Early Spring Months Research Articles

Future Derecho Potential in the United States

Abstract This study uses high-resolution, convection-permitting, dynamically downscaled regional climate simulation output to assess how long-lived, convectively induced, extratropical windstorms known as derechos may change across the CONUS during the 21st century. Three 15-year epochs including a historical period (1990 – 2005), and two, separate late-21st century periods (2085 – 2100) employing intermediate (RCP 4.5) and pessimistic (RCP 8.5) greenhouse gas concentration scenarios are evaluated. A mesoscale convective system (MCS) identification and tracking tool catalogs derecho candidates across epochs using simulated radar reflectivity and maximum 10-meter wind speed as a proxy for near-surface severe wind gusts. Results indicate that MCS-based windstorms, including derechos, are more frequent, widespread, and intense in both future climate scenarios examined for most regions of the central and eastern CONUS. Increases are suggested across all parts of the year, with significant changes in populations concentrated during the early spring and summer months, suggesting the potential for a longer, more extreme MCS windstorm season. This research provides insights for forecasters, emergency managers, and wind-vulnerable stakeholders on how these events may change across the 21st century so that they may mitigate, adapt to, and become resilient against severe convective storm perils.

Seasonal Patterns of Common Respiratory Viral Infections in Immunocompetent and Immunosuppressed Patients.

Several respiratory viruses have been shown to have seasonal patterns. The aim of our study was to evaluate and compare these patterns in immunocompetent and immunosuppressed patients for five different respiratory viruses. We performed a retrospective analysis of results for 13,591 respiratory tract samples for human metapneumovirus (HMPV), influenza virus, parainfluenza virus (PIV) and respiratory syncytial virus (RSV) in immunocompetent and immunosuppressed patients. A seasonal pattern was aligned to the data of immunocompetent patients through a logistic regression model of positive and negative test results. A narrow seasonal pattern (January to March) was documented for HMPV. Most RSV infections were detected in the winter and early spring months, from December to March, but occasional cases of RSV could be found throughout the year. The peak season for PIV-3 was during the summer months, and that for PIV-4 was mostly in autumn. A narrow seasonal pattern emerged for influenza virus as most infections were detected in the winter, in January and February. The seasonal patterns of HMPV, RSV, PIV, and influenza virus were similar for both immunocompetent and immunocompromised patients. We found no difference in the seasonality of HMPV, RSV, PIV, and influenza virus infections between immunosuppressed and immunocompetent hosts.

An evaluation of ‘pollinator-friendly’ wildflower seed mixes in Italy: are they potential vectors of alien plant species?

Wildflower areas are increasingly used in both urban and rural settings to enhance landscape aesthetics and help the conservation of pollinators, whose dramatic decline threatens both ecosystem functioning and agricultural production. Consequently, today many ‘pollinator-friendly’ wildflower seed mixes can be found on the market. Criteria for the design of these mixes are focused on the ability of the plants to attract pollinators, whereas the identity of the plants themselves in terms of their alien or native status is often not adequately considered. Moreover, seed mixes often lack sufficient floral resources in the early spring and late-season months, which are important to sustain pollinators throughout their whole life cycle. In this study, we analyzed 36 ‘pollinator-friendly’ wildflower seed mixes commercially available in Italy in terms of (1) the abundance of native and alien species, (2) the occurrence of locally alien species with reference to three Italian geographic areas (northern, peninsular, and insular Italy), and (3) the flowering period of native and alien species. Most (83%) of the analyzed seed mixes contain species alien to Italy, with three of them also including invasive alien species. Among native species, many (41%) are locally alien to at least one of the geographic areas. Overall, native species provide earlier blooms than alien species and around 35% of the seed mixes lack blooms in early-spring (March) or prolonged throughout autumn (September-November). These findings highlight the widespread use of alien plant species in ‘pollinator-friendly’ wildflower mixes, which poses serious risks for biodiversity and habitat conservation, especially when sown in agricultural areas. We suggest a more careful design and use of such wildflower mixes, promoting a wider adoption of native seeds of local origin and a greater attention to the blooming period. If properly designed, wildflower mixes can represent an effective strategy for biodiversity conservation in both urban and rural areas.

Have climate change and warmer winters altered freeze-thaw patterns?

Although an increase in the number of freeze–thaw (F/T) events are known to cause increased damage to pavement systems, further research is required to understand the impact of climate change on F/T cycles. This study aimed to determine the frequency of F/T cycles, and hence damage events, at typical air temperature sensor levels, in various layers of pavement, and at critical subgrade locations. In response to global warming, the study considered rigorously computed F/T events rooted in Minnesota climate data between 1901 and 2020. Cooperative Observer Network (COOP) and Modern-Era Retrospective Analysis Version 2.0 (MERRA-2) data were employed to examine subsurface warming conditions. The number of F/T cycles at the air temperature sensor level and individual pavement layers was determined by utilizing historical data from the COOP weather stations and Minnesota Road Test Facility (MnROAD). The evaluation was conducted on both a monthly and yearly basis. Results indicated that starting from 1981, Minnesota winters have become warmer by 0.1 to 1.2 °C in the daytime and by 0.3 to 1.5 °C during nighttime. The warmer winter weather results in fewer F/T cycles at shallow pavement levels on an annual basis while remaining erratic at deeper sub-pavement locations. The reduction of F/T events at shallower pavement depths was substantial during the late fall and early spring months. While monthly composites of F/T events at air-temperature sensor levels also reflected a decrease in F/T cycles during late fall and spring, the annual frequency of F/T events was randomly distributed.

A 16-year meteotsunami climatology in the coastal areas of southern Asia-Pacific Ocean

This study presents the meteotsunami behavior in response to different storm types in the coasts of southern Asia-Pacific Ocean from 16 years water level records. Through the size- frequency analysis, the dangerous meteotsunami, wave height exceeding 0.3 m, can occur up to 44 events per year. Notably, during the extreme waves of the 2007 event, wave heights reached approximately 0.9-1.5 m in the Taiwan Strait and the western coastal areas of Taiwan. We have classified storms into six types by radar reflectivity images and satellite-derived precipitation. Findings indicate that predicted wave heights caused by bows and typhoons could reach hazardous magnitude of exceeding 2 m in a 100-yr interval. Spatial and temporal analysis reveals that meteotsunami occurrences are most frequent in the western regions during the winter to early spring months (December to April). Of all meteotsunami occurrences, cluster storms are identified as the most prevalent atmospheric forcing, accounting for 60% of meteostunamis. Typhoons have a 20% association with meteotsunamis along the east coasts of Taiwan during late summer to autumn. On the east coasts, typhoon type-induced events may be attributed to the combination effect of meteotsunamis and infra-gravity waves. Overall, this study provides the first comprehensive examination of meteotsunami-storm characteristics and their associated hazard risks in the coastal areas of the southern Asia-Pacific Ocean.

Passive microwave Arctic sea ice melt onset dates from the advanced horizontal range algorithm 1979–2022

The onset of the summer melt season is a key stage of the Arctic sea ice seasonal cycle and is an indicator of climate change. Surface melting of the bare or snow-covered sea ice is detected using passive microwave satellite observations. The data set presented here is a 44 year record of Arctic sea ice annual melt onset (MO) dates for 1979–2022 produced using an updated version of the Advanced Horizontal Range Algorithm (AHRA). This data product contains annual maps of the sea ice MO date and a set of descriptive statistics summarizing the data. This paper describes a new update of the AHRA methodology, now AHRA V5, including key changes to the algorithm starting date and sea ice mask methodology to improve estimates of early-season MO dates especially near the sea ice periphery. AHRA V5 data are suitable for monitoring trends in Arctic and regional sea ice MO dates and for process studies of atmosphere-sea ice interactions during the early spring and summer months.

Effects of season of fire on bee-flower interaction diversity in a fire-maintained pine savanna.

Whereas the Coastal Plain of the southeastern United States historically experienced fire primarily during the mid-summer lightning season, managers today typically apply prescribed fire during the late winter or early spring months. The ecological implications of this discrepancy remain poorly understood, especially with regard to pollinators and their interactions with flowers. In a replicated field experiment, we compared the abundance and richness of bees and bee-flower interactions among pine savanna plots in Florida that were burned either during the winter, spring, summer, or fall. We netted 92 bee species from 77 species of flowers, representing 435 unique bee-flower interactions in total. When analyzing the results from each month separately, we detected significant short-term reductions in the number of bees and bee-flower interactions following fires regardless of season. Although bee abundance and richness did not differ over the entire season, bee-flower interaction richness was significantly higher overall in spring and summer plots than in fall plots and the composition of both bees and bee-flower interactions differed significantly among treatments. Several bee-flower interactions were significantly associated with one or more of the treatments. Some of these associations could be attributed to differences in flowering phenology among treatments. Taken together, our findings suggest that season of fire has modest but potentially important implications for interactions between bees and flowers in southeastern pine ecosystems. Because most flowering plants within our study region are pollinated by a variety of bees and other insects, and most bees endemic to the region are polylectic, season of fire may not be very important to either group overall. However, the timing of fire may be more important to particular species including certain flower specialists and fire-sensitive taxa such as butterflies. Future research targeting such species would be of interest.

Study of the Influence of the Inclusion of Additives in the Food of Kаrakol Sheep on the Composition of Blood Plasma Proteins and Amino Acids

The productivity of natural pastures, which are the main source of food for Karakol sheep, and the botanical and chemical composition of food undergo serious changes under the influence of climatic and seasonal factors. The productivity of pastures undergoes significant changes in years with favorable, moderately favorable and unfavorable climatic conditions, respectively. In accordance with the seasons, the consumption of food by cold animals, the supply of nutrients to their body varies significantly. Due to the insufficient supply of nutrients to the animal's body in the autumn-winter and early spring months, wool productivity and live weight decrease, as well as the deterioration of reproduction characteristics are observed. When the Karakol deer are fed with natural plants without additional nutrients throughout the year, the digestive processes in the large stomach undergo serious changes depending on the seasons or the physical conditions of the food consumed. The amount of food consumed by the karakol in the natural pasture feed, the digestibility coefficient of the nutrients in their content changed according to the level of nutrition and the amount of nutrients in the ration according to the seasons of the year. The coefficient of digestibility of nutrients, depending on the physical state of nutrients, was observed to be high in spring and summer and lowest in autumn and winter. The addition of additional nutrients to replace the missing nutrients in the feed ration of sheep allows increasing the digestibility of the nutritional components of the ration.

Low uptake of seasonal influenza vaccination in Al-Jouf region of Saudi Arabia

IntroductionSeasonal influenza is a contagious viral respiratory condition typically occurring in the fall to early spring months of the year globally. The risk of infection from seasonal influenza can be greatly reduced with vaccination. Unfortunately, research has indicated that the seasonal influenza vaccination rate in Saudi Arabia is low. This study assessed the uptake of seasonal influenza vaccination among adults residing in Al-Jouf region, Saudi Arabia. Materials and MethodsA cross-sectional survey targeting adults (20–80 years) residing in Al-Jouf region, Saudi Arabia, was conducted to gather information about their sociodemographic characteristics, chronic conditions, knowledge about periodic health examinations (PHE), regular use of PHE, and uptake of seasonal influenza vaccination. Comparative statistics and a multivariate logistic regression analysis were conducted to determine characteristics associated with the uptake of seasonal influenza vaccination. ResultsA total of 624 respondents completed the survey and participated in this study. Among the participants, 27.4% indicated they visited their primary healthcare centers or hospitals every year to get a seasonal influenza vaccination. The regression analysis showed that the odds of getting a seasonal influenza vaccination were higher among employed respondents (Odds Ratio [OR] = 1.73; P = 0.039), respondents who were employees of the healthcare sector (OR = 2.31; P = 0.001), and those with a higher PHE Knowledge Score (OR = 1.22; P = 0.008), compared to their counterparts. ConclusionsSeasonal influenza is a serious condition warranting appropriate prevention measures, including vaccination. However, this study confirmed low rates of seasonal influenza vaccination in Al-Jouf Region of Saudi Arabia. Interventions to boost vaccination uptake, in particular among unemployed individuals, those not working in the healthcare sector, and those with lower PHE knowledge Scores, are therefore recommended.

The occurrence of humpback whales across the Hawaiian archipelago revealed by fixed and mobile acoustic monitoring

The occurrence of humpback whales (Megaptera novaeangliae) across the 2600 km of Hawaiian archipelago, which include the remote atolls, banks, and seamounts of Papahānaumokuākea Marine National Monument (PMNM), remains poorly understood. Previous surveys for humpback whales beyond the main Hawaiian Islands have been scarce due to limited access and the challenging winter conditions typically found in PMNM when whales are present. To overcome these limitations, a combination of moored acoustic recorders and a Wave Glider autonomous surface vehicle were used to acoustically monitor eight locations and survey approximately 1500 km of the Hawaiian archipelago for the occurrence of humpback whale song during the 2019-2020 breeding season. Relative song prevalence was established using a machine learning tool and by quantifying the level of song chorusing. A generalized additive model framework was applied to understand the associations between habitat variables and humpback whale song occurrence, and sound propagation modeling was performed to examine whether acoustic propagation influenced observed patterns. Whale song was recorded at all monitored and surveyed locations across the archipelago, albeit in varying amounts. Among the locations monitored with moored recorders, the highest and most sustained seasonal chorusing levels were measured off Maui followed by French Frigate Shoals (Kānemilohai), Hawaii Island, Middle Bank, Oahu, Kauai, Gardner Pinnacles (Pūhāhonu) and Pearl and Hermes Reef (Holoikauaua), respectively. The Wave Glider mission to PMNM revealed that song prevalence was highest at Middle Bank and gradually decreased further to the northwest, reaching a minimum at Gardner Pinnacles (Pūhāhonu). However, song occurrence increased again at Raita Bank, remaining high between Raita Bank and the Northampton Seamounts. The results reveal that nearly the entire Hawaiian archipelago is exploited by humpback whales during the winter and early spring months. Moreover, song occurrence patterns suggest that there may be more structure in the distribution of whales in PMNM than previously known and raises questions about whether multiple subpopulations occur across the archipelago.

The Future of Supercells in the United States

Abstract A supercell is a distinct type of intense, long-lived thunderstorm that is defined by its quasi-steady, rotating updraft. Supercells are responsible for most damaging hail and deadly tornadoes, causing billions of dollars in losses and hundreds of casualties annually. This research uses high-resolution, convection-permitting climate simulations across 15-yr epochs that span the twenty-first century to assess how supercells may change across the United States. Specifically, the study explores how late-twentieth-century supercell populations compare with their late-twenty-first-century counterparts for two—intermediate and pessimistic—anthropogenic climate change trajectories. An algorithm identifies, segments, and tracks supercells in the simulation output using updraft helicity, which measures the magnitude of corkscrew flow through a storm’s updraft and is a common proxy for supercells. Results reveal that supercells will be more frequent and intense in future climates, with robust spatiotemporal shifts in their populations. Supercells are projected to become more numerous in regions of the eastern United States, while decreasing in frequency in portions of the Great Plains. Supercell risk is expected to escalate outside of the traditional severe storm season, with supercells and their perils likely to increase in late winter and early spring months under both emissions scenarios. Conversely, the latter part of the severe storm season may be curtailed, with supercells expected to decrease midsummer through early fall. These results suggest the potential for more significant tornadoes, hail, and extreme rainfall that, when combined with an increasingly vulnerable society, may produce disastrous consequences.

The effects of road salt (NaCl), predation, and competition on the growth and community interactions of spotted salamanders (Ambystoma maculatum) and wood frogs (Lithobates sylvaticus)

Road deicing salts are frequently used in northern regions of the world during the winter and early spring months. As a result, a significant portion of road runoff into surrounding aquatic habitats contains road deicing salts. Previous studies found road salt contaminations in vernal pools that pond-breeding amphibians commonly use, including spotted salamanders (Ambystoma maculatum) and wood frogs (Lithobates sylvaticus). Studies have examined the impact of road salt on both amphibian species, but to our knowledge no previous studies have examined how road salt impacts the interspecific competition between both amphibians. We hypothesized that road salt would negatively impact growth and survivorship of both amphibian species. During the spring and summer of 2017, we conducted an outdoor mesocosm experiment in which we created eight experimental conditions with three main factors: presence/absence of NaCl (1000 mg/L Cl−), presence/absence of interspecific competition between the two amphibian species (A. maculatum and L. sylvaticus), and presence/absence of predatory dragonfly larvae (Family Libellulidae). Our experiment revealed that salt delayed hatching and increased deformity in spotted salamander hatchlings. Additionally, salt reduced salamander survivorship by 62% and frog survivorship by 30%. Wood frog tadpoles and road salt interacted to diminish salamander survivorship a further 80% beyond salt alone, likely through an increase in interspecific competition. Road salt increased the larval period of salamanders and decreased the proportion metamorphosed by the end of the experiment. Dragonfly larvae reduced salamander survivorship by 35%, whereas they increased wood frog tadpole development rates. Dragonfly larvae and salt interacted to alter tadpole denticle size, with salt negating the impact of dragonfly larvae. Thus, we found that salt interfered with aquatic predatory chemical cues. Overall, the results of this study suggest that management strategies should be implemented in order to reduce the impact of road salts on freshwater aquatic ecosystems.

Abundance and Habitat Associations of Winter and Spring Birds on a Reclaimed Surface Mine (The Wilds) in Ohio, USA

Several studies have examined how grassland birds use reclaimed surface mines during the breeding season, but few studies have documented how these birds use these areas during the winter and early spring months. Using point counts, birds occupying a reclaimed surface-mine site in southeastern Ohio were surveyed from late December 2020 to April 2021. The primary objective was to document bird abundance and species richness across a temporal gradient spanning from late December 2020 through April 2021. Additionally, bird species composition was examined in habitat patches dominated by cool-season plants and in a single warm-season plot dominated by switchgrass (Panicum virgatum). A total of 1,452 bird sightings were made consisting of 40 species in 7 orders. Songbirds (order Passeriformes) comprised 60% of all sightings, and most of these (53%) were Red-winged Blackbirds (Agelaius phoeniceus), Eastern Meadowlarks (Sturnella magna), and Song Sparrows (Melospiza melodia). Thirty-nine species were observed on cool-season sites versus 13 species in the switchgrass plot. Species including returning Eastern Meadowlarks, Henslow's Sparrows (Centronyx henslowii), and Field Sparrows (Spizella pusilla) were common on the cool-season plots, but uncommon or absent in the switchgrass plot. Conversely, the switchgrass plot had more wintering American Tree Sparrows (Spizelloides arborea) and returning Swamp Sparrows (Melospiza georgiana). Return rates of long-distance migratory species fell within the time frames for these species as obtained from previous studies in this region. The diverse habitat structure of the cool-season portions of this study site attracted some winter species, including birds of prey, as well as several returning migratory species.

Secondary PM<sub>2.5</sub> decreases significantly less than NO<sub>2</sub> emission reductions during COVID lockdown in Germany

Abstract. This study estimates the influence of anthropogenic emission reductions on the concentration of particulate matter with a diameter smaller than 2.5 µm (PM2.5) during the 2020 lockdown period in German metropolitan areas. After accounting for meteorological effects, PM2.5 concentrations during the spring 2020 lockdown period were 5 % lower compared to the same time period in 2019. However, during the 2020 pre-lockdown period (winter), PM2.5 concentrations with meteorology accounted for were 19 % lower than in 2019. Meanwhile, NO2 concentrations with meteorology accounted for dropped by 23 % during the 2020 lockdown period compared to an only 9 % drop for the 2020 pre-lockdown period, both compared to 2019. SO2 and CO concentrations with meteorology accounted for show no significant changes during the 2020 lockdown period compared to 2019. GEOS-Chem (GC) simulations with a COVID-19 emission reduction scenario based on the observations (23 % reduction in anthropogenic NOx emission with unchanged anthropogenic volatile organic compounds (VOCs) and SO2) are consistent with the small reductions of PM2.5 during the lockdown and are used to identify the underlying drivers for this. Due to being in a NOx-saturated ozone production regime, GC OH radical and O3 concentrations increased (15 % and 9 %, respectively) during the lockdown compared to a business-as-usual (BAU, no lockdown) scenario. Ox (equal to NO2+O3) analysis implies that the increase in ozone at nighttime is solely due to reduced NO titration. The increased O3 results in increased NO3 radical concentrations, primarily during the night, despite the large reductions in NO2. Thus, the oxidative capacity of the atmosphere is increased in all three important oxidants, OH, O3, and NO3. PM nitrate formation from gas-phase nitric acid (HNO3) is decreased during the lockdown as the increased OH concentration cannot compensate for the strong reductions in NO2, resulting in decreased daytime HNO3 formation from the OH + NO2 reaction. However, nighttime formation of PM nitrate from N2O5 hydrolysis is relatively unchanged. This results from the fact that increased nighttime O3 results in significantly increased NO3, which roughly balances the effect of the strong NO2 reductions on N2O5 formation. Ultimately, the only small observed decrease in lockdown PM2.5 concentrations can be explained by the large contribution of nighttime PM nitrate formation, generally enhanced sulfate formation, and slightly decreased ammonium. This study also suggests that high PM2.5 episodes in early spring are linked to high atmospheric ammonia concentrations combined with favorable meteorological conditions of low temperature and low boundary layer height. Northwest Germany is a hot-spot of NH3 emissions, primarily emitted from livestock farming and intensive agricultural activities (fertilizer application), with high NH3 concentrations in the early spring and summer months. Based on our findings, we suggest that appropriate NOx and VOC emission controls are required to limit ozone, and that should also help reduce PM2.5. Regulation of NH3 emissions, primarily from agricultural sectors, could result in significant reductions in PM2.5 pollution.

Baseline of Surface and Column-Integrated Aerosol Loadings in the Pearl River Delta Region, China

Much attention has been paid to the rapid variation of aerosol loading in the urban areas of the Pearl River Delta (PRD) region. The baseline of aerosol loading in this rapidly developing region is critical in evaluating how and why the aerosol level has evolved, which absolutely requires long-term observations. Based on long-term observations of aerosol optical depth (AOD), visibility, and particulate matter (PM) mass concentrations at Xichong (114.56°E, 22.49°N), a background site in the PRD region, the variabilities of aerosol loading at multiple temporal scales are revealed. The means (±σ) of AOD, visibility, PM10, PM2.5, and PM1 are 0.38 ± 0.07, 12.6 ± 2.3 km, 23.7 ± 12.6 μg/m3, 19.7 ± 11.0 μg/m3, and 16.1 ± 10.1 μg/m3, respectively, which show that aerosol loading at the Xichong site is much lower than that in urban and suburban sites. Significant decreases in PM10, PM2.5, and PM1 mass concentrations are observed with magnitudes up to −2.13, −1.82, and −1.37 yr−1, respectively, at a 95% confidence level. The decrease in aerosol loadings at Xichong is attributed to the strict environmental regulations for improving air quality. Higher AOD and PM (lower visibility) values are observed during the early spring months as a result of long-range transport of biomass burning from Southeastern Asia. Diurnal variations of PM and visibility are dominantly determined by those of boundary layer height and relative humidity. PM mass concentrations show a generally negative (positive) correlation with visibility (AOD) at Xichong, but the correlations are weak with the R2 of 0.22 and 0.54, respectively. Low visibility and high aerosol loading are generally associated with very weak easterly and southerly winds. Understanding of variability of surface particle concentration and column-integrated aerosol loading at this background site in the PRD region would provide a scientific basis for the adoption of pollution prevention and control measures.

Utilizing Big Data From Google Trends to Map Population Depression in the United States: Exploratory Infodemiology Study.

BackgroundThe epidemiology of mental health disorders has important theoretical and practical implications for health care service and planning. The recent increase in big data storage and subsequent development of analytical tools suggest that mining search databases may yield important trends on mental health, which can be used to support existing population health studies.ObjectiveThis study aimed to map depression search intent in the United States based on internet-based mental health queries.MethodsWeekly data on mental health searches were extracted from Google Trends for an 11-year period (2010-2021) and separated by US state for the following terms: “feeling sad,” “depressed,” “depression,” “empty,” “insomnia,” “fatigue,” “guilty,” “feeling guilty,” and “suicide.” Multivariable regression models were created based on geographic and environmental factors and normalized to the following control terms: “sports,” “news,” “google,” “youtube,” “facebook,” and “netflix.” Heat maps of population depression were generated based on search intent.ResultsDepression search intent grew 67% from January 2010 to March 2021. Depression search intent showed significant seasonal patterns with peak intensity during winter (adjusted P<.001) and early spring months (adjusted P<.001), relative to summer months. Geographic location correlated with depression search intent with states in the Northeast (adjusted P=.01) having higher search intent than states in the South.ConclusionsThe trends extrapolated from Google Trends successfully correlate with known risk factors for depression, such as seasonality and increasing latitude. These findings suggest that Google Trends may be a valid novel epidemiological tool to map depression prevalence in the United States.

Analysis of seasonal and interannual river flows affecting whitewater rafting on the Franklin River in the Tasmanian Wilderness World Heritage Area

We analysed river flows in the Tasmanian Wilderness World Heritage Area to understand how they affect commercial whitewater rafting. Respectively, two river gauges have recorded river flows since 1953 and 1980 on the middle section of the Franklin on the Mt Fincham Track and at the bridge on the Collingwood River, a major tributary of the upper Franklin River. We show river heights on the Collingwood River are suitable for whitewater rafting launches all year round. Low flows on the Collingwood River, which are less than ideal for large rafts, are uncommon except for the warmest months (January, February, and March) when they occur about 50% of the time. During the late autumn, winter, and early spring months (May through October) river flows on the Franklin River are frequently (>30%) too high for rafting through the Great Ravine, the crux of Franklin River journey. There is clear evidence of reduced rainfall across Tasmania since the 1980s, and predictions of further declines in summer and autumn rainfall, nonetheless, we find no trends in river heights and flows since 1953. We conclude that climate change is likely to broaden whitewater rafting season because of low river flows in the summer months combined with increasing bushfire risk that will periodically lead to World Heritage Area tourism being shut down.

Seasonal Predictability of Sea Ice and Bottom Temperature Across the Eastern Bering Sea Shelf

AbstractSeasonal sea ice plays a key role in shaping the ecosystem dynamics of the eastern Bering Sea shelf. In particular, it leads to the formation of a characteristic pool of cold water that covers the bottom of the shelf from winter through summer; the extent of this cold pool is often used as a management index for distribution, productivity, recruitment, and survival of commercially important fish and shellfish species. Here, we quantify our ability to seasonally forecast interannual variability in Bering Sea bottom temperature and sea ice extent. Retrospective forecast simulations from two global forecast models are downscaled using a regional ocean model; the retrospective forecast simulations include 9‐month to 12‐month forecasts spanning 1982–2010. We find that dynamic forecasting can predict summer bottom temperatures across the eastern Bering Sea shelf with lead times of up to 4 months. The majority of the prediction skill derives from the persistence signal, and a persistence forecast is comparably skillful to the dynamic forecast at these lead times. However, forecast skill of sea ice advance and retreat is low when a forecast model is initialized before or during the ice season (October–February); this limits the ability of either dynamic or persistence models to predict summer bottom temperatures when initialized across the late fall to early spring months.

Climate Change and Thermal Comfort in Top Tourist Destinations—The Case of Santorini (Greece)

The Mediterranean area is one of the most visited tourist destinations of the world, but it has also been recognized as one of the most vulnerable to climate change areas worldwide with respect to increased thermal risk. The study focuses on a top worldwide tourist destination of the Mediterranean, Santorini Island in Greece, and aims to assess the past, present and future thermal environment in the island based on the advanced Universal Thermal Climate Index (UTCI). The study utilizes historical observations capturing past (late 19th to early 20th century) and more recent (1982–2019) time periods, while future projections are realized based on four regional climate models (RCMs) under the weak mitigation scenario (RCP4.5) and the non-mitigation scenario with high emissions (RCP8.5). The frequency of cold stress conditions at midday decreases during winter and early spring months by up to 19.8% (January) in the recent period compared to the historical one, while heat stress conditions increase in summer by up to 22.4% (August). Future projections suggest progressive shifts of the UTCI towards higher values in the future and an increase in the exposure time under heat stress depending on the RCM and adopted scenario. The increase in moderate and strong heat stress conditions is mainly expected during the summer months (June, July, August); nevertheless, a noticeable increase is also foreseen in September and May. The highest occurrences of favorable (no thermal stress) conditions are also projected to shift by one month, from June to May and from September to October, in the future.

The treatment of streptococcal tonsillitis/pharyngitis in young children.

Pharyngitis is common in children, accounting for nearly 12 million visits annually in the United States. Streptococcus pyogenes or group A streptococcus (GAS) is the most common bacterial cause of pharyngitis for which antibiotics are indicated. Antibiotic treatment of streptococcal pharyngitis virtually eliminates the presence of bacteria from the pharynx and thus removes the risk of subsequent rheumatic fever. GAS is spread from person to person via respiratory droplets with a short incubation period of 2∼5 days. GAS pharyngitis peaks in the late winter and early spring months when children are predominately indoors for school and sports. Colonization is also higher in winter months, and while up to 20% of school age children are colonized with GAS in their throat during this time, colonization has not been shown to contribute to the spread of disease. In low- and middle-income countries and other situations in which crowding is common (e.g., schools), outbreaks of pharyngitis are common. GAS pharyngitis can occur at all ages and it is most common in school-aged children with a peak at 7∼8 years of age. Pharyngitis caused by GAS is rare in children <3 years of age and becomes much less common in late adolescence through adulthood.