Winter Climatic Conditions Research Articles

Effect of Indaziflam Applications on ‘Tifway 419’ Bermudagrass Growth

Indaziflam {N‐[(1R,S)‐2,3‐dihyrdo‐2,6‐dimethyl‐1H‐inden‐1‐yl]‐6‐(1‐fluorethyl)1,3,5‐triazine‐2,4‐diamine} is a preemergence herbicide for annual weed control in turfgrass systems. Following indaziflam U.S. registration in 2010, sporadic cases of hybrid bermudagrass (HB) injury were reported. Field research was conducted from 2012 to 2014 evaluating indaziflam application rates [16 followed by 16 (28 d), 33, 49, or 65 g a.i. ha−1] and timings (fall‐only, fall‐plus‐spring, or spring‐only) in two environments (reduced sunlight [RS] and full sunlight [FS]) to elucidate their effect on HB growth. In Year 1, differences were not detected, while in Year 2 HB cover varied between environments. In Year 2, HB cover in the RS environment treated with 49 and 65 g ha−1 had 36 and 64% less visual cover 12 wk after initial spring treatment than the FS environment, respectively. Within the RS environment, indaziflam also reduced HB visual cover compared to the nontreated (77% cover). A bioassay study conducted with soil cores collected from field plots suggested HB cover reduction was minimally affected by indaziflam‐soil bioavailability, as perennial ryegrass biomass was not reduced beyond a 2.5‐cm depth. Weather conditions varied between years, with air temperatures ≤0°C occurring more frequently and to a greater magnitude in Year 2. The weather, coupled with reduced solar radiation in the RS environment may have contributed to HB cover reduction in Year 2. Overall, indaziflam applications to established HB in areas with suitable growth conditions were safe; however, unacceptable HB cover reductions were observed in areas with poor growth conditions. Indaziflam is safe on established bermudagrass grown in appropriate conditions. Bermudagrass‐indaziflam tolerance decreased when applied in a reduced sunlight setting. Severe winter climatic conditions exacerbated bermudagrass‐indaziflam injury.

CFD simulation of the thermal performance of an opaque water wall system for Australian climate

The thermal performance of an opaque water wall system is numerically investigated using the shear-stress transport (SST) k–ω turbulence model and the Discrete Ordinates radiation model for typical winter and summer climate conditions in Sydney, Australia. With a periodic sol-air temperature specified on the outside Perspex panel, the energy performance of the water wall system is examined over a range of water wall thicknesses. The computational fluid dynamics (CFD) model is compared with an experimentally validated transient heat balance model (THBM), and a fair agreement between the CFD model and the THBM results is achieved. The present numerical results indicate that the performance of the opaque water wall system is improved by increasing the thickness of the water column under the winter climate condition in Sydney. It is also found that less supplementary energy is required in winter than that in summer in order to maintain a comfortable interior temperature. Further, a comparison between the present water wall system and a conventional concrete wall system shows that the water wall system performs significantly better than the concrete wall system of the same thickness in the winter climate of Sydney, whereas both the water wall and concrete wall systems have a similar performance in terms of energy savings in the summer climate of Sydney.

Experimental icing affects growth, mortality, and flowering in a high Arctic dwarf shrub.

Effects of climate change are predicted to be greatest at high latitudes, with more pronounced warming in winter than summer. Extreme mid‐winter warm spells and heavy rain‐on‐snow events are already increasing in frequency in the Arctic, with implications for snow‐pack and ground‐ice formation. These may in turn affect key components of Arctic ecosystems. However, the fitness consequences of extreme winter weather events for tundra plants are not well understood, especially in the high Arctic. We simulated an extreme mid‐winter rain‐on‐snow event at a field site in high Arctic Svalbard (78°N) by experimentally encasing tundra vegetation in ice. After the subsequent growing season, we measured the effects of icing on growth and fitness indices in the common tundra plant, Arctic bell‐heather (Cassiope tetragona). The suitability of this species for retrospective growth analysis enabled us to compare shoot growth in pre and postmanipulation years in icing treatment and control plants, as well as shoot survival and flowering. Plants from icing treatment plots had higher shoot mortality and lower flowering success than controls. At the individual sample level, heavily flowering plants invested less in shoot growth than nonflowering plants, while shoot growth was positively related to the degree of shoot mortality. Therefore, contrary to expectation, undamaged shoots showed enhanced growth in ice treatment plants. This suggests that following damage, aboveground resources were allocated to the few remaining undamaged meristems. The enhanced shoot growth measured in our icing treatment plants has implications for climate studies based on retrospective analyses of Cassiope. As shoot growth in this species responds positively to summer warming, it also highlights a potentially complex interaction between summer and winter conditions. By documenting strong effects of icing on growth and reproduction of a widespread tundra plant, our study contributes to an understanding of Arctic plant responses to projected changes in winter climatic conditions.

Researches of Advanced Thermal Insulating Materials for Improving the Building Energy Efficiency

A complex model of building was developed by using Matlab. The model allows conducting for a wide range of research related to improving the energy efficiency of buildings. In this work the investigations of energy efficiency of several advanced insulation materials, which is characterized by different thermal characteristics, were carried out. Conclusions about the impact of the thermal protective envelope on the room thermal regime were made. Prognostic heat consumptions values of rooms with different characteristics of thermal insulation materials and main base-load envelopes were determined. Researches were conducted for the winter climatic conditions of Western Siberia: the average daily outdoor temperatures are -22 °C and -12 °C, the amplitude of temperature oscillation is 8 °C

Winter Conditions Correlate with Phytophthora alni Subspecies Distribution in Southern Sweden.

During the last century, the number of forest pathogen invasions has increased substantially. Environmental variables can play a crucial role in determining the establishment of invasive species. The objective of the present work was to determine the correlation between winter climatic conditions and distribution of two subspecies of the invasive forest pathogen Phytophthora alni: P. alni subspp. alni and uniformis killing black alder (Alnus glutinosa) in southern Sweden. It is known from laboratory experiments that P. alni subsp. alni is more pathogenic than P. alni subsp. uniformis, and that P. alni subsp. alni is sensitive to low temperatures and long frost periods. By studying the distribution of these two subspecies at the northern limit of the host species, we could investigate whether winter conditions can affect the geographical distribution of P. alni subsp. alni spreading northward. Sixteen major river systems of southern Sweden were systematically surveyed and isolations were performed from active cankers. The distribution of the two studied subspecies was highly correlated with winter temperature and duration of periods with heavy frost. While P. alni subsp. uniformis covered the whole range of temperatures of the host, P. alni subsp. alni was recovered in areas subjected to milder winter temperatures and shorter frost periods. Our observations suggest that winter conditions can play an important role in limiting P. alni subsp. alni establishment in cold locations, thus affecting the distribution of the different subspecies of P. alni in boreal regions.

CFD assessment of a solar honeycomb (SHC) façade element with integrated PV cells

The thermal behaviour and air flow characteristic for a solar honeycomb (SHC) façade element at different PV cell configurations was analysed in order to evaluate the thermal and ventilation performance as well as the electrical output. The base construction of this façade prototype inherited from the base façade element “GAP-Skin”, which is a development of the company “Gap3 solutions GmbH”. The aim was to find a PV cell configuration which shows the best ratio between the thermal behaviour of the SHC façade and the electrical output of the PV array.Three-dimensional CFD simulations were performed and compared with measurement data from a laboratory experiment. In order to do this, a test stand was built with a 1×1m SHC façade element and a solar simulator. The CFD models contained a detailed radiation model to take solar and thermal radiation into account. The numerical results from the developed models correlated well to a large extent with the measured data.Furthermore, this study obtained the thermal behaviour of the SHC façade element in summer and winter climate conditions in the temperate zone, considering different solar absorption characteristics of the SHC at different solar angles.

Regional Arctic sea ice variations as predictor for winter climate conditions

Seasonal prediction skill of winter mid and high northern latitudes climate from sea ice variations in eight different Arctic regions is analyzed using detrended ERA-interim data and satellite sea ice data for the period 1980–2013. We find significant correlations between ice areas in both September and November and winter sea level pressure, air temperature and precipitation. The prediction skill is improved when using November sea ice conditions as predictor compared to September. This is particularly true for predicting winter NAO-like patterns and blocking situations in the Euro-Atlantic area. We find that sea ice variations in Barents Sea seem to be most important for the sign of the following winter NAO—negative after low ice—but amplitude and extension of the patterns are modulated by Greenland and Labrador Seas ice areas. November ice variability in the Greenland Sea provides the best prediction skill for central and western European temperature and ice variations in the Laptev/East Siberian Seas have the largest impact on the blocking number in the Euro-Atlantic region. Over North America, prediction skill is largest using September ice areas from the Pacific Arctic sector as predictor. Composite analyses of high and low regional autumn ice conditions reveal that the atmospheric response is not entirely linear suggesting changing predictive skill dependent on sign and amplitude of the anomaly. The results confirm the importance of realistic sea ice initial conditions for seasonal forecasts. However, correlations do seldom exceed 0.6 indicating that Arctic sea ice variations can only explain a part of winter climate variations in northern mid and high latitudes.

On the overwintering ability of Drosophila suzukii in South Tyrol

BACKGROUND: Drosophila suzukii became one of the most dangerous pests in fruit crops and vineyards in Europe since 2009. Lacking knowledge of the overwintering biology under European environmental conditions makes an environmentally friendly control of this invasive pest difficult. OBJECTIVE: The objective of this study was to investigate its hibernation capability under the climatic conditions of South Tyrol, Italy. METHODS: Monitoring flight activity by baited traps revealed an overwintering location in the Adige valley. We determined the reproductive status of females trapped weekly at “Schlossleiten” from August 2012 until September 2013 by dissecting their abdomens. For further potential correlation between overwintering locations, reproductive status, and climatic conditions were assessed. RESULTS: The microclimatic conditions of single locations affected overwintering success and suggest the aggregation of adults in most favourable hibernation sites where a high proportion of females is able to survive. However, in spring some of the females showed degenerated reproductive organs. Dissection of abdomens evinced a reproductive diapause, which appears to be affected by winter climatic conditions, the nutritional status, and food availability. CONCLUSIONS: D. suzukii is able to overwinter in the South Tyrolean area. Control and management of the potential hibernation sites may delay the population dynamics in the following season.

Seasonal variation in carcass characteristics of korean cattle steers.

Climate temperature affects animal production. This study was conducted to evaluate whether climatic conditions affect beef carcass characteristics of Korean cattle steers. The monthly carcass characteristics of Korean cattle steers (n = 2,182,415) for 8 yr (2006 through 2013) were collected from the Korean Institute for Animal Products Quality Evaluation. Daily climate temperature (CT) and relative humidity (RH) data were collected from the Korean Meteorological Administration. Weather conditions in South Korea during summer were hot and humid, with a maximum temperature of 28.4°C and a maximum RH of 91.4%. The temperature-humidity index (THI), calculated based on CT and RH, ranges from 73 to 80 during summer. Winter in South Korea was cold, with a minimum temperature of −4.0°C and a wind-chill temperature of −6.2°C. Both marbling score (MS) and quality grade (QG) of Korean cattle steer carcasses were generally best (p<0.05) in autumn and worst in spring. A correlation analysis showed that MS and QG frequencies were not associated (p>0.05) with CT. Yield grade (YG) of Korean cattle steer carcasses was lowest (p<0.05) in winter (November to January) and highest in spring and summer (May to September). A correlation analysis revealed that YG frequency was strongly correlated (r≥0.71; p<0.01) with CT and THI values. The rib eye area, a positive YG parameter, was not associated with CT. Backfat thickness (BT), a negative YG factor, was highest in winter (November and December). The BT was strongly negatively correlated (r≤−0.74; p<0.01) with CTs. Therefore, the poor YG during winter is likely due in part to the high BT. In conclusion, YG in Korean cattle steer carcasses was worst in winter. QGs were not associated with winter or summer climatic conditions.

Investigation of energy efficiency of innovate thermal insulating materials and their influence on the building heat regime

A complex model of heat supply system of building was developed by using Matlab. The model allows conducting for a wide range of research related to improving the energy efficiency of buildings. In this work the investigations of energy efficiency of several advanced insulation materials, which is characterized by different thermal characteristics, were carried out. Conclusions about the impact of the thermal protective envelope on the room thermal regime were made. Prognostic heat consumptions values of rooms with different characteristics of thermal insulation materials and main base-load envelopes were determined. Researches were conducted for the winter climatic conditions of Western Siberia: the average daily outdoor temperature is -22 °C, the amplitude of temperature oscillation is 8 °C.

Wintertime use of natural versus artificial shelter by cattle in nature reserves in temperate areas

The current study contributes scientific observation to the ongoing debate about whether and when artificial shelter (man-made), in addition to natural shelter (vegetation), should be provided to cattle grazing in nature reserves during temperate winters. In several year-round grazing projects in Belgium, we have investigated the effect of winter climatic conditions on cattle's use of natural versus artificial shelter. In eight nature reserves with varying amount and spatial distribution of natural shelter and an artificial shelter, GPS were used collars to monitor terrain use during one, two or three winters (per 30min, 24h per day). Cattle location data were related to instantaneous open-field measurements of the Comprehensive Climatic Index (CCI). In addition, the effects of the time of day (day-time versus night-time) and the amount of natural shelter and its spatial distribution on these relationships were investigated. In most nature reserves, cattle increasingly avoided open area and sought shelter at CCI values <0°C. The strength of the effect, and whether cattle used natural or artificial shelter differed between day-time and night-time and between reserves, and was partially explained by the amount of natural shelter and its spatial distribution across the reserve. Although artificial shelters with three closed walls provided better protection against cold (especially wind chill), cattle were more likely to use natural shelter as long as it was sufficiently available. Providing an artificial shelter in nature reserves appears to have added value for cattle's thermal comfort only when natural shelter is scarce.

Climate change. Six centuries of variability and extremes in a coupled marine-terrestrial ecosystem.

Reported trends in the mean and variability of coastal upwelling in eastern boundary currents have raised concerns about the future of these highly productive and biodiverse marine ecosystems. However, the instrumental records on which these estimates are based are insufficiently long to determine whether such trends exceed preindustrial limits. In the California Current, a 576-year reconstruction of climate variables associated with winter upwelling indicates that variability increased over the latter 20th century to levels equaled only twice during the past 600 years. This modern trend in variance may be unique, because it appears to be driven by an unprecedented succession of extreme, downwelling-favorable, winter climate conditions that profoundly reduce productivity for marine predators of commercial and conservation interest.

Application of a water-saturated MEPCM-PV for reducing winter chilling damage on aqua farms

In this study, a microencapsulated phase change material (MEPCM) layer was attached to the back of a photovoltaic (PV) panel to form a MEPCM-PV module that floated on the water surface. Subsequently, numerical simulations were used to determine if this PV module could effectively store solar radiation energy at the bottom of the MEPCM layer and release it to the underneath water at night during the winter season. This analysis was based on local winter climatic conditions, such as air temperature, sky temperature, wind speed, solar irradiation, water temperature, and water flow rate. The investigated parameters included the melting point (18 and 17°C) and thickness (5 and 3cm) of the MEPCM. The PV treated with a 5cm/ melting point 17°C MEPCM layer effectively released the energy that was stored during the daytime to the water. This energy release provided a local high temperature area for the aqua farms during cold weather and reduced the cold damage.

Natural Ventilation Potential in Portuguese Residential Buildings under Winter Conditions – An Opportunity for Hybrid Ventilation

This paper presents a study of the potential for the use of natural ventilation systems in Portuguese multi-family residential buildings under winter climatic conditions. The behaviour of various natural ventilation systems is tested in a standard residential dwelling, using the TRNSYS 15 and COMIS 3.1 software programs. This study leads to the conclusion that the use of hybrid ventilation systems can save a considerable amount of the energy normally spent on continuously operating mechanical ventilation systems. Hybrid ventilation systems will not be adequate if there are no ventilation inlets in the façade and air intake is only by means of infiltration, especially in the case of certain modern windows with better seals; in such situations, the use of continuous mechanical ventilation systems is recommended. Therefore, it is essential to equip buildings with air inlets in the façades, preferably self-adjustable grilles, to ensure the best use of hybrid systems.

Climate change and habitat fragmentation drive the occurrence of Borrelia burgdorferi, the agent of Lyme disease, at the northeastern limit of its distribution.

Lyme borreliosis is rapidly emerging in Canada, and climate change is likely a key driver of the northern spread of the disease in North America. We used field and modeling approaches to predict the risk of occurrence of Borrelia burgdorferi, the bacteria causing Lyme disease in North America. We combined climatic and landscape variables to model the current and future (2050) potential distribution of the black-legged tick and the white-footed mouse at the northeastern range limit of Lyme disease and estimated a risk index for B. burgdorferi from these distributions. The risk index was mostly constrained by the distribution of the white-footed mouse, driven by winter climatic conditions. The next factor contributing to the risk index was the distribution of the black-legged tick, estimated from the temperature. Landscape variables such as forest habitat and connectivity contributed little to the risk index. We predict a further northern expansion of B. burgdorferi of approximately 250–500 km by 2050 – a rate of 3.5–11 km per year – and identify areas of rapid rise in the risk of occurrence of B. burgdorferi. Our results will improve understanding of the spread of Lyme disease and inform management strategies at the most northern limit of its distribution.

Winter Climate Limits Subantarctic Low Forest Growth and Establishment

Campbell Island, an isolated island 600 km south of New Zealand mainland (52°S, 169°E) is oceanic (Conrad Index of Continentality = −5) with small differences between mean summer and winter temperatures. Previous work established the unexpected result that a mean annual climate warming of c. 0.6°C since the 1940's has not led to upward movement of the forest limit. Here we explore the relative importance of summer and winter climatic conditions on growth and age-class structure of the treeline forming species, Dracophyllum longifolium and Dracophyllum scoparium over the second half of the 20th century. The relationship between climate and growth and establishment were evaluated using standard dendroecological methods and local climate data from a meteorological station on the island. Growth and establishment were correlated against climate variables and further evaluated within hierarchical regression models to take into account the effect of plot level variables. Winter climatic conditions exerted a greater effect on growth and establishment than summer climatic conditions. Establishment is maximized under warm (mean winter temperatures >7 °C), dry winters (total winter precipitation <400 mm). Growth, on the other hand, is adversely affected by wide winter temperature ranges and increased rainfall. The contrasting effect of winter warmth on growth and establishment suggests that winter temperature affects growth and establishment through differing mechanisms. We propose that milder winters enhance survival of seedlings and, therefore, recruitment, but increases metabolic stress on established plants, resulting in lower growth rates. Future winter warming may therefore have complex effects on plant growth and establishment globally.

Synoptyczne uwarunkowania intensywnych opadów śniegu w wybranych regionach Europy

The aim of the work described here has been to determine synoptic situations associated with intensive snowfalls in selected regions of Europe. Specifi cally, an analysis was carried out for three stations representing regions with different climatic conditions in winter. Synoptic conditions were characterized on the basis of atmospheric pressure at sea level, the height of the 500 hPa isobaric area and air temperature at the 850 hPa isobaric level. Typical features of synoptic situations leading to intensive snowfalls in Belgrade are negative SLP anomalies and a lowering height of the 500 hPa isobaric area over SouthernEurope, as indicating the presence of a low-pressure system. Heavy snowfalls in Suwalki, Poland, are in turn associated with the occurence of a low-pressure system centred on the south-eastern Baltic Sea. Finally, the occasional snowstorms characterising Ubachsberg in The Netherlands are associated with extensive low-pressure troughs that bring in humid and cold air masses from the north and north-west.

Thermal modeling aspects of solar greenhouse microclimate control: A review on heating technologies

Modeling of greenhouse microclimate is very important to maintain optimum inside environment during different stages of plant growth. To formulate an accurate thermal model, computation of precise solar radiation input and overall heat transfer coefficient is important as these affect the greenhouse energy and mass balance. Initially, we briefly review the modular studies related to solar radiation capture and overall heat transfer coefficient for greenhouse applications. Numerous thermal models have been developed to describe the microclimate of a greenhouse and validated at various locations, climates and crops. We review all these independent thermal models (static as well as dynamic) and discuss in detail the representative ones. In adverse winter climatic conditions, greenhouse has to be coupled with various active or passive heating systems to maintain the inside microclimate according to crop needs. We also review greenhouse thermal models integrated with heating/heat storage systems such as: rock-bed, phase change materials, earth-tube heat exchanger systems, all types of water heating systems (water thermal mass storage, heat-pipe heating system, shallow solar pond heating systems, geothermal based heating systems viz. ground source heat pump system, solar-assisted ground source heat pump system, aquifer coupled heat exchanger system), ground air collector system, north wall and thermal curtain, and soil heat exchanger system. Important aspects of each representative model such as: type, tool/program used for solution/simulation, input data used to run simulations, interactive components, parameters studied, assumption made, important model characteristics and results obtained are discussed at length. Based on the compiled information, a generalized procedure is devised to formulate greenhouse thermal model. Finally, based on the main characteristics and results of the study, some important conclusions are drawn and suggestions made for further studies.

Alkanes, compound-specific carbon isotope measures and climate variation during the last millennium from varved sediments of Lake Xiaolongwan, northeast China

Annually laminated sediments in Lake Xiaolongwan, northeast China, contain a suite of n-alkanes (C17–C33) with a strong odd over even carbon number predominance. Biomarker n-alkane proxies (average chain length, Paq ratio, grass/tree ratio, carbon preference index and compound-specific δ13C values) were used to reconstruct climate changes that occurred over the last millennium. Compound-specific δ13C values show large differences between the distinctive chain length groups of n-alkanes that originate from algae, aquatic macrophytes and terrestrial plants. Long-chain n-alkanes (C27–C33) are predominantly derived from leaf wax lipids in the forest. Variations in long-chain n-alkane δ13C values may mainly record water-use efficiency, inasmuch as the contribution from C4 plants is negligible in the Lake Xiaolongwan catchment. Short- and middle-chain n-alkanes are mainly from algae and aquatic plants. They are strongly depleted in 13C. This feature may be linked to a methane-derived, negative δ13C pool and lake overturn, which regulates dinoflagellate blooms. Parallel fluctuations are observed in δ13C27–31 values, Paq, and the grass/tree ratio throughout the record. Variations in δ13C27–31 values and Paq are in agreement with historical documents on summer and winter climate conditions. They support earlier suggestions that δ13C values in the long-chain n-alkanes and Paq may be useful indicators of effective precipitation or drought stress in this forested area. The δ13C27–31 index and Paq show distinct decadal variations. Periods with high δ13C27–31 values and a low Paq index correspond with the warm phases of the Pacific Decadal Oscillation (PDO). Values are reversed during PDO cool phases. At the decadal timescale, summer monsoon rainfall in northeast China over the last millennium may have been regulated mainly by the PDO.

Impacts of the EA and SCA patterns on the European twentieth century NAO–winter climate relationship

AbstractMuch of the twentieth century multidecadal variability in the relationship between North Atlantic Oscillation (NAO) and winter climate over the North Atlantic–European sector can be linked to the combined effects of the NAO and either the East Atlantic pattern (EA) or the Scandinavian pattern (SCA). Our study documents how different NAO–EA and NAO–SCA combinations influence winter climatic conditions (temperature and precipitation) as a consequence of NAO dipole migrations. Using teleconnectivity maps, we find that the zero‐correlated line of the NAO–winter‐climate relationship migrates southwards when the EA is in the opposite phase to the NAO, related to a southwestwards migration of the NAO dipole under these conditions. Similarly, a clockwise movement of the NAO–winter‐climate correlated areas occurs when the phase of the SCA is opposite to that of the NAO, reflecting a clockwise movement of the NAO dipole under these conditions. Our study provides new insights into the causes of spatial and temporal nonstationarity in the climate–NAO relationships, particularly with respect to winter precipitation. Furthermore, interannual variability in the north–south winter precipitation gradient in the UK appears to reflect the migration of the NAO dipole linked to linear combinations of the NAO and the EA. The study also has important implications for studies of the role of the NAO in modulating the wind energy resource of the UK and Ireland, as well as for the selection of locations for terrestrial proxy archive reconstruction of past states of the NAO.