scholarly journals Changes in Winter Warming Events in the Nordic Arctic Region

2016 ◽  
Vol 29 (17) ◽  
pp. 6223-6244 ◽  
Author(s):  
Dagrun Vikhamar-Schuler ◽  
Ketil Isaksen ◽  
Jan Erik Haugen ◽  
Hans Tømmervik ◽  
Bartlomiej Luks ◽  
...  
Keyword(s):  
Arctic Region ◽  
The Arctic ◽  
Climate Indices ◽  
Ecological Disturbance ◽  
Winter Warming ◽  
The Past ◽  
Temperature And Precipitation ◽  
Weather Events ◽  
Warm Weather ◽  
Soil Temperatures

Abstract In recent years extreme winter warming events have been reported in arctic areas. These events are characterized as extraordinarily warm weather episodes, occasionally combined with intense rainfall, causing ecological disturbance and challenges for arctic societies and infrastructure. Ground-ice formation due to winter rain or melting prevents ungulates from grazing, leads to vegetation browning, and impacts soil temperatures. The authors analyze changes in frequency and intensity of winter warming events in the Nordic arctic region—northern Norway, Sweden, and Finland, including the arctic islands Svalbard and Jan Mayen. This study identifies events in the longest available records of daily temperature and precipitation, as well as in future climate scenarios, and performs analyses of long-term trends for climate indices aimed to capture these individual events. Results show high frequencies of warm weather events during the 1920s–30s and the past 15 years (2000–14), causing weak positive trends over the past 90 years (1924–2014). In contrast, strong positive trends in occurrence and intensity for all climate indices are found for the past 50 years with, for example, increased rates for number of melt days of up to 9.2 days decade−1 for the arctic islands and 3–7 days decade−1 for the arctic mainland. Regional projections for the twenty-first century indicate a significant enhancement of the frequency and intensity of winter warming events. For northern Scandinavia, the simulations indicate a doubling in the number of warming events, compared to 1985–2014, while the projected frequencies for the arctic islands are up to 3 times higher.

Speleothem record of enhanced hydroclimate during MIS15a in Northeast Greenland

2020 ◽  
Author(s):  
Gina Moseley ◽  
R. Lawrence Edwards ◽  
Christoph Spötl ◽  
Hai Cheng
Keyword(s):  
Arctic Region ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Climate History ◽  
Sea Levels ◽  
Temperature And Precipitation ◽  
Arctic Sea ◽  
History Of ◽  
Forcing Mechanisms ◽  
Essential Knowledge

<p>The Arctic region is predicted to be one of the most sensitive areas of the world to future anthropogenically-forced climate change, the consequences of which will affect vast numbers of people worldwide, for instance through changes to mid-latitude weather systems and rising eustatic sea levels. Recent changes in temperature and precipitation, and those projected for the future, indicate that some of the greatest changes will occur in Northeast Greenland. Essential knowledge on the climate history of this region, which can be used to validate models and understand forcing mechanisms and teleconnections, is however absent. Here, we present a speleothem palaeoclimate record for Northeast Greenland (80 °N) that formed during Marine Isotopes Stage 15a  between 588 ka to 537 ka. The record indicates that at that time, Northeast Greenland was warmer and wetter than at present associated with a reduction in Arctic sea ice, thawing of permafrost in eastern Siberia (55 °N and 60 °N), and elevated warm conditions at Lake El’gygytgyn (67.5 °N), Russia.</p>

scholarly journals Recent changes in seasonal variations of climate within the range of northern caribou populations

Rangifer ◽  
2005 ◽  
Vol 25 (4) ◽  
pp. 11 ◽  
Author(s):  
Paul H. Whitfield ◽  
Don Russell
Keyword(s):  
Heavy Precipitation ◽  
The Arctic ◽  
Recent Past ◽  
Potential Significance ◽  
Precipitation Regime ◽  
Climatic Variations ◽  
The Past ◽  
Temperature And Precipitation ◽  
Different Seasons ◽  
Derivatives Of

The Arctic is one region where it is expected that the impacts of a globally changing climate will be readily observed. We present results that indicate that climate derivatives of potential significance to caribou changed during the past 50 years. Many temperature derivatives reflect the increasing overall temperature in the Arctic such as decreases in the number of days with low temperatures, increases in the number of days with thaw, and days with extremely warm temperatures. Other derivatives reflect changes in the precipitation regime such as days with heavy precipitation and number of days when rain fell on snow. Our results indicate that specific caribou herds from across the Arctic were subjected to different variations of these derivatives in different seasons in the recent past. Examination of temperature and precipitation at finer time-steps than annual or monthly means, shows that climatic variations in the region are neither consistent through the seasons nor across space. Decadal changes in seasonal patterns of temperature and precipitation are shown for selected herds. A process for assessing caribou-focused climate derivatives is proposed.

scholarly journals Early Holocene cold snaps and their expression in the moraine record of the Eastern European Alps

2021 ◽  
Author(s):  
Sandra M. Braumann ◽  
Joerg M. Schaefer ◽  
Stephanie M. Neuhuber ◽  
Christopher Lüthgens ◽  
Alan J. Hidy ◽  
...  
Keyword(s):  
Climate Change ◽  
Arctic Region ◽  
Climate System ◽  
Early Holocene ◽  
Ice Age ◽  
The Arctic ◽  
European Alps ◽  
Eastern European ◽  
Exposure Dating ◽  
The Past

Abstract. Glaciers preserve climate variations in their geological and geomorphological records, which makes them prime candidates for climate reconstructions. Investigating the glacier-climate system over the past millennia is particularly relevant because, first, the amplitude and frequency of natural climate variability during the Holocene provides the climatic context against which modern, human-induced climate change must be assessed. Second, the transition from the last glacial to the current interglacial promises important insights into the climate system during warming, which is of particular interest with respect to ongoing climate change. Evidence of stable ice margin positions that record cooling during the past 12 ka are preserved in two glaciated valleys of the Silvretta Massif in the Eastern European Alps, the Jamtal (JAM) and the Laraintal (LAR). We mapped and dated moraines in these catchments including historical ridges using Beryllium-10 Surface Exposure Dating (10Be SED) techniques, and correlate resulting moraine formation intervals with climate proxy records to evaluate the spatial and temporal scale of these cold phases. The new geochronologies indicate two moraine formation intervals (MFI) during the Early Holocene (EH): 10.8 ± 0.7 ka (n = 9) and 11.2 ± 0.8 ka (n = 12). Boulder ages along historical moraines (n = 6) imply at least two glacier advances during the Little Ice Age (LIA; c. 1250–1850 CE), around 1300 CE and in the second half of the 18th century. An earlier advance to the same position may have occurred around 500 CE. The Jamtal and Laraintal moraine chronologies provide evidence that millennial scale EH warming was superimposed by centennial scale cooling. The timing of EH moraine formation is contemporaneous with brief temperature drops identified in local and regional paleoproxy records, most prominently with the Preboreal Oscillation (PBO), and is consistent with moraine deposition in other catchments in the European Alps, and in the Arctic region. This consistency points to cooling beyond the local scale and therefore a regional or even hemispheric climate driver. Freshwater input sourced from the Laurentide Ice Sheet (LIS), which changed circulation patterns in the North Atlantic, is a plausible explanation for EH cooling and moraine formation in the Nordic region and in Europe.

Future Climate Projection and Zoning of Extreme Temperature Indices

2021 ◽  
Author(s):  
Mohammad Askari Zadeh ◽  
Gholamali Mozaffari ◽  
Mansoureh Kouhi ◽  
Younes Khosravi
Keyword(s):  
Carbon Dioxide Emissions ◽  
Extreme Temperature ◽  
Extreme Weather Events ◽  
Base Period ◽  
The Past ◽  
Temperature And Precipitation ◽  
Weather Events ◽  
The Future ◽  
Temperature Indices ◽  
Future Climate Projection

Abstract Global warming due to increasing carbon dioxide emissions over the past two centuries has had numerous climatic consequences. The change in the behavior and characteristics of extreme weather events such as temperature and precipitation is one of the consequences that have been of interest to researchers worldwide. In this study, the trend of 3 extreme indices of temperature: SU35, TR20, and DTR over two future periods have been studied using downscaled output of 3 GCMs in Razavi Khorasan province, Iran. The results show that the range of temperature diurnal variation (DTR) at three stations of Mashhad, Torbat-e-Heydarieh and Sabzevar during the base period has been reduced significantly. The trend of the number of summer days with temperatures above 35°C (SU35) in both Mashhad and Sabzevar stations was positive and no significant trend was found at Torbat-e-Heydarieh station. The number of tropical nights index (TR20) also showed a positive and significant increase in the three stations under study. The results showed highly significant changes in temperature extremes. The percentage of changes in SU35 index related to base period (1961–2014) for all three models (CNCM3, HadCM3 and NCCCSM) under A1B and A2 scenarios indicated a significant increase for the future periods of 2011–2030 and 2046–2065. TR20 is also expected to increase significantly during the two future periods. The percentage of changes of DTR into the future is negligible.

scholarly journals Protest and Apology in the Arctic: Enacting Citizenship in Two Recent Swedish Films

Humanities ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 49
Author(s):  
Lydia Kokkola ◽  
Annbritt Palo ◽  
Lena Manderstedt
Keyword(s):  
School System ◽  
Arctic Region ◽  
First Century ◽  
The Arctic ◽  
Cultural Group ◽  
Female Protagonists ◽  
The Past ◽  
International Reputation ◽  
Rights Issues ◽  
The Arctic Region

Today, Sweden enjoys a positive international reputation for its commitment to human rights issues, for instance, in relation to the recent migrant crisis. Abuses committed by the Swedish state against certain ethnic groups within the country are less well known, both within and beyond its borders. These included systematic attempts to curtail the use of indigenous and local languages, thereby causing communicative and ideological rifts between children and their parents. These policies were enacted through the school system from the 1920s until the 1970s, and particularly affected people living in the Arctic region where the national borders are disputed. In this article, we examine two twenty-first-century films set during this era, featuring feisty female characters responding to the school policy. Elina: As though I wasn’t there is a children’s film created by people “outside” the cultural group represented; and Sámi Blood features an adolescent protagonist (and her older self), created by “insiders” of the cultural group represented. In both films, the female protagonists’ relative lack of agency within the state school system is contrasted with their powerful connections to the Arctic landscape. We seek to examine how these films contribute to the work of apology, beginning with a public acknowledgement of the wrongs of the past. Whilst one of the films concludes with a celebration of the female protagonists’ agency, the other proffers a more ambiguous portrayal of power in relation to culture, nationality, and identity.

scholarly journals Increased persistence of large-scale circulation regimes over Asia in the era of amplified Arctic warming, past and future

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jennifer A. Francis ◽  
Natasa Skific ◽  
Stephen J. Vavrus
Keyword(s):  
Large Scale ◽  
Weather Conditions ◽  
First Century ◽  
The Arctic ◽  
Extreme Weather Events ◽  
Temperature And Precipitation ◽  
Weather Events ◽  
Long Duration ◽  
Pattern Recognition Approach ◽  
Insight Into

Abstract Extreme weather events in Asia have been occurring with increasing frequency as the globe warms in response to rising concentrations of greenhouse gases. Many of these events arise from weather regimes that persist over a region for days or even weeks, resulting in disruptive heatwaves, droughts, flooding, snowfalls, and cold spells. We investigate changes in the persistence of large-scale weather systems through a pattern-recognition approach based on daily 500 hPa geopotential height anomalies over the Asian continent. By tracking consecutive days that the atmosphere resides in a particular pattern, we identify long-duration events (LDEs), defined as lasting longer than three days, and measure their frequency of occurrence over time in each pattern. We find that regimes featuring positive height anomalies in high latitudes are occurring more often as the Arctic warms faster than mid-latitudes, both in the recent past and in model projections for the twenty-first century assuming unabated greenhouse gas emissions. The increased dominance of these patterns corresponds to a higher likelihood of LDEs, suggesting that persistent weather conditions will occur more frequently. By mapping observed temperature and precipitation extremes onto each atmospheric regime, we gain insight into the types of disruptive weather events that will become more prevalent as particular patterns become more common.

scholarly journals Variations of Twentieth-Century Temperature and Precipitation Extreme Indicators in the Northeast United States

2007 ◽  
Vol 20 (21) ◽  
pp. 5401-5417 ◽  
Author(s):  
Michael L. Griffiths ◽  
Raymond S. Bradley
Keyword(s):  
United States ◽  
Southern Oscillation ◽  
Precipitation Extreme ◽  
The Arctic ◽  
The Past ◽  
Orthogonal Function ◽  
Northeast United States ◽  
Temperature And Precipitation ◽  
The Arctic Oscillation ◽  
Consecutive Dry Days

Abstract An examination of five temperature and five precipitation extreme indicators reveals an increase in both temperature and precipitation extremes over the 1926–2000 period in the northeast United States, with most of this increase occurring over the past four decades. Empirical orthogonal function (EOF) analysis of winter frost days (FD) and warm nights (TN90) and also winter consecutive dry days (CDD) and very wet days (R95T) over the 1950–2000 period reveals that some of the variability associated with changes in these extremes may be explained by variations in the Arctic Oscillation (AO), El Niño–Southern Oscillation (ENSO), and Pacific–North American (PNA) pattern. The most prominent feature of these results was the high correlation between the leading EOF of frost days and warm nights and the AO. Winter composites of temperature and precipitation extreme indicators were examined for different phases of the AO and ENSO during the 1926–2000 period. Overall, the AO is a better predictor of winter warm nights, while the ENSO is a better predictor of consecutive dry days in the northeast United States.

scholarly journals An n-Dimensional Generalization of the Rhombus Tiling

2001 ◽  
Vol DMTCS Proceedings vol. AA,... (Proceedings) ◽  
Author(s):  
Joakim Linde ◽  
Cristopher Moore ◽  
Mats G. Nordahl
Keyword(s):  
Mixing Time ◽  
Arctic Region ◽  
Physical Models ◽  
The Arctic ◽  
Height Functions ◽  
The Past ◽  
Arctic Regions ◽  
Coupling From The Past ◽  
Rhombus Tiling ◽  
Random Tilings

International audience Several classic tilings, including rhombuses and dominoes, possess height functions which allow us to 1) prove ergodicity and polynomial mixing times for Markov chains based on local moves, 2) use coupling from the past to sample perfectly random tilings, 3) map the statistics of random tilings at large scales to physical models of random surfaces, and and 4) are related to the "arctic circle"' phenomenon.However, few examples are known for which this approach works in three or more dimensions.Here we show that the rhombus tiling can be generalized to n-dimensional tiles for any $n ≥ 3$. For each $n$, we show that a certain local move is ergodic, and conjecture that it has a mixing time of $O(L^{n+2} log L)$ on regions of size $L$. For $n=3$, the tiles are rhombohedra, and the local move consists of switching between two tilings of a rhombic dodecahedron.We use coupling from the past to sample random tilings of a large rhombic dodecahedron, and show that arctic regions exist in which the tiling is frozen into a fixed state.However, unlike the two-dimensional case in which the arctic region is an inscribed circle, here it seems to be octahedral.In addition, height fluctuations between the boundary of the region and the center appear to be constant rather than growing logarithmically.We conjecture that this is because the physics of the model is in a "smooth" phase where it is rigid at large scales, rather than a "rough" phase in which it is elastic.

scholarly journals The Role of Downward Infrared Radiation in the Recent Arctic Winter Warming Trend

2017 ◽  
Vol 30 (13) ◽  
pp. 4937-4949 ◽  
Author(s):  
Tingting Gong ◽  
Steven Feldstein ◽  
Sukyoung Lee
Keyword(s):  
Infrared Radiation ◽  
Moisture Flux ◽  
Warming Trend ◽  
The Arctic ◽  
Winter Warming ◽  
Planetary Scale ◽  
The Past ◽  
Rossby Wave Response ◽  
Total Column

During the past three decades, the most rapid warming at the surface has occurred during the Arctic winter. By analyzing daily ERA-Interim data, it is found that the majority of the winter warming trend north of 70°N can be explained by the trend in the downward infrared radiation (IR). This downward IR trend can be attributed to an enhanced poleward flux of moisture and sensible heat into the Arctic by poleward-propagating Rossby waves, which increases the total column water and temperature within this region. This enhanced moisture flux is mostly due to changes in the planetary-scale atmospheric circulation rather than an increase in moisture in lower latitudes. The results of this study lead to the question of whether Arctic amplification has mostly arisen through changes in the Rossby wave response to greenhouse gas forcing and its impact on moisture transport into the Arctic.

scholarly journals Early Holocene cold snaps and their expression in the moraine record of the eastern European Alps

2021 ◽  
Vol 17 (6) ◽  
pp. 2451-2479
Author(s):  
Sandra M. Braumann ◽  
Joerg M. Schaefer ◽  
Stephanie M. Neuhuber ◽  
Christopher Lüthgens ◽  
Alan J. Hidy ◽  
...  
Keyword(s):  
Climate Change ◽  
Arctic Region ◽  
Climate System ◽  
Early Holocene ◽  
Ice Age ◽  
The Arctic ◽  
European Alps ◽  
Eastern European ◽  
Exposure Dating ◽  
The Past

Abstract. Glaciers preserve climate variations in their geological and geomorphological records, which makes them prime candidates for climate reconstructions. Investigating the glacier–climate system over the past millennia is particularly relevant first because the amplitude and frequency of natural climate variability during the Holocene provides the climatic context against which modern, human-induced climate change must be assessed. Second, the transition from the last glacial to the current interglacial promises important insights into the climate system during warming, which is of particular interest with respect to ongoing climate change. Evidence of stable ice margin positions that record cooling during the past 12 kyr are preserved in two glaciated valleys of the Silvretta Massif in the eastern European Alps, the Jamtal (JAM) and the Laraintal (LAR). We mapped and dated moraines in these catchments including historical ridges using beryllium-10 surface exposure dating (10Be SED) techniques and correlate resulting moraine formation intervals with climate proxy records to evaluate the spatial and temporal scale of these cold phases. The new geochronologies indicate the formation of moraines during the early Holocene (EH), ca. 11.0 ± 0.7 ka (n = 19). Boulder ages along historical moraines (n = 6) suggest at least two glacier advances during the Little Ice Age (LIA; ca. 1250–1850 CE) around 1300 CE and in the second half of the 18th century. An earlier advance to the same position may have occurred around 500 CE. The Jamtal and Laraintal moraine chronologies provide evidence that millennial-scale EH warming was superimposed by centennial-scale cooling. The timing of EH moraine formation coincides with brief temperature drops identified in local and regional paleoproxy records, most prominently with the Preboreal Oscillation (PBO) and is consistent with moraine deposition in other catchments in the European Alps and in the Arctic region. This consistency points to cooling beyond the local scale and therefore a regional or even hemispheric climate driver. Freshwater input sourced from the Laurentide Ice Sheet (LIS), which changed circulation patterns in the North Atlantic, is a plausible explanation for EH cooling and moraine formation in the Nordic region and in Europe.

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