Seasonal Transition Research Articles

Analisis Kondisi Atmosfer pada Kejadian Hujan ES di Kota Palembang 04 November 2023

Seasonal transitions in Indonesia are typically accompanied by extreme weather phenomena, such as hail that occurred in the city of Palembang on November 4, 2023. The analysis of atmospheric conditions is intended to understand the dynamics of the atmosphere during the occurrence of the hailstorm phenomenon. The data used in this study include satellite imagery from Himawari-9 channels 8, 11, 13, 15, GSM data, ECMWF modelling data, and SST anomaly data. The research results indicate that anomalies in sea surface temperature and vertical convergence profiles, as well as relative humidity (RH), strengthen the potential for convective activity leading to extreme weather conditions. Based on Himawari-9 satellite imagery, the time series graph shows the lowest peak cloud temperature at around -80°C, with the Atmospheric Stability Index based on the GSM method indicating a labile atmospheric condition. Furthermore, using the RGB 24 Hour Microphysics and CCO methods, Cumulonimbus clouds were observed to begin growing at 07:20 UTC, entering the mature stage at 09:20 UTC, and starting to decay at 10:20 UTC.

Dampak Perubahan Iklim terhadap Penurunan Pendapatan Petani

Climate change due to global warming is inevitable and will have a broad impact on many aspects of life. Changes in rainfall patterns, increased frequency of extreme weather events, and rising temperatures and sea levels are serious impacts of climate change that affect the agricultural sector. For Indonesia, the threat of climate change has serious implications for the achievement of the Sustainable Development Goals. In Indonesia, changes in rainfall due to climate change disrupt water supply to various sectors, including agriculture. This is evident from the fact that the area of land that was previously suitable for rice cultivation decreased by 20% between 1990 and 2009. Changes in rainfall patterns that result in the transition of the dry season and rainy season make current rice cultivation patterns no longer suitable as they used to be.

Energy characteristics of multi-chiller load distribution algorithms in a large office building

This study evaluates the energy efficiency of multi-chiller systems in large office buildings, focusing on their optimization across various climate zones as defined by ASHRAE. Using EnergyPlus for simulations, the research examines five different load distribution algorithms in multi-chiller systems that range from one to ten chillers, aiming to understand their effectiveness in 15 distinct climate zones. The primary objectives of the study include identifying the energy efficiency of multi-chiller systems in each climate zone, determining the appropriate number of chillers for each zone, and evaluating the performance of the load distribution algorithms. Based on the U.S. Department of Energy’s commercial building model, the results suggest that multi-chiller systems can significantly reduce cooling energy consumption in various climates. Among the algorithms evaluated, the Sequential Uniform Part Load Ratio (SUPLR) algorithm demonstrates notable efficiency, especially in the 4A climate zone (Baltimore), where it achieves substantial energy savings. Applying the SUPLR algorithm in a multi-chiller setup with four chillers in this zone leads to an estimated 24.5 % reduction in energy usage, equivalent to 183 MW annually. The research indicates that a range of 3 to 5 chillers is typically optimal for most climate zones. In-depth analysis in the 4A climate zone highlights the importance of minimizing operation hours at low Part Load Ratios (PLR) to ensure that chillers operate at a high Coefficient of Performance (COP). This strategy underscores the potential of well-designed multi-chiller systems to reduce cooling energy demand, particularly in climates with transitional seasons. This study provides an overview of the energy-saving potential of multi-chiller systems, applicable across a variety of climatic scenarios.

A hűtési és fűtési időszakot jellemző éghajlati klímaindexek változása Magyarországon

Összefoglalás. Az elmúlt évtizedekben a globális felmelegedés hatásai Európában, azon belül a Kárpát-medencében is nyilvánvalóvá váltak, s ez a hatás jelentős mértékű az energiaszektorra is. A kizárólag az időjárás által befolyásolt függő fűtési és hűtési energiaigényt leíró technikai klímaindexek alakulását mutatjuk be Magyarországon, nevezetesen a fűtési foknap (Heating Degree Days) és a hűtési foknap (Cooling Degree Days) paramétereket vizsgáljuk. A jelen klímát leginkább jellemző éves és havi normálértékek mellett a változásokat is elemezzük. A múlt század elejétől a fűtési foknapok egyértelmű csökkenése, míg a hűtési foknapok egyértelmű emelkedése figyelhető meg. Országos átlagban 314,6 foknappal [°C nap] csökkent a fűtési foknapok éves összege a lineáris trendmodell szerint 1901-től, míg ugyanerre az időszakra 79,4 ℃ nappal nőtt a hűtési foknap értéke. A legutóbbi három évtizedben, a legintenzívebb melegedés időszakában igen markánsak a változások, s ez a folyamat minden bizonnyal folytatódik a század végéig és azon túl is. Summary. In recent decades, the effects of global warming have become evident in Europe, including the Carpathian Basin, and this impact is significant for the energy sector. The most obvious impact of climate change in Hungary is the increase in extremes associated with high temperatures. Not only summer, but also winter and transition seasons show a warming trend, affecting all productive and service sectors. Rising temperatures could lead to shorter heating seasons and milder cold months, potentially reducing heating energy demand. However the heat waves have become more frequent and intense due to warming, leading to an increase in cooling energy demand. In the first part of this article, we present the evolution of heating degree-days from the beginning of the last century to the present day for the whole area of Hungary. The heating degree day is an indicator of the energy consumption for heating of buildings, which depends only on the weather. That is a temperature value, expressed in °Cday, which is proportional to the amount of energy required to heat the indoor environment to a given temperature on a given day, taking into account the daily minimum, maximum and mean temperature for a specific base temperature (15.5°Cday). Importantly, its value does not depend on the insulation of the buildings, economic indicators or the type of energy sources. Essentially, the colder the weather, the more the air temperature deviates from the base temperature of 15.5 degrees Celsius, the more energy is needed to heat the indoor environment and the higher the heating degree day value will be. In addition, we present the analysis of cooling degree days. The cooling degree day is derived in a similar way, following the logic of the heating degree day derivation. Therefore, the warmer the weather and the higher the air temperature is above the base temperature of 22°C, the more energy is needed to cool the indoor environment. Based on the results presented in the article, we can conclude that the annual as well as the monthly amounts of heating degree-days have decreased since the beginning of the last century, with the greatest decrease in mountainous areas and in Western Hungary. One of the few benefits of climate change is that less energy is needed to heat interiors, and this is particularly true for the last decades, when annual heating degree-day amounts were usually lower than normal. At the same time, as heating degree-days have decreased, as the heat waves have become more frequent and intense with warming, resulting in an increase in cooling degree-days. In Hungary, on average, the last 30 years have been characterised by the highest cooling degree-day values over the last century’s climate normal periods. On a national average, the annual amount of heating degree-days has decreased by 314.6°Cday according to the linear trend model since 1901, while the cooling degree-day value has increased by 79.4°Cday over the same period. During the period of most intense warming, the August weather-dependent cooling energy demand increased the most. Due to the urban heat island effect in the inner-city environment, cooling of buildings requires additional energy. The recent trends is likely to continue until the end of the century and beyond. Therefore important to monitor changes in climate parameters affecting energy security and to develop an effective strategy and action plans to address the climate risks for the energy sector.

Rainfall seasonality shapes microbial assembly and niche characteristics in Yunnan Plateau lakes, China

Microorganisms are crucial components of freshwater ecosystems. Understanding the microbial community assembly processes and niche characteristics in freshwater ecosystems, which are poorly understood, is crucial for evaluating microbial ecological roles. The Yunnan Plateau lakes in China represent a freshwater ecosystem that is experiencing eutrophication due to anthropogenic activities. Here, variation in the assembly and niche characteristics of both prokaryotic and microeukaryotic communities was explored in Yunnan Plateau lakes across two seasons (dry season and rainy season) to determine the impacts of rainfall and environmental conditions on the microbial community and niche. The results showed that the environmental heterogeneity of the lakes decreased in the rainy season compared to the dry season. The microbial (bacterial and microeukaryotic) α-diversity significantly decreased during the rainy season. Deterministic processes were found to dominate microbial community assembly in both seasons. β-Diversity decomposition analysis revealed that microbial community compositional dissimilarities were dominated by species replacement processes. The co-occurrence networks indicated reduced species complexity for microbes and a destabilized network for prokaryotes prior to rainfall, while the opposite was found for microeukaryotes following rainfall. Microbial niche breadth decreased significantly in the rainy season. In addition, lower prokaryotic niche overlap, but greater microeukaryotic niche overlap, was observed after rainfall. Rainfall and environmental conditions significantly affected the microbial community assembly and niche characteristics. It can be concluded that rainfall and external pollutant input during the seasonal transition alter the lake environment, thereby regulating the microbial community and niche in these lakes. Our findings offer new insight into microbiota assembly and niche patterns in plateau lakes, further deepening the understanding of freshwater ecosystem functioning.

Effects of sublethal methylmercury and food stress on songbird energetic performance: metabolic rates, molt and feather quality.

Organisms regularly adjust their physiology and energy balance in response to predictable seasonal environmental changes. Stressors and contaminants have the potential to disrupt these critical seasonal transitions. No studies have investigated how simultaneous exposure to the ubiquitous toxin methylmercury (MeHg) and food stress affects birds' physiological performance across seasons. We quantified several aspects of energetic performance in song sparrows, Melospiza melodia, exposed or not to unpredictable food stress and MeHg in a 2×2 experimental design, over 3 months during the breeding season, followed by 3 months post-exposure. Birds exposed to food stress had reduced basal metabolic rate and non-significant higher factorial metabolic scope during the exposure period, and had a greater increase in lean mass throughout most of the experimental period. Birds exposed to MeHg had increased molt duration, and increased mass:length ratio of some of their primary feathers. Birds exposed to the combined food stress and MeHg treatment often had responses similar to the stress-only or MeHg-only exposure groups, suggesting these treatments affected physiological performance through different mechanisms and resulted in compensatory or independent effects. Because the MeHg and stress variables were selected in candidate models with a ΔAICc lower than 2 but the 95% confidence interval of these variables overlapped zero, we found weak support for MeHg effects on all measures except basal metabolic rate, and for food stress effects on maximum metabolic rate, factorial metabolic scope and feather mass:length ratio. This suggests that MeHg and food stress effects on these measures are statistically identified but not simple and/or were too weak to be detected via linear regression. Overall, combined exposure to ecologically relevant MeHg and unpredictable food stress during the breeding season does not appear to induce extra energetic costs for songbirds in the post-exposure period. However, MeHg effects on molt duration could carry over across multiple annual cycle stages.

Understanding watershed sources of pollution in Vinh Long Province, Vietnamese Mekong Delta

We explore point source (PS) and non-point source (NPS) pollution impacts on surface water quality in Vinh Long Province, Vietnam. We used data from 60 surface water quality monitoring stations across dry, transitional, and wet seasons from 2017 to 2021, in addition to sampling data collected from 12 wastewater outlets from June to October 2021 to determine the sources of pollution loads. Surface water quality was assessed using both the water quality index (WQI) and the Vietnamese standards QCVN 08:2015, whilst cluster analysis (CA) and principal components analysis (PCA) were used to evaluate spatial variation and key influencing factors. We observed seasonal variation in surface water quality, with a decline in quality during the rainy season. Moreover, the water quality parameters such as chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total nitrogen (TN), and total phosphorus (TP) frequently exceeded the QCVN 08:2015 standard. Across, the different monitoring fixed points and seasons, COD levels were found to range from 8.94 to 15.14 mg/L, while TN levels varied between 0.24 and 0.53 mg/L. The cluster analysis categorized the monitoring fixed points into three groups, based on their water quality parameters, while PCA identified four principal components that explain 69% of the variance, distinguishing between pollution sources and seasonal factors. Our findings emphasize that poor water quality in many areas is affected by non-point source pollution, underscoring the need for watershed and land management. The results and applied methodologies provide insights for watershed management, policy development, and adaptation, applicable to regions facing similar environmental challenges.

CONTAMINATION SALMONELLA SPP. IN BROILER CHICKEN MEAT SOLD IN THE BADUNG MARKET DURING THE TRANSITIONAL SEASON PERIOD

The presence of Salmonella spp. in animal food products is highly undesirable and strictly regulated in Indonesian law. One of the factors that causes contamination is the climate and conditions of the place of sale. This study aims to determine the presence of Salmonella spp. bacteria in broiler meat that sold at Badung Market during the transitional season period. The research sample was fresh broiler chicken meat, namely 15 samples taken randomly from 15 broiler chicken traders. The isolation stage begins with enrichment using Selenite broth media, followed by isolation of bacteria using selective media, namely Salmonella Shigella Agar (SSA), identification using the Gram staining method, and Biochemical Tests including the Triple Sugar Iron Agar Test, Methyl Red, Indole, and Citrate tests. The results of the research found that 5 of 15 (33,3%) samples were identified as contaminated with Salmonella spp. Based on the research results, it can be concluded that broiler chicken meat sold in the Badung market during the transitional season is of poor quality. It is hoped that the government will pay more attention and provide education regarding the procedures and procedures for selling chicken meat according to standards and implement the applicable regulations more strictly, because this can have a serious impact on public health.

CONTAMINATION ESCHERICHIA COLI IN BROILER CHICKEN MEAT SOLD AT BADUNG MARKET, DENPASAR, BALI DURING THE TRANSITION SEASON

Escherichia coli is reported as an intensive bacterial contaminant of chicken meat, including broiler meat. Factors that support the occurrence of contamination are the environment, equipment and sellers. This study aims to determine the presence of Escherichia coli bacteria in broiler meat sold in Badung market, Denpasar, Bali during the transitional season. The samples used were fresh broiler meat totaling 15 samples by taking randomly from 15 broiler meat traders. Samples will be taken to the laboratory for isolation and identification of Escherichia coli. The isolation stage uses selective media, namely Eosin Methylen Blue Agar (EMBA), identifying with the gram staining method, and biochemical tests consisting of Triple Sugar Iron Agar (TSIA), Citrate, Indol and Methyl Red tests. The results of the study found 3 (20%) of the 15 samples identified were contaminated by Escherichia coli bacteria. From the results of this study there is still contamination of Escherichia coli bacteria and needs to get more attention from the government in order to get education about the procedures for selling broiler meat according to standards and implement applicable regulations more strictly, because it affects public health.

Performance Analysis and Optimization of Solar-Coupled Mine Water-Source Heat Pump Combined Heating and Cooling System

To address the energy consumption issue in mining area buildings, this paper proposed a solar-coupled mine water-source heat pump combined heating and cooling (SMWHP-CHC) system, taking the employee dormitory building group of a coal mining enterprise in Tongchuan City, China, as a case study. The system utilizes renewable solar energy and waste heat recovered from mine water as composite heat sources, and utilizes the cold energy in mine water as a cooling source to meet the demands for space heating, space cooling, and annual domestic hot water of the building in a sustainable manner. The simulation model of the system was established by TRNSYS to analyze the system’s annual operational performance. The results indicated that the system exhibited a positive energy efficiency and environmental performance under different operating conditions. The heating coefficients of the performance of the system (COPsys) during the space heating season and transition season were 3.54 and 18.6, and the cooling energy efficiency ratio of the system (EERsys) was 3.79. In addition, aiming to minimize the annual cost of the system, multiple crucial device parameters were synchronously optimized employing the PSO-HJ hybrid optimization algorithm through the GenOpt 2 software. The annual cost of the optimized system was reduced by 8.82%, and the investment cost was significantly reduced, while the performance was also improved. This study can provide theoretical support for the sustainable engineering application of the SMWHP-CHC system in mining area buildings.

UJI VALIDITAS IBFWS (IMPACT BASE FORECAST AND WARNING SERVICES) DALAM MEMPREDIKSIKAN WILAYAH YANG BERPOTENSI TERDAMPAK BANJIR DI KALIMANTAN SELATAN

South Kalimantan is one of the provinces in Indonesia which has a high risk of flood disasters seen from its physical condition, which geographically is mostly located below sea level. In 2021, 11 out of a total of 13 districts and cities in South Kalimantan were affected by flooding on a large scale, which caused tens of thousands of residents to suffer losses and even lost family members. IBFWS (Impact Base Forecast and Warning Services) is present as the latest innovation from the Meteorology, Climatology and Geophysics Agency as an impact-based weather forecast information service. To determine the accuracy of the IBFWS service information, it is necessary to validate the prediction results issued by IBFWS with the actual situation. By using spatial analysis methods, it is hoped that it can describe which areas are potentially affected by flooding and continued with the calculation of the contingency table so that the accuracy value of IBFWS is obtained in predicting areas potentially affected by flooding in South Kalimantan. IBFWS validation results in predicting areas potentially affected by flooding in South Kalimantan during the rainy season range between 0.85 – 1.00 which mean 85% - 100% the IBFWS prediction results are correct, during the transition season in general is 0.77 which mean 77% the IBFWS prediction results are correct, and during the dry season it ranges between 0.92 – 1.00 which mean 92% - 100% the IBFWS prediction results are correct.

Vertical Characteristic of Water Mass in The Flores Sea: The Effect of The ITF on The Transitional Season

Abstract Indonesian Through Flow (ITF) forms unique water mass characteristics in Indonesian Marine Waters. This water mass enters through the Makassar Strait into the Banda Sea by crossing the Flores Sea. This study aims to analyse the characteristics of water masses in the Flores Sea during the transition season. In situ data was obtained using conductivity temperature depth (CTD) at four stations in the Flores Sea from April to May 2023. Next, the data was processed and analysed for layer thickness through vertical stratification and water mass characteristics using T-S diagrams. The analysis results show that the thickness of the homogeneous layer in the Flores Sea in the first transition season is between a depth of 0-40 m, the thermocline layer is at a depth of 40-300 m, and the depth layer is from a depth of 400-900 m. Apart from that, the characteristics of the water mass identified through the T-S diagram are: North Pacific Subtropical Water (NPSW) is found at a depth of 100-150 m with a temperature between 20-26° C and a salinity between 34.9-35.4 psu. Another water mass is South Pacific Intermediate Water (SPIW) at a depth of 500-800 m with a temperature of 6-8° C and a salinity of 34.55-34.65 psu. In contrast, the Antarctic Intermediate Water (AAIW) was found at a depth of >750 m with a temperature of 5-6° C and a salinity of 34.5-34.6 psu.

Primary Productivity Variation in Banten Bay and Java Sea and Its Relationship with Fish Catches

Abstract Ecosystems carry out internal activities, one of which is by carrying out production which is the process of inputting and storing energy from sunlight as a primary energy source called primary productivity. The development of wider coastal areas is a major factor in the importance of assessing the quality of water fertility as a measure of ecosystem change. The aim of this research is to predict the value of primary productivity in Banten Bay and the Java Sea seasonally from 2005-2020 based on MODIS Fluorescence satellite image data and processed using the Vertically Generalized Production Model (VGPM). Net Primary Productivity results obtained in Banten Bay in the West Season 148.23 mgC.m−3.d−1; Transitional Season I 148.06 mgC.m−3.d−1. East Season with 154.05 mgC.m−3.d−1; Transitional Season II 170.10 mgC.m−3.d−1 while in the Java Sea in the West Season 100.05 mgC.m−3.d−1; Transitional Season I 82.20 mgC.m−3.d−1; East Season 110.84 mgC.m−3.d−1; Transitional Season II 95.97 mgC.m−3.d−1 which decreased in value from 2005 to 2020 in both regions. Water fertility in Banten Bay and the Java Sea is higher in the nearshore area than the open sea which is influenced by chlorophyll-a, PAR availability, day length, temperature, maximum carbon fixation, euphotic zone depth, and area. Trophic status in each season in Banten Bay is included in the Oligotrophic class while in the Java Sea it is included in the Oligotrophic and Mesotrophic classes. NPP has a positive correlation with the overall capture of small pelagic fish species of 0.654 (average).

Eating Habits and Dietary Strategies of the Glass Perchlet Fish (Ambassis macracanthus) In Benoa Bay Waters, Bali in Two Different Seasons

The Benoa Bay area and its surroundings are a center of biodiversity at the ecosystem level in the southern coastal region of Bali. This area exhibits diverse ecosystems, including mangrove ecosystems, coral reefs, seagrass beds, and tidal flats. This research aims to analyze and describe the feeding ecology of Ambassis macracanthus in the waters of Benoa Bay. The study was conducted in May, at the end of the transitional season, and in July and August, during the eastern monsoon season in Benoa Bay Waters. Modified gill nets with mesh sizes of 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 cm were used for capturing the fish. The fish were caught at three stations, which represented the characteristic conditions of the Benoa Bay Waters. Out of the 396 individuals caught during the study, only 100 were selected for examination. The average relative fullness gut index (RGI) of Ambassis macracanthus ranged from 0.39 to 0.67. The total Important Relative Index (IRI) value for the food of Ambassis macracanthus in Benoa Bay Waters was 951.27. Ambassis macracanthus in Benoa Bay Waters is an omnivorous species with a tendency towards herbivory, and 21 different organisms were found in its diet, including three classes of phytoplankton and three classes of zooplankton. The feeding strategy developed by Ambassis macracanthus in Benoa Bay Waters is generalist. This information about the fish can be used as a fundamental basis for managing fish in the waters of Benoa Bay.

Evaluation of GSMaP Rainfall Data in the Aceh Region

Rainfall measurement data in the field is quite limited, however, satellite data obtained by remote sensing methods are widely available. However, its accuracy must still be tested using observational rainfall data. The objective of this research was to validate GSMaP satellite estimated rainfall data with Automatic Rain Gauge (ARG) rainfall data at rain stations dispersed over Aceh Province's west-central region, as well as to identify the primary drivers for GSMaP data error. ARG and GSMaP data sources. A comparison of GSMaP data accuracy using a combination of Pearson and RMSE tests shows that GSMaP performance is very low in the dry and transition seasons and significantly better in the rainy season. GSMaP, on the other hand, is still unable to offer sufficient precise rainfall estimation data for each season. Meanwhile, a comparison by elevation shows that GSMaP data is not fully reliable.

Daily temperature variability and mental health-related hospital visits in New York State

BackgroundDespite plausible behavioral and physiological pathways, limited evidence exists on how daily temperature variability is associated with acute mental health-related episodes. ObjectivesWe aimed to explore associations between daily temperature range (DTR) and mental health-related hospital visits using data of all hospital records in New York State during 1995–2014. We further examined factors that may modify these associations, including age, sex, hospital visit type and season. MethodsUsing a case-crossover design with distributed lag non-linear DTR terms (0–6 days), we estimated associations between ZIP Code-level DTR and hospital visits for mood (4.6 million hospital visits), anxiety (2.4 million), adjustment (∼368,000), and schizophrenia disorders (∼211,000), controlling for daily mean temperature, via conditional logistic regression models. We assessed potential heterogeneity by age, sex, hospital visit type (in-patient vs. out-patient), and season (summer, winter, and transition seasons). ResultsFor all included outcomes, we observed positive associations from period minimum DTR (0.1 °C) until 25th percentile (5.2 °C) and between mean DTR (7.7 °C) and 90th percentile (12.2 °C), beyond which we observed negative associations. For mood disorders, an increase in DTR from 0.1 °C to 12.2 °C was associated with a cumulative 16.0% increase (95% confidence interval [CI]: 12.8, 19.2%) in hospital visit rates. This increase was highest during transition seasons (32.5%; 95%CI: 26.4, 39.0%) compared with summer (10.7%; 95%CI: 4.8, 16.8%) and winter (−1.6%; 95%CI: −7.6, 4.7%). For adjustment and schizophrenia disorders, the strongest associations were seen among the youngest group (0–24 years) with almost no association in the oldest group (65+ years). We observed no evidence for modification by sex and hospital visit type. DiscussionDaily temperature variability was positively associated with mental health-related hospital visits within specific DTR ranges in New York State, after controlling for daily mean temperature. Given uncertainty on how climate change modifies temperature variability, additional research is crucial to comprehend the implications of these findings, particularly under different scenarios of future temperature variability.

Forest cover percentage drives the peak biting time of Nyssorhynchus darlingi (Diptera: Culicidae) in the Brazilian Amazon

BackgroundDeforestation is an important driver of malaria dynamics, with a relevant impact on mosquito ecology, including larval habitat availability, blood-feeding behaviour, and peak biting time. The latter is one of several entomological metrics to evaluate vectorial capacity and effectiveness of disease control. This study aimed to test the effect of forest cover percentage on the peak biting time of Plasmodium-uninfected and infected Nyssorhynchus darlingi females.MethodsMosquitoes were captured utilizing human landing catch (HLC) in the peridomestic habitat in field collections carried out in the wet, wet-dry transition, and dry seasons from 2014 to 2017 in areas with active malaria transmission in Amazonian Brazil. The study locations were in rural settlements in areas with the mean annual malaria parasite incidence (Annual Parasite Incidence, API ≥ 30). All Ny. darlingi females were tested for Plasmodium spp. infection using real time PCR technique. Forest cover percentage was calculated for each collection site using QGIS v. 2.8 and was categorized in three distinct deforestation scenarios: (1) degraded, < 30% forest cover, (2) intermediate, 30–70% forest cover, and (3) preserved, > 70% forest cover.ResultsThe highest number of uninfected female Ny. darlingi was found in degraded landscape-sites with forest cover < 30% in any peak biting time between 18:00 and 0:00. Partially degraded landscape-sites, with (30–70%) forest cover, showed the highest number of vivax-infected females, with a peak biting time of 21:00–23:00. The number of P. falciparum-infected mosquitoes was highest in preserved sites with > 70% forest cover, a peak biting at 19:00–20:00, and in sites with 30–70% forest cover at 22:00–23:00.ConclusionsResults of this study show empirically that degraded landscapes favour uninfected Ny. darlingi with a peak biting time at dusk (18:00–19:00), whereas partially degraded landscapes affect the behaviour of Plasmodium-infected Ny. darlingi by shifting its peak biting time towards hours after dark (21:00–23:00). In preserved sites, Plasmodium-infected Ny. darlingi bite around dusk (18:00–19:00) and shortly after (19:00–20:00).

Decadal preference of seasonal ENSO transition through a southern hemisphere climate mode

El Niño Southern Oscillation (ENSO) is the leading interannual coupled climate mode in the tropical Pacific. The seasonal transition of ENSO from boreal winter to the following summer can significantly affect the global climate. One of the major hurdles in understanding the seasonal transition of ENSO is the spring predictability barrier. Here, we show that ENSO’s seasonal transition is modulated by a multidecadal climate mode of boreal spring sea-level pressure (SLP) in the extratropical Southern Hemisphere. This ENSO transition mode (ETM), when characterised by a decrease in SLP and associated clockwise circulation of the surface winds centred over the southeastern subtropical Pacific Ocean, produces westerly anomalies at the equator. These wind anomalies in the equatorial eastern Pacific aid the seasonal warming of Niño3.4 sea surface temperature anomalies (N34SST) from boreal winter to the following summer. The ETM time series shows prominent multidecadal variations at around 50 years. This creates a conducive environment for alternate cold and warm seasonal transitions leading to multidecadal variations in boreal summer N34SST. Thus, ETM provides a physical insight into the seasonal transition of ENSO and leads to a new paradigm for ENSO evolution beyond its peak. This has implications for seasonal ENSO forecasts and decadal climate predictions.

Integrating the Living Wall with Mechanical Ventilation to Improve Indoor Thermal Environment in the Transition Season

A living wall, when integrated with a mechanical ventilation system, can effectively improve the indoor thermal environment and reduce indoor CO2 concentration during the transition season. In this study, a control experiment was conducted to analyze the effect of a living wall integrated with mechanical ventilation (LW-V) on indoor air quality. During the experiment, indoor air temperature, relative humidity, indoor air speed, and CO2 concentration were measured, while the skin temperature was monitored and subjective questionnaires were administered to 60 subjects. The results show that the indoor environment was effectively improved by employing the LW-V system, with the average indoor temperature decreasing by 1.45 °C, while relative humidity increased by 19.1%. Due to the plant photosynthesis, CO2 concentrations were reduced by 13.83 ppm. Meanwhile, the mean skin temperature was reduced by 0.18 °C and was closer to the neutral mean skin temperature. Questionnaire analysis reveals the LW-V system improved overall air freshness sensation and thermal comfort level by 1.09 and 0.53, respectively. The LW-V system improved the indoor thermal environment as well as air quality during the transition season significantly.

Chasing and surfing seasonal waves: Avian migration through the US tracks land surface phenology in fall, but not spring.

Climate change is altering the timing of seasonal events for many taxa. There is limited understanding of how northward/southward songbird migration follows or is limited by the latitudinal progression of seasonal transitions. Consistent environmental conditions that migrating birds encounter across latitudes likely represent or correlate with important resources or limiting factors for migration. We tested whether migratory passage-observed via radar-consistently tracked land surface variables and phenophases across latitudes in the US Central Flyway in both spring and fall. The daily temperatures, precipitation and vegetation greenness occurring on 10%, 50% and 90% cumulative passage dates changed substantially with latitude, indicating that most migrants experienced rapidly changing conditions as they headed north or south. Temperature did not limit the progression of migration in either season. Peak spring migration in the southern US occurred nearly 40 days after the spring green wave, the northward progression of vegetation growth, but nearly caught up to green-up at 48° N. Spring migration phenology may have evolved to prioritize earlier arrival for breeding. Across all latitudes, peak fall migration coincided with the same land surface phenophase, an interval of 26 days prior to dormancy onset. Migrants may rely on phenological events in vegetation during fall stopovers. Considering that (a) migratory passage tracked fall land surface phenology across latitudes at a continental scale, (b) previous studies at local scales have demonstrated the importance of fruit during fall migratory stopover and (c) fruiting phenology in North America is occurring later over time while fall migration is advancing, the potential for mismatch between fall fruiting and bird migration phenology urgently needs further investigation.