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 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.

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 Temperature and Precipitation Extremes over the Iberian Peninsula under Climate Change Scenarios: A Review

Climate ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 139
Author(s):  
Susana C. Pereira ◽  
David Carvalho ◽  
Alfredo Rocha
Keyword(s):  
Climate Change ◽  
Iberian Peninsula ◽  
Climate Modeling ◽  
Heavy Precipitation ◽  
Precipitation Extremes ◽  
Maximum Temperature ◽  
Climate Change Signal ◽  
Climate Change Scenarios ◽  
The Past ◽  
Temperature And Precipitation

This paper presents the results of a systematic review of temperature and precipitation extremes over the Iberian Peninsula, focusing on observed changes in temperature and precipitation during the past years and what are the projected changes by the end of the 21st century. The purpose of this review is to assess the current literature about extreme events and their change under global warming. Observational and climate modeling studies from the past decade were considered in this review. Based on observational evidence and in climate modeling experiments, mean and maximum temperatures are projected to increase about 2 °C around the mid-century and up to 4 °C by the end of the century. The more pronounced warming is expected in summer for the central-south region of IP, with temperatures reaching 6 °C to 8 °C around 2100. Days with maximum temperature exceeding 30 °C and 40 °C will become more common (20 to 50 days/year), and the heatwaves will be 7 to 10 times more frequent. Significative reduction in events related to cold extremes. The climate change signal for precipitation in IP shows a considerable decline in precipitation (10–15%) for all seasons except winter. It is predicted that heavy precipitation will increase by 7% to 15%. Extreme precipitation will increase slightly (5%) by mid-century, then decline to 0% by 2100. Significant reduction in wet days (40% to 60%) followed by a dryness trend more pronounced by the end of the century.

The morphology of experimentally produced charcoal distinguishes fuel types in the Arctic tundra

The Holocene ◽  
2020 ◽  
Vol 30 (7) ◽  
pp. 1091-1096 ◽  
Author(s):  
Eleanor MB Pereboom ◽  
Richard S Vachula ◽  
Yongsong Huang ◽  
James Russell
Keyword(s):  
Arctic Tundra ◽  
Global Carbon Cycle ◽  
Fire Frequency ◽  
The Arctic ◽  
Fuel Type ◽  
The Past ◽  
Primary Means ◽  
Forested Ecosystems ◽  
Global Carbon ◽  
Tundra Ecosystems

Wildfires in the Arctic tundra have become increasingly frequent in recent years and have important implications for tundra ecosystems and for the global carbon cycle. Lake sediment–based records are the primary means of understanding the climatic influences on tundra fires. Sedimentary charcoal has been used to infer climate-driven changes in tundra fire frequency but thus far cannot differentiate characteristics of the vegetation burnt during fire events. In forested ecosystems, charcoal morphologies have been used to distinguish changes in fuel type consumed by wildfires of the past; however, no such approach has been developed for tundra ecosystems. We show experimentally that charcoal morphologies can be used to differentiate graminoid (mean = 6.77; standard deviation (SD) = 0.23) and shrub (mean = 2.42; SD = 1.86) biomass burnt in tundra fire records. This study is a first step needed to construct more nuanced tundra wildfire histories and to understand how wildfire will impact the region as vegetation and fire change in the future.

scholarly journals Temperature and precipitation regime in LGM human refugia of southwestern Europe inferred from δ13C and δ18O of large mammal remains

2021 ◽  
Vol 255 ◽  
pp. 106796
Author(s):  
Christophe Lécuyer ◽  
Claude Hillaire-Marcel ◽  
Ariane Burke ◽  
Marie-Anne Julien ◽  
Jean-François Hélie
Keyword(s):  
Precipitation Regime ◽  
Large Mammal ◽  
Temperature And Precipitation ◽  
Δ13c And Δ18o

scholarly journals Stable Carbon and Sulfur Isotope Characteristics of Stream Water in a Typical Karst Small Catchment, Southwest China

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 523
Author(s):  
Yang Tang ◽  
Ruiyin Han
Keyword(s):  
Water Samples ◽  
Chemical Weathering ◽  
Stream Water ◽  
Mean Value ◽  
Small Catchment ◽  
Temperature And Precipitation ◽  
Δ13c Value ◽  
Different Seasons ◽  
Sources Of Solutes ◽  
Surface Water Samples

Surface water samples from the Maolan National Natural Reserved Park (MNNRP) were analyzed from Sept. 2013 to June 2014, for major ion concentrations (K+, Na+, Ca2+, Mg2+, Cl−, SO42−, HCO3−), δ13C-DIC and δ34S-SO42− to quantify the sources of solutes and chemical weathering. The results show that HCO3− and SO42− are the main anions in Banzhai watershed, which account for 86.2 and 10.4% of the total anion equivalent, respectively. While Ca2+ and Mg2+ account for 76.9 and 20.5%, respectively. Considerable Mg2+ in stream water indicates that it may be affected by dolomite weathering. stream water samples present the δ13C-DIC values in the range of −16.9‰~−10.8‰ (mean value was −13.9‰), which were lower than that of the groundwater. The δ34S-SO42− values ranged from −15.2‰ to 1.7‰ (mean value was −4.4‰). There was a negative correlation between HCO3− content and δ13C value, implying the result of the interaction of temperature and precipitation intensity in different seasons. The significant positive correlation between SO42− content and δ13C-DIC indicates that H2SO4 may be involved in the weathering process of carbonate rocks in small watershed scale. The content of SO42− in a school sample site was much higher than that of other sample sites for the interference from human sources. The δ34S values show that the average δ34S-SO42− in most sites is close to the δ34S isotopic values of Guizhou coal and rain, indicating that they may be affected by local coal.

scholarly journals Changes in Intense Precipitation over the Central United States

2012 ◽  
Vol 13 (1) ◽  
pp. 47-66 ◽  
Author(s):  
Pavel Ya. Groisman ◽  
Richard W. Knight ◽  
Thomas R. Karl
Keyword(s):  
United States ◽  
Extreme Precipitation ◽  
Heavy Precipitation ◽  
The Past ◽  
Extreme Precipitation Events ◽  
Intense Precipitation ◽  
Central United States ◽  
Extreme Rain ◽  
Rain Events ◽  
Precipitation Events

Abstract In examining intense precipitation over the central United States, the authors consider only days with precipitation when the daily total is above 12.7 mm and focus only on these days and multiday events constructed from such consecutive precipitation days. Analyses show that over the central United States, a statistically significant redistribution in the spectra of intense precipitation days/events during the past decades has occurred. Moderately heavy precipitation events (within a 12.7–25.4 mm day−1 range) became less frequent compared to days and events with precipitation totals above 25.4 mm. During the past 31 yr (compared to the 1948–78 period), significant increases occurred in the frequency of “very heavy” (the daily rain events above 76.2 mm) and extreme precipitation events (defined as daily and multiday rain events with totals above 154.9 mm or 6 in.), with up to 40% increases in the frequency of days and multiday extreme rain events. Tropical cyclones associated with extreme precipitation do not significantly contribute to the changes reported in this study. With time, the internal precipitation structure (e.g., mean and maximum hourly precipitation rates within each preselected range of daily or multiday event totals) did not noticeably change. Several possible causes of observed changes in intense precipitation over the central United States are discussed and/or tested.

scholarly journals Joint Occurrence of Daily Temperature and Precipitation Extreme Events over Canada

2014 ◽  
Vol 53 (9) ◽  
pp. 2148-2162 ◽  
Author(s):  
Bárbara Tencer ◽  
Andrew Weaver ◽  
Francis Zwiers
Keyword(s):  
Climate Models ◽  
Regional Climate ◽  
Heavy Precipitation ◽  
Maximum Temperature ◽  
Daily Minimum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Negative Consequences ◽  
Temperature And Precipitation ◽  
Joint Occurrence

AbstractThe occurrence of individual extremes such as temperature and precipitation extremes can have a great impact on the environment. Agriculture, energy demands, and human health, among other activities, can be affected by extremely high or low temperatures and by extremely dry or wet conditions. The simultaneous or proximate occurrence of both types of extremes could lead to even more profound consequences, however. For example, a dry period can have more negative consequences on agriculture if it is concomitant with or followed by a period of extremely high temperatures. This study analyzes the joint occurrence of very wet conditions and high/low temperature events at stations in Canada. More than one-half of the stations showed a significant positive relationship at the daily time scale between warm nights (daily minimum temperature greater than the 90th percentile) or warm days (daily maximum temperature above the 90th percentile) and heavy-precipitation events (daily precipitation exceeding the 75th percentile), with the greater frequencies found for the east and southwest coasts during autumn and winter. Cold days (daily maximum temperature below the 10th percentile) occur together with intense precipitation more frequently during spring and summer. Simulations by regional climate models show good agreement with observations in the seasonal and spatial variability of the joint distribution, especially when an ensemble of simulations was used.

scholarly journals Changes in Temperature and Precipitation Extremes in Superparameterized CAM in Response to Warmer SSTs

2017 ◽  
Vol 30 (24) ◽  
pp. 9827-9845 ◽  
Author(s):  
Xin Zhou ◽  
Marat F. Khairoutdinov
Keyword(s):  
Large Scale ◽  
Rain Rate ◽  
Precipitable Water ◽  
Heavy Precipitation ◽  
Global Scale ◽  
Precipitation Extremes ◽  
Temperature And Precipitation ◽  
Hourly Data ◽  
Cloud Resolving Model ◽  
Cold Extremes

Subdaily temperature and precipitation extremes in response to warmer SSTs are investigated on a global scale using the superparameterized (SP) Community Atmosphere Model (CAM), in which a cloud-resolving model is embedded in each CAM grid column to simulate convection explicitly. Two 10-yr simulations have been performed using present climatological sea surface temperature (SST) and perturbed SST climatology derived from the representative concentration pathway 8.5 (RCP8.5) scenario. Compared with the conventional CAM, SP-CAM simulates colder temperatures and more realistic intensity distribution of precipitation, especially for heavy precipitation. The temperature and precipitation extremes have been defined by the 99th percentile of the 3-hourly data. For temperature, the changes in the warm and cold extremes are generally consistent between CAM and SP-CAM, with larger changes in warm extremes at low latitudes and larger changes in cold extremes at mid-to-high latitudes. For precipitation, CAM predicts a uniform increase of frequency of precipitation extremes regardless of the rain rate, while SP-CAM predicts a monotonic increase of frequency with increasing rain rate and larger change of intensity for heavier precipitation. The changes in 3-hourly and daily temperature extremes are found to be similar; however, the 3-hourly precipitation extremes have a significantly larger change than daily extremes. The Clausius–Clapeyron scaling is found to be a relatively good predictor of zonally averaged changes in precipitation extremes over midlatitudes but not as good over the tropics and subtropics. The changes in precipitable water and large-scale vertical velocity are equally important to explain the changes in precipitation extremes.

Entertainment and Resonance

2021 ◽  
pp. 122-137
Author(s):  
Peter Vorderer
Keyword(s):  
Media Use ◽  
Affective States ◽  
Recent Past ◽  
The Past ◽  
First Case ◽  
Self Transcendence ◽  
Entertainment Theory

This chapter aims to differentiate between two kinds of media use experiences that in the past twenty some years have uniformly been labeled entertainment experiences. In the background of four identified fundamental assumptions in entertainment theory (entertainment as reception phenomenon, disparity between what media users want and what they should want, entertainment between approaching and avoiding affective states, entertainment as self-transcendence) media experiences are dichotomized between those that serve users’ hedonic motivations, needs, and interests and others, more fundamental experiences of resonance (which in the recent past have often been labeled eudaimonic) that connect users to the content of a media narrative and ultimately changes them. The argument is made here for communication scholars and media psychologists to refer to entertainment experiences only in the first case in order to be less vague and ambiguous in explicating entertainment theory.

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