summer temperatures
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2022 ◽  
Vol 18 (1) ◽  
pp. 23-44
Author(s):  
Irene Schimmelpfennig ◽  
Joerg M. Schaefer ◽  
Jennifer Lamp ◽  
Vincent Godard ◽  
Roseanne Schwartz ◽  
...  

Abstract. Mid-latitude mountain glaciers are sensitive to local summer temperature changes. Chronologies of past glacier fluctuations based on the investigation of glacial landforms therefore allow for a better understanding of natural climate variability at local scale, which is relevant for the assessment of the ongoing anthropogenic climate warming. In this study, we focus on the Holocene, the current interglacial of the last 11 700 years, which remains a matter of dispute regarding its temperature evolution and underlying driving mechanisms. In particular, the nature and significance of the transition from the early to mid-Holocene and of the Holocene Thermal Maximum (HTM) are still debated. Here, we apply an emerging approach by combining in situ cosmogenic 10Be moraine and 10Be–14C bedrock dating from the same site, the forefield of Steingletscher (European Alps), and reconstruct the glacier's millennial recession and advance periods. The results suggest that, subsequent to the final deglaciation at ∼10 ka, the glacier was similar to or smaller than its 2000 CE extent for ∼7 kyr. At ∼3 ka, Steingletscher advanced to an extent slightly outside the maximum Little Ice Age (LIA) position and until the 19th century experienced sizes that were mainly confined between the LIA and 2000 CE extents. These findings agree with existing Holocene glacier chronologies and proxy records of summer temperatures in the Alps, suggesting that glaciers throughout the region were similar to or even smaller than their 2000 CE extent for most of the early and mid-Holocene. Although glaciers in the Alps are currently far from equilibrium with the accelerating anthropogenic warming, thus hindering a simple comparison of summer temperatures associated with modern and paleo-glacier sizes, our findings imply that the summer temperatures during most of the Holocene, including the HTM, were similar to those at the end of the 20th century. Further investigations are necessary to refine the magnitude of warming and the potential HTM seasonality.


2021 ◽  
Vol 214 (11) ◽  
pp. 2-7
Author(s):  
Viktor Valdayskih ◽  
Elena Artem'eva ◽  
Mihail Karpuhin ◽  
R. Mihalischev

Abstract. The purpose of the research is to isolate species of annual and perennial herbaceous plants that are promising for the tasks of accelerating the sequestration of atmospheric carbon, resistant to local soil and climatic conditions and having high productivity from the collection fund of the botanical garden of the Ural Federal University. Methods. The article presents data on the productivity of four types of herbaceous plants: Amaranthus caudatus L., Amaranthus cruentus L., Polygonum weyrichii F. Schmidt and Echinops sphaerocephalus L., grown in the botanical garden. All the research objects were grown under the same conditions. Productivity was measured at the beginning of September. The data were processed using standard statistical methods. Results. It was revealed that the plants P. weyrichii is the most productive in terms of both fresh and dry yield. The yield of the P. weyrichii increases in years with sufficiently high moisture content. Aridity and high summer temperatures have a negative impact on the growth of the P. weyrichii. Amaranths gain a large aboveground mass due to their belonging to the group with the C4 type of photosynthesis. High summer temperatures have a positive effect on the growth and development of amaranths, while correlations with the amount of precipitation are statistically insignificant. The plants E. sphaerocephalus showed average values for productivity and requires further study. It is recommended to grow the plants P. weyrichii in a sufficiently humid area. Amaranth, being a drought-resistant plant, is highly productive in any years, especially in years with the value of the hydrothermal coefficient (HTC) less than 1.0. The scientific novelty lies in the fact that the features of the cultivation of the studied crops are considered not only for forage purposes but also from the point of view of atmospheric carbon deposition and cultivation on potential carbon farms in the changing climate of the region.


Insects ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1118
Author(s):  
Priscillia Hanache ◽  
Thierry Thomann ◽  
Valerie Caron ◽  
Gaylord A. Desurmont

Terrestrial snails that live in hot and dry climates have developed strategies to cope with high summer temperatures. Several species estivate during the warmest months of the years by resting on vertical supports, typically in groups. Understanding how snails choose their estivation sites and aggregate may lead to the development of new management tools in areas where these snails are invasive. Here, we investigated the preferences of four snail species for vertical supports varying in widths and heights under laboratory and field conditions, and tested whether the presence of conspecifics or snails of other species affected these preferences. The results show that the snails strongly preferred wider supports in laboratory dual-choice tests, and one species (Theba pisana) showed a consistent preference for taller supports as well. These results were confirmed in the field, where more snails were found on wider and taller supports 24 h after being placed in test quadrats. The percentage of snails found in groups on a support was strongly density-dependent. The presence of conspecifics or their mucus did not affect the choices of the snails, nor did the presence of snails of other species or their mucus. Taken together, these results could lead to the development of attractive supports that could be used to mass-capture snails in the field.


2021 ◽  
Vol 13 (23) ◽  
pp. 13056
Author(s):  
Yutao Huang ◽  
Xuezhen Zhang ◽  
Dan Zhang ◽  
Lijuan Zhang ◽  
Wenshuai Zhang ◽  
...  

In the context of global warming, a key scientific question for the sustainable development of the Arctic tourism industry is whether the region’s climate is becoming more suitable for tourism. Based on the ERA5-HEAT (Human thErmAl comforT) dataset from the European Center for Medium-range Weather Forecasts (ECMWF), this study used statistical methods such as climatic tendency rate and RAPS to analyze the spatial-temporal changes in Arctic summer climate comfort zones from 1979 to 2019 and to explore the influence of changes in climate comfort on Arctic tourism. The results showed the following: (1) With the increase in the Arctic summer temperature, the universal thermal climate index (UTCI) rose significantly from 1979 to 2019 at a rate of 0.457 °C/10a. There was an abrupt change in 2001, when the climate comfort changed from “colder” to “cool”, and the climate comfort has remained cool over the past decade (2010–2019). (2) With the increase in Arctic summer temperatures, the area assessed as “comfortable” increased significantly from 1979 to 2019 at a rate of 2.114 × 105 km2/10a. Compared with the comfortable area in the 1980s, the comfortable area increased by 6.353 × 105 km2 over the past 10 years and expanded to high-latitude and high-altitude areas, mainly in Kola Peninsula, Putorana Plateau, and Verkhoyansk Mountains in Russia, as well as the Brooks Mountains in Alaska. (3) With the increase in Arctic summer temperatures, the number of days rated comfortable on 30% of the grid increased significantly from 1979 to 2019 (maximum increase: 31 days). The spatial range of the area with a low level of comfortable days narrowed and the spatial range of the area with a high level of such days expanded. The area with 60–70 comfortable days increased the most (4.57 × 105 km2). The results of this study suggest that global warming exerts a significant influence on the Arctic summer climate comfort level and provides favorable conditions for further development of regional tourism resources.


2021 ◽  
Vol 9 ◽  
Author(s):  
Sarah R. Hoy ◽  
Leah M. Vucetich ◽  
Rolf O. Peterson ◽  
John A. Vucetich

Climate change is expected to modify host-parasite interactions which is concerning because parasites are involved in most food-web links, and parasites have important influences on the structure, productivity and stability of communities and ecosystems. However, the impact of climate change on host–parasite interactions and any cascading effects on other ecosystem processes has received relatively little empirical attention. We assessed host-parasite dynamics for moose (Alces alces) and winter ticks (Dermacentor albipictus) in Isle Royale National Park over a 19-year period. Specifically, we monitored annual tick burdens for moose (estimated from hair loss) and assessed how it covaried with several aspects of seasonal climate, and non-climatic factors, such as moose density, predation on hosts by wolves (Canis lupus) and wolf abundance. Summer temperatures explained half the interannual variance in tick burden with tick burden being greater following hotter summers, presumably because warmer temperatures accelerate the development of tick eggs and increase egg survival. That finding is consistent with the general expectation that warmer temperatures may promote higher parasite burdens. However, summer temperatures are warming less rapidly than other seasons across most regions of North America. Therefore, tick burdens seem to be primarily associated with an aspect of climate that is currently exhibiting a lower rate of change. Tick burdens were also positively correlated with predation rate, which could be due to moose exhibiting risk-sensitive habitat selection (in years when predation risk is high) in such a manner as to increases the encounter rate with questing tick larvae in autumn. However, that positive correlation could also arise if high parasite burdens make moose more vulnerable to predators or because of some other density-dependent process (given that predation rate and moose density are highly correlated). Overall, these results provide valuable insights about interrelationships among climate, parasites, host/prey, and predators.


2021 ◽  
Author(s):  
◽  
Lisa French

<p>Analysis of indoor temperature measurements taken in 397 randomly selected houses has revealed that New Zealand houses are becoming warmer in summer. Houses built at the end of the 20th century are during the daytime (9 am to 5 pm), on average, 2.5 degrees C warmer during summer months (December to February) than houses built at the start. For example, in houses built during the 1990s, temperatures above 25 degrees C are found 40% of the time during the summer early evening (4 pm to 6 pm) - temperatures that could be considered as uncomfortably warm in a temperate climate. Since 2006 there has been a rapid uptake of heat pumps in New Zealand, and a survey provides evidence of a growing number of households actively cooling, when traditionally very little cooling has been done. The ability for occupants to cool during the warm summer early evening has the potential to create an additional peak load on the electricity network. The trend towards increasing indoor summer temperatures could be due to a range of features, including house design, construction and operation. These have been explored through analysis of the temperature data and thermal modelling using SUNREL with validated models of five houses. Although the monitored sample was sizable, the variation in occupant behaviour means it was not possible to explore all potential drivers or eliminate other influences. The use of thermal modelling permitted parametric investigation of the role of different features to be explored. The analysis of monitoring data and the thermal modelling showed that the main causes of increasing temperatures are: increasing glazing area; lower ventilation rates; reduction of external shading through reduced eave size; and to a lesser extent increased levels of thermal insulation. These findings have been used to provide guidance for new house designers as well as suggestions for modifications of existing houses.</p>


2021 ◽  
Author(s):  
◽  
Lisa French

<p>Analysis of indoor temperature measurements taken in 397 randomly selected houses has revealed that New Zealand houses are becoming warmer in summer. Houses built at the end of the 20th century are during the daytime (9 am to 5 pm), on average, 2.5 degrees C warmer during summer months (December to February) than houses built at the start. For example, in houses built during the 1990s, temperatures above 25 degrees C are found 40% of the time during the summer early evening (4 pm to 6 pm) - temperatures that could be considered as uncomfortably warm in a temperate climate. Since 2006 there has been a rapid uptake of heat pumps in New Zealand, and a survey provides evidence of a growing number of households actively cooling, when traditionally very little cooling has been done. The ability for occupants to cool during the warm summer early evening has the potential to create an additional peak load on the electricity network. The trend towards increasing indoor summer temperatures could be due to a range of features, including house design, construction and operation. These have been explored through analysis of the temperature data and thermal modelling using SUNREL with validated models of five houses. Although the monitored sample was sizable, the variation in occupant behaviour means it was not possible to explore all potential drivers or eliminate other influences. The use of thermal modelling permitted parametric investigation of the role of different features to be explored. The analysis of monitoring data and the thermal modelling showed that the main causes of increasing temperatures are: increasing glazing area; lower ventilation rates; reduction of external shading through reduced eave size; and to a lesser extent increased levels of thermal insulation. These findings have been used to provide guidance for new house designers as well as suggestions for modifications of existing houses.</p>


2021 ◽  
Vol 10 ◽  
Author(s):  
Ole Bennike ◽  
Theis Zetner Trolle Jensen ◽  
Alberto John Taurozzi ◽  
Meaghan Mackie ◽  
Lone Claudi-Hansen ◽  
...  

A small, shed antler fragment of a reindeer from Sjælland, Denmark has been dated to the Mid-Holocene, ca., 4700 cal B.C. Reindeer was an important component of the Lateglacial fauna in Denmark, and the species survived for ca. 1400 years into the Holocene. However, we consider it highly unlikely that this species inhabited Denmark during the Mid-Holocene, when dense forests characterized the vegetation and summer temperatures were somewhat higher than at present. We suggest that the reindeer antler came to Sjælland from Norway or Sweden as a result of trade, perhaps involving flint.


Plant Biology ◽  
2021 ◽  
Author(s):  
N. Kunert ◽  
P. Hajek ◽  
P. Hietz ◽  
H. Morris ◽  
S. Rosner ◽  
...  

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