End Of Autumn Research Articles

Estimation of annual evaporation losses for the Makhoul Dam reservoir (under construction)

The Evaporation problem is considered one of the most important problems that dam reservoirs suffer from because of the economic losses and costs of treating. Makhoul Dam, which is a dam under construction in Iraq. In this research, a study was conducted to estimate the evaporation losses from the dam’s reservoir. The type A pan was used to measure daily evaporation for a full year, starting from July 2022 until June 2023. The GES program was used to estimate the shape of the reservoir based on Based on the information available for the dam and DEM satellite images of the area with a resolution of 30 meters. Two sites were chosen to measure evaporation, one in the city of Al-Zab, approximately in the center of the reservoir, and the other in the village of Tal Ali, about 30 km from the dam. The results showed that the cumulative total of annual evaporation from the Al-Zab measuring station reached 1547 mm/year, and the cumulative total of annual evaporation from Tal Ali station reached 1766 mm/year. The evaporation rate from the two stations was taken to calculate the annual rate of evaporation from the reservoir, which amounted to 1656 mm/year. Two hypotheses were imposed for the method of evaporation from the reservoir. The first assumed that the reservoir was full throughout the year. In this case, the evaporation losses from the reservoir would be 380,631,600 cubic meters/year, or the equivalent of 15% of the volume of the storage. As for the second hypothesis, it assumed that the reservoir is variable throughout the year, starting with the highest level in the spring and then decreasing. Gradually until the end of autumn, then it increases again in winter. In this hypothesis, the annual losses will be 288,175,555 cubic meters / year, or the equivalent of 11% of the volume of the storage

The Emergence of the Family Scirtidae (Insecta: Coleoptera) in Lotic Karst Habitats: A Case Study over 15 Years.

Due to ongoing changes and a decline in biodiversity, science today should rely on long-term species-based ecological studies. We have conducted a long-term ecological dynamics study on the water beetle family Scirtidae, which, although it is very abundant in benthic communities, is still poorly studied. The main objective of this study was to investigate the population aspects (composition, diversity, sex ratio) and ecological aspects (emergence patterns, seasonal dynamics and preferences for environmental factors) of the family Scirtidae over 15 years in Plitvice Lakes NP, Croatia. The study was conducted at three sites and in five different substrate types. A total of three taxa with different distributions were recorded in the study area: Hydrocyphon novaki and H. deflexicollis on the tufa barriers and the Elodes sp. in the spring area. The sex ratio was in favour of males in spring and early summer, while it shifted in favour of females towards the end of autumn. The abundance and emergence of the family were primarily determined by the environmental parameters which showed the greatest fluctuations over a period of 15 years: water temperature, water discharge and oxygen saturation. Our results clearly show that Scirtidae can be used as indicators of stream zonation and habitat quality. Based on the methodology and the results of this study, we conclude that Scirtidae should be used in future monitoring and protection measures in karst freshwater habitats in southeastern Europe.

ПРОСТОРОВО ЧАСОВЕ РОЗПОВСЮДЖЕННЯ МАСОВИХ ВІДКЛАДІВ МОКРОГО СНІГУ НА ТЕРИТОРІЇ УКРАЇНИ ПРОТЯГОМ 1991-2020 рр. ПО ОКРЕМИХ ДЕСЯТИРІЧЧЯХ

The presented article is dedicated to the study of the spatio-temporal distribution of mass deposits of wet snow on the territory of Ukraine during certain decades of the period 1991-2020. The case of mass distribution of wet snow deposits is considered to be the case when such deposits were observed in 1 day at at least 10 stations located on territories of at least 2 regions. Each of the three ten-year periods was analyzed, taking into account all the studied months regarding the features of the distribution of mass deposits of wet snow separately, and the features of the distribution of such cases on the territory of Ukraine were clarified. For the first decade of 1991-2000, it was established that for the winter months and at the end of autumn, such deposits, in cases of their mass distribution, are mostly observed in the territory of the northern and northeastern regions (Kyiv, Chernihiv, Sumy, Kharkiv), as well as in the central regions ( Cherkasy, Kirovohrad, Poltava, Dnipropetrovsk). In the south, at this time, they are mostly observed in Odesa, Kherson and Autonomous Republic of Crimea. In March, they are mostly found in the northeast (Kharkiv region), the center (Poltav region, Cherkasy region) and the south (Zaporizhia, Kherson region, Autonomous Republic of Crimea). In April, such deposits with their massive distribution are mostly observed in Volyn and Zhytomyr Oblast. In 2001-2010, with an increase in the number of cases of mass spreading of wet snow deposits, their territorial distribution underwent changes. In winter and at the end of autumn, Kyiv region joins the regions of the northeast where increased recurrence is observed. Among the central regions, Cherkasy and Kirovohrad regions also had the highest recurrence rate. In March and April, such deposits are mostly observed in the north, northeast (Kyiv Oblast, Chernihiv Oblast, Sumy Oblast, Kharkiv Oblast), the center (mostly Cherkasy Oblast), as well as in the south (Zaporizhia, Autonomous Republic of Crimea). In April, the frequency of such cases increases in Odesa and Crimea. In 2011-2020, during the cold period of the year, the situation is similar to the previous decade. In March, the frequency of such deposits increased in Khmelnytskyi and Poltava regions.

Studying the process of phenological monitoring of late varieties of plums grown in the climatic conditions of Namangan region

In this article, the study and analysis of late varieties of plum grown by farmers and private entrepreneurs in the Yangikurgan district of Namangan region, the area where plum orchards are located, the height above sea level, during the phenological observation of Plum (Burton) variety's phenological observations show that from 10.10.2022 to 10.10.2023 budding, the beginning of vegetation, the beginning of flowering, the end of flowering, the end of branch growth, the beginning and end of autumn, the periods of watering the field, information about pesticide spraying dates, herbicide spraying dates, number, biological control.

Winter trends

The end of autumn and the arrival of winter is always a little bittersweet. But the passing of the seasons gives order to our busy lives, provides a necessary rhythm, and, of course, it's always reassuring to know that spring is moving closer on the seasonal carousel. Winter is the season of coats, colds and Christmas. With that in mind, check out the picks that are catching my eye and softening the blustery blow of the season.

The Level of Selected Blood Parameters in Young Soccer Players in Relation to the Concentration of 25(OH)D at the Beginning and End of Autumn.

This study aimed to demonstrate the changes of selected blood parameters in relation to 25(OH)D concentration during the autumn period in young soccer players. A total of 35 participants' results (age: 17.5 ± 0.6 years, body mass 71.3 ± 6.9 kg) were tested twice: in mid-September and in mid-December and divided into subgroups with regard to two criteria. First, according to the initial level of the 25(OH)D concentration (optimal group-ODG, suboptimal group-SDG), second, according to drops in 25(OH)D concentration (high drop group-HDG, low drop group-LDG). A significant decrease (p < 0.001) in the 25(OH)D concentration was reported in the total group (TGr) and in all subgroups. Blood parameters such as white blood cells, red blood cells, haemoglobin and haematocrit increased significantly (p < 0.05) in TGr during the analysed period of time. The analysis of changes in the lipid profile did not expose significant differences except triglycerides. The asparagine amino transferase and creatine kinase activity decreased significantly after autumn in all analysed groups. The declining level of 25(OH)D concentration should be compensated (e.g., with vitamin D supplementation) during autumn. Applied training loads could also influence the blood parameters variability in young soccer players. Regular measurements of 25(OH)D concentration are helpful in identifying potential drops and allows for the preparation of individual supplementation plans for the players.

The influence of organo-mineral fertilizers on the growth of evening apple varieties throughout the year

The article describes the research of the apple varieties grown in the areas in the Yangikurgan district of the Namangan region and proper use of apple fruit production and post-harvest activities in the region. "Iskavot" districts "Nazirjon Ilkhomjon Arabboy" farm in the apple orchards of semirenko, golden delicacies, starcrimson, (five stars), local variety (boyken) 4 types, i.e. N120 P100 K30, N50 P30 K10 organic1000, N25 P20 Phenological and biometric evaluations of K5 Organomineral500, Organomineral1000 fertilizers were studied. Apple cultivars were studied at the beginning of vegetation, beginning of flowering, end of flowering, end of branch growth, beginning and end of autumn, the periods of watering the field, the periods of spraying pesticides, the periods of spraying herbicides.

Factors Affecting Habitat Selection of Endangered Steppe Eagle (Aquila nipalensis) in Pakistan: Implications for Raptors Conservation

The steppe eagle (Aquila nipalensis) is an endangered migratory raptor species that migrates in winter to Pakistan and neighbouring countries. In Pakistan, the species migrate at the end of autumn and utilise different habitats across the country. Very little information is available about the species’ population status, distribution, and factors affecting its distribution in Pakistan. In the present study, we predicted the distribution of steppe eagles in Pakistan associated with different environmental variables. We used 149 presence points of the species from an online source (GBIF), published literature, and wildlife photographers. The MaxEnt analysis showed that highly suitable habitats were mostly present in Azad Jammu and Kashmir (AJK), federally administered areas and surrounding areas, southern areas of Sindh Province, and some parts of Khyber Pakhtunkhwa (KP) Province. In addition, some patches were also predicted by MaxEnt in Balochistan Province. Human population density (27.0%), chicken density (16.6%), temperature seasonality (11.1%), and rivers (10.3%) were identified as the main environmental factors that affect the habitat distribution of steppe eagle in Pakistan. Only a small percentage (2.62%) of the total Pakistan area was estimated to be a highly suitable area for steppe eagles, while 20.58% and 7.46% were identified as the least and moderately suitable areas, respectively. Conservation of identified habitats and mitigation of anthropogenic impacts to conserve this endangered eagle species are recommended for immediate and long-term conservation across Pakistan.

Spatial and Seasonal Variations of the Island Mass Effect at the Sub-Antarctic Prince Edward Islands Archipelago

At the sub-Antarctic Prince Edward Islands (PEIs) in the Southern Ocean, the Island Mass Effect (IME) plays an important role in maintaining an ecosystem able to support diverse biological communities; however, limited in situ sampling has severely constrained our understanding of it. As such, our study used satellite chlorophyll a (chla) to provide the first detailed characterisation of the spatial extent and seasonal variability of the IME at the PEIs. Seasonal surface chla variations were remarkable, with localised increases observed from mid-austral spring to the end of autumn (October to May). In contrast, during June to September, there were no distinguishable differences between chla at the PEIs and that further afield. Seasonal chla changes were significantly correlated with higher light levels, warmer waters, and shallow upper mixed layer depths reflecting enhanced water column stability during summer and autumn, with the opposite pattern in winter and spring. The IME extended northeast of the islands and remained spatially distinct from elevated chla around the northern branch of the sub-Antarctic Front and the southern branch of the Antarctic Polar Front. From December to February, the IME was spatially connected to the island shelf. In contrast, during March–May and in October, higher chla was observed only to the northeast, some distance away from the islands, suggesting a delayed IME, which has not previously been observed at the PEIs. The clear association of this higher chla with the weak mean geostrophic circulation northeast of the islands suggested retention and accumulation of nutrients and phytoplankton biomass, which was likely aided by wind-driven northeastward transport of water from the shelf. Climatological mean chla to the northeast was generally higher than that on the PEI shelf, and further research is required to determine the importance of this region to ecosystem functioning at the islands.

НЕСПРИЯТЛИВІ АГРОМЕТЕОРОЛОГІЧНІ ЯВИЩА НА ТЕРИТОРІЇ УКРАЇНИ ПРОТЯГОМ 2006-2020 рр.

The article is devoted to the study of weather conditions of adverse agrometeorological phenomena (droughts) on the territory of Ukraine during the fifteen-year period of 2006-2020. The purpose of the work is to establish the peculiarities of the temperature and humidity regime in the months of the warm period of the year during certain years of the last fifteen-year period, taking into account the droughts that were observed in this period. For each year and month of the studied period, an analysis of the relevant weather conditions accompanying droughts in the territory of Ukraine was carried out. The influence of temperature conditions and features of humidification on the territorial distribution and duration of droughts has been proven. In general, during the studied period, it was established that drought phenomena were not observed only in 2012, 2016, 2018 and 2019. Droughts could start in the air or in the soil and eventually develop into air-soil droughts. In 10 years of the studied period, severe air and soil droughts were observed in large areas. Mostly droughts were observed from the end of June to the end of July, but in some years droughts could start from April and be observed with certain breaks until the beginning (mid) of autumn. In 2011, there was a case of air drought at the end of February and in March. In addition, in some years, air-soil droughts could be observed in autumn not only from its beginning, but also until its end (November 2011, 2015). For the most part, territorial droughts during 2006-2020 were observed in the east, southeast, and south, but they could also be observed in most of the country, including part of the northern territories. In some years, droughts were accompanied by droughts and dust storms. It was established that in the months of the warm period of the year, the average monthly air temperature was mostly above the norm by 1-2º C, while in some months and years the norm could be significantly exceeded, especially in the summer months from 4 to 7º. In autumn, for the most part, the average monthly air temperature was within normal limits, but in some years it was 1-3º degrees above normal. Precipitation during the studied months was extremely unevenly distributed across the territory of Ukraine. In the spring, precipitation was mostly close to normal. In the summer months, precipitation was often insufficient, sometimes less than half of the norm. In autumn, the amount of precipitation increased mostly to the norm and above, but in some years a deficit of precipitation was observed in most of the territory of Ukraine. At the end of autumn, mostly precipitation fell close to norm, and in some places even more than normal.

Surface runoff and losses of phosphorus from hydrophobic pastoral soils

The impact of soil water repellency (SWR) on soil phosphorus (P) mobility in surface water runoff remains contentious. Although SWR may cause a significant increase in surface runoff, especially in post-summer rainfall events, whether it contributes to background phosphorus losses remains unclear. Surface runoff and P concentrations in runoff were measured on hilly Allophanic pastoral soils with different water repellency levels using seven runoff collectors. Phosphorus fertilizer was broadcasted at 18 kg P ha−1 in the summer over dry soils. Runoff volumes and P concentrations were measured after each natural rain event prompting surface runoff. The highest runoff/rainfall ratios were observed at the early rainfall events following the dry summer and then decreased significantly by the end of autumn and winter. The post-summer surface runoff correlation with SWR had an R2 of 0.46, and hydrophobic soils had significantly higher runoff ratios than wettable soils. Measurements of the dissolved reactive phosphorus (DRP) and total phosphorus (TP) in the surface runoff showed decreasing exponential trends, with the highest values recorded in the first runoff event following P fertilizer application, where over 90% of losses occurred (incidental losses). After the incidental loss phase, DRP concentrations were related to surface runoff ratio, soil P extractability by water, and SWR. Our data point to non-incidental TP loads being related to SWR (R2 = 0.53). The present results will improve the understanding of the SWR effect on surface runoff and will reconcile the controversy regarding its contribution to non-incidental P losses.

Racial Disparity in COVID-19 Deaths: Seeking Economic Roots with Census Data

Abstract This note seeks the socio-economic roots of racial disparities in COVID-19 mortality, using monthly county-level mortality, economic, and demographic data from 3140 counties through December 2020. The county-level approach shows a sharp disparity affecting all minority groups in the sample, peaking in spring or summer 2020 and then dissipating by the end of autumn. The effect disappears for Asian Americans when occupation and other controls are added, but not for other minorities; for them, the racial disparity, as long as it lasts, does not seem to be due to differences in income, poverty rates, education, occupational mix, or even access to healthcare insurance, although in April public transit use explains a large part of it. This is a puzzle, but the rapid change in the disparities over the year show that they are not immutable – an important message for future pandemics.

On the question of studying the examination system during the reign of the Manchu Qing Dynasty. The image of a student in the stories of Pu Songling

The stories of the Chinese writer Pu Songling about the extraordinary are well known all over the world: there are translations in English, French, German and Spanish. The article, based on the study of the stories of Pu Songling in the translations of the outstanding Russian orientalist Vasiliy Mikhailovich Alekseev (1881-1951), presents the image of a student and the features of the examination system (keju) during the reign of the Manchu Qing Dynasty in China (1644-1911). The importance of fiction in the study of the content of the institution of state examinations is emphasized. Artistic images help to see the uniqueness and specificity of the keju system. Highly qualified translations of Liao Zhai's stories and V.M. Alekseev's comments create the image of a student - "a criminal in prison", "a bee frozen by the end of autumn", "a sick bird released from a cage", "a monkey on a leash", "a fly that has drunk poison", "a turtle dove whose eggs have broken". The materials of the article can be useful in preparing for classes in "History" study field. These stories allow considering the system of state examinations (keju) during the Qing Dynasty as a specific phenomenon of Chinese culture. The author considers three types of exams in the period of the Manchu Qing Dynasty - county-regional, provincial and metropolitan with a specific system of tasks and levels of difficulty for each level.

Detecting the annual areal extent of sugarcane crops in Queensland, Australia

Sugarcane is an economically important crop for Queensland, Australia, that is increasingly a focus of environmental management, due to proximity to the Great Barrier Reef. This study responds to the demand for an ongoing, objective, and transparent assessment of the areal extent of sugarcane grown. I have combined Landsat and Sentinel-2 satellite imagery with time-series analysis, image-segmentation, and machine-learning, into a model that detects the annual areal extent of sugarcane in Queensland, since 2004. I then contrasted two variants of the model: one applied at the end of autumn (i.e. May), just before the annual harvest begins, and another applied earlier, in mid-summer (end of January), to help expedite the delivery of information for the current growing season. Both models relied heavily on contemporary land-use mapping, and the behaviour of enhanced vegetation index through summer, to detect accurately. The end-of-autumn model detected sugarcane with a user's accuracy of 93%, and a producer's accuracy of 98%, based on 596 random validation points. In comparison with historical published statistics, the end-of-autumn predictions of areal extent were typically in error by 7.1–10.1% of the observed mean, depending on the spatial scale of interest. The mid-summer model was slightly more volatile, typically in error by 6.8–11.0% of the observed mean. Overall, the results indicate that it is possible to detect—in near-real-time and with reasonable accuracy—the areal extent of sugarcane grown in Queensland in the summer of each year.

Cattle Horn Shavings: A Possible Nitrogen Source for Apple Trees

The circular economy concept promotes the recycling of agricultural waste. This study was aimed at investigating the effects of cattle horn shavings on apple tree nitrogen nutrition. Ligol apple trees on P 60 rootstock were the object of the study. The experiment was conducted in the experimental orchard of the Institute of Horticulture, Lithuanian Research Centre for Agriculture and Forestry, from 2015 to 2018. Two fertiliser rates were tested: 50 and 100 kg/ha N. Horn shavings (14.1% N) were applied at the end of autumn or at the beginning of vegetation in the spring and in one treatment 100 kg/ha N rate was divided into two equal parts and applied both in autumn and spring. The effects of the horn shavings were compared with the effects of ammonium nitrate (34.4% N) and the unfertilised treatment. The lowest mineral nitrogen content was found in the unfertilised orchard soil and the soil fertilised with horn shavings in the spring at 50 kg/ha N equivalent. In all other cases, the fertilisers increased the soil’s mineral nitrogen content. The lowest leaf nitrogen content was found in apple trees that grew in the unfertilised orchard soil or soil fertilised in the spring with 50 kg/ha N of horn shavings (1.58–2.13%). In other cases, leaf nitrogen content was higher (1.77–2.17%). The apple trees with the lowest leaf nitrogen content produced the smallest average yield (34.5–36.6 t/ha). The highest yield was recorded from fruit trees fertilised with 50 kg/ha N of ammonium nitrate applied in spring or horn shavings applied in autumn (42.4 and 41.4 t/ha, respectively). The influence of horn shavings on the other studied parameters was similar to that of ammonium nitrate. Horn shavings, like nitrogen fertiliser, could facilitate nitrogen nutrition management in apple trees, especially in organic orchards, where the use of synthetic fertilisers is prohibited.

Can Soil pH Correction Reduce the Animal Supplementation Needs in the Critical Autumn Period in Mediterranean Montado Ecosystem?

Extensive livestock production in Mediterranean climate conditions and acidic soils requires animal feed supplementation. This occurs during the summer and, frequently, also in the autumn and winter, depending on the prevailing rainfall patterns. The purpose of this study was to evaluate the effect of dolomitic limestone application and of tree canopy on availability, quality, and floristic composition of a permanent pasture, grazed by sheep. At the end of autumn, winter, and spring of 2018/2019 and 2019/2020 pasture green and dry matter production (GM and DM, respectively), crude protein (CP), and fiber (neutral detergent fiber) were monitored in 24 sampling points. Half of these points were located in areas amended with dolomitic limestone (COR) and half in unamended areas (UCOR). In each of these, half of the sampling points were located under tree canopy (UTC) and half outside tree canopy (OTC). Pasture floristic composition was monitored in spring 2020. The results show, in autumn, a positive and significant effect (i) of soil pH amendment on pasture DM and CP daily growth rate (kg·ha−1·day−1) (+28.8% and +42.6%, respectively), and (ii) of tree canopy on pasture CP daily growth rate (+26.4%). Both factors affect pasture floristic composition. Pasture species were identified as potential bio-indicators, characteristic of each field area. These results show the practical interest of the soil pH correction to reduce the animal supplementation needs in the critical autumn period in the Mediterranean montado ecosystem.

The true picture of environmental DNA, a case study on harvested fishponds

The applications of environmental DNA (eDNA) metabarcoding are constantly increasing. Many validation studies have been performed in laboratories, however, field experiments are necessary to verify the robustness of eDNA based monitoring. In summer and autumn 2019 water samples in 39 sites and an inflow across three ponds of sizes of approximately 3 (A), 10 (B) and 29 (C) hectares in the Czech Republic were collected. 500 ml from each sample was filtered through 0.45 µl membrane filters and extracted using the Mu-DNA water protocol. Uniquely indexed vertebrate primers aligning mitochondrial 12S ribosomal RNA gene were utilised for eDNA amplification. PCR negative and positive controls were included to each sublibrary. Sequence reads were analysed using metaBEAT pipeline. The sequences were assigned to species level with exception Perca fluviatilis and Sander lucioperca which could not be differentiated, further referred as Perca+Sander and used as a single species. At the end of autumn, ponds were harvested and 319,833 fish of 27,054 kg of 22 species were captured. The most abundant species was Gymnocephalus cernua (on average 34.8%) followed by Cyprinus carpio and Pseudorasbora parva. Cyprinus carpio was also the dominant species in biomass (on average 90.7%), followed by the Ctenopharyngodon idella and Esox Lucius. The total number of sequences across 240 eDNA samples was 35,627,310. 21,540,396 sequences remained after bioinformatic filtering with an average read count per sample of 68,111. All samples detected 1–6 species, except for summer pond B where 64% were negative. In total, more species were detected in autumn than summer in pond A 12/10 and pond B 9/2 and the same in pond C 11/11. The only species detected in all campaigns was Cyprinus carpio with the highest average reads count of 28,961. Ctenopharyngodon idella, Rutilus rutilus, and Scardinius erythrophthalmus were detected in all campaigns except the summer pond B samples. The site occupancy values were variable between ponds and seasons with exception of ubiquitous Cyprinus carpio. The numbers of detected species in inflows were higher in autumn compared to summer in pond A (7/5) and B (9/4) and identical in pond C (6/6). The detected species in inflows were mostly the same as species detected in ponds. Gobio gobio was the only detected species in all campaigns. Lota lota was detected in eDNA in summer and autumn only in inflow to pond A. In pond B Perca+Sander and in pond C Pseudorasbora parva were detected in eDNA inflow in both periods and in harvest, but not in eDNA in ponds. The percentage of shared species detected by eDNA and at pond harvests was >50% in all ponds. During the pond harvest 1, 5 and 4 species were captured not detected in ponds´ eDNA compared to 3, 0, and 2 species detected only in ponds´ eDNA in ponds A, B and C, respectively. Significant positive relationships were observed between fish read counts/species site occupancy and fish abundance/biomass with exception of data from pond B in autumn. This study highlights the importance of field experiments and methods validation. Dominant species detection is relatively straightforward; however, detection of rare species is more challenging depending on species behaviour, habitat complexity. It further supports that eDNA should be applied in optimal conditions to achieve highest overall detection, which has important implications for applying this method to aid management and policy initiatives. This study was supported by projects MSM200961901, “The true picture of eDNA”, QK1920011 ”Methodology of predatory fish quantification in drinking-water reservoirs to optimize the management of aquatic ecosystems”, and by CAS within the program of the Strategy AV 21.

Structure and Dynamics of the Ras al Hadd Oceanic Dipole in the Arabian Sea

The Ras al Hadd oceanic dipole is a recurrent association of a cyclone (to the northeast) and of an anticyclone (to the southwest), which forms in summer and breaks up at the end of autumn. It lies near the Ras al Hadd cape, southeast of the Arabian peninsula. Its size is on the order of 100 km. Along the axis of this dipole flows an intense jet, the Ras al Had jet. Using altimetric data and an eddy detection and tracking algorithm (AMEDA: Angular Momentum Eddy Detection and tracking Algorithm), we describe the life cycle of this oceanic dipole over a year (2014–2015). We also use the results of a numerical model (HYCOM, the HYbrid Coordinate Ocean Model) simulation, and hydrological data from ARGO profilers, to characterize the vertical structure of the two eddies composing the dipole, and their variability over a 15 year period. We show that (1) before the dipole is formed, the two eddies that will compose it, come from different locations to join near Ras al Hadd, (2) the dipole remains near Ras al Hadd during summer and fall while the wind stress (due to the summer monsoon wind) intensifies the cyclone, (3) both the anticyclone and the cyclone reach the depth of the Persian Gulf Water outflow, and (4) their horizontal radial velocity profile is often close to Gaussian but it can vary as the dipole interacts with neighboring eddies. As a conclusion, further work with a process model is recommended to quantify the interaction of this dipole with surrounding eddies and with the atmosphere.

Annual phytoplankton dynamics in coastal waters from Fildes Bay, Western Antarctic Peninsula

Year-round reports of phytoplankton dynamics in the West Antarctic Peninsula are rare and mainly limited to microscopy and/or pigment-based studies. We analyzed the phytoplankton community from coastal waters of Fildes Bay in the West Antarctic Peninsula between January 2014 and 2015 using metabarcoding of the nuclear and plastidial 18/16S rRNA gene from both size-fractionated and flow cytometry sorted samples. Overall 14 classes of photosynthetic eukaryotes were present in our samples with the following dominating: Bacillariophyta (diatoms), Pelagophyceae and Dictyochophyceae for division Ochrophyta, Mamiellophyceae and Pyramimonadophyceae for division Chlorophyta, Haptophyta and Cryptophyta. Each metabarcoding approach yielded a different image of the phytoplankton community with for example Prymnesiophyceae more prevalent in plastidial metabarcodes and Mamiellophyceae in nuclear ones. Diatoms were dominant in the larger size fractions and during summer, while Prymnesiophyceae and Cryptophyceae were dominant in colder seasons. Pelagophyceae were particularly abundant towards the end of autumn (May). In addition of Micromonas polaris and Micromonas sp. clade B3, both previously reported in Arctic waters, we detected a new Micromonas 18S rRNA sequence signature, close to, but clearly distinct from M. polaris, which potentially represents a new clade specific of the Antarctic. These results highlight the need for complementary strategies as well as the importance of year-round monitoring for a comprehensive description of phytoplankton communities in Antarctic coastal waters.

Trail camera networks provide insights into satellite-derived phenology for ecological studies

Repeat digital photography at or near ground-level is a proven and efficient approach for tracking plant phenology. Here, we explored the potential to monitor phenology using the Snapshot Wisconsin (SW) trail camera network, a citizen science program. Using three curve-fitting methods for characterizing phenological transition dates, we assessed the phenological offset between understory vegetation and the overstory canopy in the trailcam observations and compared variations in derived phenology over the different spatial scales represented by trailcams (~20–50 m), Harmonized Landsat and Sentinel-2 (HLS, 30 m), and Moderate Resolution Imaging Spectroradiometer (MODIS, 500 m). Our results showed that the apparent phenological offset between understory and overstory vegetation differed among forest types: in broadleaf deciduous forests, understory vegetation had an earlier start-of-spring (SOS) and later end-of-autumn (EOA) than the overstory canopy; in mixed forests, the understory showed an earlier SOS than the overstory, but no significant difference in EOA; in evergreen conifer forests, neither SOS nor EOA differed significantly between the understory and overstory. We found moderate correlations (0.25 ≤ r ≤ 0.57) between trailcam- and satellite-derived phenological dates. Moreover, those derived dates varied significantly among the applied curve-fitting methods: total growing season length (from SOS to EOA) could be 19 days longer for a threshold-based method than for a logistic curve-fitting method (our reference model), but 17 days shorter than the logistic method when using a piecewise-continuous method based on fitted sine curves. Despite the spatial limitations of trailcams for characterizing phenology on landscape and regional scales, trailcam networks have considerable potential for informing local phenological studies and disentangling the many drivers of phenology that can remain undetected from the satellite perspective.