Spring Peak Research Articles

Annual variations of abundance, egg production rate, and community structure of Oithona similis in Jiaozhou Bay, the Yellow Sea

In marine ecosystems, copepods (<2 mm) play an important role in the transfer of carbon and energy to higher tropic levels. Investigations in Jiaozhou Bay were carried out throughout 2017–2018, combined with laboratory experiments. The annual abundance, egg production, female prosome length, female carbon mass, clutch size, population composition, and development time of Oithona similis at different temperatures were analyzed to assess the life strategies and estimate generation cycles of O.similis in typical temperate regions at mid-latitude, represented by Jiaozhou Bay. The results include: 1) O.similis abundance was characterized by bimodal cycles, with the major peak in winter (1471 ± 206 ind/m³) and the minor peak in spring (740 ± 320 ind/m³). O. similis abundance was not subject to food limitations except in January. The lower abundance was mainly affected by temperature (>20°C) and low salinity in August. Predation from large size zooplankton was one of the factors in regulating O. similis abuncance in Jiaozhou Bay. 2) Over the year, the egg production rate, female prosome length, and female carbon mass of O.similis ranged from 0.03 ± 0.02 to 1.21 ± 0.25 eggs female-1d-1, 410 ± 6 to 472 ± 4 μm, and 0.35 ± 0.05 to 0.43 ± 0.03 μg c female-1 respectively. Female prosome length, and female carbon were both significantly negative correlated with temperature(P<0.01). The clutch size of O.similis varied between 4 and 21 and we did’t find it was related with other factors. 3) O. similis appeared at almost all stages, and reproduced continuously throughout the year. According to the sex ratio of O.similis and other factors, we inferred that O. similis produced four generations per year in Jiaozhou Bay.

The Atlantic Meridional Mode and Associated Wind–SST Relationship in the CMIP6 Models

The Atlantic Meridional Mode (AMM) is the dominant mode of interannual climate variability in the tropical Atlantic, maintained primarily by the positive wind–evaporation–sea surface temperature (SST) feedback in which the wind anomalies lead the SST anomalies by ~2 months. A previous study revealed that climate models from Coupled Model Intercomparison Project Phase 5 (CMIP5) show poor performance in simulating the AMM-related wind–SST relationship, but the possible causes remain unclear. This study assesses the representation of the AMM and associated wind–SST relationship in the climate models from CMIP6. Results show that most of the CMIP6 models can reasonably reproduce the observed spatial pattern of the AMM, with significant SST and wind anomalies in the northern tropical Atlantic and weak anomalies in the equatorial–southern oceans. However, the simulated wind–SST relationship associated with the AMM varies among the models. In particular, several models fail to capture the observed wind–SST relationship; that is, the simulated wind anomalies peak in boreal spring as in the observations, but no obvious peak occurs in the corresponding SST anomalies. Further analysis suggests the models that fail to capture the observed wind–SST relationship tend to simulate a stronger mean trade wind and a thicker mixed layer in the northern tropical Atlantic, leading to a weaker ocean–atmosphere coupling and, thus, a weaker SST response to the wind forcing. Moreover, there exists a significant out-of-phase relationship between the strength of ocean–atmosphere coupling and mean mixed layer depth among the models, supporting the impact of mean state biases on the AMM variability in the models.

Statistical Modelling of the Annual Rainfall Pattern in Guanacaste, Costa Rica

Rainfall in Guanacaste, Costa Rica, has marked wet/dry phases: the rainy season is punctuated by a short midsummer drought, and the dry season frequently has months of no rain. In this region, spring and summer rainfall peaks are important for local rain-fed agriculture and annual total for groundwater recharge and hydroelectricity production. We propose a novel model of rainfall in this region, the double-Gaussian model, which uses monthly total rainfall data collected from 1980 to 2020 from two meteorological observation stations. Our model provides an intuitive way of describing the seasonality of rainfall, the inter-annual variability of the cycle, and variability due to the monthly Oceanic Niño Index, ONI. We also consider two alternative models, a regression model with ARMA errors and a Tweedie model, as a means of assessing the robustness of our conclusions to violations of the assumptions of the double-Gaussian model. We found that the data provide strong evidence of an increase/decrease in rainfall in both temporal maxima during La Niña/El Niño (negative/positive ONI) conditions but no evidence of a decade-scale trend after accounting for ONI effects. Finally, we investigated the problem of forecasting future rainfall based on our three models. We found that when ONI is incorporated as a predictor variable, our models can produce substantial gains in prediction accuracy of spring, summer, and annual totals over naive methods based on monthly sample means or medians.

Epidemiology and direct health care costs of hospitalised legionellosis in New Zealand, 2000-2020.

Legionellosis is a collective term used for disease caused by Legionella species which result in community and hospital acquired pneumonia worldwide. The aim of this analysis was to describe the epidemiology of legionellosis hospitalisations in Aotearoa New Zealand (NZ) over a 21-year period and quantify the health care costs. This study combined national legionellosis notification and hospital discharge data that were linked via the National Health Index (NHI) to provide a more complete dataset of hospitalised cases. The direct cost of hospital care was estimated by multiplying the diagnosis-related group cost-weight by the national price and inflating to 2020/2021 values. There were 1479 records matched across notifications and discharge databases, including 990 with principal and 489 with additional diagnosis of legionellosis. Incidence rose to an average of 143 cases per annum for 2016-2020, a rate of 3·2/100,000. The median LOS was 6 days (IQR 4-13·5) with direct costs of $2·1 million per annum over that period. Rates were highest in those aged 65 years and above, male, and of European/Other ethnicity. Hospitalisations showed a peak in spring and summer. The rate of hospitalised legionellosis in New Zealand rose from 2000 to 2015, largely reflecting improved diagnosis. This preventable disease results in substantial health care costs. Greater efforts are needed to identify and control sources of exposure. Surveillance could be improved by routine integration of notification and hospital discharge data.

Assessing the national burden of allergic asthma by web-search data, pollen counts, and drug prescriptions in Germany and Sweden

BackgroundAsthma and its main phenotype allergic asthma are prevalent, chronic, and complex diseases affecting 4% of the population. One main trigger for allergic asthma exacerbations is pollen. Online health information search behavior by people is increasing, and analysis of web-search data can provide valuable insight into disease burden and risk factors of a population. ObjectivesWe sought to perform a web-search data analysis and correlation to climate factors and pollen in 2 European countries. MethodsWe analyzed the national web-search volume for allergic asthma-related keywords in Germany and Sweden from 2018 to 2021 and correlated it to local pollen counts, climatic factors, and drug prescription rates. ResultsPer capita, more searches were conducted in Sweden than in Germany. A complex geographic stratification within the countries was observed. Search results were seasonal with a peak in spring and correlated with pollen counts in both countries. However, anti-asthmatic drug prescription rates in Sweden, as well as temperature and precipitation in both countries, did not correlate with search volume. ConclusionOur analysis offers population-level insights about this complex disease by reporting its needs and establishing the correlation to pollen counts, which enables a targeted approach in the public health management of allergic asthma. Local pollen counts, as opposed to temperature or precipitation, might be good predictors of allergic asthma disease burden.

Latitudinal-dependent emergence of phytoplankton seasonal blooms in the Kuroshio Extension

The bimodal and unimodal seasonal cycles of surface Chlorophyll-a (Chl-a) concentration (SCC) are ubiquitous in the mid-latitude oceans. The nutrient and light are regarded as two key factors affecting such seasonal differences. However, our quantitative knowledge of distinguishing these two factors is still inadequate in mid-latitude regions where they limit primary productivity simultaneously. It hinders the full understanding of the underlying mechanisms of seasonal blooms. In this study, the bimodal and unimodal variations of SCC in the Kuroshio Extension (KE) region have been investigated, with a special focus on the emergence latitudes of the secondary peak, i.e., the phytoplankton fall bloom. Based on satellite observations, we have found that the SCC bloom emerges in spring and fall in the northern region, and that spring (fall) bloom starts later (earlier) as the latitude gets higher. In the southern part of KE, by contrast, the SCC tends to peak in late winter or early spring with its bloom time delaying gradually with increasing latitude. A regression model regarding the role of the nutrient and light has been proposed to reconstruct the seasonal variations of the observed SCC, and the relative contributions of the two factors have been assessed quantitatively. It is shown that the regression model has reasonably captured the seasonal variations of SCC in terms of the bimodal/unimodal feature as well as the time of occurrence. Specifically, we have found the boundary between bimodality and unimodality areas moves northward as KE flows eastward, which corresponds to the equivalent contribution of the nutrient and light to the SCC variation and the eastward-decreasing nutrient at the same latitude. Moreover, we have used the model to explore the lag effect of light on regulating the seasonal cycle of SCC, which is associated with the light-heating process, the resultant ocean vertical stratification and the nutrient deficiency, the time interval between the growth rate and SCC, as well as light attenuation within the mixed layer. In the context of global warming, our study has provided insights into the switch pattern between bimodality and unimodality of SCC in mid-latitude oceans.

Sensing and Mapping the Effects of Cow Trampling on the Soil Compaction of the Montado Mediterranean Ecosystem

The economic and environmental sustainability of extensive livestock production systems requires the optimisation of soil management, pasture production and animal grazing. Soil compaction is generally viewed as an indicator of soil degradation processes and a determinant factor in crop productivity. In the Montado silvopastoral ecosystem, characteristic of the Iberian Peninsula, animal trampling is mentioned as a variable to consider in soil compaction. This study aims: (i) to assess the spatial variation in the compaction profile of the 0-0.30 m deep soil layer over several years; (ii) to evaluate the effect of animal trampling on soil compaction; and (iii) to demonstrate the utility of combining various technological tools for sensing and mapping indicators of soil characteristics (Cone Index, CI; and apparent electrical conductivity, ECa), of pastures' vegetative vigour (Normalised Difference Vegetation Index, NDVI) and of cows' grazing zones (Global Positioning Systems, GPS collars). The significant correlation between CI, soil moisture content (SMC) and ECa and between ECa and soil clay content shows the potential of using these expedient tools provided by the development of Precision Agriculture. The compaction resulting from animal trampling was significant outside the tree canopy (OTC) in the four evaluated dates and in the three soil layers considered (0-0.10 m; 0.10-0.20 m; 0.20-0.30 m). However, under the tree canopy (UTC), the effect of animal trampling was significant only in the 0-0.10 m soil layer and in three of the four dates, with a tendency for a greater CI at greater depths (0.10-0.30 m), in zones with a lower animal presence. These results suggest that this could be a dynamic process, with recovery cycles in the face of grazing management, seasonal fluctuations in soil moisture or spatial variation in specific soil characteristics (namely clay contents). The NDVI shows potential for monitoring the effect of livestock trampling during the peak spring production phase, with greater vigour in areas with less animal trampling. These results provide good perspectives for future studies that allow the calibration and validation of these tools to support the decision-making process of the agricultural manager.

Climate and landuse change enhance spatio-temporal variability of Dongjiang river flow and ammonia nitrogen

The adverse impacts of climate and landuse change are threatening the availability of water quantity and its quality, yet there are limited understandings in the response of water availability to changing environment at different spatio-temporal scales. Aimed at quantifying the individual and superimposed effects of climate and landuse change on streamflow and ammonia nitrogen (NH3−N) load in the Dongjiang River Basin (DRB), we dynamically simulated the historical (1981–2010) and future (2030–2070) variation of runoff depth and NH3-N load coupling multiple regional climate model and landuse data. The increase in runoff depth (avg. +233.9 mm) due to climate change was about 33 times greater than that caused by landuse change (avg. -7.2 mm). Especially in the downstream of DRB (Hong Kong, Shenzhen and Dongguan cities, etc.), the maximum rise of runoff depth under climate change was near twice compared with baseline period, indicating the dominant control of climate change on runoff. Also there existed higher coefficient of variation (Cv) value of runoff in the dry season of downstream DRB, contributing potential great fluctuation in runoff. Besides, the variation of NH3-N load was jointly influenced by climate and landuse change, revealing an offset or amplification effect. Moreover, the variability of NH3-N load (Cv value as the metric) increased from 2030, reached a maximum in 2050, following decreased to 2070. The spatial distribution of NH3-N load, in general, presented a downward trend and concentrated near the water body, while the monthly average NH3-N load showed distinct peaks in spring and late summer temporally. Overall, the results highlight the significance of investigating the water availability under changing environment and more adaptive strategies should be proposed for better basin water management.

Characteristics of atmospheric boundary layer structure and its influencing factors under different sea and land positions in Europe

This study identifies quantitatively the dominant contributions of meteorological factors on the development of the boundary layer heights (BLH) in the European region, based on 32 years (1990−2021) of radiosonde observations. The spatial variability of the BLH is further discussed by location, by classifying recording stations as inland, coastal, or bay. We find that the BLH in Europe varies considerably from day to night and with the seasons. Nighttime BLH is higher in winter and lower in summer, with the highest BLH recorded at coastal stations. Daytime BLH at coastal stations shows a bimodal structure with peaks in spring and autumn; at inland and bay stations, daytime BLH is lower in winter and higher in summer. The daily amplitudes of BLH at the inland and bay stations are stronger than those at coastal stations. Based on our multiple linear regression analysis and our decoupling analysis of temperature and specific humidity, we report that the development of the nighttime BLH at all types of stations is strongly dominated by the variations of surface wind speed (and, at coastal stations, wind directions). The main contributors to daytime BLH are the near-surface temperature variability at most coastal and inland stations, and, at most bay stations, the variation of the near-surface specific humidity.

Conservation of the surface-nesting Kermadec Petrel Pterodroma neglecta neglecta in the South Pacific: clarifying breeding ecology and the threat of avian ground predators

Summary Understanding population dynamics and impacts on island ecology remain top priorities for the conservation management of seabirds, particularly when attempting species-recovery for island restoration. Identifying suitable nesting habitat is a keystone detail in seabird restoration which can be complicated when predator pressures impact colony productivity and population viability. The surface-nesting Kermadec Petrel Pterodroma neglecta neglecta is dispersed on remote islands through the tropics and subtropics. We examined their breeding ecology on Phillip Island, Norfolk Group in the South Pacific and considered the limitations to re-establishment at their previous breeding location on Lord Howe Island (900 km south-east). On Phillip Island, the petrels were mostly monogamous with nesting locations generally within the vicinity of the previous season’s attempts. Breeding sites were limited to sloping terrain 182–228 m above the shoreline and up to 85 m from the coast in small sub-colonies under low scrubby woodland. Based on observations of 56 pairs and data gleaned from Global Light Sensing devices, we determined that breeding (incubation and provisioning) occurs in all calendar months of the year, with a laying peak in the late austral spring. Breeding success in the first year of study was 25% but improved to 56% once management of Purple Swamphens Porphyrio melanotus was implemented. Successful nests were located at sites with naturally limited egress from cleared or lightly vegetated areas. Prudent management of the petrel population on Phillip Island could aid in the regional recovery of the species and, in the process, assist the island’s restoration by significantly increasing transfers of marine-derived nutrient. Their reintroduction to Lord Howe Island is also possible but will likely rely upon consistent productivity of the Phillip Island population for founding immigrants. Moreover, successful establishment will require adaptive management of selected sites to ensure native avian predators do not overly impact breeding.

Precipitation as a Possible Risk Factor for Development of Lyme Nephritis in Dogs.

To determine whether increased precipitation in the months before diagnosis is predictive of Lyme nephritis in dogs, a symmetrical bidirectional case-crossover study was performed on 87 dogs with presumptive Lyme nephritis. Cases were geographically linked to the nearest precipitation monitoring station, and monthly total precipitation for the 4 mo preceding diagnosis was compared to monthly total precipitation 1 yr before and 1 yr after. Breeds affected included Labrador retrievers (n = 31), mixed-breed dogs (n = 19), and golden retrievers (n = 10), with a possible seasonal bimodal peak in spring and fall. In age-adjusted analysis, each additional inch of precipitation 3 mo before diagnosis was associated with an increase in the odds of developing Lyme nephritis (odds ratio 1.13, 95% confidence interval 1.01-1.25). The results suggest that increased precipitation is a possible risk factor for Lyme nephritis in dogs. These findings may provide useful information for the accurate diagnosis of dogs with protein-losing nephropathy and may guide future studies of risk factors for Lyme nephritis. The methodology employed here reinforces the concept that case-crossover designs have utility beyond acute exposures and outcomes and offer an attractive alternative for studies in companion animals.

Exploration of influenza incidence prediction model based on meteorological factors in Lanzhou, China, 2014-2017.

Humans are susceptible to influenza. The influenza virus spreads quickly and behave seasonally. The seasonality and spread of influenza are often associated with meteorological factors and have spatio-temporal differences. Based on the influenza cases and daily average meteorological factors in Lanzhou from 2014 to 2017, this study firstly aimed to analyze the characteristics of influenza incidence in Lanzhou and the impact of meteorological factors on influenza activities. Then, SARIMA(X) models for the prediction were established. The influenza cases in Lanzhou from 2014 to 2017 was more male than female, and the younger the age, the higher the susceptibility; the epidemic characteristics showed that there is a peak in winter, a secondary peak in spring, and a trough in summer and autumn. The influenza cases in Lanzhou increased with increasing daily pressure, decreasing precipitation, average relative humidity, hours of sunshine, average daily temperature and average daily wind speed. Low temperature was a significant driving factor for the increase of transmission intensity of seasonal influenza. The SARIMAX (1,0,0)(1,0,1)[12] multivariable model with average temperature has better prediction performance than the university model. This model is helpful to establish an early warning system, and provide important evidence for the development of influenza control policies and public health interventions.

Dimensionality-Transformed Remote Sensing Data Application to Map Soil Salinization at Lowlands of the Syr Darya River

The problem of saving soil resources and their reclamation measures under current climate change conditions attracts the world community’s close attention. It is relevant in the Syr Darya River’s lowlands, where the secondary soil salinization processes have intensified. The demand for robust methods to assess soil salinity is high, and the primary purpose of this study was to develop a quantitative analysis method for soil salinity estimation. We found a correspondence between the sum of salts in a topsoil layer to the Landsat 8 data in the Tasseled cap transformation of the image values. After testing several methods, we built a prediction model. The K-nearest neighborhood (KNN) model with a coefficient of determination equal to 0.96 using selected predictors proved to be the most appropriate for soil salinity assessment. We also performed a quantitative assessment of soil salinity. A significant increase in a salt-affected area and the mean soil sum expressing an intensification of secondary soil salinization from 2018 to 2021 was found. The increasing temperature values, decreasing soil moisture, and agricultural use affect the extension of salt-affected ground areas in the study area. Thus, the soil moisture trend in the Qazaly irrigation zone is negative and declining, with the highest peaks in early spring. The maximum temperature has a mean value of 15.6 °C (minimum = −15.1 °C, maximum = 37.4 °C) with an increasing trend. These parameters are evidence of climate change that also affects soil salinization. PCA transformation of the Landsat-8 satellite images helped to remove redundant spectral information from multiband datasets and map soil salinity more precisely. This approach simultaneously extends mapping opportunities involving visible and invisible bands and results in a smaller dataset.

Response of the Black Sea Zooplankton to the Marine Heat Wave 2010: Case of the Sevastopol Bay

Global warming is increasing the frequency and severity of the marine heat waves, which poses a serious threat to the marine ecosystem. This study analyzes seasonal and interannual dynamics in the abundance and structure of the mesozooplankton community in Sevastopol Bay based on bi-monthly routine observations over 2003–2014. The focus is on the impact of the summer 2010 marine heat wave (MHW2010) on crustaceans belonging to different ecological groups. As a response to the MHW2010, three warm-water species (O. davisae, A. tonsa and P. avirostris) exhibiting the maximum seasonal density in latter summer showed a sharp increase in the annual abundance and their share in the mesozooplankton community. The increase in the annual abundance in 2010 of the eurythermal species P. parvus and P. polyphemoides exhibiting seasonal peaks in spring and autumn is not related to the MHW2010 but can be explained by a rise of temperature in the first part of the year. O. davisae and A. tonsa showed the most pronounced response among the species to the MHW2010, confirming that non-native species exhibited great flexibility as an adaptive response to environmental changes, especially in the case of climate warming. Among crustaceans observed in this study, O. davisae can be considered as an indicator of the environmental conditions associated with the warming of the Black Sea and the Mediterranean basin as a whole.

Mysterious increases of whiting events in the Bahama Banks

“Whiting” events in the Bahama Banks, due to high concentrations of carbonate-rich particles suspended in the water, have been reported and discussed widely in the past 80 years. However, little is known about their distributions and particularly about their long-term changes. Here, using a deep learning (DL) model, we objectively delineate and quantify whiting features from Aqua MODIS (Moderate Resolution Imaging Spectroradiometer) satellite images (250-m resolution) and establish an 18-year data record (2003−2020) of whiting occurrences in the Bahama Banks. Both the Great Bahama Bank (GBB) and the Little Bahama Bank (LBB) show clear seasonality in whiting areas, where a primary peak in spring and a secondary peak in winter are found in the GBB but only one peak in winter is found in the LBB. Such a seasonality may be explained using a hydrodynamic hypothesis on calcium carbonate precipitation. The mean size of individual whiting patches in the GBB is about 2.4 ± 6.1 km2 (∼0.1 to 226 km2), while in the LBB is 1.4 ± 2.7 km2 (∼0.1 to 95 km2). The total whiting coverage in a typical cloud-free image is 87.1 km2 in the GBB and 32.0 km2 in the LBB, representing 0.14% and 0.76% of the entire GBB and LBB, respectively. Significant increases in the mean coverage have been found in the GBB since 2011, with peak coverage (∼200 km2) in 2013–2015 being at least 4 times higher than before (20–70 km2). Although the whiting area started to decrease after 2015, it did not reach the pre-2011 level until 2020. On the other hand, correlation analysis and principal component analysis of several environmental factors (pH, light, salinity, carbonate, aragonite, winds, currents) provided some hints on which factors may have contributed. From these, we infer a potential ‘Goldilocks’ scenario, whereby decreases in pH and carbonate concentration, concomitant with increases in Sea Surface Temperature (SST) and current speeds, created conditions increasingly favorable for whitings from 2011 to 2015. Continuation of these environmental trends after 2015, however, resulted in conditions increasingly unfavorable for whiting formation, yet without field-based measurements it is difficult to conclude the potential reasons for increases and decreases of whiting formation in the GBB.

Assessment of spatiotemporal features and potential sources of atmospheric aerosols over the Tianshan Mountains in arid central Asia

Arid central Asia is characterized by a dry climate with little precipitation and frequent dust storms. At the same time, the Tianshan Mountains, a vitally important water resource supply zone and ecological barrier, are located in the heart of arid central Asia. Frequent dust storms in this region endanger snow and ice melting as well as ecological security within the Tianshan Mountains. In the present study, the CALIPSO data and HYSPLIT model were combined to assess the spatiotemporal features and potential sources of aerosols over the North Tianshan (NT), East Tianshan (ET), Central Tianshan in the East (CTE), Central Tianshan in the West (CTW), West Tianshan (WT), and South West Tianshan (SW). Results showed that the atmospheric aerosol subtypes had an apparent spatial variability. Dust and polluted dust were the two most dominant aerosol subtypes with the two accounting for over 76% of detected aerosols. The occurrence frequency of the dust within NT, ET, CTE, and CTW showed seasonal variation with two peaks in spring and autumn, while that of WT and SW peaked only in summer. The occurrence frequency of polluted dust in the ET region differed from that found in NT, CTE, CTW, WT, and SW. During all seasons, polluted dust was the dominant aerosol subtype recorded at heights from 2 km to 5 km in NT and WT. Vertically, dust and polluted dust were the most common subtypes observed between 1 and 8 km in SW. The top altitude of the dust and polluted dust layer over most of the Tianshan Mountains was greater than 5 km. The thickest dust layer over the Tianshan Mountains appeared in summer with a value larger than 2.0 km, and the thickness of the polluted dust layer was approximately between 1.0 and 1.5 km in spring. In comparison, the southwesterly transport pathways are the primary route for atmospheric aerosols to the Tianshan Mountains, which have the greater potential to carry natural and anthropogenic aerosols. Therefore, the Karakum Desert, Kyzylkun Desert, Moyunkum Desert, and Gurbantunggut Desert are the primary potential sources of dust and polluted dust aerosols over the Tianshan Mountains in arid central Asia.

One-year spatiotemporal variations of air pollutants in a major chemical-industry park in the Yangtze River Delta, China by 30 miniature air quality monitoring stations

Fine chemical industrial park (FCIP) is a major source of atmospheric pollutants in China. A long-term high spatial resolution monitoring campaign on air pollutants had been firstly conducted in a major FCIP in Yangtze River Delta (YRD) from December 2019 to November 2020. The grid-based monitoring platform consisting of 30 miniature air quality monitoring stations (AQMSs) provided comprehensive coverage of a FCIP, and long-term monitoring studies solved the problem of lack of clarity about pollution sources in industrial parks. Overall, NO2 pollution was particularly high in the pharmaceutical industry, while TVOCs and O3 pollution were most serious in the textile dyeing industry, with PM pollution much higher in the metal smelting industry than in other industries, and in the leather industry, O3 pollution was relatively severe. The spatial and temporal variations of air pollutants showed that higher PM, CO and NO2 concentrations were revealed in winter while lower in summer due to better meteorological diffusion conditions. TVOCs concentrations were higher with an average of 1954 ppb in summer possibly due to their increased volatilization from their sources at higher ambient temperatures. O3 concentrations were at their peaks in spring (88.8 μg m−3) and early fall (78.5 μg m−3). The daily trends of O3 precursors (TVOCs and NO2) were clearly negatively correlated with O3, and they showed bimodal peaks due to anthropogenic activities, plant emissions, lowering of the mixed boundary layer, etc. The O3 formed in FCIP was judged to be NO2-limited during the monitoring period based on the ratios of NO2 to TVOCs. Therefore, the effective strategy to reduce O3 formation in FCIP is to decrease the ambient NO2 concentration. Based on Pearson correlation coefficients, it appeared that WS promoted O3 formation through long-term transport and that high air temperatures also contributed to O3 formation in the environment. It was also stated in the study that the closer the residential area is to the industrial sources, the more significant the correlation. Thus, the results of this study will also be helpful for policymakers to design pollutant control strategies for different industries to mitigate the impact of pollutants on human health.

Nitrogen addition promotes foliar litterfall and element return in a subtropical forest, southwestern China

Nitrogen deposition has a considerable impact on biogeochemical cycling in terrestrial ecosystems. However, how litter production and element return respond to N addition remains poorly understood in nitrogen-rich subtropical regions. In this study, a 4-year nitrogen addition experiment explored its effects on foliar litter production and carbon, nitrogen and phosphorus in a subtropical Michelia wilsonii forest. A clear seasonal pattern in foliar litterfall was observed, regardless of nitrogen treatments, with a peak in spring and a smaller one in autumn. Foliar litter increased with increasing nitrogen but did not affect litter carbon concentrations and often decreased nitrogen and phosphorous concentrations. The effect of nitrogen addition was dependent on time (month/year). Carbon, nitrogen and phosphorous return showed similar bimodal seasonal patterns. Nitrogen addition increased carbon and nitrogen return but did not affect phosphorous. Our results suggest that the addition of nitrogen stimulates carbon and nutrient return via litterfall.

Land Use and Land Cover Influence on Sentinel-2 Aerosol Optical Depth below City Scales over Beijing

Atmospheric aerosols can impact human health, necessitating the understanding of their distribution determinants, especially in urban areas. The study discusses the relationships between five major land cover types and aerosol optical depth (AOD) within a city combining the high-resolution satellite-derived AOD products (derived from Sentinel-2) and land cover products (60 m and 100 m, respectively) for Beijing and its surroundings from 2017 to 2019. Contribution analysis is performed to quantitatively evaluate the influences of land cover on regional AOD over the study area. Patterns of aerosol distribution remarkably vary in time and space. Statistics of seasonal average AOD peak in spring and then progressively decline from summer through autumn to winter. High AOD values coincide with a low normalized difference vegetation index (NDVI) and a high normalized difference built-up index (NDBI). Urban and built-up land is a major contributor to regional AOD in the study area, especially in spring; forest and grassland always reduce AOD. Anthropogenic activities have a non-negligible influence on AOD and can even reverse the contribution of a land cover type to aerosols. Insights of the study promote the comprehension of the impacts of land cover on aerosols and air pollution and contribute to the planning of land use within a city.

Impact of meteorological factors and psychiatric disorders : a French exploratory study.

Introduction : The objective of our work was to study the link between meteorological factors (temperature, sunshine duration, rain, wind, humidity) and psychiatric disorders. For this purpose, we conducted two exploratory studies in France : the first one, studying the link between the weather and suicidal behaviors (suicides and suicide attempts); the other one between alcohol use disorders (AUD) and the weather. Methods : We analyzed the number of deaths by suicide and suicide attempts in metropolitan France (2009-2018) from French national hospitalization databases; patients who were admitted to an emergency department for an alcohol related condition were included using the Oscour database, and we used meteorological database from national weather services. Based on this model, we determined the association of suicides and suicide attempts with weather factors, and then between AUD and meteorological factors. Results: The number of suicides and suicide attempts decreased over the last ten years in France (mean decrease of 14.49% and 11.69% per year). We observed a significant and recurrent seasonal pattern of suicides and suicide attempts in France, with a peak in spring. The suicide and suicide attempt rates were higher in the northern departments of France. We found significant positive correlations between the number of alcohol-related ED visits and the mean temperature (r = 0.55; p = 1.87e) and the duration of sunlight (r = 0.42; p = .0015). Negative correlations were also found significant with rain (r = −0.40; p = .0014), humidity (r = –0.41; p = .0023) and wind speed (r = −0.40; p = .0031).  Conclusion: The number of suicides and suicide attempts decreased in France over the last 10 years, with large and recurrent seasonal variations. Emergency visits for AUD seem to increase with the temperature and duration of sunlight, and decrease with rain, humidity and wind speed.