scholarly journals Characterization of the cloud microphysical and optical properties and aerosol-cloud interaction in the Arctic from in situ ground-based measurements during the CLIMSLIP-NyA campaign, Svalbard

2017 ◽  
Author(s):  
Gwennolé Guyot ◽  
Frans Olofson ◽  
Peter Tunved ◽  
Christophe Gourbeyre ◽  
Guy Fevbre ◽  
...  
Keyword(s):  
Indirect Effect ◽  
Climate Models ◽  
Droplet Diameter ◽  
Arctic Region ◽  
The Arctic ◽  
Blowing Snow ◽  
Aerosol Cloud ◽  
Arctic Aerosol

Abstract. This study will focus on cloud microphysical and optical characterization of three different types of episodes encountered during the ground based CLIMSLIP-NyA campaign performed in Ny-Alesund, Svalbard: the Mixed Phase Cloud (MPC), snow precipitation and Blowing Snow (BS) events. These in situ cloud measurements will be combined with aerosol measurements and air mass backtrajectory simulations to qualify and parameterize the arctic aerosol cloud interaction and to assess the influence of anthropogenic pollution transported into the Arctic. The results show a cloud bimodal distribution with the droplet mode at 10 µm and the crystal mode centered at 250 µm, for the MPC cases. The precipitation cases presents a crystal distribution centered around 350 µm with mostly of dendritic shape. The BS cases show a higher concentration but smaller crystals, centered between 150 and 200 µm, with mainly irregular crystals. A polluted case, where aerosol properties are influenced by anthropogenic emission from Europe and East Asia, was compared to a clean case with local aerosol sources. These anthropogenic emissions seem to cause higher Black Carbon, aerosol and droplet concentrations, a more pronounced accumulation mode, smaller droplet sizes and a higher activation fraction Fa. Moreover, the activation diameter decreases as the droplet diameter increases and Fa increases showing that smaller particles are activated and droplets grow when the aerosol number decreases. This is in agreement with the first (Twomey) and second (Albrecht) aerosol indirect effect. The quantification of the variations of droplet concentration and size leads to IE (Indirect Effect) and NE (Nucleation Efficiency) coefficients values around 0.2 and 0.43, respectively. These values are close to those found by other studies in the arctic region which confirms these parameterizations of arctic aerosol-cloud interaction in climate models.

scholarly journals Ice particle properties of Arctic cirrus

2018 ◽  
Author(s):  
Veronika Wolf ◽  
Thomas Kuhn ◽  
Mathias Milz ◽  
Peter Voelger ◽  
Martina Krämer ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Shape ◽  
Climate Models ◽  
Arctic Region ◽  
Weather Conditions ◽  
Number Concentration ◽  
Cirrus Clouds ◽  
The Arctic ◽  
Almost All

Abstract. Ice particle and cloud properties such as particle size, particle shape and number concentration influence the net radiation effect of cirrus clouds. Measurements of these features are of great interest for the improvement of weather and climate models, especially for the Arctic region. In this study, balloon-borne in-situ measurements of Arctic cirrus clouds have been analysed for the first time with respect to their origin. Eight cirrus cloud measurements were carried out in Kiruna (68° N), Sweden. Ice particle diameters between 10 μm and 1200 μm were found and the shape could be recognised from 20 μm upwards. Great variability in particle size and shape was observed. This cannot simply be explained by local environmental conditions. However, if sorted by cirrus origin, wind, and weather conditions, the observed differences can be assessed. Number concentrations between 3/L and 400/L were measured, but only for two cases the number concentration reached values above 100/L. These two cirrus clouds were of in-situ origin and were caused by gravity and mountain lee-waves. For all other measurements, the maximum ice particle concentration was below 50/L and for one in-situ origin cirrus case only 3/L. In the case of in-situ origin clouds, the particles were all smaller than 350 μm diameter. The number size distribution for liquid origin clouds was much broader with particle sizes between 10 μm and 1200 μm. Furthermore, it is striking that in the case of in-situ origin clouds almost all particles were compact (61 %) or irregular (25 %) when examining the particle shape. In liquid origin clouds, on the other hand, most particles were irregular (48 %), rosettes (25 %) or columnar (14 %). There were hardly any plates in cirrus regardless of their origin. It is also noticeable that in the case of liquid origin clouds the rosettes and columnar particles were almost all hollow.

STORM ICE OIL WIND WAVE WATCH SYSTEM (SIOWS): WEB GIS APPLICATION FOR MONITORING THE ARCTIC

2017 ◽  
Author(s):  
Alexander Myasoedov ◽  
Alexander Myasoedov ◽  
Sergey Azarov ◽  
Sergey Azarov ◽  
Ekaterina Balashova ◽  
...  
Keyword(s):  
Satellite Data ◽  
Wind Wave ◽  
Arctic Region ◽  
Web Gis ◽  
The Arctic ◽  
Flexible Tool ◽  
In Situ Data ◽  
Current State ◽  
Watch System

Working with satellite data, has long been an issue for users which has often prevented from a wider use of these data because of Volume, Access, Format and Data Combination. The purpose of the Storm Ice Oil Wind Wave Watch System (SIOWS) developed at Satellite Oceanography Laboratory (SOLab) is to solve the main issues encountered with satellite data and to provide users with a fast and flexible tool to select and extract data within massive archives that match exactly its needs or interest improving the efficiency of the monitoring system of geophysical conditions in the Arctic. SIOWS - is a Web GIS, designed to display various satellite, model and in situ data, it uses developed at SOLab storing, processing and visualization technologies for operational and archived data. It allows synergistic analysis of both historical data and monitoring of the current state and dynamics of the "ocean-atmosphere-cryosphere" system in the Arctic region, as well as Arctic system forecasting based on thermodynamic models with satellite data assimilation.

scholarly journals Multi-modal albedo distributions in the ablation area of the southwestern Greenland Ice Sheet

2015 ◽  
Vol 9 (3) ◽  
pp. 905-923 ◽  
Author(s):  
S. E. Moustafa ◽  
A. K. Rennermalm ◽  
L. C. Smith ◽  
M. A. Miller ◽  
J. R. Mioduszewski ◽  
...  
Keyword(s):  
Surface Albedo ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Arctic Region ◽  
Bimodal Distribution ◽  
The Arctic ◽  
Remotely Sensed Data ◽  
Data Set ◽  
Ablation Area

Abstract. Surface albedo is a key variable controlling solar radiation absorbed at the Greenland Ice Sheet (GrIS) surface and, thus, meltwater production. Recent decline in surface albedo over the GrIS has been linked to enhanced snow grain metamorphic rates, earlier snowmelt, and amplified melt–albedo feedback from atmospheric warming. However, the importance of distinct surface types on ablation area albedo and meltwater production is still relatively unknown. In this study, we analyze albedo and ablation rates using in situ and remotely sensed data. Observations include (1) a new high-quality in situ spectral albedo data set collected with an Analytical Spectral Devices Inc. spectroradiometer measuring at 325–1075 nm along a 1.25 km transect during 3 days in June 2013; (2) broadband albedo at two automatic weather stations; and (3) daily MODerate Resolution Imaging Spectroradiometer (MODIS) albedo (MOD10A1) between 31 May and 30 August 2012 and 2013. We find that seasonal ablation area albedos in 2013 have a bimodal distribution, with snow and ice facies characterizing the two peaks. Our results show that a shift from a distribution dominated by high to low albedos corresponds to an observed melt rate increase of 51.5% (between 10–14 July and 20–24 July 2013). In contrast, melt rate variability caused by albedo changes before and after this shift was much lower and varied between ~10 and 30% in the melting season. Ablation area albedos in 2012 exhibited a more complex multimodal distribution, reflecting a transition from light to dark-dominated surface, as well as sensitivity to the so called "dark-band" region in southwest Greenland. In addition to a darkening surface from ice crystal growth, our findings demonstrate that seasonal changes in GrIS ablation area albedos are controlled by changes in the fractional coverage of snow, bare ice, and impurity-rich surface types. Thus, seasonal variability in ablation area albedos appears to be regulated primarily as a function of bare ice expansion at the expense of snow, surface meltwater ponding, and melting of outcropped ice layers enriched with mineral materials, enabling dust and impurities to accumulate. As climate change continues in the Arctic region, understanding the seasonal evolution of ice sheet surface types in Greenland's ablation area is critical to improve projections of mass loss contributions to sea level rise.

scholarly journals CMIP5 Projections of Arctic Amplification, of the North American/North Atlantic Circulation, and of Their Relationship

2015 ◽  
Vol 28 (13) ◽  
pp. 5254-5271 ◽  
Author(s):  
Elizabeth A. Barnes ◽  
Lorenzo M. Polvani
Keyword(s):  
North Atlantic ◽  
Climate Models ◽  
Coupled Model ◽  
Arctic Region ◽  
The Arctic ◽  
Cmip5 Models ◽  
Arctic Amplification ◽  
Arctic Warming ◽  
The North ◽  
Sequence Of Events

Abstract Recent studies have hypothesized that Arctic amplification, the enhanced warming of the Arctic region compared to the rest of the globe, will cause changes in midlatitude weather over the twenty-first century. This study exploits the recently completed phase 5 of the Coupled Model Intercomparison Project (CMIP5) and examines 27 state-of-the-art climate models to determine if their projected changes in the midlatitude circulation are consistent with the hypothesized impact of Arctic amplification over North America and the North Atlantic. Under the largest future greenhouse forcing (RCP8.5), it is found that every model, in every season, exhibits Arctic amplification by 2100. At the same time, the projected circulation responses are either opposite in sign to those hypothesized or too widely spread among the models to discern any robust change. However, in a few seasons and for some of the circulation metrics examined, correlations are found between the model spread in Arctic amplification and the model spread in the projected circulation changes. Therefore, while the CMIP5 models offer some evidence that future Arctic warming may be able to modulate some aspects of the midlatitude circulation response in some seasons, the analysis herein leads to the conclusion that the net circulation response in the future is unlikely to be determined solely—or even primarily—by Arctic warming according to the sequence of events recently hypothesized.

scholarly journals Climate change between the mid and late Holocene in northern high latitudes – Part 2: Model-data comparisons

2010 ◽  
Vol 6 (5) ◽  
pp. 609-626 ◽  
Author(s):  
Q. Zhang ◽  
H. S. Sundqvist ◽  
A. Moberg ◽  
H. Körnich ◽  
J. Nilsson ◽  
...  
Keyword(s):  
Sea Ice ◽  
Climate Models ◽  
Barents Sea ◽  
Arctic Region ◽  
Summer Temperature ◽  
The Arctic ◽  
High Latitudes ◽  
Climate Response ◽  
Model Data ◽  
Model Simulations

Abstract. The climate response over northern high latitudes to the mid-Holocene orbital forcing has been investigated in three types of PMIP (Paleoclimate Modelling Intercomparison Project) simulations with different complexity of the modelled climate system. By first undertaking model-data comparison, an objective selection method has been applied to evaluate the capability of the climate models to reproduce the spatial response pattern seen in proxy data. The possible feedback mechanisms behind the climate response have been explored based on the selected model simulations. Subsequent model-model comparisons indicate the importance of including the different physical feedbacks in the climate models. The comparisons between the proxy-based reconstructions and the best fit selected simulations show that over the northern high latitudes, summer temperature change follows closely the insolation change and shows a common feature with strong warming over land and relatively weak warming over ocean at 6 ka compared to 0 ka. Furthermore, the sea-ice-albedo positive feedback enhances this response. The reconstructions of temperature show a stronger response to enhanced insolation in the annual mean temperature than winter and summer temperature. This is verified in the model simulations and the behaviour is attributed to the larger contribution from the large response in autumn. Despite a smaller insolation during winter at 6 ka, a pronounced warming centre is found over Barents Sea in winter in the simulations, which is also supported by the nearby northern Eurasian continental and Fennoscandian reconstructions. This indicates that in the Arctic region, the response of the ocean and the sea ice to the enhanced summer insolation is more important for the winter temperature than the synchronous decrease of the insolation.

Geochemical researches in situ (LA-ICP-MS) of accessory and ore minerals from multimetal (PGE, Cu-Ni) deposits in the Arctic zone (Fennoscandian Shield) of the Russian Federation

2020 ◽  
Author(s):  
Svetlana Drogobuzhskaya ◽  
Tamara Bayanova ◽  
Andrey Novikov
Keyword(s):  
Inductively Coupled Plasma ◽  
Arctic Region ◽  
Sulfide Minerals ◽  
Fennoscandian Shield ◽  
The Arctic ◽  
Local Analysis ◽  
Icp Ms ◽  
Ore Minerals ◽  
Rfbr Grant

<p>The laser ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS) is a unique method for local analysis that allows studying mineral grains in situ. The aims of these geochemical researches are to estimate concentrations and distributions of REE, Hf, U, Th, Y, Ti, PGE and other elements in accessory and ore minerals from complex deposits in the Arctic region (Fennoscandian Shield), using the LA-ICP-MS local analysis of trace elements. Accessory minerals of zircon and baddeleyite are much valued to study distributions of rare and rare earth elements (REE). Besides, pyrite, pentlandite, pyrrhotite and other sulfides are important for determining platinum-group elements (PGE), REE, etc.</p><p>The electron (LEO-1415) and optic (LEICA OM 2500 P, camera DFC 290) spectroscopy have been applied to study the morphology of the samples. Analytical points have been selected on baddeleyite, zircon crystals and sulfide minerals based on analyses of their BSE, CL and optical images. REE, PGE and other elements have been estimated in situ by ICP-MS, using an ELAN 9000 DRC-e (Perkin Elmer) quadrupole mass spectrometer equipped with UP-266 MAСRO laser (New Wave Research).</p><p>More than 19 elements were profiled during each measurement in zircon or baddeleyite. For the first time, LA-ICP-MS techniques have been applied to estimate PGE, REE and other (S, Cr, Fe, Cu, Ni, Co, As, Se, Mo, Cd, Sn, Sb, Re, Te, Tl, Hf, W, Bi, Pb, Th, U) elements in sulfide minerals. NIST 610, NIST 612 and tandem graduation (using solutions), considering sensitivity coefficients of isotopes have been used to check the accuracy of estimations. Fe, Ni and Cu have been used as internal standards, being most evenly distributed elements in minerals, when concentrations of elements in sulphides were calculated. The estimates have been carried out, using inter-laboratory standards of chalcopyrite, pentlandite and pyrrhotite, which had been preliminarily prepared and studied using micro probe analysis (Cameca MS-46).</p><p>These techniques had been used to estimate elements in zircon extracted from basic and acidic rocks of the Lapland belt (1.9 Ga), the Keivy zone (2.7 Ga), the Kandalaksha and Kolvitsa zone (2.45 Ga) and from the Cu-Ni deposit (Terrace, Mt. Nyud, 2.5 Ga). Novel techniques have been used to analyze baddeleyite from rocks of layered PGE intrusions of the Monchegorsk ore area (2.5 Ga) and carbonatites of Kovdor and Vuoriyarvi (380 Ma). Elaborated LA-ICP-MS techniques have been applied to provide in situ measurements of PGE, Au, Ag, siderophile and chalcophile elements in sulphide minerals from the Pechenga and Allarechka Cu-Ni deposits (1.98 Ga), Fedorova Tundra and Severny Kamennik PGE deposits (2.5 Ga).</p><p>The scientific researches are supported by RFBR Grant No 18-05-70082, scientific themes 0226-2019-0032 and 0226-2019-0053.</p>

scholarly journals Analysis of IASI tropospheric O<sub>3</sub> data over the Arctic during POLARCAT campaigns in 2008

2012 ◽  
Vol 12 (16) ◽  
pp. 7371-7389 ◽  
Author(s):  
M. Pommier ◽  
C. Clerbaux ◽  
K. S. Law ◽  
G. Ancellet ◽  
P. Bernath ◽  
...  
Keyword(s):  
Arctic Region ◽  
Anthropogenic Sources ◽  
The Arctic ◽  
International Polar Year ◽  
Air Masses ◽  
Infrared Radiance ◽  
In Situ Data ◽  
Clean Air ◽  
International Polar

Abstract. Ozone data retrieved in the Arctic region from infrared radiance spectra recorded by the Infrared Atmospheric Sounding Interferometer (IASI) on board the MetOp-A European satellite are presented. They are compared with in situ and lidar observations obtained during a series of aircraft measurement campaigns as part of the International Polar Year POLARCAT activities in spring and summer 2008. Different air masses were sampled during the campaigns including clean air, polluted plumes originating from anthropogenic sources, forest fire plumes from the three northern continents, and stratospheric-influenced air masses. The comparison between IASI O3 [0–8 km], [0–12 km] partial columns and profiles with collocated aircraft observations is achieved by taking into account the different sensitivity and geometry of the sounding instruments. A detailed analysis is provided and the agreement is discussed in terms of vertical sensitivity and surface properties at the location of the observations. Overall, IASI O3 profiles are found to be in relatively good agreement with smoothed in situ and lidar profiles in the free troposphere with differences of less than 40% (25% over sea for both seasons) and 10%, respectively. The correlation between IASI O3 retrieved partial columns and the smoothed aircraft partial columns is good with DC-8 in situ data in spring over North America (r = 0.68), and over Greenland with ATR-42 lidar measurements in summer (r = 0.67). Correlations with other data are less significant highlighting the difficulty of IASI to capture precisely the O3 variability in the Arctic upper troposphere and lower stratosphere (UTLS). This is particularly noted in comparison with the [0–12 km] partial columns. The IASI [0–8 km] partial columns display a low negative bias (by less than 26% over snow) compared to columns derived from in situ measurements. Despite the relatively high biases of the IASI retrievals in the Arctic UTLS, our analysis shows that IASI can be used to identify, using O3 / CO ratios, stratospheric intrusions.

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