Seasonal Occurrence Research Articles

Annual and Seasonal Occurrence Pattern of Auroral Kilometric Radiation Associated with the Interplanetary Magnetic Field* *Released on March 1st, 2024.

Auroral kilometric radiation (AKR) is a widely existing strong radio emission from the Earth’s magnetosphere and is generated by suprathermal (1–10 keV) electrons in the polar cavity. Previous works have demonstrated that AKR can contribute to the coupling of the magnetosphere–ionosphere–atmosphere, but its relation to the interplanetary magnetic field (IMF) has not been studied so far. Here, we examine the data of Van Allen Probes and identify a total of 5000 AKR events from 2012 October to 2019 July. Most AKR events (4282) correspond to the dominant parallel component B∥(=(Bx)2+(By)2) of IMF. There are the most (1391) events in 2018 (the solar minimum year) and the least (258) events in 2014 (the solar maximum year), corresponding to more (less) occurrences for the longer duration (> 30 minutes) of southward IMF (B z < 0) in 2018 (2014). In the Earth’s Northern Hemisphere, there are the most (865) events in the autumn (August–October), corresponding to dominant B x < 0. In the Earth’s Southern Hemisphere, there are the most (830) events in the autumn (February–April), corresponding to dominant B x > 0. The probable reason for the above results is that the longer duration of B z < 0 can yield the longer magnetic reconnection, and the dominant B x < 0 (B x > 0) is favorable for the single-lobe magnetic reconnection in the northern (southern) hemisphere, allowing more suprathermal electrons into the polar source cavity and generating more AKRs. These current results suggest that IMF is very important for the occurrence of AKR and can be widely applied to similar auroral radio emissions in other magnetized planets of the solar system.

Warming drives phenological changes in coastal zooplankton

Climate warming has led to phenological changes over time, typically displayed as earlier emergence of various organisms in spring or summer in temperate terrestrial and marine systems alike. Similarly, warm conditions can extend seasonal occurrence. Using a time series of zooplankton data from a coastal area in the Gulf of Finland, we calculated the start, end and the length of the season for the occurrence in rotifers and for adult and juvenile stages of three calanoid copepods. We investigated whether the start and end of the season of these taxa have shifted earlier and later, respectively, and whether the season length has increased. We further investigated if potential changes are driven by climate warming. We show that both copepods and rotifers do indeed emerge earlier, but that the pattern in recent years was not conclusive, and that both temperature and ice conditions influenced the seasonal abundance patterns of some taxa. Warmer years led to earlier occurrence of Temora longicornis copepodites. Earlier ice break-up coincided with longer seasons for Acartia and earlier emergence of Eurytemora affinis. The phenological changes in zooplankton demonstrated here may have cascading effects on other trophic levels in the food web. We also demonstrate how decreased sample number influences the ability to capture intra-annual abundance patterns and discuss the implications for monitoring.

Occurrence and Removal Efficiencies of Four Antibiotics in Kisii and Kabarnet Waste Water Treatment Plants, Kenya

Background: Antibiotics are presently considered as emerging contaminants with adverse effects in the environment and the population such as the development of antimicrobial resistant genes (ARG) and antimicrobial resistant bacteria (ARB). This study was guided by objective entailing to determine the seasonal occurrences and removal efficiencies of four antibiotics in Kisii and Kabarnet waste water treatment plants in Kenya. &#x0D; Place and Duration of Study: Waste water samples were picked from Suneka wastewater treatment plant in Kisii county and Kabarnet Level V Hospital in Baringo County Kenya in the months of June and December 2020&#x0D; Methodology: Multiple samples were picked in Kisii and Kabarnet waste water treatment plants in the months of June and December correspond to the dry and wet seasons in Kenya. Collected waste water samples were centrifuged and filtered with glass microfiber filter papers and subsequently passed through a Solid phase extractor cartridge. High Performance Liquid Chromatography was used for quantification of antibiotics as per international commission for harmonization and subsequently applied for analysis.&#x0D; Results: The results revealed that the dry season had higher antibiotic concentrations at 1.29, 0.09, 2.92 and 1.82 µg/l for sulphamethoxazole, trimethoprim, ampicillin and amoxicillin respectively for the Kisii waste water treatment plant and 0.18, 0.05, 1.34 and 0.09 µg/l respectively for Kabarnet waste water treatment plant. During the wet seasons the measured concentrations were 1.11, 0.14, 2.04 and 1.34 µg/l for sulphamethoxazole, trimethoprim, ampicillin and amoxicillin at the Kisii WWTP, and 0.14, 0.06, 1.01 and 0.09 µg/l for Kabarnet WWTP. The removal efficiencies in the WWTPs, ranged from a high of 94 % to a low of 11.11 % depending on the type of antibiotic in both wet and dry seasons.&#x0D; Conclusion: Amoxicillin, ampicillin, trimethoprim and sulphamethaxazole were found in both Kisii WWTPs and Kabarnet WWTPs with nearly all antibiotics having a higher concentration of in the dry season than in the wet season. The highest calculated percentage removal was 94.03 % while the lowest calculated percentage removal was 7.14 %. The results suggest that the two WWTPs are effective for the removal of different types of antibiotics.

Global properties of SARS‐CoV‐2 and IAV coinfection model with distributed‐time delays and humoral immunity

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) and influenza A virus (IAV) are two respiratory viruses and are similar concerning seasonal occurrence, transmission routes, clinical manifestations, and related immune responses. Recent studies showed that a substantial number of patients infected by SARS‐CoV‐2 were also coinfected with IAV. In this paper, we study the global properties of SARS‐CoV‐2 and IAV coinfection model in vivo. The role of humoral (antibody) immunity in controlling the coinfection is modeled. The model tracks uninfected epithelial cells, latent SARS‐CoV‐2‐infected epithelial cells, latent IAV‐infected epithelial cells, active SARS‐CoV‐2‐infected epithelial cells, active IAV‐infected epithelial cells, free SARS‐CoV‐2 particles, free IAV particles, SARS‐CoV‐2‐specific antibodies and IAV‐specific antibodies. The model includes six distributed‐time delays, two delays for the formation of latent SARS‐CoV‐2‐infected and latent IAV‐infected cells; two delays for the reactivation of latent SARS‐CoV‐2‐infected cells and latent IAV‐infected cells; and two delays for the maturation of new released SARS‐CoV‐2 and IAV virions. The regeneration and death of the uninfected epithelial cells are considered. We first examine the basic qualitative properties of the model, then we calculate all equilibria and prove their global stability. The global stability of equilibria is established using the Lyapunov method. The theoretical findings are demonstrated via numerical simulations. The importance of considering humoral immunity in the coinfection dynamics model is discussed. It is found that without modeling the humoral immunity, the case of IAV and SARS‐CoV‐2 coexistence will not occur. We discuss the effect of time delays on the dynamics of SARS‐CoV‐2 and IAV coinfection. It is noted that increasing the time delay length has similar impact as antiviral therapies.

Clinical manifestations and seasonal occurrence of patients with dengue hospitalized at Dhaka city of Bangladesh in 2021

For the past few years, the intensity of dengue in Bangladesh has been rising. The current study was done among 533 dengue patients hospitalized in 2021 in Dhaka to observe the different aspects of clinical manifestations and seasonal occurrence of dengue. Due to COVID-19 restriction, hospital entry and face-to-face interview of the patients was not possible. Hence, contact numbers of the hospitalized dengue patients were collected from Directorate General of Health Services (DGHS) and patients were interviewed over the phone. Out of 533 patients, majority were from Dhaka south city corporation (DSCC) (53.7%), had a monthly household income of 30001≥ BDT (67.4%), and lived in small sized families (76.9%). High fever (p=0.013), headache (p&lt;0.001), body pain (p&lt;0.001), vomiting/nausea (p=0.0085), skin rash (p=0.033), eye lesion/red eyes (p=0.0011), pleural effusion (p=0.0404), weakness (p=0.017) and gum bleeding (p=0.014)- were significantly associated with age groups whereas vomiting/nausea (p=0.048), skin rash (p=0.002) and eye lesion/red eyes (p=0.032) were significantly associated with gender. 86.7% suffered from thrombocytopenia (&lt;150000 per microliter blood), while 27% were in serious condition with lowest platelet count ≤ 20000 per microliter blood. 3.6% patients were admitted to ICU and 1.7% died of dengue. Death due to dengue was significantly associated with age groups (p &lt;0.05) and majority among them were children (≤ 10 years). Family members of 44.6% patients were also affected with dengue and majority of the patients belonged to small sized families. Dengue occurrence had significant association with season where majority of the patients were from monsoon season (65.29%) followed by post-monsoon (33.21%) season. Dengue manifests a wide spectrum of symptoms as shown by the study, so now it is necessary to identify the changes in pattern of the clinical manifestations, and effective disease management to lessen the severity of the outbreak. Dhaka Univ. J. Biol. Sci. 33(1): 33-46, 2024 (January)

Impacts of Climate Change on Vector-Borne Diseases of Animals and Humans with Special Emphasis on Afghanistan

Vectors are organisms that transmit pathogenic microorganisms among animals and humans. Infections transmitted by the bites of blood-sucking arthropods are called vector-borne diseases (VBDs). This review highlights the impacts of climate change on the distribution, seasonal variation, and socioeconomic effects of VBDs in affected countries, especially Afghanistan. There is good enough evidence indicating that recent climate change has affected the interaction of the vector-pathogen-host cycle in many parts of the world. The emergence and re-emergence of bluetongue virus (BTV), Rift Valley Fever (RVF), lumpy skin disease (LSD), West Nile Virus (WNV), and malaria in new areas previously considered free of the diseases, and shift of seasonal occurrence of many VBDs in endemic areas, are the clear examples of climate change impacts on VDBs. Although significant progress has been made regarding VBD surveillance systems, diagnostic capacity, vaccine development, and vector control programs in resource-rich countries, failure in adaptation programs and ineffective mitigation strategies against VBDs in developing countries, especially in low and middle-income countries (LMICs), including Afghanistan facilitate widespread distribution of VBDs in these regions. Furthermore, developing drug resistance among the pathogens and their vectors makes the conditions more suitable for VBDs wide dispersion. Such situations cause severe health and socio-economic burdens to affected countries. Developing early-warning systems for detecting VBDs, identifying and developing resistant livestock species and breeds, and applying interceptive measures based on integrated research programs are crucial to effectively reduce the harmful impacts of VBDs on human and animal populations.

Frequent and strong cold-air pooling drives temperate forest composition.

Cold-air pooling is an important topoclimatic process that creates temperature inversions with the coldest air at the lowest elevations. Incomplete understanding of sub-canopy spatiotemporal cold-air pooling dynamics and associated ecological impacts hinders predictions and conservation actions related to climate change and cold-dependent species and functions. To determine if and how cold-air pooling influences forest composition, we characterized the frequency, strength, and temporal dynamics of cold-air pooling in the sub-canopy at local to regional scales in New England, USA. We established a network of 48 plots along elevational transects and continuously measured sub-canopy air temperatures for 6-10 months (depending on site). We then estimated overstory and understory community temperature preferences by surveying tree composition in each plot and combining these data with known species temperature preferences. We found that cold-air pooling was frequent (19-43% seasonal occurrences) and that sites with the most frequent inversions displayed inverted forest composition patterns across slopes with more cold-adapted species, namely conifers, at low instead of high elevations. We also observed both local and regional variability in cold-air pooling dynamics, revealing that while cold-air pooling is common, it is also spatially complex. Our study, which uniquely focused on broad spatial and temporal scales, has revealed some rarely reported cold-air pooling dynamics. For instance, we discovered frequent and strong temperature inversions that occurred across seasons and in some locations were most frequent during the daytime, likely affecting forest composition. Together, our results show that cold-air pooling is a fundamental ecological process that requires integration into modeling efforts predicting future forest vegetation patterns under climate change, as well as greater consideration for conservation strategies identifying potential climate refugia for cold-adapted species.

Statistics of Traveling Ionospheric Disturbances at High Latitudes Using a Rapid‐Run Ionosonde

AbstractThe potential of deep learning for the investigation of medium scale traveling ionospheric disturbances (MSTIDs) has been exploited through the Sodankylä rapid‐run ionosonde in this statistical study. The complementing observations of the Sodankylä ionosonde with those of the Sodankylä meteor radar reveals the diurnal and seasonal occurrence rate of high‐latitude MSTIDs in the recent low solar activity period, 2018–2020. In our results, the daytime, nighttime and dusk MSTIDs are predominantly identified during winter, summer, and equinoctial months, respectively. The winter daytime higher (lower) occurrence rate is well correlated with the lower (higher) altitude of the height of the F2‐layer peak (hmF2), and the low occurrence rate of the summer daytime is well correlated with the mesosphere‐lower‐thermosphere wind shear and higher gradient of temperature. Relatively high occurrence rate (&gt;0.4) of summer nighttime MSTIDs has a general—but not one‐to‐one agreement—with post‐noon to evening IU (eastward auroral current index) inferred ionospheric conductivity. Rather, we see a one‐to‐one relationship between the summer nighttime MSTIDs and zonal wind shear suggesting that the wind shear‐induced electrodynamic processes could play significant roles for higher occurrence rate of MSTIDs. Furthermore, significant MSTIDs with ∼0.4 occurrence rate are so far revealed during spring and autumn transition periods. The enhanced nighttime MSTID amplitudes during the equinox are observed to be well correlated with IL index (westward auroral current indicator) suggesting that the particle precipitation during substorms could be the primary cause.

Seasonal occurrence and damage caused by Phycodes radiata Ochsenheimer (Lepidoptera, Brachodidae) on Ficus spp. in Uttar Pradesh, India

A field study was conducted from 2019 to 2021 in the Saharanpur district of Uttar Pradesh to record the seasonal occurrence, infestation, and damage of the fig leaf roller, Phycodes radiata Ochsenheimer (Lepidoptera, Brachodidae), simultaneously on four host plants, Ficus benjamina L., F. benghalensis L., F. glomerata L. and F. religiosa Linn. During the three years, the peak density of P. radiata larvae was observed from March to August that declined gradually till December. The maximum larval population, infestation and damage were recorded on F. religiosa followed by F. benjamina, F. glomerata, and the lowest on F. benghalensis. The incidence of P. radiata larvae was observed on F. benjamina even in the month of January, while it was nil on other three host plants.

Influence of weather parameters on the population of Bactrocera spp. (Diptera, Tephritidae) in the mango orchards of Padanakkad, Kerala, India

An investigation was conducted to study the seasonal occurrence of Bactrocera spp. (Diptera, Tephritidae) in the mango orchards College of Agriculture, Kerala Agricultural University, Padannakkad. Surveillance of fruit flies was conducted using bottle traps with methyl eugenol lure. A total of 10,546 fruit flies were trapped with the predominant species being Bactrocera dorsalis. Four species viz., B. dorsalis, B. zonata, Zeugodacus tau and Z. cucurbitae were identified from the population collected in that order of dominance. Out of fruit flies captured, B. dorsalis, account for 97.97 per cent. The highest weekly population of fruit flies was recorded in the 14th standard meteorological week (SMW) of 2022 from April 2 to April 8, 2022, with 793 fruit flies, while the lowest population in 50th SMW from December 10 to December 16, 2021 with only one fruit fly. The monthly average population was highest in May with 667.5 flies per month and lowest in December with 16 flies per month. During the period of host availability (April to June), the population of fruit flies exhibited significant positive correlation with minimum temperature (0.805), and a significant negative correlation with soil temperature (-0.512). There was a negative correlation with maximum temperature (-0.329) and wind speed (-0.192) while a positive correlation was observed with rainfall (+0.204).

Fruit and Seed Phenological studies of Rauvolfia species distributed in the Southern Western Ghats

Fruiting pattern of five Rauvolfia species in the southern Western Ghats were observed to get an insight and limitations impacting their fruiting cycles. These species displayed parallel seasonal occurrences in their flowering and fruiting. Over two continuous years, from January to December in 2011 and 2012, monthly observations highlighted discrepancies in the duration of flowering and fruiting, despite the shared seasonal aspects. The peaks and patterns of fruiting varied among these species, demonstrating differences in key factors like fruiting duration, peak times, single/double fruit ratio, and seed purity. Moreover, it was observed that annual precipitation influences the flowering and fruiting behaviors of Rauvolfia.

Building size and disinfectant type influence the detection and concentration of Mycobacterium spp. in hot water plumbing

The number of nontuberculous mycobacteria (NTM) lung disease cases is increasing in the United States (US). This respiratory disease is primarily caused by three NTM species: Mycobacterium avium, M. intracellulare, and M. abscessus. Since disease transmission could occur through water aerosolization, this study investigated these three species' occurrence (sporadic and persistent) in hot water samples collected from residences (n = 70) and office buildings (n = 30) across the US. A longitudinal survey design was used. Three quantitative Polymerase Chain Reaction (qPCR) assays were used to measure the mycobacterial species in the water samples. Additionally, the water's disinfectant residual was measured. A structure's age and square footage were evaluated to predict mycobacterial contamination. Also, the seasonal occurrence of each species was assessed by structure type. Residences had a 43 % (30/70), and office buildings had a 77 % (23/30) detection frequency of one or more Mycobacterium spp. in their hot water. The age of the structure influenced M. intracellulare detection frequency but not M. avium and M. abscessus. The structure's square footage affected M. avium and M. intracellulare detection frequency but not M. abscessus. In chlorinated water, M. intracellulare was detected 1.4× more often in office buildings' hot water than in chloraminated water. In chloraminated water, the Mycobacterium spp. were detected 2–2.5× more often in residences, while M. avium and M. abscessus were detected 1.5–2.3× more often in office buildings, compared to chlorinated water. Each Mycobacterium spp. had a different trend associated with the type of structure and disinfectant. Further research is needed to better understand NTM occurrence in the built environment to improve public health.

An illustrated guide to lady beetles (Coleoptera: Coccinellidae) of the Indian Subcontinent. Part 3. Tribe Aspidimerini

The tribe Aspidimerini (Coleoptera: Coccinellidae) is entirely Asiatic in distribution and most of the known species are primarily aphidophagous and occasionally feed on mealybugs, scales, and whiteflies. This illustrated guide to 26 species in four genera of Asidimerini of the Indian subcontinent is presented with diagnostic descriptions and supporting illustrations, including genitalia, wherever available. Details of distribution, prey and plant associations, and seasonal occurrence are provided based on collections, label data and literature. Immature stages are illustrated for three species of Pseudaspidimerus Kapur and one species of Trigonocarinatus Huo &amp; Ren. One new species, Aspidimerus dissimilis sp. n., is described from Arunachal Pradesh, Northeastern India. Cryptogonus bilineatus Kapur, 1948, and Cryptogonus bryanti Kapur, 1948 are transferred to Trigonocarinatus Huo &amp; Ren, 2015 (new combinations). The following new specific synonyms are proposed (junior synonym listed first): Cryptogonus kapuri Ghorpade, 1974 (=Trigonocarinatus bryanti (Kapur, 1948)); Cryptogonus nepalensis Bielawski, 1972 and C. nepalensis bhutanensis Bielawski, 1979 (=Cryptogonus ariasi (Mulsant, 1853)) (new synonyms). An updated checklist of the tribe Aspidimerini of the Indian subcontinent is also provided.

SEASONAL INCIDENCE OF Rhopalosiphum maidis (Fitch) ON MAIZE CROP IN GUNTUR AND KRISHNA DISTRICTS OF ANDHRA PRADESH

The seasonal occurrence of Rhopalosiphum maidis (Fitch) on maize was carried out in the Guntur and Krishna districts of Andhra Pradesh during rabi, 2021-2022 and rabi, 2022-2023. A total of 30 farmer fields were selected from six mandals of maize growing areas viz., Bapatla, Tsunduru, Ponnur, Karlapalem in Guntur district and two mandals viz., Mopidevi and Avanigadda in Krishna district.The population of aphids was recorded at weekly intervals on randomly selected 25 plants of each farmer field from germination to harvesting stage of the crop. The aphids were counted as number of aphids on 1 cm2 leaf area from three leaves (top, middle, lower) of eachplant. The data was statistically analyzed using SPSS for Windows (version 20.0) and Microsoft Excel 2016. In rabi 2021-22 the initial incidence of aphids was commenced from SMW5 (0.21 aphids sq. cm-1) and the highest mean population was recorded in SMW 9 (3.64 aphids sq. cm-1). In rabi 2022-23 the initial incidence was first noticed during SMW4 (1.71 aphids sq. cm-1) and the peak incidence was noticed during SMW 6(4.96 aphids sq. cm-1).The population of aphids showed a positive significant correlation with maximum temperature in both the seasons i.e., rabi, 2021- 22 (r=0.685**) and rabi, 2022-23 (r=0.612*).

Foraging behaviour and ecology of transient killer whales within a deep submarine canyon system.

Transient killer whales have been documented hunting marine mammals across a variety of habitats. However, relatively little has been reported about their predatory behaviours near deep submarine canyons and oceanic environments. We used a long-term database of sightings and encounters with these predators in and around the Monterey Submarine Canyon, California to describe foraging behaviour, diet, seasonal occurrence, and habitat use patterns. Transient killer whales belonging to the outer coast subpopulation were observed within the study area 261 times from 2006-2021. Occurrences, behaviours, and group sizes all varied seasonally, with more encounters occurring in the spring as grey whales migrated northward from their breeding and calving lagoons in Mexico (March-May). Groups of killer whales foraged exclusively in open water, with individuals within the groups following the contours of the submarine canyon as they searched for prey. Focal follows revealed that killer whales spent 51% of their time searching for prey (26% of their time along the shelf-break and upper slope of the canyon, and 25% in open water). The remainder of their time was spent pursuing prey (10%), feeding (23%), travelling (9%), socializing (6%), and resting (1%). Prey species during 87 observed predation events included California sea lions, grey whale calves, northern elephant seals, minke whales, common dolphins, Pacific white-sided dolphins, Dall's porpoise, harbour porpoise, harbour seals, and sea birds. The calculated kill rates (based on 270 hours of observing 50 predation events) were 0.26 California sea lions per killer whale over 24 hours, 0.11 grey whale calves, and 0.15 for all remaining prey species combined. These behavioural observations provide insights into predator-prey interactions among apex predators over submarine canyons and deep pelagic environments.

Correlation of Rate of TEC Index and Spread F over European Ionosondes

One of the most popular indices for monitoring the occurrence and intensity of ionospheric L-band irregularities is the Rate of TEC Index (ROTI). Due to low TEC in the mid-latitude ionosphere, ROTI has received significantly less attention than the equatorial and polar ionosphere. On the other hand, spread F is an established ionogram irregularity signature. The present study aims to correlate ROTI and spread F activity over European Digisonde stations for a low-to-moderate solar activity year (2011). With a focus on the latitude-dependent occurrence, the analysis demonstrates that range spread F (RSF) has been identified for all notable ROTI (&gt;0.15 TECU/min) cases which also coincide with MSTID activity over the stations, suggesting induced gravity waves or polarization electric fields as the driving mechanism for enhanced ROTI activity. The diurnal and seasonal features are also presented. Maximum irregularity occurrence was observed around the 45° N from 18:00 to 05:00 UT with the seasonal maximum occurrence in January. Over lower mid-latitude Digisonde stations (latitude &lt; 45° N), the diurnal and seasonal occurrence was observed from 19:00 to 04:30 UT in July.

Exploring the potential of extreme citizen science with Danish high school students using environmental DNA for marine monitoring

Citizen science involves non-professionals assisting with scientific research, contributing data, and conducting experiments under professional guidance. In this paper, we describe the citizen science project DNA &amp;amp; life, based at the Natural History Museum of Denmark, which actively engages high school students in both fieldwork and advanced laboratory analyses by collecting and analyzing eDNA samples from marine environments across Denmark. The analysis is performed via species-specific real-time PCR and in a case study we present data gathered in the project from 2017-2023 with focus on the potential of eDNA detecting in use for species monitoring. The results include seasonal occurrence of Mnemiopsis leidyi and national distributions of selected species of particular ecological interest Perca fluviatilis, Anguilla anguilla, Neogobius melanostomus and Alexandrium ostenfeldii. In addition to the eDNA case study, we present a new way of conducting citizen science and eDNA analysis, as a development of the established DNA &amp;amp; life project. Local DNA laboratories are created to shorten the path from sampling site to laboratory facility, creating the possibility for Danish high schools to participate in a new version of the project. In close collaboration with the academic staff of the DNA &amp;amp; life project both teachers and students help develop facilities, protocols and laboratory analyses in an extreme citizen science and co-creation approach, where the participants are involved in a higher level of laboratory work and data analysis. Allowing high school students to perform intricate molecular lab analyzes through an extreme citizen science approach has demonstrated encouraging outcomes and potential for data of high quality in terms of sampling and analyzing eDNA with the purpose of species monitoring and conservation.

Depth distribution of plant-parasitic nematodes on bentgrass golf greens in Missouri and Indiana.

Control of plant-parasitic nematodes (PPNs) on golf putting greens with nematicides is dependent on the seasonal occurrence and depth distribution of target PPN populations. This study aimed to determine if plant-parasitic nematode populations on golf course putting greens in Missouri and Indiana peaked at a targetable depth at a specific time in the year, focusing primarily on lance (Hoplolaimus spp.) and root-knot (Meloidogyne spp.) nematodes. To elucidate species diversity in the region, rDNA from a subset of lance and root-knot nematodes was sequenced and analyzed, with additional micromorphology of a lance nematode assessed in scanning electron micrographs (SEM). Soil samples were taken to a depth of 25 cm and stratified into 5 cm increments during April, June, August and October at seven sites across Missouri, three in the Kansas City metro of Kansas in 2021 and in ten sites across Indiana in 2022. Samples were stratified in five-centimeter increments and aggregated for a total of 100 cm3 of soil at each depth for each sampling. Samples were processed using a semi-automatic elutriator followed by the sucrose-flotation method, and populations were counted using a hemocytometer and recorded. For molecular characterization, rDNA was extracted and analyzed from 31 individual lance nematodes from one site in Missouri and eight sites in Indiana, and 13 root-knot nematodes from nine sites across Indiana. A significant interaction occurred between sampling month and depth for lance and ring nematodes Missouri/KS, with both PPN populations peaking at the 0-5 cm depth during October, which is well after most targeted nematicide applications are applied. Ring nematodes in Indiana did not follow this trend and were most abundant in August at a depth of 0-5 cm. No significant interaction between depth and month occurred for lance or root-knot nematodes in Indiana, or root-knot nematodes in Missouri/KS. Hoplolaimus stephanus and H. magnistylus were the lance species identified on golf greens, and Meloidogyne naasi, M. graminicola and M. marylandi were the root-knot species identified. Scanning-electron micrographs confirmed morphological characteristics unique to H. stephanus.

Predictability of marine heatwaves: assessment based on the ECMWF seasonal forecast system

Abstract. Marine heatwaves (MHWs), defined as prolonged period of extremely warm sea surface temperature (SST), have been receiving a lot of attention in the past decade as their frequency and intensity increase in a warming climate. This paper investigates the extent to which the seasonal occurrence and duration of MHWs can be predicted with the European Centre for Medium-Range Weather Forecast (ECMWF) operational seasonal forecast system. The prediction of the occurrence of MHW events, the number of MHW days per season, and their intensity and spatial extent are derived from seasonal SST forecasts and evaluated against an observation-based SST analysis using both deterministic and probabilistic metrics over the 1982–2021 period. Forecast scores show useful skill in predicting the occurrence of MHWs globally for the two seasons following the starting date. The skill is the highest in the El Niño region, the Caribbean, the wider tropics, the north-eastern extra-tropical Pacific, and southwest of the extra-tropical basins. The skill is not as good for other midlatitude eastern basins nor for the Mediterranean, with the forecast system being able to represent the low-frequency modulation of MHWs but showing poor skill in predicting the interannual variability of the MHW characteristics. Linear trend analysis shows an increase in MHW occurrence at a global scale, which the forecasts capture well.

Climatological comparison of polar mesosphere summer echoes over the Arctic and Antarctica at 69°

Abstract. Polar mesosphere summer echoes (PMSE) have been observed for more than 30 years with 50 MHz VHF radars at various locations in the Northern Hemisphere. Continuous observation of PMSE is conducted on the northern Norwegian island of Andøya (69.3° N) using the ALWIN radar (1999–2008) and MAARSY (since 2010). The same kind of PMSE measurements began in 2004 in the Southern Hemisphere with the Australian Antarctic Division's VHF radar at Davis Station in Antarctica (68.6° S), which is at an opposite latitude to Andøya. Since the radars at both sites are calibrated, the received echo strength of PMSE from more than 1 decade of mesospheric observations on both hemispheres could be converted to absolute signal power, allowing for direct comparison of the measurements. Comparison of PMSE observations obtained at both radar sites during a period of 23 boreal summers (Andøya) and 15 austral summers (Davis) shows that their PMSE signal strengths are of the same order of magnitude, but significantly fewer PMSE are observed in the Southern Hemisphere than in the Northern Hemisphere. Compared to Andøya, the PMSE season over Davis starts about 7 d later on average and ends 9 d earlier, making it 16 d shorter. PMSE over Davis occur less frequently but with greater variability in seasonal, diurnal, and altitudinal occurrence. For example, PMSE over Davis reach maximum altitudes about 1.5 km higher than those over Andøya.