seasonal heat
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2021 ◽  
Vol 40 ◽  
Author(s):  
Fabian E.Z. Ercan ◽  
Daan Blok ◽  
Stef Weijers ◽  
Astrid Odé ◽  
Friederike Wagner-Cremer

The North Atlantic Oscillation (NAO) determines wind speed and direction, seasonal heat, moisture transport, storm tracks, cloudiness and sea-ice cover through atmospheric mass balance shifts between the Arctic and the subtropical Atlantic. The NAO is characterized by the typical, yet insufficiently understood, seesaw pattern of warmer winter and spring temperatures over Scandinavia and cooler temperatures over Greenland during the positive phase of the NAO, and vice versa during the negative phase. We tested the potential to reconstruct NAO variation beyond the meteorological record through the application of a microphenological proxy. We measured the Undulation Index (UI) in Betula nana epidermal cells from herbarium leaf samples and fossil peat fragments dating back to 1865—exceeding most meteorological records in the Arctic—to estimate imprints of spring thermal properties and NAO in Greenland and Finland. We found negative relations between Greenland UI and late winter, spring and early summer NAO, and mostly positive, but not significant, relations between Finland UI and NAO in years with pronounced NAO expression. The direction of the UI response in this common circumpolar species is, therefore, likely in line with the NAO seesaw effect, with leaf development response to NAO fluctuations in northern Europe opposing the response in Greenland and vice versa. Increased knowledge of the UI response to climate may contribute to understanding ecological properties of key Arctic species, whilst additionally providing a proxy for NAO dynamics.


Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7958
Author(s):  
Els van der Roest ◽  
Stijn Beernink ◽  
Niels Hartog ◽  
Jan Peter van der Hoek ◽  
Martin Bloemendal

In the energy transition, multi-energy systems are crucial to reduce the temporal, spatial and functional mismatch between sustainable energy supply and demand. Technologies as power-to-heat (PtH) allow flexible and effective utilisation of available surplus green electricity when integrated with seasonal heat storage options. However, insights and methods for integration of PtH and seasonal heat storage in multi-energy systems are lacking. Therefore, in this study, we developed methods for improved integration and control of a high temperature aquifer thermal energy storage (HT-ATES) system within a decentralized multi-energy system. To this end, we expanded and integrated a multi-energy system model with a numerical hydro-thermal model to dynamically simulate the functioning of several HT-ATES system designs for a case study of a neighbourhood of 2000 houses. Results show that the integration of HT-ATES with PtH allows 100% provision of the yearly heat demand, with a maximum 25% smaller heat pump than without HT-ATES. Success of the system is partly caused by the developed mode of operation whereby the heat pump lowers the threshold temperature of the HT-ATES, as this increases HT-ATES performance and decreases the overall costs of heat production. Overall, this study shows that the integration of HT-ATES in a multi-energy system is suitable to match annual heat demand and supply, and to increase local sustainable energy use.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12252
Author(s):  
Yajun Chen ◽  
Zhixin Guo ◽  
Lili Dong ◽  
Zhenxuan Fu ◽  
Qianjiao Zheng ◽  
...  

Rapid rise in temperature in summer causes severe injury to cool-season turfgrass of both native species and introduced ones in Heilongjiang of Northeast China. The objectives of this study were to compare physiological responses to seasonal heat stresses and turf performances between native and introduced commercial Poa accessions. Three Chinese native Poa species (i.e., P. pratensis, P. sibirica and P. sphondylodes) and three USA Kentucky bluegrass cultivars (ie. ‘Midnight’, ‘Moonlight’ and ‘BlueChip’) were evaluated under field conditions in 2017 and 2018. All accessions showed unique characteristics and considerable seasonal differences in response to temperatures. However, performances over all accessions were largely similar in early spring and autumn. In summer, native P. pratensis performed similar to ‘Midnight’, ‘Moonlight’ or ‘BlueChip’, with respect to such traits or parameters as quality, coverage, color intensity, growth rate, osmolytes, ROS and anti-oxidant production. Native P. pratensis could be used as a new turf resource for further improvement and application under the specific climatic conditions in Heilongjiang; native P. sphondylodes may be used in repairing damaged environments or for alternative seasonal greenness.


Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6118
Author(s):  
Marek Cierpiał-Wolan ◽  
Bogdan Wierzbiński ◽  
Dariusz Twaróg

Biogas production in Poland and Ukraine seems to be a good way to both reduce greenhouse gas emissions and increase energy self-sufficiency by supplementing conventional energy sources. The aim of the research was to assess the potential of biogas production and the possibility of increasing it at the regional level of both studied countries and was conducted in 2018. The study included an analysis of seasonal heat demand, and the results showed biogas heat surpluses and shortages in each region. The financial side of the investment discussed using the example of the selected administrative unit showed that the construction costs of the biogas plant would be paid back after 7~9 years. The presented results also showed that Polish regions have much higher variation of biogas production potential (0.14~1.09 billion m3) than Ukrainian regions (0.09~0.3 billion m3). The analysis of the possibilities of increasing the potential based on the cultivation of maize in wastelands showed that in this respect, the Ukrainian regions have better opportunities compared to Polish regions. In the case of 20 regions, the maximum use of the potential of biogas should result in an increase in the share of renewable sources in the energy mix to above the level of 25%. Poland and Ukraine have comparable biogas production potentials of ~10 billion m3 annually, which results in a comparable number of biogas plants needed to consume that potential as well as the number of new jobs. The above analyses were also carried out at the LAU level (powiats and raions) where the potential of regional cooperation for four border regions is discussed.


Horticulturae ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 229
Author(s):  
Tommaso Frioni ◽  
Cecilia Squeri ◽  
Filippo Del Zozzo ◽  
Paolo Guadagna ◽  
Matteo Gatti ◽  
...  

Breeding technologies exploiting marker-assisted selection have accelerated the selection of new cross-bred pathogen-resistant grapevine varieties. Several genotypes have been patented and admitted to cultivation; however, while their tolerance to fungal diseases has been the object of several in vitro and field studies, their productive and fruit composition traits during ripening are still poorly explored, especially in warm sites. In this study, five white pathogen-resistant varieties (PRVs) listed as UD 80–100, Soreli, UD 30–080, Sauvignon Rytos, Sauvignon Kretos were tested over two consecutive seasons in a site with a seasonal heat accumulation of about 2000 growing degree days (GDDs), and their performances were compared to two Vitis vinifera L. traditional varieties, Ortrugo and Sauvignon Blanc. Berries were weekly sampled from pre-veraison until harvest to determine total soluble solids (TSS) and titratable acidity (TA) dynamics. All tested PRV exhibited an earlier onset of veraison and a faster sugar accumulation, as compared to Ortrugo and Sauvignon Blanc, especially in 2019. At harvest, Sauvignon Blanc was the cultivar showing the highest titratable acidity (8.8 g/L). Ortrugo and PRV varieties showed very low TA (about 4.7 g/L), with the exception of Sauvignon Rytos (6.5 g/L). However, data disclose that Sauvignon Rytos higher acidity at harvest relies on higher tartrate (+1.1 to +2.2 g/L, as compared to other PRV), whereas in Sauvignon Blanc, high TA at harvest is due to either tartaric (+1 g/L, compared to PRV) and malic (+2.5 g/L, compared to PRV) acid retention. Overall, Sauvignon Rytos is the most suited PRV to be grown in a warm climate, where retaining adequate acidity at harvest is crucial to produce high-quality white wines. Nevertheless, canopy and ripening management strategies must be significantly adjusted, as compared to the standard practice employed for the parental Sauvignon Blanc.


2021 ◽  
Vol 65 (2-4) ◽  
pp. 337-344
Author(s):  
Giuseppe Emmi ◽  
Alessia Natali ◽  
Silvia Cesari ◽  
Patrizio Fausti ◽  
Michele Bottarelli

The improvement of energy efficiency in the building sector is one of the most promising actions for achieving the energy and environmental goals of the European Community. The deep retrofit of buildings is obviously the best solution in terms of energy performance result. When the deep retrofit is not allowed or possible, the simple maintenance of the building envelope and plant is usually done to assure the operation over time. This type of intervention could require the installation of new HVAC systems that could include a HP, which nowadays represents one of the key devices for the energy saving and the sustainable development. This work regards the study of the energy performance of a swimming Pool Centre in North-East Italy. The objective of this work is the exploitation of an outdoor swimming pool as a heat source for a HP system. The HP system uses two different heat sources, the air and the water. The final SCOP of the double source HP system has been calculated and compared with an air source HP solution. This analysis has been carried out by means of dynamic energy simulations in TRNSYS environment.


2021 ◽  
Author(s):  
Xue Chen ◽  
Jia Nan Dong ◽  
Ji Ye Rong ◽  
Jun Xiao ◽  
Wei Zhao ◽  
...  

Abstract This study aimed to explore the seasonal heat stress affects the milk yield, antioxidative levels and serum metabolites in primiparous and multiparous dairy cows during early lactation. A total of two hundred dairy cows were selected according to their calving months (June, temperature humidity index (THI) =66.72; July, THI=70.30; August, THI=69.32; September, THI=67.20; October, THI=59.45). Blood samples were collected on day 0, 21, 50, 80, 100 after calving for serum oxidative status analysis and milk yield was recorded every day. The lower average daily milk yield in cows that calved in June and July (P<0.05), and average daily milk yield of multiparous cows was higher than that of primiparous cows that calved in the same month (P<0.05), suggesting that seasonal (June) heat stress negatively affected milk yield in both primiparous and multiparous cows at early lactation. Besides, 15 and 11 serum metabolites were changed in heat stress (average THI = 70.30) group compared with non heat stress (average THI = 59.45) group in primiparous cows and multiparous cows, respectively. These metabolites were mainly involved in the pathways of aminoacyl-tRNA biosynthesis, glyoxylate and dicarboxylate metabolism, and the metabolism of glycine, serine and threonine. These data suggested that heat stress negatively affected the milk yield and thus caused the the elevation of 2 the serum oxidative and antioxidative index Metabolic biomarkers associated with the heat stress 29 in serum were found 0 which providing the basement of evaluating indicator between heat stress and non heat stress groups in primiparous and multiparous cows.


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