Ice microphysics of low-level ice clouds in the Arctic: Satellite analysis

2021 ◽  
Author(s):  
Iris Papakonstantinou-Presvelou ◽  
Johannes Quaas
Keyword(s):  
Sea Ice ◽  
Large Scale ◽  
Arctic Region ◽  
Open Ocean ◽  
The Arctic ◽  
Ice Crystal ◽  
Ice Clouds ◽  
Low Level ◽  
Level Ice ◽  
Satellite Analysis

<p>This study investigates low-level ice clouds in the Arctic and their potential relation to the surface aerosols. These aerosols or ice nucleating particles (INPs), are necessary for the heterogeneous nucleation of ice in temperatures above -38°C. Several studies in the past have investigated the sources of INPs and their nucleating behavior with response to the temperature. According to these studies, it has been suggested that a marine source of INPs coming from sea spray is able to nucleate ice in temperatures close to -5<sup>o</sup>C. What we do here is a large-scale comparison of boundary-layer ice clouds over open ocean and sea ice, over the whole Arctic region for the time period of 2006-2016. We use for this purpose a satellite-retrieved quantity, the ice crystal number concentration (N<sub>i</sub>), which we investigate in relation to the temperature. We study clouds with regard to the region and season they form and we examine their coupling to the surface. Our findings show - contrary to previous expectation - enhanced ice crystal numbers over sea ice compared to open ocean, in temperatures above -10<sup>o</sup>C. In lower temperatures this difference still persists for the lower Arctic latitudes (<70<sup>o</sup>N), especially for clouds that are coupled to the surface.</p>

scholarly journals Sensitivity of CAM5-Simulated Arctic Clouds and Radiation to Ice Nucleation Parameterization

2013 ◽  
Vol 26 (16) ◽  
pp. 5981-5999 ◽  
Author(s):  
Shaocheng Xie ◽  
Xiaohong Liu ◽  
Chuanfeng Zhao ◽  
Yuying Zhang
Keyword(s):  
Radiative Forcing ◽  
Large Scale ◽  
Arctic Region ◽  
Atmospheric Model ◽  
Ice Nucleation ◽  
The Arctic ◽  
Liquid Water Path ◽  
Arctic Clouds ◽  
Water Path ◽  
Low Level

Abstract Sensitivity of Arctic clouds and radiation in the Community Atmospheric Model, version 5, to the ice nucleation process is examined by testing a new physically based ice nucleation scheme that links the variation of ice nuclei (IN) number concentration to aerosol properties. The default scheme parameterizes the IN concentration simply as a function of ice supersaturation. The new scheme leads to a significant reduction in simulated IN concentration at all latitudes while changes in cloud amounts and properties are mainly seen at high- and midlatitude storm tracks. In the Arctic, there is a considerable increase in midlevel clouds and a decrease in low-level clouds, which result from the complex interaction among the cloud macrophysics, microphysics, and large-scale environment. The smaller IN concentrations result in an increase in liquid water path and a decrease in ice water path caused by the slowdown of the Bergeron–Findeisen process in mixed-phase clouds. Overall, there is an increase in the optical depth of Arctic clouds, which leads to a stronger cloud radiative forcing (net cooling) at the top of the atmosphere. The comparison with satellite data shows that the new scheme slightly improves low-level cloud simulations over most of the Arctic but produces too many midlevel clouds. Considerable improvements are seen in the simulated low-level clouds and their properties when compared with Arctic ground-based measurements. Issues with the observations and the model–observation comparison in the Arctic region are discussed.

scholarly journals On the Arctic Wintertime Climate in Global Climate Models

2011 ◽  
Vol 24 (22) ◽  
pp. 5757-5771 ◽  
Author(s):  
Gunilla Svensson ◽  
Johannes Karlsson
Keyword(s):  
Sea Ice ◽  
Arctic Region ◽  
Precipitable Water ◽  
Open Ocean ◽  
Global Climate Models ◽  
The Arctic ◽  
Turbulent Heat ◽  
Skin Temperatures ◽  
Longwave Flux ◽  
The Arctic Region

Abstract Energy fluxes important for determining the Arctic surface temperatures during winter in present-day simulations from the Coupled Model Intercomparison Project phase 3 (CMIP3) multimodel dataset are investigated. The model results are evaluated over different surfaces using satellite retrievals and ECMWF interim reanalysis (ERA-Interim). The wintertime turbulent heat fluxes vary substantially between models and different surfaces. The monthly median net turbulent heat flux (upward) is in the range 100–200 W m−2 and −15 to 15 W m−2 over open ocean and sea ice, respectively. The simulated net longwave radiative flux at the surface is biased high over both surfaces compared to observations but for different reasons. Over open ocean, most models overestimate the outgoing longwave flux while over sea ice it is rather the downwelling flux that is underestimated. Based on the downwelling longwave flux over sea ice, two categories of models are found. One group of models that shows reasonable downwelling longwave fluxes, compared with observations and ERA-Interim, is also associated with relatively high amounts of precipitable water as well as surface skin temperatures. This group also shows more uniform airmass properties over the Arctic region possibly as a result of more frequent events of warm-air intrusion from lower latitudes. The second group of models underestimates the downwelling longwave radiation and is associated with relatively low surface skin temperatures as well as low amounts of precipitable water. These models also exhibit a larger decrease in the moisture and temperature profiles northward in the Arctic region, which might be indicative of too stagnant conditions in these models.

Analyzing the Arctic Feedback Mechanism between Sea Ice and Low-Level Clouds Using 34 Years of Satellite Observations

2020 ◽  
Vol 33 (17) ◽  
pp. 7479-7501
Author(s):  
Daniel Philipp ◽  
Martin Stengel ◽  
Bodo Ahrens
Keyword(s):  
Sea Ice ◽  
Radiative Forcing ◽  
Large Scale ◽  
The Arctic ◽  
Turbulent Heat ◽  
Arctic Amplification ◽  
Surface Warming ◽  
Low Level ◽  
Gc Analysis ◽  
Csi Feedback

AbstractSatellite-based cloud, radiation flux, and sea ice records covering 34 years are used 1) to investigate autumn cloud cover trends over the Arctic, 2) to assess its relation with declining sea ice using Granger causality (GC) analysis, and 3) to discuss the contribution of the cloud–sea ice (CSI) feedback to Arctic amplification. This paper provides strong evidence for a positive CSI feedback with the capability to contribute to autumnal Arctic amplification. Positive low-level cloud fractional cover (CFClow) trends over the Arctic ice pack are found in October and November (ON) with magnitudes of up to about +9.6% per decade locally. Statistically significant anticorrelations between sea ice concentration (SIC) and CFClow are observed in ON over melting zones, suggesting an association. The GC analysis indicated a causal two-way interaction between SIC and CFClow. Interpreting the resulting F statistic and its spatial distribution as a relation strength proxy, the influence of SIC on CFClow is likely stronger than the reverse. ERA-Interim reanalysis data suggest that ON CFClow is impacted by sea ice melt through surface–atmosphere coupling via turbulent heat and moisture fluxes. Due to weak solar insolation in ON, net cloud radiative forcing (CRF) exerts a warming effect on the Arctic surface. Increasing CFClow induces a large-scale surface warming trend reaching magnitudes of up to about +8.3 W m−2 per decade locally. Sensitivities of total CRF to CFClow ranges between +0.22 and +0.66 W m−2 per percent CFClow. Increasing surface warming can cause a melt season lengthening and hinders formation of perennial ice.

Prévoir les variations saisonnières de la glace de mer arctique et leurs impacts sur le climat

2020 ◽  
pp. 024
Author(s):  
Rym Msadek ◽  
Gilles Garric ◽  
Sara Fleury ◽  
Florent Garnier ◽  
Lauriane Batté ◽  
...  
Keyword(s):  
Sea Ice ◽  
Arctic Region ◽  
Arctic Sea Ice ◽  
Climate Impacts ◽  
The Arctic ◽  
Recent Effort ◽  
Sea Ice Thickness ◽  
Arctic Sea ◽  
Ice Conditions ◽  
Upper Level

L'Arctique est la région du globe qui s'est réchauffée le plus vite au cours des trente dernières années, avec une augmentation de la température de surface environ deux fois plus rapide que pour la moyenne globale. Le déclin de la banquise arctique observé depuis le début de l'ère satellitaire et attribué principalement à l'augmentation de la concentration des gaz à effet de serre aurait joué un rôle important dans cette amplification des températures au pôle. Cette fonte importante des glaces arctiques, qui devrait s'accélérer dans les décennies à venir, pourrait modifier les vents en haute altitude et potentiellement avoir un impact sur le climat des moyennes latitudes. L'étendue de la banquise arctique varie considérablement d'une saison à l'autre, d'une année à l'autre, d'une décennie à l'autre. Améliorer notre capacité à prévoir ces variations nécessite de comprendre, observer et modéliser les interactions entre la banquise et les autres composantes du système Terre, telles que l'océan, l'atmosphère ou la biosphère, à différentes échelles de temps. La réalisation de prévisions saisonnières de la banquise arctique est très récente comparée aux prévisions du temps ou aux prévisions saisonnières de paramètres météorologiques (température, précipitation). Les résultats ayant émergé au cours des dix dernières années mettent en évidence l'importance des observations de l'épaisseur de la glace de mer pour prévoir l'évolution de la banquise estivale plusieurs mois à l'avance. Surface temperatures over the Arctic region have been increasing twice as fast as global mean temperatures, a phenomenon known as arctic amplification. One main contributor to this polar warming is the large decline of Arctic sea ice observed since the beginning of satellite observations, which has been attributed to the increase of greenhouse gases. The acceleration of Arctic sea ice loss that is projected for the coming decades could modify the upper level atmospheric circulation yielding climate impacts up to the mid-latitudes. There is considerable variability in the spatial extent of ice cover on seasonal, interannual and decadal time scales. Better understanding, observing and modelling the interactions between sea ice and the other components of the climate system is key for improved predictions of Arctic sea ice in the future. Running operational-like seasonal predictions of Arctic sea ice is a quite recent effort compared to weather predictions or seasonal predictions of atmospheric fields like temperature or precipitation. Recent results stress the importance of sea ice thickness observations to improve seasonal predictions of Arctic sea ice conditions during summer.

Co-producing Sea-Ice Predictions with Stakeholders Using Simulation

2021 ◽  
Keyword(s):  
Sea Ice ◽  
Local Community ◽  
Economic Value ◽  
Arctic Region ◽  
Production Model ◽  
The Arctic ◽  
Simulation Game ◽  
Climate Services ◽  
Diverse Range ◽  
Uncertainty Information

Abstract Forecasts of sea-ice evolution in the Arctic region for several months ahead can be of considerable socio-economic value for a diverse range of marine sectors and for local community supply logistics. However, subseasonal-to-seasonal (S2S) forecasts represent a significant technical challenge, while translating user needs into scientifically manageable procedures and robust user confidence requires collaboration among a range of stakeholders. We developed and tested a novel, transdisciplinary co-production approach that combined socio-economic scenarios and participatory, research-driven simulation-gaming to test a new S2S sea-ice forecast system with experienced mariners in the cruise tourism sector. Our custom-developed computerized simulation-game ICEWISE integrated sea-ice parameters, forecast technology and human factors, as a participatory environment for stakeholder engagement. We explored the value of applications-relevant S2S sea-ice prediction and linked uncertainty information. Results suggest that the usefulness of S2S services is currently most evident in schedule-dependent sectors but expected to increase due to anticipated changes in the physical environment and continued growth in Arctic operations. Reliable communication of uncertainty information in sea-ice forecasts must be demonstrated and trialed before users gain confidence in emerging services and technologies. Mariners’ own intuition, experience, and familiarity with forecast service provider reputation impact the extent to which sea-ice information may reduce uncertainties and risks for Arctic mariners. Our insights into the performance of the combined foresight/simulation co-production model in brokering knowledge across a range of domains demonstrates promise. We conclude with an overview of the potential contributions from S2S sea-ice predictions and from experiential co-production models to the development of decision-driven and science-informed climate services.

Problems of development of Arctic hydrocarbon resources under the current conditions.

2021 ◽  
pp. 70-81
Author(s):  
Anna Borisovna Nikolaeva ◽  
Keyword(s):  
Economic Development ◽  
Alternative Energy ◽  
New Technologies ◽  
Recovery Period ◽  
Arctic Region ◽  
The Arctic ◽  
Expert Assessment ◽  
Low Level ◽  
The World ◽  
The Arctic Region

The Arctic is the richest and at the same time the most difficult region to develop in the world. Exploration and exploitation of its deposits are inevitable for Russia and mankind as a whole. The Arctic region is characterized by extreme nature-climatic conditions, with a rather low level of economic development and remoteness from industrial centers, a low level or lack of any infrastructure as well as by instability of the ecological system to anthropogenic impact and a long recovery period. Since the potential of the resources currently being developed will be exhausted within several decades, and the world economies are not yet ready for a full transition to alternative energy resources, it is necessary to search for and develop new hydrocarbon reserves that determines the relevance of the study.The aim of the study is to identify the main problems arising when exploiting hydrocarbons in the Arctic region. The set of problems identified predetermines an integrated approach to their solutions. In this case, it is about reforming legislation, increasing funding, and attracting new participants in the international cooperation. Since the export of oil and gas is traditional for the Russian Federation, exploitation of hydrocarbons in the region is a prerequisite for the further economic development of the country. A state policy aimed at development and improvement of new technologies, reducing environmental risks, and deep scientific research of the Arctic, is needed. The method of expert assessment was used, which is applied for solving complex tasks with lack of information, and impossibility of mathematical formalization of the solution process. The basis for the application of this method is the possibility and ability of experts to assess the importance of the problem under study and development prospects for a certain research direction. The expert assessments were highlighted during the study and analysis of the literature.

Global mapping of seasonal variations in tides from tide gauge and satellite altimeter data

2021 ◽  
Author(s):  
Inger Bij de Vaate ◽  
Henrique Guarneri ◽  
Cornelis Slobbe ◽  
Martin Verlaan
Keyword(s):  
Seasonal Variation ◽  
Sea Level ◽  
Seasonal Variations ◽  
Large Scale ◽  
Arctic Region ◽  
The Arctic ◽  
Altimeter Data ◽  
Tide Gauges ◽  
Tidal Constituents ◽  
The Arctic Region

<p>The existence of seasonal variations in major tides has been recognized since decades. Where Corkan (1934) was the first to describe the seasonal perturbation of the M2 tide, many others have studied seasonal variations in the main tidal constituents since. However, most of these studies are based on sea level observations from tide gauges and are often restricted to coastal and shelf regions. Hence, observed seasonal variations are typically dominated by local processes and the large-scale patterns cannot be clearly distinguished. Moreover, most tide models still perceive tides as annually constant and seasonal variation in tides is ignored in the correction process of satellite altimetry. This results in reduced accuracy of obtained sea level anomalies. </p><p>To gain more insight in the large-scale seasonal variations in tides, we supplemented the clustered and sparsely distributed sea level observations from tide gauges by the wealth of data from satellite altimeters. Although altimeter-derived water levels are being widely used to obtain tidal constants, only few of these implementations consider seasonal variation in tides. For that reason, we have set out to explore the opportunities provided by altimeter data for deriving seasonal modulation of the main tidal constituents. Different methods were implemented and compared for the principal tidal constituents and a range of geographical domains, using data from a selection of satellite altimeters. Specific attention was paid to the Arctic region where seasonal variation in tides was expected to be significant as a result of the seasonal sea ice cycle, yet data availability is particularly limited. Our study demonstrates the potential of satellite altimetry for the quantification of seasonal modulation of tides and suggests the seasonal modulation to be considerable. Already for M2 we observed changes in tidal amplitude of the order of decimeters for the Arctic region, and centimeters for lower latitude regions.</p><p> </p><div>Corkan, R. H. (1934). An annual perturbation in the range of tide. <em>Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character</em>, <em>144</em>(853), 537-559.</div>

scholarly journals Summertime observations of ultrafine particles and cloud condensation nuclei from the boundary layer to the free troposphere in the Arctic

2016 ◽  
Author(s):  
Julia Burkart ◽  
Megan D. Willis ◽  
Heiko Bozem ◽  
Jennie L. Thomas ◽  
Kathy Law ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Ultrafine Particles ◽  
Cloud Condensation Nuclei ◽  
Particle Diameter ◽  
Open Ocean ◽  
The Arctic ◽  
Condensation Nuclei ◽  
Aerosol Composition ◽  
Low Level ◽  
20 Nm

Abstract. The Arctic is extremely sensitive to climate change. Shrinking sea ice extent increases the area covered by open ocean during Arctic summer, which impacts the surface albedo and aerosol and cloud properties among many things. In this context extensive aerosol measurements (aerosol composition, particle number and size, cloud condensation nuclei, and trace gases) were made during 11 flights of the NETCARE July, 2014 airborne campaign conducted from Resolute Bay, Nunavut (74N, 94W). Flights routinely included vertical profiles from about 60 to 3000 m a.g.l. as well as several low-level horizontal transects over open ocean, fast ice, melt ponds, and polynyas. Here we discuss the vertical distribution of ultrafine particles (UFP, particle diameter, dp: 5–20 nm), size distributions of larger particles (dp: 20 nm to 1 μm), and cloud condensation nuclei (CCN, supersaturation = 0.6 %) in relation to meteorological conditions and underlying surfaces. UFPs were observed predominantly within the boundary layer, where concentrations were often several hundreds to a few thousand particles per cubic centimeter. Occasionally, particle concentrations below 10 cm−3 were found. The highest UFP concentrations were observed above open ocean and at the top of low-level clouds, whereas numbers over ice-covered regions were substantially lower. Overall, UFP formation events were frequent in a clean boundary layer with a low condensation sink. In a few cases this ultrafine mode extended to sizes larger than 40 nm, suggesting that these UFP can grow into a size range where they can impact clouds and therefore climate.

scholarly journals Record high Pacific Arctic seawater temperatures and delayed sea ice advance in response to episodic atmospheric blocking

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Tsubasa Kodaira ◽  
Takuji Waseda ◽  
Takehiko Nose ◽  
Jun Inoue
Keyword(s):  
Sea Ice ◽  
Arctic Region ◽  
Arctic Sea Ice ◽  
Sea Surface ◽  
The Arctic ◽  
Atmospheric Blocking ◽  
Sea Ice Extent ◽  
The Pacific ◽  
Arctic Sea ◽  
Highly Correlated

AbstractArctic sea ice is rapidly decreasing during the recent period of global warming. One of the significant factors of the Arctic sea ice loss is oceanic heat transport from lower latitudes. For months of sea ice formation, the variations in the sea surface temperature over the Pacific Arctic region were highly correlated with the Pacific Decadal Oscillation (PDO). However, the seasonal sea surface temperatures recorded their highest values in autumn 2018 when the PDO index was neutral. It is shown that the anomalous warm seawater was a rapid ocean response to the southerly winds associated with episodic atmospheric blocking over the Bering Sea in September 2018. This warm seawater was directly observed by the R/V Mirai Arctic Expedition in November 2018 to significantly delay the southward sea ice advance. If the atmospheric blocking forms during the PDO positive phase in the future, the annual maximum Arctic sea ice extent could be dramatically reduced.

scholarly journals Cryospheric Impacts of Soviet River Diversion Schemes

1984 ◽  
Vol 5 ◽  
pp. 61-68 ◽  
Author(s):  
T. Holt ◽  
P. M. Kelly ◽  
B. S. G. Cherry
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
River Discharge ◽  
Large Scale ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Sea Ice Concentration ◽  
Ice Concentration ◽  
The Arctic Ocean ◽  
The Impact

Soviet plans to divert water from rivers flowing into the Arctic Ocean have led to research into the impact of a reduction in discharge on Arctic sea ice. We consider the mechanisms by which discharge reductions might affect sea-ice cover and then test various hypotheses related to these mechanisms. We find several large areas over which sea-ice concentration correlates significantly with variations in river discharge, supporting two particular hypotheses. The first hypothesis concerns the area where the initial impacts are likely to which is the Kara Sea. Reduced riverflow is associated occur, with decreased sea-ice concentration in October, at the time of ice formation. This is believed to be the result of decreased freshening of the surface layer. The second hypothesis concerns possible effects on the large-scale current system of the Arctic Ocean and, in particular, on the inflow of Atlantic and Pacific water. These effects occur as a result of changes in the strength of northward-flowing gradient currents associated with variations in river discharge. Although it is still not certain that substantial transfers of riverflow will take place, it is concluded that the possibility of significant cryospheric effects and, hence, large-scale climate impact should not be neglected.

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