Seasonal Temperature Changes Research Articles

Attribution of seasonal temperature changes in Sri Lanka to anthropogenic and natural forcings using CMIP5 simulations

Attribution of seasonal temperature changes in Sri Lanka to anthropogenic and natural forcings using CMIP5 simulations

SEASONAL FORECAST OF AVERAGE MONTHLY TEMPERATURE FIELDS AT TERRITORIES OF WESTERN SIBERIA

The article is devoted to the problems of seasonal changes of temperature in the warm and cold periods of the year. To describe the development of the process over time, a spatial statistical model has been created that allows predicting physical fields over the entire specified information space. To predict seasonal changes in temperature, we used a two-dimensional model with an interval of the process history within a three-year period. The results of testing the spatial model for the territory of Western Siberia on large statistical material are compared with the forecast results obtained using the one-dimensional model. The obtained results are also compared with the forecast results using the climate model and the inertial model. The possibilities of modifying the model in order to increase its efficiency are discussed.

Assessment of potential invasion for six phytophagous quarantine pests in Taiwan

Pest risk assessment is typically performed by expert taxonomists using a pest’s biological data. However, the biological data or expert taxonomists may be difficult to find. Here, we used species distribution modelling to predict potential invasion in which phytophagous quarantine pests survive in Taiwan; the pests (unrecorded yet in Taiwan) included were three notorious quarantine whiteflies (Crenidorsum aroidephagus, Aleurothrixus trachoides, and Paraleyrodes minei) and three aphids (Nasonovia ribisnigri, Macrosiphum euphorbiae, and Viteus vitifoliae). In brief, maximum entropy modelling (MaxEnt) was used to predict the suitability of the pests’ habitats under certain climatic conditions, and then receiver operating characteristic curve analysis was performed (to verify the prediction result). We then analysed environmental variables affecting the habitat suitability and matched them with Taiwan’s crop cultivation areas for the assessment of potential invasion. We observed that the habitat suitability of the cultivation areas of host plants was low for C. aroidephagus, A. trachoides, and N. ribisnigri but was high for the remaining three species. Moreover, precipitation of coldest quarter negatively affected habitat suitability for C. aroidephagus, P. minei, N. ribisnigri, and M. euphorbiae. Seasonal temperature changes also negatively affected the habitat suitability for A. trachoides. This is the first study to demonstrate the use of species distribution modelling as the preliminary step for the pest risk assessment of these emerging pests with limited biological data before their invasion.

Assessment and prediction of seasonal land surface temperature change using multi-temporal Landsat images and their impacts on agricultural yields in Rajshahi, Bangladesh

Climate change threatens agricultural productivity. Understanding climate change, especially its effects on land surface temperature (LST), is critical for policymakers, agriculturalists, and crop breeders if global food security is to be assured. Rajshahi produces substantial agricultural yields (e.g., crops, vegetables, and fruits) in the country each year. The average LST increase in this region, especially in the winter season, poses a significant threat to winter agricultural productivity. Therefore, the study used Landsat images to evaluate seasonal (summer and winter) LST transitions, distribution over Land Use/Land Cover (LULC) changes (from 2000 to 2020 at 10-year intervals), and predict these two variables (for 2030 and 2040) using Cellular Automata (CA) and Artificial Neural Network (ANN) algorithms. Furthermore, studies of Focus Group Discussions (FGDs) and Key Informant Interviews (KIIs) were conducted to determine the effects of temperature rise on agricultural production, and an analytic hierarchy process (AHP) based suitability analysis was performed to determine the most productive areas. The results showed that agricultural land and water bodies were reduced by 24.53 % and 39.71%, respectively. During the summer season, high temperatures of more than 35°C are expected to hit more than 27% (2030) and 37% (2040) of the total area. The high-temperature zone (≥ 35°C) will likely cover more than 1% and 3% of the area in 2030 and 2040, respectively, for estimated winter LST. The validation of CA model showed outstanding precision, with a kappa value of 0.84. Similarly, validation of the ANN model with Mean Square Error (0.59 and 0.66 for summer) and Correlation coefficient (0.832 and 0.827 for winter) values showed strong prediction accuracy. Furthermore, as an agricultural productive region, only 40% of the total area was defined as a highly suitable zone for agriculture. This study offers useful guidance for urban planners, agricultural officers, and environmental engineers in developing effective policy initiatives to preserve agricultural land for environmental sustainability.

Response relationships between abrupt seasonal temperature changes/warming (cooling) hiatuses in China and their influencing factors.

The mechanisms of abrupt seasonal temperature changes and warming (cooling) hiatuses remain unclear. Clarifying how they respond to various influencing factors is critically important to understanding their mechanisms. In this study, the influencing factors to which the abrupt changes in Tav, Tnav, and Txav were most sensitive followed the order of (AGG and CO2) > SR > WS > AMO > PDO > MEI > AO > AP > RH. Seasonal Tav had the greatest sensitivity to all influencing factors, followed by seasonal Tav and lastly by seasonal Txav. An abrupt temperature change occurred when AGG, AMO, or SR increased continuously to a certain value, when PDO was in a positive phase (warm phase) and increased continuously to a certain value, when MEI changed abruptly, when WS and RH continued to decline for a certain time and reached a certain tendency rate, or when AP continued to decline for a certain time and reached a certain value. During the period before and after the warming (cooling) hiatuses, the temperature at most of the stations only had a significant relationship with a few influencing factors, and the hiatuses in seasonal Tav, Tnav, and Txav were overall most sensitive to changes in WS, followed by changes in RH and lastly by changes in AP. The occurrence of warming (cooling) hiatuses was highly consistent with the variation trend of some influencing factors, which to some extent affected the warming (cooling) hiatuses. Abrupt seasonal temperature changes/warming (cooling) hiatuses are the combined effects of multiple influencing factors.

Thermomechanical characteristics of an energy pile-raft foundation under heating operations

This study aims to comprehensively explore the thermomechanical characteristics of energy pile-raft foundations through in situ full-scale field tests. The foundation of interest was subjected to the joint effect of building loading and cooling thermal loading. The temperature, strain, and stress variability in both the employed pile and raft were measured and analysed. The basement of the building acted as an insulator, and the near-surface ground temperatures under the basement were affected less by seasonal changes in the air temperature. The stabilized heat exchange rate of the energy pile was approximately 75.0 W/m. The overlying raft and building at the pile head and the expanded foot and sandstone at the pile toe imposed greater restraints than those observed at other parts of the pile. The thermally induced stress per centigrade near the pile head and toe was approximately −0.160 MPa/°C and −0.202 MPa/°C, respectively. The thermally induced stresses of this kind of pile were mostly stabilized after 16 days of heating operation. When the pile was under thermomechanical loading, the axial tensile stress was mobilized along the lower half of the pile, and the maximum measured tensile stress was approximately 0.25 MPa, which did not exceed the tensile strength of the employed concrete. The cooling (contracting) of the energy pile also influenced the nearby raft. The raft temperature decreased by 6.2 °C, and the additional tensile stress was approximately 0.88 MPa (40.0% of the upper bound).

Distinct growth stages controlled by the interplay of deterministic and stochastic processes in functional anammox biofilms

Mainstream anaerobic ammonium oxidation (anammox) represents one of the most promising energy-efficient mechanisms of fixed nitrogen elimination from wastewaters. However, little is known about the exact processes and drivers of microbial community assembly within the complex microbial biofilms that support anammox in engineered ecosystems. Here, we followed anammox biofilm development on fresh carriers in an established 8m3 mainstream anammox reactor that is exposed to seasonal temperature changes (~25-12°C) and varying NH4+ concentrations (5-25 mg/L). We use fluorescence in situ hybridization and 16S rRNA gene sequencing to show that three distinct stages of biofilm development emerge naturally from microbial community composition and biofilm structure. Neutral modelling and network analysis are employed to elucidate the relative importance of stochastic versus deterministic processes and synergistic and antagonistic interactions in the biofilms during their development. We find that the different phases are characterized by a dynamic succession and an interplay of both stochastic and deterministic processes. The observed growth stages (Colonization, Succession and Maturation) appear to be the prerequisite for the anticipated growth of anammox bacteria and for reaching a biofilm community structure that supports the desired metabolic and functional capacities observed for biofilm carriers already present in the system (~100gNH4-N m3 d−1). We discuss the relevance of this improved understanding of anammox-community ecology and biofilm development in the context of its practical application in the start-up, configuration, and optimization of anammox biofilm reactors.

Intra-specific variation in movement and habitat connectivity of a mobile predator revealed by acoustic telemetry and network analyses

Few studies have considered linkages of mobile predators across large spatial scales despite their significant and often critical role in maintaining ecosystem function and health. The bull shark (Carcharhinus leucas) is a large, widespread coastal predator capable of undertaking long-range movement, but there is still limited understanding of intra-regional differences in movement and habitat connectivity across latitudes within the same coastline. This study used acoustic telemetry data and network analyses to investigate long-range movements, residency patterns and seasonal habitat linkages of sub-adult and adult C. leucas along the east coast of Australia. Our results revealed that C. leucas tagged in Sydney Harbour were mainly present within this temperate estuary in summer and autumn; the rest of the year individuals were detected in tropical and subtropical habitats from southern and central Queensland. In contrast, the detection probability of C. leucas tagged in the Townsville Reefs (central Great Barrier Reef) peaked in spring, with a portion of the tagged population migrating south during the summer months. Differences in residency time between tagging locations were also detected, as all C. leucas tagged in Sydney Harbour were absent between June and November, but 35% of the tropical-reef tagged population remained resident year-round. Network analyses complemented these findings by revealing different seasonal habitat use between regions, thus highlighting complex seasonal-habitat linkages of C. leucas along the coast. Our findings support the hypothesis that the timing, duration, and drivers involved in the long-range movements and connectivity of sub-adult and adult C. leucas vary between latitudinal regions, most likely driven by the interaction between seasonal temperature changes, foraging and reproduction.

Terrestrial activity patterns of the Lumholtz’s Tree‐Kangaroo (Dendrolagus lumholtzi) in a restored riparian habitat – Implications for its conservation

SummaryLarge‐scale deforestation and forest fragmentation in the tropical area of the Atherton Tablelands in Far North Queensland, Australia, have placed extensive strains on populations of many endemic species of this area, such as the Lumholtz’s Tree‐Kangaroo (LTK). Despite LTKs predominantly arboreal life and their ability to quickly colonize and adapt to restored forested habitats, little is known about their terrestrial activity patterns within these habitats which put them at risk to predation by canines and to roadkill when crossing nearby roads. Using motion‐sensing cameras, forest floor‐related activities of LTKs were recorded in a restored riparian rainforest habitat in relation to seasons and moon phases. The results show that LTKs exhibit a cathemeral activity pattern of forest floor‐related movements with a tendency towards crepuscular activity at dawn. While there was a significant association between the daytime recordings and the seasons with more activity during the days of the wet season, there was no association between the nighttime recordings and the seasons, as well as the moon phases. These results suggest that seasonal changes in temperature and precipitation, but potentially also in food quality, are likely to affect the frequency at which LTKs access the forest floor. Mitigating threats to LTKs in restored habitats should focus on facilitating terrestrial movements of LTKs, the control of feral dogs, enlarging and connecting available habitat, and educating drivers about peak times of LTK movements on the ground.

Model analysis of temperature impact on the Norway spruce provenance specific bud burst and associated risk of frost damage

The annual growth cycle of boreal trees is synchronized with seasonal changes in photoperiod and temperature. A warmer climate can lead to an earlier bud burst and increased risk of frost damage caused by temperature backlashes. In this study we analysed site- and provenance specific responses to interannual variation in temperature, using data from 18 Swedish and East-European provenances of Norway spruce (Picea abies), grown in three different sites in southern Sweden. The temperature sum requirements for bud burst, estimated from the provenance trials, were correlated with the provenance specific place of origin, in terms of latitudinal and longitudinal gradients. Frost damage had a significant effect on tree height development. Earlier timing of bud burst was linked to a higher risk of frost damage, with one of the sites being more prone to spring frost than the other two. The estimated provenance specific temperature sum requirements for bud burst were used to parametrize a temperature sum model of bud burst timing, which was then used together with the ensemble of gridded climate model data (RCP8.5) to assess the climate change impact on bud burst and associated risk of frost damage. In this respect, the simulated timing of bud burst and occurrence of frost events for the periods 2021–2050 and 2071–2100 were compared with 1989–2018. In response to a warmer climate, the total number of frost events in southern Sweden will decrease, while the number of frost events after bud burst will increase due to earlier bud burst timing. The provenance specific assessments of frost risk under climate change can be used for a selection of seed sources in Swedish forestry. In terms of selecting suitable provenances, knowledge on local climate conditions is of importance, as the gridded climate data may differ from local temperature conditions. A comparison with temperature logger data from ten different sites indicated that the gridded temperature data were a good proxy for the daily mean temperatures, but the gridded daily minimum temperatures tended to underestimate the local risk of frost events, in particular at the measurements 0.5 m above ground representing the height of newly established seedlings.

Functional Diversity Facilitates Stability Under Environmental Changes in an Outdoor Microalgal Cultivation System.

Functionally uniform monocultures have remained the paradigm in microalgal cultivation despite the apparent challenges to avoid invasions by other microorganisms. A mixed microbial consortium approach has the potential to optimize and maintain biomass production despite of seasonal changes and to be more resilient toward contaminations. Here we present a 3-year outdoor production of mixed consortia of locally adapted microalgae and bacteria in cold temperate latitude. Microalgal consortia were cultivated in flat panel photobioreactors using brackish Baltic Sea water and CO2 from a cement factory (Degerhamn, Cementa AB, Heidelberg Cement Group) as a sustainable CO2 source. To evaluate the ability of the microbial consortia to maintain stable biomass production while exposed to seasonal changes in both light and temperature, we tracked changes in the microbial community using molecular methods (16S and 18S rDNA amplicon sequencing) and monitored the biomass production and quality (lipid, protein, and carbohydrate content) over 3 years. Despite changes in environmental conditions, the mixed consortia maintained stable biomass production by alternating between two different predominant green microalgae (Monoraphidium and Mychonastes) with complementary tolerance to temperature. The bacterial population was few taxa co-occured over time and the composition did not have any connection to the shifts in microalgal taxa. We propose that a locally adapted and mixed microalgal consortia, with complementary traits, can be useful for optimizing yield of commercial scale microalgal cultivation.

Impact of climate warming on the surface water temperature of plateau lake

Lake surface water temperature (LSWT) is a vital indicator in evaluating the ecological environment and has a direct or indirect impact on regulating physical, chemical, and ecological processes of lakes. Changes in LSWT have a huge impact on the water quality, ecosystem function, and biome composition of the entire lake. In this study, we selected Dianchi Lake as the research area, the monthly average LSWT data collected at the monitoring station from 1998 to 2009 were used as the calibration dataset. The error analysis dataset is the average annual temperatures of the Dianchi Lake extracted from MODIS remote sensing images from 2001 to 2017. The daily average LSWT of Dianchi Lake was estimated by the air–water model and the historical changes from 1980 to 2017 of the LSWT were reproduced. The research draws a conclusion that the LSWT of Dianchi Lake has been greatly affected by air temperature over the past 37 years. LSWT and the annual average air temperature correlation coefficient were R > 0.9. Both the air temperature and LSWT assumed an increasing tendency. The annual average LSWT increased with the rate of 0.36 °C/decade, and the annual average warming rate of the air temperature was 0.47 °C/decade. The monthly average LSWT and air temperature showed a significant correlation at a confidence interval of α = 0.001. The LSWT of Dianchi Lake increased significantly in February, March, and December. The periodicity of the seasonal mean air temperature change was consistent with that of the LSWT in Dianchi Lake. The relative lag of the thermal response of the LSWT to climate warming was also observed. This study fills in the gaps in the long-term sequence data on the LSWT of Dianchi Lake and reveals the effect of climate warming on the LSWT of low-latitude plateau lakes.

How Are Greenhouse Gases Coupled Across Seasons in a Large Temperate River with Differential Land Use?

Rivers are known to emit large amounts of greenhouse gases globally, however, few studies have evaluated the interacting influence of land use, within river features (for example, sites of major confluence, changes in shape), and hydrology on the coupled dynamics of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). Here, we measured CO2, CH4 and N2O concentrations and fluxes at 15 sites along a 146.6 km stretch of the main stem of a large north temperate river: the Riviere du Nord, which experiences an abrupt change in geology and land use and winter ice cover. Each site along the river was sampled once per season, at targeted low flow and high flow moments, for three consecutive years. Overall, highest concentrations of all gases were found in the lower reaches where urban and agricultural activity are most intensive. CO2 and N2O were highest overall under ice during winter, whereas CH4 was highest during summer. The river was always supersaturated in CH4 whereas surface water was occasionally undersaturated in N2O and CO2, particularly during the summer low flow period in pristine upper reaches. Spatial variability was, however, minimized during periods of high flow. Emissions varied along the continuum, with peaks occurring at turbulent sites of major confluence. Although land use influenced the spatial variability in concentrations along the river, seasonal changes in temperature influenced the relative importance of the different gases to global warming potential, and hydrology mediated where they were produced as well as their overall concentrations and emissions.

Woodchip bioreactors provide sustained denitrification of brine from groundwater desalination plants

Woodchip bioreactors are widely known as a best management practice to reduce excess nitrate loads that are discharged with agricultural leachates. The aim of this study was to evaluate the performance of citrus woodchip bioreactors for denitrification of brine (electrical conductivity ≈ 17 mS cm−1) from groundwater desalination plants with high nitrate content (NO3−-N ≈ 48 mg L−1) in the Campo de Cartagena agricultural watershed, one of the main providers of horticultural products in Europe. The performance was evaluated relative to seasonal changes in temperature, dissolved organic carbon (DOC) provided by woodchips, hydraulic residence time (HRT) and woodchip aging. Bioreactors (capacity 1 m3) operated for 2.5 years (121 weeks) in batch mode (24 h HRT) with three batches per week. Denitrification efficiency was modulated by DOC concentration, temperature, hydraulic residence time and the drying-rewetting cycles. High salinity of brine did not prevent nitrate removal from occurring. The high DOC availability (>25 mg C L−1) during the first ≈48 weeks resulted in high nitrate removal rate (>75%) and nitrate removal efficiency (until ≈ 25 g N m−3 d−1) regardless of temperature. Moreover, the high DOC contents in the effluents during this period may present environmental drawbacks. Denitrification was still high after 2.5 years (reaching ≈9.3 g N m−3 d−1 in week 121), but dependence on warm temperature became more apparent with woodchips aging from week ≈49 onwards. Nitrate removal efficiency was highest on the first weekly batch, immediately after woodchips had been unsaturated for four days. It was attributable to a flush of DOC produced by aerobic microbial metabolism during drying that stimulated denitrification following re-saturation. Hence, alternance of drying-rewetting cycles is an operation practice that increase bioreactors nitrate removal performance.

Migratory birds’ physiology: A review

Migration has come from the latin word “migrare” may be defined as the seasonal movement of animals from one place to another. Bird migration was described by L. Thomson as “changes of habitat periodically recurring and alternating in direction, which tend to secure optimum environment conditions at all times”. Temperature, food supply, or the amount of daylight animals migrate, breeding is one of the purposes. Migratory birds undergo two migrations per year: a fall migration and a spring migration. Pre-migratory fattening is the behavior shown by the migratory birds in which they eat food in excess (hyperphagia) and gain weight quickly just to deal with the high energy demands for long migratory flight. This fueling is done before the migratory take off as well as at stopover sites of their routes. Fuel reserves reach maximum levels when birds start long non-stop flight. Feathers’ aerodynamic and insulatory functions are affected by long flight and its exposure to light therefore, the plumage is replaced periodically through a process known as molt. The corticosterone plays a major role in metabolic and behavioral functions to manage fuel utilization on a daily and seasonal basis. Migratory birds usually fly in a V formation and they follow a definite order during migration. Generally adults or old birds start first and the young follow them. Variety of senses helps in the navigation during migratory flight. It’s one of the peculiar system followed by the birds to know their route of migration and is followed by them each and every yearly of their flight. The most commonly used navigation tool is the use of sun compass. Using the sun for direction involves the need for making compensation based on the time. Other abilities include detecting the magnetic fields, visual landmarks and olfactory cues. Anatomical, physiological and molecular analyses have revealed that in birds independent clocks are present at a minimum of three levels: retina of the eyes, pineal gland and hypothalamus. Each of these has input, pacemaker and output components. It is becoming clearer that environmental input to the clock, such as seasonal changes in temperature, rainfall and food abundance, can regulate temporal relationships between physiology and behavior, linked with migration and reproduction.

Oral Pycnogenol® Intake Benefits the Skin in Urban Chinese Outdoor Workers: A Randomized, Placebo-Controlled, Double-Blind, and Crossover Intervention Study

Background: Oral supplementation with a standardized extract from the bark of the French pine (Pycnogenol®) has been reported to benefit the skin. It might thus represent an easy-to-use strategy to improve the skin health of individuals who are exposed to considerable environmental stress in large urban areas. Objective: We investigated if oral intake of Pycnogenol® can benefit the skin of Han Chinese working outdoors in Beijing, China. Methods: In a monocentre, double-blind, randomized, placebo-controlled, and crossover study, the effects of Pycnogenol® intake (2 × 50 mg/day for a total of 12 weeks) on a variety of skin physiological parameters was studied in Chinese subjects (n = 76), from spring to autumn, who were working outdoors in Beijing, China. Results: During the intervention period, study subjects were constantly exposed to increased levels of particulate matter (PM)_2.5 as well as seasonal changes in humidity and temperature. Despite this environmental stress, Pycnogenol® intake prevented (i) a decrease in the skin hydration, (ii) transepidermal water loss (TEWL), and (iii) skin darkening during the dry autumn season. In addition, Pycnogenol® intake improved (iv) viscoelastic skin properties such as gross elasticity and elastic recovery irrespective of the season. These beneficial effects were not observed if the same subjects were supplemented with placebo. Conclusion: Oral intake of Pycnogenol® benefits the skin in Han Chinese, who are working outdoors under considerable environmental stress.

Математическое моделирование воздействия температурных изменений на искусственные ледовые острова

The article is devoted to the numerical solution of the Stefan problem for thermal effects on an artificial ice island. For modern tasks of the development of the Arctic, associated with the exploration and production of minerals, it is important to create artificial ice islands in the Arctic shelf, due to the speed of their construction, economic feasibility and other factors. The most important task for the exploitation of such islands is their stability, including against melting. This paper discusses the issue of the stability of ice islands to melting. For this, the Stefan problem on the change in the phase state of matter is formulated. An enthalpy solution method is constructed, and the applicability of this method is considered. For the numerical solution, the Peasman-Reckford scheme is used, which is unconditionally spectrally stable in the two-dimensional case, which allows to freely choose the time step. In addition, the developed approach takes into account the flow of water and the flow of melted water, which is important in the task at hand. The developed computational algorithms are parallelized for use on modern multiprocessor computing systems An approach is implemented for modeling thermal processes in the thickness of an arbitrary mass of substances, taking into account arbitrary initial conditions, environmental conditions, tidal currents of water, and solar radiation. This approach was used to calculate the temperature distribution in the thickness of the ice island, as well as to study the impact of seasonal temperature changes on the stability of the island.

Seasonal changes in depth position and temperature of European catfish (Silurus glanis) tracked by acoustic telemetry in the Danube River

AbstractThe giant European catfish, Silurus glanis (total length = 200 cm; total weight ≈ 80 kg) was caught downstream of Iron Gate II hydropower dam (Danube River, 863 rkm) and tagged with an ultrasonic transmitter (V16TP; Vemco Ltd.) equipped with depth and temperature sensors. Changes in catfish diving behavior and temperature exposure were monitored over a period of roughly 2 years. Transmitter detections were recorded by nine autonomous receivers (VR2W, installed in 2015 between Serbia and Romania, as well as near Romanian shiplock and upstream Romanian turbines). The first signals were recorded on April 28, 2015 and the last on February 13, 2017. Altogether 59,355 and 59,175 detections of the catfish depth and water temperature were recorded, respectively. The greatest number of signals were recorded by the two receivers closest to the location where the catfish was caught, 72.3% and 27.1%, while only 0.6% of signals were recorded by other receivers. The mean catfish depth was 8.4 m, while minimum and maximum depths were 1.2 and 16.2 m. Results obtained showed that this catfish exhibited high site fidelity, while changes in depth at certain periods are possibly related to its search for prey and upstream migration during the spawning period. Hydropower dam and shiplock were obstacles on its migration upstream and telemetry studies could ensure habitat requirements and meet the development of restoration and conservation strategies for the fish resources in the future.

Weather effects on U.S. cow‐calf production: A long‐term panel analysis

AbstractExtreme weather events can significantly affect beef cow production. For example, unfavorable weather conditions deteriorate pasture quality and reduce pasture growth, forcing livestock producers to use high‐cost alternative feedstuffs, which consequently increases production costs. Extreme weather may also reduce overall animal performance, including decreased feed gain efficiency, and breeding performance. By exploiting seasonal weather changes and using 67 years of state‐level beef cow inventories, we estimate the impact of weather on cow‐calf production throughout 25 states in the United States. Results suggest that the U.S. cow‐calf industry is sensitive to changes in seasonal temperature. Results of an out‐of‐sample prediction using rolling window assessments prove that adding seasonal weather information to the forecasting model improves the prediction accuracy of state‐level beef cow inventories. Investigating the effects of seasonal temperature and precipitation on cow‐calf production will enhance the management and future production planning. [EconLit Citations: Q11].

An Overview of Atmospheric Features Over the Western North Atlantic Ocean and North American East Coast—Part 2: Circulation, Boundary Layer, and Clouds

AbstractThe Western North Atlantic Ocean (WNAO) is a complex land‐ocean‐atmosphere system that experiences a broad range of atmospheric phenomena, which in turn drive unique aerosol transport pathways, cloud morphologies, and boundary layer variability. This work, Part 2 of a 2‐part paper series, provides an overview of the atmospheric circulation, boundary layer variability, three‐dimensional cloud structure, and precipitation over the WNAO; the companion paper (Part 1) focused on chemical characterization of aerosols, gases, and wet deposition. Seasonal changes in atmospheric circulation and sea surface temperature explain a clear transition in cloud morphologies from small shallow cumulus clouds, convective clouds, and tropical storms in summer, to stratus/stratocumulus and multilayer cloud systems associated with winter storms. Synoptic variability in cloud fields is estimated using satellite‐based weather states, and the role of postfrontal conditions (cold‐air outbreaks) in the development of stratiform clouds is further analyzed. Precipitation is persistent over the ocean, with a regional peak over the Gulf Stream path, where offshore sea surface temperature gradients are large and surface fluxes reach a regional peak. Satellite data show a clear annual cycle in cloud droplet number concentration with maxima (minima) along the coast in winter (summer), suggesting a marked annual cycle in aerosol‐cloud interactions. Compared with satellite cloud retrievals, four climate models qualitatively reproduce the annual cycle in cloud cover and liquid water path, but with large discrepancies across models, especially in the extratropics. The paper concludes with a summary of outstanding issues and recommendations for future work.