oxides (NOx = NO + NO2), ozone (O3) and other constituents were carried out during three field campaigns (29 March–30 April 2010, 1–26 April 2011, 18 May–8 October 2015) at Ny-Ålesund. The study focused on the variability of important O3 precursors, such as NOx, in the Arctic troposphere, and on the impact from anthropogenic sources on their measured concentrations: higher NO and NO2 levels were mostly associated with the lowest wind speeds and northern directions, indicating local pollution. Long-range transported sources from Russia and Europe were also identified with an occurrence of high NOx levels. Several ozone depletion events were observed and associated to winds blowing from the north-west direction (Arctic Ocean). Most of these events were connected to the lower NO and NO2 concentrations. Measurements of halogen and low molecular weight carbonyl compounds in 2010 and 2011, respectively, showed variable effects during the ozone depletion events. Other data, such as high time-resolved radon progeny measurements, were used in 2015 to identify source tracking and transport of air masses, local effects and atmospheric stability dynamics that could influence the NOx concentrations at Ny-Ålesund.

scholarly journals Clouds damp the radiative impacts of polar sea ice loss

2020 ◽  
Vol 14 (8) ◽  
pp. 2673-2686 ◽  
Author(s):  
Ramdane Alkama ◽  
Patrick C. Taylor ◽  
Lorea Garcia-San Martin ◽  
Herve Douville ◽  
Gregory Duveiller ◽  
...  
Keyword(s):  
Sea Ice ◽  
Climate Models ◽  
Surface Radiation ◽  
Radiation Budget ◽  
The Arctic ◽  
Cloud Properties ◽  
Surface Radiation Budget ◽  
Cloud Radiative Effect ◽  
Radiative Impact ◽  
The Impact

Abstract. Clouds play an important role in the climate system: (1) cooling Earth by reflecting incoming sunlight to space and (2) warming Earth by reducing thermal energy loss to space. Cloud radiative effects are especially important in polar regions and have the potential to significantly alter the impact of sea ice decline on the surface radiation budget. Using CERES (Clouds and the Earth's Radiant Energy System) data and 32 CMIP5 (Coupled Model Intercomparison Project) climate models, we quantify the influence of polar clouds on the radiative impact of polar sea ice variability. Our results show that the cloud short-wave cooling effect strongly influences the impact of sea ice variability on the surface radiation budget and does so in a counter-intuitive manner over the polar seas: years with less sea ice and a larger net surface radiative flux show a more negative cloud radiative effect. Our results indicate that 66±2% of this change in the net cloud radiative effect is due to the reduction in surface albedo and that the remaining 34±1 % is due to an increase in cloud cover and optical thickness. The overall cloud radiative damping effect is 56±2 % over the Antarctic and 47±3 % over the Arctic. Thus, present-day cloud properties significantly reduce the net radiative impact of sea ice loss on the Arctic and Antarctic surface radiation budgets. As a result, climate models must accurately represent present-day polar cloud properties in order to capture the surface radiation budget impact of polar sea ice loss and thus the surface albedo feedback.

scholarly journals The Impact of Regional Arctic Sea Ice Loss on Atmospheric Circulation and the NAO

2016 ◽  
Vol 29 (2) ◽  
pp. 889-902 ◽  
Author(s):  
Rasmus A. Pedersen ◽  
Ivana Cvijanovic ◽  
Peter L. Langen ◽  
Bo M. Vinther
Keyword(s):  
Sea Ice ◽  
Atmospheric Circulation ◽  
General Circulation ◽  
Ice Cover ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Near Surface ◽  
Arctic Sea ◽  
The Impact ◽  
Sea Ice Reduction

Abstract Reduction of the Arctic sea ice cover can affect the atmospheric circulation and thus impact the climate beyond the Arctic. The atmospheric response may, however, vary with the geographical location of sea ice loss. The atmospheric sensitivity to the location of sea ice loss is studied using a general circulation model in a configuration that allows combination of a prescribed sea ice cover and an active mixed layer ocean. This hybrid setup makes it possible to simulate the isolated impact of sea ice loss and provides a more complete response compared to experiments with fixed sea surface temperatures. Three investigated sea ice scenarios with ice loss in different regions all exhibit substantial near-surface warming, which peaks over the area of ice loss. The maximum warming is found during winter, delayed compared to the maximum sea ice reduction. The wintertime response of the midlatitude atmospheric circulation shows a nonuniform sensitivity to the location of sea ice reduction. While all three scenarios exhibit decreased zonal winds related to high-latitude geopotential height increases, the magnitudes and locations of the anomalies vary between the simulations. Investigation of the North Atlantic Oscillation reveals a high sensitivity to the location of the ice loss. The northern center of action exhibits clear shifts in response to the different sea ice reductions. Sea ice loss in the Atlantic and Pacific sectors of the Arctic cause westward and eastward shifts, respectively.

scholarly journals The relative impact of cloud condensation nuclei and ice nucleating particle concentrations on phase partitioning in Arctic mixed-phase stratocumulus clouds

2018 ◽  
Vol 18 (23) ◽  
pp. 17047-17059 ◽  
Author(s):  
Amy Solomon ◽  
Gijs de Boer ◽  
Jessie M. Creamean ◽  
Allison McComiskey ◽  
Matthew D. Shupe ◽  
...  
Keyword(s):  
Cloud Condensation Nuclei ◽  
Mixed Phase ◽  
Radiative Properties ◽  
Condensation Nuclei ◽  
Phase Partitioning ◽  
Cloud Dynamics ◽  
Stratocumulus Clouds ◽  
Cloud Ice ◽  
Mixed Phase Clouds ◽  
The Impact

Abstract. This study investigates the interactions between cloud dynamics and aerosols in idealized large-eddy simulations (LES) of Arctic mixed-phase stratocumulus clouds (AMPS) observed at Oliktok Point, Alaska, in April 2015. This case was chosen because it allows the cloud to form in response to radiative cooling starting from a cloud-free state, rather than requiring the cloud ice and liquid to adjust to an initial cloudy state. Sensitivity studies are used to identify whether there are buffering feedbacks that limit the impact of aerosol perturbations. The results of this study indicate that perturbations in ice nucleating particles (INPs) dominate over cloud condensation nuclei (CCN) perturbations; i.e., an equivalent fractional decrease in CCN and INPs results in an increase in the cloud-top longwave cooling rate, even though the droplet effective radius increases and the cloud emissivity decreases. The dominant effect of ice in the simulated mixed-phase cloud is a thinning rather than a glaciation, causing the mixed-phase clouds to radiate as a grey body and the radiative properties of the cloud to be more sensitive to aerosol perturbations. It is demonstrated that allowing prognostic CCN and INPs causes a layering of the aerosols, with increased concentrations of CCN above cloud top and increased concentrations of INPs at the base of the cloud-driven mixed layer. This layering contributes to the maintenance of the cloud liquid, which drives the dynamics of the cloud system.

scholarly journals Modeling the present and future impact of aviation on climate: an AOGCM approach with online coupled chemistry

2013 ◽  
Vol 13 (19) ◽  
pp. 10027-10048 ◽  
Author(s):  
P. Huszar ◽  
H. Teyssèdre ◽  
M. Michou ◽  
A. Voldoire ◽  
D. J. L. Olivié ◽  
...  
Keyword(s):  
Co2 Emissions ◽  
General Circulation ◽  
Circulation Model ◽  
Ocean General Circulation Model ◽  
Climate Impacts ◽  
Ozone Production ◽  
The Arctic ◽  
Near Surface ◽  
Aviation Emissions ◽  
The Impact

Abstract. Our work is among the first that use an atmosphere-ocean general circulation model (AOGCM) with online chemistry to evaluate the impact of future aviation emissions on temperature. Other particularities of our study include non-scaling to the aviation emissions, and the analysis of models' transient response using ensemble simulations. The model we use is the Météo-France CNRM-CM5.1 earth system model extended with the REPROBUS chemistry scheme. The time horizon of our interest is 1940–2100, assuming the A1B SRES scenario. We investigate the present and future impact of aviation emissions of CO2, NOx and H2O on climate, taking into account changes in greenhouse gases, contrails and contrail-induced cirrus (CIC). As in many transport-related impact studies, we distinguish between the climate impacts of CO2 emissions and those of non-CO2 emissions. Aviation-produced aerosol is not considered in the study. Our modeling system simulated a notable sea-ice bias in the Arctic, and therefore results concerning the surface should be viewed with caution. The global averaged near-surface CO2 impact reaches around 0.1 K by the end of the 21st century, while the non-CO2 impact reaches 0.2 K in the second half of the century. The NOx emissions impact is almost negligible in our simulations, as our aviation-induced ozone production is small. As a consequence, the non-CO2 signal is very similar to the CIC signal. The seasonal analysis shows that the strongest warming due to aviation is modeled for the late summer and early autumn. In the stratosphere, a significant cooling is attributed to aviation CO2 emissions (−0.25 K by 2100). A −0.3 K temperature decrease is modeled when considering all the aviation emissions, but no significant signal appears from the CIC or NOx forcings in the stratosphere.

scholarly journals Seasonal Patterns in Ocean Ambient Noise near Sachs Harbour, Northwest Territories + Supplementary Appendix 1 (See Article Tools)

ARCTIC ◽  
2017 ◽  
Vol 70 (3) ◽  
pp. 239 ◽  
Author(s):  
Stephen J. Insley ◽  
William D. Halliday ◽  
Tyler De Jong
Keyword(s):  
Sea Ice ◽  
Northwest Territories ◽  
Ambient Noise ◽  
Anthropogenic Sources ◽  
The Arctic ◽  
Ambient Conditions ◽  
Noise Levels ◽  
Marine Animals ◽  
Marine Fauna ◽  
The Impact

Ocean ambient noise is a crucial habitat feature for marine animals because it represents the lower threshold of their acoustically active space. Ambient noise is affected by noise from both natural sources, like wind and ice, and anthropogenic sources, such as shipping and seismic surveys. During the ice-covered season, ambient conditions in the Arctic are quieter than those in other regions because sea ice has a dampening effect. Arctic warming induced by climate change can raise noise levels by reducing sea ice coverage and increasing human activity, and these changes may negatively affect several species of marine mammals and other acoustically sensitive marine fauna. We document ambient noise off the west coast of Banks Island near Sachs Harbour, Northwest Territories, to provide baseline noise levels for the eastern Beaufort Sea. Noise levels were comparable to those found in other studies of the Canadian Arctic and Alaska and were typically much lower than levels reported farther south. Stronger wind increased noise, whereas greater ice concentration decreased it, dampening the effect of wind speed. Future work should expand monitoring to other locations in the Arctic, model the impact of increased human activities on ambient noise levels, and predict the impact of these changing levels on marine animals.

scholarly journals Stratospheric Nudging And Predictable Surface Impacts (SNAPSI): A Protocol for Investigating the Role of the Stratospheric Polar Vortex in Subseasonal to Seasonal Forecasts

2022 ◽  
Author(s):  
Peter Hitchcock ◽  
Amy Butler ◽  
Andrew Charlton-Perez ◽  
Chaim Garfinkel ◽  
Tim Stockdale ◽  
...  
Keyword(s):  
Winter Season ◽  
Polar Vortex ◽  
Forecast Skill ◽  
The Arctic ◽  
Seasonal Forecasts ◽  
Stratospheric Polar Vortex ◽  
Near Surface ◽  
Forecast Models ◽  
The Impact

Abstract. Major disruptions of the winter season, high-latitude, stratospheric polar vortices can result in stratospheric anomalies that persist for months. These sudden stratospheric warming events are recognized as an important potential source of forecast skill for surface climate on subseasonal to seasonal timescales. Realizing this skill in operational subseasonal forecast models remains a challenge, as models must capture both the evolution of the stratospheric polar vortices in addition to their coupling to the troposphere. The processes involved in this coupling remain a topic of open research. We present here the Stratospheric Nudging And Predictable Surface Impacts (SNAPSI) project. SNAPSI is a new model intercomparison protocol designed to study the role of the Arctic and Antarctic stratospheric polar vortices in sub-seasonal to seasonal forecast models. Based on a set of controlled, subseasonal, ensemble forecasts of three recent events, the protocol aims to address four main scientific goals. First, to quantify the impact of improved stratospheric forecasts on near-surface forecast skill. Second, to attribute specific extreme events to stratospheric variability. Third, to assess the mechanisms by which the stratosphere influences the troposphere in the forecast models, and fourth, to investigate the wave processes that lead to the stratospheric anomalies themselves. Although not a primary focus, the experiments are furthermore expected to shed light on coupling between the tropical stratosphere and troposphere. The output requested will allow for a more detailed, process-based community analysis than has been possible with existing databases of subseasonal forecasts.

Comparison of Arctic cloud properties over sea ice and open ocean based on airborne spectral solar remote sensing

2021 ◽  
Author(s):  
Marcus Klingebiel ◽  
André Ehrlich ◽  
Elena Ruiz-Donoso ◽  
Manfred Wendisch
Keyword(s):  
Remote Sensing ◽  
Sea Ice ◽  
Open Water ◽  
Open Ocean ◽  
Arctic Sea Ice ◽  
Radiative Properties ◽  
Radiation Budget ◽  
The Arctic ◽  
Liquid Water Path ◽  
Cloud Properties

<p>Over the last decades, the Arctic has experienced an enhanced warming, which is known as Arctic amplification. This process leads to a decrease in the amount of Arctic sea ice, which is linked by different feedback mechanisms to clouds and the related radiative properties. To analyze how the properties of these Arctic clouds could change in a future sea ice free Arctic, we completed three airborne campaigns in the marginal sea ice zone between 2017 and 2020 covering summer and winter conditions. During these campaigns we performed in-situ and remote sensing measurements to study cloud micro- and macrophysical properties and analyzed how these clouds affect the radiation budget. In this study we use the passive remote sensing measurements from these airborne observations to retrieve cloud top effective radius, liquid water path and cloud optical thickness. We found that these cloud properties differ between a sea ice surface and over open water. The airborne observations are supported by an analysis of the cloud product from the MODIS satellite. The systematic differences of clouds over sea ice and the open ocean suggests that clouds may change in a future warming Arctic environment.</p>

Impact of a multi-layer snow scheme on near-surface weather forecasts

2020 ◽  
Author(s):  
Gabriele Arduini ◽  
Gianpaolo Balsamo ◽  
Emanuel Dutra ◽  
Jonathan J. Day ◽  
Irina Sandu ◽  
...  
Keyword(s):  
Snow Depth ◽  
Positive Impact ◽  
Radiative Properties ◽  
Polar Regions ◽  
Snow Layer ◽  
Near Surface ◽  
Weather Forecasts ◽  
Surface Weather ◽  
Weather Parameters ◽  
The Impact

<p>Snow cover properties have a large impact on the partitioning of surface energy fluxes and thereby on near-surface weather parameters. Snow schemes of intermediate complexity have been widely used for hydrological and climate studies, whereas their impact on typical weather forecast time-scales has received less attention. A new multi-layer snow scheme is implemented in the ECMWF Integrated Forecasting System (IFS) and its impact on snow and 2-metre temperature forecasts is evaluated. The new snow scheme is evaluated offline at well instrumented field sites and compared to the current single-layer scheme. The new scheme largely improves the representation of snow depth for most of the sites considered, reducing the root-mean-square-error averaged over all sites by more than 30%. The improvements are due to a better description of snow density in thick and cold snowpacks, but also due to an improved representation of sporadic melting episodes thanks to the inclusion of a thin top snow layer with a low thermal inertia. The evaluation of coupled 10-day weather forecasts shows an improved representation of snow depth at all lead times, demonstrating a positive impact at the global scale. Regarding the impact on weather parameters, the use of the multi-layer snow scheme improves the simulated daily minimum 2-metre temperature, by decreasing the positive bias and improving the amplitude of the diurnal cycle over snow-covered regions. The analysis indicates that a more realistic representation of snow processes is essential to improve the simulation of low temperature extremes at high latitudes, where snow is a key component of the climate system. The work also highlights that other errors in polar regions still need to be addressed, such as cloud radiative properties, despite the improvements in the responsiveness of snow-covered surfaces with respect to the atmospheric forcing.</p>

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