Periods Of Cold Weather Research Articles

Lipid Production by Arctic Microalga Chlamydomonas sp. KNF0008 at Low Temperatures.

A lipid-producing microalga, Chlamydomonas sp. KNF0008, collected from the Arctic was capable of growing at temperatures ranging from 4 to 20°C, and the highest cell density was measured at 15°C and 100μmol photonsm-2s-1 light intensity under continuous shaking and external aeration. KNF0008 showed the elevated accumulation of lipid bodies under nitrogen-deficient conditions, rather than under nitrogen-sufficient conditions. Fatty acid production of KNF0008 was 4.2-fold (104mgL-1) higher than that of C. reinhardtii CC-125 at 15°C in Bold's Basal Medium. The dominant fatty acids were C16:0, C16:4, C18:1, and C18:3, and unsaturated fatty acids (65.69%) were higher than saturated fatty acids (13.65%) at 15°C. These results suggested that Arctic Chlamydomonas sp. KNF0008 could possibly be utilized for production of biodiesel during periods of cold weather because of its psychrophilic characteristics.

Variable and Assured Peak Electricity Production from Base-Load Light-Water Reactors with Heat Storage and Auxiliary Combustible Fuels

In a low-carbon world (nuclear, wind, solar, and hydro) there is the need for assured dispatchable electricity to replace the historical role of fossil fuels. Base-load reactors can provide variable electricity to the grid by (1) sending some of their output (steam) to storage at times of low electricity prices and (2) using stored heat to produce added peak electricity at times of high electricity prices. Heat storage (steam accumulators, sensible heat, etc.) is less expensive than electricity storage (batteries, hydro pumped storage, etc.). The added cost of incrementally larger or standalone turbine generators for peak electricity production is small. However, energy storage systems (heat or electricity) can’t provide assured capacity for extreme events, be it supply side (extended low-wind or low-solar conditions in systems with high wind or solar capacity) or demand side (long periods of cold or hot weather). With heat storage systems there is the option to provide peak electricity output when heat storage is depleted by heat addition with a water-tube boiler using natural gas, biofuels, or ultimately hydrogen. Fuel consumption for assured peaking capacity is small because most of the time the heat storage system meets peak electricity demands. The same systems enable reliable low-cost heat production for industry. Such systems enable an all nuclear or nuclear/hydro/wind/solar/geothermal low-carbon electricity grid.

The energetic significance of communal roosting and insulated roost nests in a small arid-zone passerine

Small endotherms have evolved behavioural mechanisms for reducing rest-phase energy expenditure, which reduce the likelihood of mismatches between energy supply and demand during periods of cold weather and/or food scarcity. Although the energetic consequences of communal roosting and the use of insulated roosts have been the subject of numerous studies, less is known about the energy savings achieved by species that use these two behaviours simultaneously. We hypothesised that communal roosting in insulated roost nests by a small arid-zone passerine, the Scaly-feathered Finch Sporopipes squamifrons, results in additive energetic benefits that reduce nocturnal energy requirements far below those of individual birds roosting in the open. We measured metabolic rates in finches over air temperatures (Ta) between −5 and 20 °C using flow-through respirometry. Measurements were taken from single finches and groups varying in size from two to 12 individuals, with or without a roost nest. Consistent with our predictions, rest-phase resting metabolic rate (RMR) of finches decreased when the birds roosted communally and decreased further when groups were roosting in a nest. In the absence of a nest, groups of eight or 12 birds reduced RMR by >30% compared with single birds. These energy savings increased further when groups roosted in nests; at Ta = 0 °C, groups of eight or 12 finches approximately halved their RMR compared with that of groups without nests. Our data confirm that Scaly-feathered Finches save considerable energy by roosting communally in roost nests, and these behaviours likely are a key reason why this small species from subtropical latitudes can occur in areas with winter night-time temperatures as low as −10 °C.

Development and visualization of time-based building energy performance metrics

ABSTRACT In the face of climate change, and as building codes and standards evolve to promote increased building energy efficiency and reduced carbon footprints, it is also important to ensure that buildings, especially housing, can withstand prolonged power outages during extended periods of both extreme cold and hot weather to provide habitable shelter passively. This paper examines an approach for visualizing the impact of robust passive measures in multi-unit residential buildings by examining the ‘weakest links in the chain’ – the suites most susceptible to underperforming – in three climatic zones: Toronto and Vancouver, Canada; and Adana, Turkey. Two time-based and thermal comfort-related metrics are explored: thermal autonomy, a measure of what fraction of the time a building can deliver comfort without supplemental active systems; and passive survivability (also termed thermal resilience), a measure of the length of time a building remains habitable following the onset of a prolonged power outage during a period of extended extreme weather. A visualization of the results of parametric building energy simulations helps guide the selection of passive architectural parameters at the early stages of design to promote enhanced environmental performance and resilience.

Extreme temperature differences in the city of Lahti, southern Finland: Intensity, seasonality and environmental drivers

Abstract The extremes of month-specific spatial temperature differences were studied for a first time in the high-latitude city of Lahti and its surroundings in southern Finland. During the 2-year observation period (6/14–5/16), the largest momentary temperature difference, 11.1 °C, was detected in February, and the smallest, 6.2 °C, in April. The impacts of various environmental factors during the extreme situations were estimated by site-specific analysis of the warmest and coldest observation sites and a stepwise multiple linear regression model including all the 8 observation sites. The extreme temperature differences were characterised by inversions especially in winter and spring, the warmest site being the hill-top location in Kivistonmaki. In summer the role of urban heating was more apparent, and the temperature was the highest in the relatively low-lying city centre. In autumn the heating impact of the relatively warm Lake Vesijarvi caused the largest temperature differences with harbour as the warmest site. The weather during all of the momentary extreme situations was calm and in the majority of the situations also clear. The impact of cloud cover was less critical than that of wind speed in reducing spatial temperature differences. The momentary extreme situations existed at night or at dawn, with one exception: only in January, during the cold weather period dominated by high pressure, the delayed break of inversion in the vicinity of Lake Vesijarvi caused the extreme temperature difference to exist in the afternoon, reflecting for its part the substantial stabilising impact of seasonal ice cover on Lake Vesijarvi.

Rainfall Profile of Cauvery Delta Zone of Tamil Nadu

Thanjavur and Nagapattinam districts of Cauvery Delta Zone (CDZ) depend on canal irrigation for agriculture and are subjected to the vagaries of monsoon. This creates water crisis and affects agriculture of the region considered as rice bowl of Tamil Nadu. This necessitated the study of rainfall to plan and mitigate water scarcity. Rainfall data from Adhirampattinam, Aduthurai stations of Thanjavur district (Inland) and Nagapattinam station (Coastal area of Nagapattinam district) were utilized for the study. Normal rainfall of CDZ is 956 mm; Nagapattinam receives highest (1350 mm) and aduthurai (994 mm) recorded lowest. November is the wettest month for all locations while driest month differs among locations. Northeast monsoon (NEM) was considered as stable monsoon for CDZ as could be seen from the seasonal mean of 641 mm, 620 mm and 919 mm recorded by Adhirampattinam, Aduthurai and Nagapattinam, respectively. Trend analysis of seasons revealed that Adhirampattinam and Nagapattinam follow a decreasing trend for rainfall and rainydays during NEM and Southwest monsoon (SWM), with an increasing trend for Hot weather period (HWP) and Cold weather period (CWP). An interesting deviation is that Aduthurai recording an increasing trend for NEM while it followed same trend for HWP and SWM.

Bioavailable zinc in soil for pecan tree nutrition

El nogal pecanero es uno de los frutales más cultivados a nivel nacional por su alta rentabilidad. Este frutal tiene necesidades importantes de zinc (Zn), el cual se ubica como uno de los micronutrientes más requeridos por este cultivo. Los principales efectos del Zn en el metabolismo de la planta se observan en la síntesis de clorofila y triptófano. También está involucrado en la actividad de enzimas relacionadas con la detoxificación de las especies reactivas de oxígeno. La deficiencia de este nutriente se relaciona con el tipo de suelo. Con el objetivo de conocer los factores que inf luyen en la biodisponibilidad del Zn en el suelo para la nutrición del nogal pecanero se presenta la siguiente revisión. Se concluye que la deficiencia de Zn en las huertas de nogal es más común en periodos fríos, primaveras húmedas, y suelos arenosos con bajo contenido de materia orgánica, pH alcalino y altos contenidos de carbonatos. Esta deficiencia ocasiona un escaso desarrollo radical.

Habitat Preference of German Mantis religiosa Populations (Mantodea: Mantidae) and Implications for Conservation.

In Germany, the thermophilic European mantid (Mantis religiosa L.) is endangered. Here, we study habitat requirements during its life, and discuss the applicability of the two conservation measures grazing and mowing to this insect species. At two study sites in south-western Germany, which were each subject to one of these measures, we recorded structural and climatic conditions within different microhabitats. We also conducted capture-mark-recapture studies for adult M. religiosa, and mapped adult roosting, oothecae deposition, egg hatching, and imaginal molting in microhabitats over two vegetation periods. In order to assess microhabitat preference of M. religiosa during its life, and identify climatic conditions driving preferences, we applied the Lille habitat preference index and conducted logistic regression analysis for life phases. Our results suggest that temperature is important for egg and nymph development. For egg deposition, females preferred solid substrates with high heat-storing capacities, as those attenuate the negative influence of cold weather periods on egg development. Being ambush predators, males and females preferred roosting sites with sufficient shelter and high prey abundance. Contrary to our expectation, the conservation measures reduced adult population sizes, and presumably reproduction rates. We thus suggest that mowing during the adult phase should reduce vegetation height to a moderate level to keep prey abundance high. Mowing with a clearing saw or grazing over a short period in small fenced areas should be preferred over prolonged grazing, as grazers collaterally stamp down the vegetation. Grazers indirectly reduce prey availability by deteriorating prevailing microclimatic conditions.

A Mid-Term Forecast of Maximum Demand for Electricity in Poland

Forecasting of demand for electricity plays an important role in planning of seasonal operations and expansion of power facilities. Power plants must ensure the continuity of supply of energy, without producing the excess due to problems associated with its storage, and at the same time they must be prepared for increased demand e.g. during the periods of cold weather.

Performance Analysis of Strength Development of FRC Base Depending on Maturity

PURPOSES : In this study, we analyzed the compressive strength characteristics of lean base concrete in relation to changes in the outdoor temperature after analyzing the cold and hot weather temperature standards and calculated the minimum and maximum temperatures when pouring concrete. We examined the rate of strength development of lean base concrete in relation to the temperature change and derived an appropriate analysis formula for FRC base structures by assigning the accumulated strength data and existing maturity formula. METHODS : We measured the strength changes at three curing temperatures (5, 20, and ) by curing the concrete in a temperature range that covered the lowest temperature of the cold period, , to the highest temperature of the hot period, . We assigned the general lean concrete and FRC as test variables. A strength test was planned to measure the strength after 3, 5, 7, 14, and 28 days. RESULTS : According to the results of compressive strength tests of plain concrete and FRC in relation to curing temperature, the plain concrete had a compressive strength greater than 5 MPa at all curing temperatures on day 5 and satisfied the lean concrete standard. In the case of FRC, because the initial strength was substantially reduced as a result of a 30% substitution of fly ash, it did not satisfy the strength standard of 5 MPa when it was cured at on day 7. In addition, because the fly ash in the FRC caused a Pozzolanic reaction with the progress into late age, the amount of strength development increased. In the case of a curing temperature of , the FRC strength was about 66% on day 3 compared with the plain concrete, but it is increased to about 77% on day 28. In the case of a curing temperature of , the FRC strength development rate was about 63% on day 3 compared with the plain concrete, but it increased to about 88% on day 28. CONCLUSIONS : We derived a strength analysis formula using the maturity temperatures with all the strength data and presented the point in time when it reached the base concrete standard, which was 5 MPa for each air temperature. We believe that our findings could be utilized as a reference in the construction of base concrete for a site during a cold or hot weather period.

Effect of roost choice on winter torpor patterns of a free-ranging insectivorous bat

Gould’s wattled bat (Chalinolobus gouldii) is one of only three native Australian mammals with an Australia-wide distribution. However, currently no data are available on the thermal physiology of free-ranging C. gouldii. Therefore, we aimed to quantify the effect of roost choice on daily skin temperature fluctuations during winter in C. gouldii living in an agricultural landscape in a temperate region. Ambient conditions consisted of long periods below 0°C and snow. Some individuals roosted high in dead branches whereas one individual roosted in a large cavity located low in a live tree. Torpor was employed on every day of the study period by all bats, with bouts lasting for over five days. The skin temperature of individuals in the dead branches tracked ambient temperature, with skin temperatures below 3°C on 67% of bat-days (lowest recorded –0.2°C). In contrast, the individual in the tree cavity maintained a larger skin-ambient temperature differential, likely influenced by the internal cavity temperature. Our study presents the lowest skin temperature recorded for a free-ranging Australian microbat and reveals that roost choice affects the thermal physiology of C. gouldii, ensuring survival during periods of cold weather and limited food supply.

Social huddling and physiological thermoregulation are related to melanism in the nocturnal barn owl.

Endothermic animals vary in their physiological ability to maintain a constant body temperature. Since melanin-based coloration is related to thermoregulation and energy homeostasis, we predict that dark and pale melanic individuals adopt different behaviours to regulate their body temperature. Young animals are particularly sensitive to a decrease in ambient temperature because their physiological system is not yet mature and growth may be traded-off against thermoregulation. To reduce energy loss, offspring huddle during periods of cold weather. We investigated in nestling barn owls (Tyto alba) whether body temperature, oxygen consumption and huddling were associated with melanin-based coloration. Isolated owlets displaying more black feather spots had a lower body temperature and consumed more oxygen than those with fewer black spots. This suggests that highly melanic individuals display a different thermoregulation strategy. This interpretation is also supported by the finding that, at relatively low ambient temperature, owlets displaying more black spots huddled more rapidly and more often than those displaying fewer spots. Assuming that spot number is associated with the ability to thermoregulate not only in Swiss barn owls but also in other Tytonidae, our results could explain geographic variation in the degree of melanism. Indeed, in the northern hemisphere, barn owls and allies are less spotted polewards than close to the equator, and in the northern American continent, barn owls are also less spotted in colder regions. If melanic spots themselves helped thermoregulation, we would have expected the opposite results. We therefore suggest that some melanogenic genes pleiotropically regulate thermoregulatory processes.

A meta‐analysis of American black duck winter habitat use along the Atlantic Coast

ABSTRACTAmerican black duck (Anas rubripes) populations declined by more than 50% between the 1950s and 1990s, and the species serves as a flagship for conserving salt marsh habitats along the Atlantic Coast. Black ducks have generally been well studied throughout the annual cycle, but surprisingly, we lack a synthetic, quantitative understanding of their space use during the winter. This limits our ability to prioritize habitat acquisition and restoration efforts. We used >17,000 telemetry locations from 235 black ducks ranging from Connecticut to Virginia to study home range composition and space use during winter in relation to habitat quality, urbanization, and severe weather. Despite substantial environmental variation, home range sizes were similar among regions and years. Smaller home and core ranges contained a greater proportion of salt marsh habitat, and ducks experiencing more 4‐day freeze events had larger home and core ranges. Ducks exposed to prolonged periods of cold weather had smaller core ranges when those areas comprised more energy‐rich freshwater habitats. When we examined individual telemetry locations, we found that ducks used irregularly inundated high marsh more at night, presumably for foraging, and urban habitats more during the day and evening crepuscular periods. We found that black ducks used regularly inundated low marsh less on days where the temperature never rose above freezing, and instead used subtidal areas and forested wetlands more. Finally, we found ducks were marginally more likely to use freshwater habitats during high tides. Our study confirms that black ducks depend on salt marsh for wintering habitat, and points to an unexpectedly important role for forested wetlands during periods of cold weather. We found no evidence that black ducks avoided urban areas or roads, which supports the inclusion of all available habitats in carrying capacity modeling. We emphasize that new hypothesis‐driven, local telemetry studies are needed to further elucidate the relationships between black duck movements and environmental variation, especially cold weather. Further, given that most remaining coastal wetlands are currently protected via state and federal lands, we suggest black duck habitat management should strive to acquire and restore brackish and forested wetlands in close proximity to coastal marshes. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Dense water flow and carbonate system in the southern Adriatic: A focus on the 2012 event

The active deep overturning circulation of the Mediterranean is emerging as one of the most effective mechanisms in transporting the atmospheric imprint on the carbon cycle to the interior of the basin. There is growing evidence that sites of dense water formation over the continental shelf, such as the Northern Adriatic Sea, play a key role in this process. Nevertheless, little is known about the inorganic carbon chemistry of the Adriatic sea, and CO2 absorption and its fate.The winter of 2012 experienced peculiar meteorological conditions with an extended period of cold weather with strong winds that triggered, in February, a massive formation of an extremely cold and dense (potential density anomaly >30.00kgm−3) Northern Adriatic Dense Water (NAdDW) water mass. This event provided a unique opportunity to study this process at sub-basin scale taking into account CO2 adsorption within the NAdDW source area (the Gulf of Trieste in the northern Adriatic), and its spreading over the shelf and into the Southern Adriatic Pit.The northern Adriatic and the Gulf of Trieste, during winter, act as a CO2 sink. The average air-sea CO2 flux of 60mmolm−2 d−1 estimated during the exceptional 2012 event was at least 3 times higher than the flux measured in winter 2008 when dense water was produced through the same mechanism but under less extreme conditions. In winter 2012, absorbed CO2 resulted in the decrease of pHT25 down to 7.907 (− 0.034 pHT units) and the strong evaporation induced by wind-increased total alkalinity (TA) to 2673 (+ 16μmolkg−1).Following its formation in the North, the NAdDW plume entering the Southern Adriatic, observed in March 2012, exhibited significantly modified values. The plume was characterized by colder temperature (~ 10°C), lower pHT25 (7.947 pHT units) and higher alkalinity (2635μmolkg−1) than the surrounding water masses along the western Adriatic shelf. However, the signal of atmospheric CO2 enrichment was weaker than in the northern Adriatic source region, as well as positive apparent oxygen utilization (AOU) values (~ 20μmolkg−1) were recorded. This is suggestive of oxygen consumption in the water mass.Observed changes in both physical and biogeochemical properties were similar to those observed in 2008, suggesting that mixing with Levantine Intermediate Waters (LIW) was the main driver modulating the changes of AOU and inorganic carbon chemistry in both winters. The rising of pHT25 and AOU due to the mixing indicates that NAdDW, at its origin, was richer in atmospheric CO2 than the LIW was, thus confirming the relevance of the Northern Adriatic Sea for CO2 adsorption.The study provides the first characterization of inorganic carbon chemistry, including carbonate minerals saturation states (ΩAr and ΩCa), in the bottom waters both on the slope and along the expected pathways of dense water cascading in the Adriatic Sea. Therefore, it can represent a baseline to improve the knowledge on the acidification process and impacts as well as being useful for comparison with other benthic environments.

Seasonal variation of total lipid, fatty acids, fucoxanthin content, and antioxidant properties of two tropical brown algae (Nizamuddinia zanardinii and Cystoseira indica) from Iran

The present study investigates the seasonal changes in lipid components, fucoxanthin (Fx), and functional long-chain n-3 (omega-3) polyunsaturated fatty acids (PUFAs) and also evaluates for their antioxidant activity of two tropical brown algae, Nizamuddinia zanardinii and Cystoseira indica, collected from the southeast coast of Iran. Results show a significant amount of fucoxanthin that is possibly due to the specific conditions of sampling area in terms of oxidative stress and the waves of southwest monsoon and thermal stress. Total lipid in October and November was higher compare to rest of the year. The percent of PUFA in N. zanardinii increased coinciding with a period of relative cold weather, but PUFA in C. indica increased in May when the weather is warm. However, in both species, seasonal variation in DPPH radical scavenging activity, CUPRAC, and total phenolic content did not show a particular pattern. A correlation between fucoxanthin content and DPPH radical scavenging activity was evident. Both algal species had higher phenolic content over the peak of maturity and fertility when the plant was tallest (October to December for both species and April for N. zanardinii). In general, variation of these factors in a tropical area such as Oman Sea is different from temperate regions. These changes in many cases are not as tangible, and further investigations are required to assess the variations.

The impact of the mean daily air temperature change on electricity consumption

This paper presents the analysis of the impact of weather conditions on the consumption of electricity in the City of Kragujevac (the Republic of Serbia) during the seven-year period from 2006 to 2012. It points out the mean daily air temperature as the most influential climate (meteorological) parameter, and gives an overview of deviations from the mean values compared to the reference period. Increases and decreases in the power consumption depending on the deviations of the mean daily temperature from the normal (average) values are also indicated. In periods of strong and long-lasting cold spells in the winter months, there is increased power consumption as a result of heating in residential and office buildings. During extremely hot and long summer periods, there is also a tendency of increasing electricity consumption because of home air conditioning. In the transitional seasons, especially when the remote heating system is not active, sudden and relatively long periods of cold weather also have a significant influence on increases in the electricity consumption. A timely and accurate weather forecast can certainly help prevent the electrical power system overload and reduce the risk of possible power system damages.

The effects of cold and exercise on the cardiovascular system

### Learning objectives Acute coronary syndromes Decreased exercise tolerance and worsening of angina symptoms during the winter months is a well-documented phenomenon among patients with coronary artery disease (CAD).1 There...

New York City Panel on Climate Change 2015 Report. Chapter 1: Climate observations and projections.

Radley Horton,1,a Daniel Bader,1,a Yochanan Kushnir,2 Christopher Little,3 Reginald Blake,4 and Cynthia Rosenzweig5 1Columbia University Center for Climate Systems Research, New York, NY. 2Ocean and Climate Physics Department, Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY. 3Atmospheric and Environmental Research, Lexington, MA. 4Physics Department, New York City College of Technology, CUNY, Brooklyn, NY. 5Climate Impacts Group, NASA Goddard Institute for Space Studies; Center for Climate Systems Research, Columbia University Earth Institute, New York, NY

Spatial and indoor/outdoor gradients in urban concentrations of ultrafine particles and PM2.5 mass and chemical components

In order to investigate relationships between outdoor air pollution and concentrations indoors, a novel design of experiment has been conducted at two sites, one heavily trafficked and the other residential. The novel design aspect involves the introduction of air directly to the centre of an unoccupied room by use of a fan and duct giving a controlled air exchange rate and allowing an evaluation of particle losses purely due to uptake on indoor surfaces without the losses during penetration of the building envelope which affect most measurement programmes. The rooms were unoccupied and free of indoor sources, and consequently reductions in particle concentration were due to deposition processes within the room alone. Measurements were made of indoor and outdoor concentrations of PM2.5, major chemical components and particle number size distributions. Despite the absence of penetration losses, indoor to outdoor ratios were very similar to those in other studies showing that deposition to indoor surfaces is likely to be the major loss process for indoor air. The results demonstrated a dramatic loss of nitrate in the indoor atmosphere as well as a selective loss of particles in the size range below 50 nm, in comparison to coarser particles. Depletion of indoor particles was greater during a period of cold weather with higher outdoor concentrations probably due to an enhancement of semi-volatile materials in the outdoor particulate matter. Indoor/outdoor ratios for PM2.5 were generally higher at the trafficked site than the residential site, but for particle number were generally lower, reflecting the different chemical composition and size distributions of particles at the two sites.

Efficiency verification of a combination of high performance and conventional insulation layers in retrofitting a 130-year old building

The performance and applicability of a newly developed high efficiency insulation material to retrofit old buildings was investigated in a pilot project supported by the Swiss Federal Office of Energy (SFOE). One half of an old stone walled building situated in the city of Zurich dating from 1877 has been retrofitted by means of a high efficiency thermal insulation layer of 20mm thickness containing aerogel on the external side, and a conventional insulation material of 20mm on the inner side of the stone walls. This procedure promised a theoretical reduction of the steady state U-value of the wall by approximately a factor of 3 without compromising the original appearance of the building. To verify this, in-situ measurement of the U-value as well as infrared thermography has been performed during the cold weather period of early 2011 when there was a large temperature gradient between indoor and outdoor climate.