Microphysical cloud parameters of optically thin clouds in the Arctic in summer 2017

2020 ◽  
Author(s):  
Philipp Richter ◽  
Mathias Palm ◽  
Christine Weinzierl ◽  
Penny Rowe ◽  
Justus Notholt
Keyword(s):  
Aerosol Particles ◽  
Microwave Radiometer ◽  
Arctic Region ◽  
Open Water ◽  
The Arctic ◽  
Arctic Amplification ◽  
Cloud Parameters ◽  
Microphysical Properties ◽  
Infrared Spectrometer

<p>As a precursor of the current MOSAiC campaign, the PASCAL campaign took place in summer 2017 around Svalbard [1]. In the scope of the project (AC)3, infrared radiation emitted by clouds was measured using a calibrated Fourier Transform Infrared Spectrometer (EM-FTIR). EM-FTIR can be used for different purposes, like the observation of trace gases or microphysical cloud parameters (MCP) like cloud optical depths and cloud effective droplet radii. In the observation of MCP, EM-FTIR can be used to measure optically thin clouds with very low amounts of liquid water paths below 30 gm-2, where microwave radiometer face problems because of their larger measuring uncertainty. </p><p>The retrieval of the MCP is performed using the newly introduced retrieval code CLARRA [2]. CLARRA shows a high accuracy in the retrieval of MCP from low-level clouds, which were often observed during the measurements. </p><p>The measurements were performed between June 2017 and August 2017 around Svalbard and include measurements of clouds over sea ice and open water. The spatial distribution of the MCP around Svalbard and a comparison to model results will be shown. This dataset can later serve as a reference for the question, how representative the measurements in Ny-Alesund on Spitzbergen are for the nearby arctic region.</p><p>[1] Wendisch et al., 2019: The Arctic Cloud Puzzle: Using ACLOUD/PASCAL Multi-Platform Observations to Unravel the Role of Clouds and Aerosol Particles in Arctic Amplification, Bull. Amer. Meteor. Soc., 100 (5), 841–871, doi:10.1175/BAMS-D-18-0072.1<br>[2] Rowe et al., 2019: Toward autonomous surface-based infrared remote sensing of polar clouds: retrievals of cloud optical and microphysical properties, Atmos. Meas. Tech., 12, 5071–5086, https://doi.org/10.5194/amt-12-5071-2019</p>

scholarly journals Frequency and distribution of winter melt events from passive microwave satellite data in the pan-Arctic, 1988–2013

2016 ◽  
Author(s):  
Libo Wang ◽  
Peter Toose ◽  
Ross Brown ◽  
Chris Derksen
Keyword(s):  
Snow Cover ◽  
Microwave Radiometer ◽  
Surface Air Temperature ◽  
Arctic Region ◽  
Temporal Variations ◽  
Passive Microwave ◽  
The Arctic ◽  
Winter Period ◽  
Strongly Correlated ◽  
Air Temperatures

Abstract. This study presents an algorithm for detecting winter melt events in seasonal snow cover based on temporal variations in the brightness temperature difference between 19 and 37 GHz from satellite passive microwave measurements. An advantage of the passive microwave approach is that it is based on the physical presence of liquid water in the snowpack, which may not be the case with melt events inferred from surface air temperature data. The algorithm is validated using in situ observations from weather stations, snowpit surveys, and a surface-based passive microwave radiometer. The results of running the algorithm over the pan-Arctic region (north of 50º N) for the 1988–2013 period show that winter melt days are relatively rare averaging less than 7 melt days per winter over most areas, with higher numbers of melt days (around two weeks per winter) occurring in more temperate regions of the Arctic (e.g. central Quebec and Labrador, southern Alaska, and Scandinavia). The observed spatial pattern was similar to winter melt events inferred with surface air temperatures from ERA-interim and MERRA reanalysis datasets. There was little evidence of trends in winter melt frequency except decreases over northern Europe attributed to a shortening of the duration of the winter period. The frequency of winter melt events is shown to be strongly correlated to the duration of winter period. This must be taken into account when analyzing trends to avoid generating false increasing trends from shifts in the timing of the snow cover season.

Exploring the representation of clouds and humidity in the Arctic with cloud-resolving simulations using ICON-LEM

2021 ◽  
Author(s):  
Theresa Kiszler ◽  
Giovanni Chellini ◽  
Kerstin Ebell ◽  
Stefan Kneifel ◽  
Vera Schemann
Keyword(s):  
Microwave Radiometer ◽  
Remote Sensing Data ◽  
Large Data ◽  
Research Unit ◽  
Rain Gauge ◽  
The Arctic ◽  
Arctic Amplification ◽  
Data Set ◽  
Microphysical Processes ◽  
Mixed Phase Clouds

<p>The discussions around Arctic Amplification have led to extensive research, as done in the transregional collaboration (AC)³. One focus are the feedback mechanisms that are strengthening or weakening the warming. Several of these feedbacks involve moisture in the atmosphere in all phases. To understand these better we have been running and analysing daily cloud-resolving simulations. We performed these simulations for a region more strongly affected by the warming around Ny-Ålesund (Svalbard), which is challenging due to its diverse surface properties and mountainous surrounding. We have created an outstandingly large data set of several months of these simulations with 600 m resolution, using the Icosahedral non-hydrostatic model in the large-eddy mode (ICON-LEM).</p> <p>To gain some understanding of how well the model can represent such a complex location, we evaluated the performance of the model. For this, we used a range of observations from the measurement super-site located at Ny-Ålesund. This included radiosondes [1], a rain gauge, a microwave radiometer and further processed remote sensing data. Combining the measurements and simulations enables us to provide thorough statistics for different variables connected to clouds and to establish an understanding of how well they are represented.</p> <p>We show that the model is capable of simulating the two distinct flow regimes in the boundary layer and the free troposphere. Further, we found a tendency in the model to misrepresent liquid and mixed-phase clouds as purely ice clouds. Though the water vapour is well captured, we found further steps in the chain towards precipitation formation are insufficiently represented. Through the use of forward simulations and expanded model output, we can continue to get a better picture of possibilities to understand and improve the microphysical processes.</p> <p><em>This work was supported by the</em><em> DFG funded Transregio-project TR 172 “Arctic Amplification </em>(AC)3<em>“.</em></p> <p><strong>References</strong></p> <p>[1] M. Maturilli, High resolution radiosonde measurements from station Ny-Ålesund (2017-04 et seq). <em>Alfred</em> <em>Wegener Institute - Research Unit Potsdam, PANGAEA</em>, https://doi.org/10.1594/PANGAEA.914973 (2020)</p>

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 Ground-based remote sensing of thin clouds in the Arctic

2012 ◽  
Vol 5 (6) ◽  
pp. 8653-8699 ◽  
Author(s):  
T. J. Garrett ◽  
C. Zhao
Keyword(s):  
Water Vapor ◽  
Thermal Emission ◽  
Stratospheric Ozone ◽  
Microwave Radiometer ◽  
Single Layer ◽  
Primary Source ◽  
The Arctic ◽  
Liquid Water Path ◽  
Water Path ◽  
Microphysical Properties

Abstract. This paper describes a method for using interferometer measurements of downwelling thermal radiation to retrieve the properties of single-layer clouds. Cloud phase is determined from ratios of thermal emission in three "micro-windows" where absorption by water vapor is particularly small. Cloud microphysical and optical properties are retrieved from thermal emission in two micro-windows, constrained by the transmission through clouds of stratospheric ozone emission. Assuming a cloud does not approximate a blackbody, the estimated 95% confidence retrieval errors in effective radius, visible optical depth, number concentration, and water path are, respectively, 10%, 20%, 38% (55% for ice crystals), and 16%. Applied to data from the Atmospheric Radiation Measurement program (ARM) North Slope of Alaska – Adjacent Arctic Ocean (NSA-AAO) site near Barrow, Alaska, retrievals show general agreement with ground-based microwave radiometer measurements of liquid water path. Compared to other retrieval methods, advantages of this technique include its ability to characterize thin clouds year round, that water vapor is not a primary source of retrieval error, and that the retrievals of microphysical properties are only weakly sensitive to retrieved cloud phase. The primary limitation is the inapplicability to thicker clouds that radiate as blackbodies.

scholarly journals The role of moisture transport for precipitation in the inter-annual and inter-daily fluctuations of the Arctic sea ice extension

2019 ◽  
Vol 10 (1) ◽  
pp. 121-133 ◽  
Author(s):  
Luis Gimeno-Sotelo ◽  
Raquel Nieto ◽  
Marta Vázquez ◽  
Luis Gimeno
Keyword(s):  
Sea Ice ◽  
Moisture Transport ◽  
Arctic Region ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Ice Melting ◽  
Sea Ice Extent ◽  
Moisture Sources ◽  
Arctic Sea

Abstract. By considering the moisture transport for precipitation (MTP) for a target region to be the moisture that arrives in this region from its major moisture sources and which then results in precipitation in that region, we explore (i) whether the MTP from the main moisture sources for the Arctic region is linked with inter-annual fluctuations in the extent of Arctic sea ice superimposed on its decline and (ii) the role of extreme MTP events in the inter-daily change in the Arctic sea ice extent (SIE) when extreme MTP simultaneously arrives from the four main moisture regions that supply it. The results suggest (1) that ice melting at the scale of inter-annual fluctuations against the trend is favoured by an increase in moisture transport in summer, autumn, and winter and a decrease in spring and, (2) on a daily basis, extreme humidity transport increases the formation of ice in winter and decreases it in spring, summer, and autumn; in these three seasons extreme humidity transport therefore contributes to Arctic sea ice melting. These patterns differ sharply from that linked to the decline on a long-range scale, especially in summer when the opposite trend applies, as ice melt is favoured by a decrease in moisture transport for this season at this scale.

scholarly journals Five Basic Cornerstones of Sustainability Education in the Arctic

2020 ◽  
Vol 12 (4) ◽  
pp. 1431 ◽  
Author(s):  
Kaarina Määttä ◽  
Sanna Hyvärinen ◽  
Tanja Äärelä ◽  
Satu Uusiautti
Keyword(s):  
Educational Psychology ◽  
Teaching And Learning ◽  
Arctic Region ◽  
The Arctic ◽  
Learning And Teaching ◽  
Sustainable Education ◽  
Economic Climate ◽  
New Ideas ◽  
The Arctic Region

The Arctic region faces many threats but also opportunities due to economic, climate, environmental, cultural, social, professional, educational, and institutional changes, which also necessitate new perspectives on sustainable education. When implementing sustainable education in the Arctic, it is important to increase knowledge and understanding of the special features of Arctic areas—their opportunities and vulnerabilities. In this article, the model of Arctic sustainable education (ASE) has been introduced. It is based on a new kind of lifestyle that illustrates respectful and responsible attitudes toward other people and nature. What are the special features of the teaching and learning of ASE and how to organize it? In this theoretical article, we have discussed the challenges and goals, and possibilities and significance of ASE by leaning on the five cornerstones, concerning learning and teaching of SE in schools and organizations: why, what, how, who, and when. The ASE may provide new ideas to develop sustainable education not just in the Arctic region but also elsewhere as it gets its special opportunities and expectations in a context- and time-bound manner. In conclusion, the role of educational psychology in ASE has been viewed and discussed.

scholarly journals The Role of the Russian Language in the Historic and Cultural Development of the Arctic Region of the Russian Federation (as Exemplified by the Murmansk Region)

2018 ◽  
Vol 7 (3.15) ◽  
pp. 253
Author(s):  
Olga Nikolaevna Ivanishcheva ◽  
Anasstasija Vjacheslavovna Koreneva ◽  
Alexandra Vjacheslavovna Burtseva ◽  
Tatjana Alexandrovna Rychkova
Keyword(s):  
18Th Century ◽  
Arctic Region ◽  
Cultural Development ◽  
Russian Language ◽  
The Arctic ◽  
Murmansk Region ◽  
The Russian Federation ◽  
The Russian Language ◽  
The Arctic Region

The article aims to analyze the functioning of the Russian language within the ethnic space of the Murmansk Region. The analysis of the state statistical and archive documents for the Murmansk Region has shown that the Russian language has dominated within the region since at least the 18th century, and this had its obvious economic and communicative advantages, in particular, in education. The Saami, the indigenous small-numbered people of the Murmansk Region, understood and mastered the conversational Russian language since the 18th century. The Russian language dominates within the current polyethnic linguistic environment of the Murmansk Region due to the numerical superiority of the Russians in the region, as well as due to its position as the language of the dominant ethnic group. 

scholarly journals Revisiting Russian Presidency in the Arctic Council

2021 ◽  
Vol 21 (3) ◽  
pp. 62-68
Author(s):  
Valery Zhuravel ◽  
Keyword(s):  
Arctic Region ◽  
The Arctic ◽  
Arctic Council ◽  
Shift Method ◽  
The Sustainable Development ◽  
Arctic Regions ◽  
Difficult Time ◽  
Environmental Requirements ◽  
And Control

The article notes that in the period of preparation for the chairmanship of the Arctic Council (2021–2023), in order to further develop the Arctic zone of the Russian Federation, new strategic documents, a package of benefits and preferences for business development were prepared and approved, measures were taken for the sustainable development of indigenous peoples, and to increase the role of science in Arctic research. The author draws attention to some unsolved problems of socio-economic development of the Arctic region (outflow of the population, especially young people; shortcomings of the organization of the shift method of work and centralized coordination and control of state orders and supplies to the population of hard-to-reach Arctic regions; violation of environmental requirements). It is emphasized that Russia assumes the post of chairman of the Arctic Council at a difficult time: the coronavirus pandemic, political tensions in relations with the West, including on issues of management and security of the Arctic, economic sanctions from the Arctic states, which creates certain difficulties in the activities in the Arctic direction. The author concludes that the developed program, the plan of main events, the activity of ministries and departments in the next 2 years will allow us to successfully cope with the chairmanship, show our foreign colleagues all the best that is available in the Russian Far North, and contribute to the strengthening of the Arctic Council.

scholarly journals Estimating subpixel turbulent heat flux over leads from MODIS thermal infrared imagery with deep learning

2021 ◽  
Vol 15 (6) ◽  
pp. 2835-2856
Author(s):  
Zhixiang Yin ◽  
Xiaodong Li ◽  
Yong Ge ◽  
Cheng Shang ◽  
Xinyan Li ◽  
...  
Keyword(s):  
Heat Flux ◽  
Spatial Resolution ◽  
Arctic Region ◽  
Open Water ◽  
Turbulent Heat Flux ◽  
The Arctic ◽  
Turbulent Heat ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Thermal Infrared Imagery ◽  
Ice Surface Temperature

Abstract. The turbulent heat flux (THF) over leads is an important parameter for climate change monitoring in the Arctic region. THF over leads is often calculated from satellite-derived ice surface temperature (IST) products, in which mixed pixels containing both ice and open water along lead boundaries reduce the accuracy of calculated THF. To address this problem, this paper proposes a deep residual convolutional neural network (CNN)-based framework to estimate THF over leads at the subpixel scale (DeepSTHF) based on remotely sensed images. The proposed DeepSTHF provides an IST image and the corresponding lead map with a finer spatial resolution than the input IST image so that the subpixel-scale THF can be estimated from them. The proposed approach is verified using simulated and real Moderate Resolution Imaging Spectroradiometer images and compared with the conventional cubic interpolation and pixel-based methods. The results demonstrate that the proposed CNN-based method can effectively estimate subpixel-scale information from the coarse data and performs well in producing fine-spatial-resolution IST images and lead maps, thereby providing more accurate and reliable THF over leads.

scholarly journals The Arctic Five: search for a balance of power in the region

2020 ◽  
Vol 7 (3) ◽  
pp. 276-287
Author(s):  
I. S. Doroshenko
Keyword(s):  
Development Strategy ◽  
Arctic Region ◽  
Balance Of Power ◽  
The Arctic ◽  
The North ◽  
Northern Latitudes ◽  
The Development Strategy ◽  
Northern Territories ◽  
The Arctic Region

Due to climate change, the Arctic region becomes a place of geopolitical rivalry of both Arctic and non-Arctic states. Traditional formats for determining the agenda in the region are effective, but with the advent of the interest of an increasing number of international actors, these formats are transforming, which may affect the balance of power in the region. The growing activity of Asian countries in the Arctic, primarily China, is forcing regional states to make adjustments to the development strategy of the region. The rapid renewal of its potential in the northern territories of Russia caused a negative reaction from the western countries, especially after 2014.Such aspirations have emerged as the internationalization of the region by Northern Europe and China, the desire to draw clear boundaries on the part of Russia and Canada, and the buildup of US influence on its colleagues in the North Atlantic bloc. This situation may cause an uncontrolled increase in tension in the region, especially if new alliances between the Arctic and non-Arctic countries are created. The author considers the current approaches of the countries of the Arctic five, analyzes the true motives of internationalization and the role of the format of the Arctic five in maintaining a balance of power and stability in the northern latitudes.

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