Equatorial Climate Research Articles

Seasonal anomaly of particulate matter concentration in an equatorial climate: Evaluating the transboundary impact from neighboring provinces on Padang City, Indonesia.

This study investigated the anomalous seasonal variations in particulate matter (PM) concentrations-specifically PM2.5 and PM10-in Padang City, Indonesia, situated within the Equatorial climate zone. A one-year dataset of half-hourly PM measurements from January to December 2023, collected by the Air Quality Monitoring System (AQMS) managed by the Environmental Agency of West Sumatra (DLH), was utilized. Maps of hotspots and air mass backward trajectories were used to identify possible transboundary emissions affecting Padang City. Despite the region experiencing nearly continuous rainfall, significant elevations in PM levels were observed during the typically drier months of August to October. Specifically, PM2.5 levels peaked at 36.57µg/m3 and PM10 at 39.58µg/m3 in October, significantly higher than in other months and indicating a substantial deviation from the typical expectations for equatorial climates. These results suggest that the high PM concentrations are not solely due to local urban emissions or normal seasonal variations but are also significantly influenced by transboundary smoke from peatland fires and agricultural burning in neighboring provinces such as Bengkulu, Riau, Jambi, and South Sumatra. Backward trajectory analysis further confirmed the substantial impact of regional activities on degradation of air quality in Padang City. The study underscores the need for integrated air quality management that includes both local and transboundary pollution sources. Enhanced monitoring, public engagement, and inter-regional collaboration are emphasized as crucial strategies for mitigating the adverse effects of PM pollution in equatorial regions like Padang City.

Review of aging mechanisms, mechanical properties, and prediction models of fiber‐reinforced composites in natural environments

AbstractFiber‐reinforced composites are widely used in civil engineering, aerospace, automotive, and medical sectors. However, these composites undergo aging due to factors such as temperature, humidity, load, and so on, during their usage. As a result, their performance deteriorates, and predicting their durability under real service conditions is a significant challenge. In order to better understand the durability of fiber‐reinforced composites, this article summarizes their microscopic aging mechanism under natural aging conditions and analyzes the changing rules of tensile, bending, and shear properties of composites under seven typical climate types, including tropical desert climate, temperate continental climate, temperate oceanic climate, Mediterranean climate, seasonal climate, tropical rainforest climate, and seawater immersion. This article reviews various durability prediction models, such as the Arrhenius model, prediction models based on residual modulus of elasticity and residual strength, and median strength regression analysis. To enhance the accuracy of aging life prediction during the natural aging process of composites, it is important to consider the influence of loads under real service conditions, incorporate different climatic types, utilize comprehensive mechanical property indices, establish an equivalent conversion relationship between natural aging and accelerated aging, and create a database with unified test standards.Highlights The aging mechanisms of FRP after exposure in natural aging environments are discussed. The tensile, bending, and shear properties of FRP after exposure under seven climate types are discussed. The predictive models are proposed for the FRP used in natural aging. The future research needs are proposed for the FRP used in natural aging.

Performance analysis of air-to-ground heat exchanger in equatorial Yaoundé: Hourly and daily thermal behaviour and efficiency optimization

This study examines an air-to-ground heat exchanger operating continuously during Yaoundé’s hottest month. The paper focuses on identifying cooling and heating periods based on the local thermal comfort range. We equally determine the duct length needed for 70 % efficiency at various air inlet speeds. Ground temperature measurements are taken to inform an analytical model predicting air outlet temperatures. Additionally, calculations are made for hourly thermal efficiency and potential. The results reveal ground temperatures ranging from 20.8 °C to 23.4 °C within 5 m of the surface. To achieve 70 % efficiency, duct lengths range from 44.3m to 48.7m depending on air inlet speed (0.5–1.5 m/s). The air-to-ground heat exchanger system can effectively cool buildings between 8am and 10pm, delivering comfortable air temperatures (23.5–25.5 °C). The air-to-ground heat exchanger can also provide heating from midnight to 5am before switching to cooling for the rest of the day. This demonstrates the potential of air-to-ground heat exchanger systems in equatorial climates to maintain comfortable indoor temperatures throughout the day by both heating and cooling buildings. The study's implications suggest that AGHEs can significantly enhance energy efficiency in building systems in equatorial regions, offering a sustainable solution for climate control. The novelty of this research lies in its detailed analysis of AGHE performance in a specific equatorial climate, addressing previously unexplored aspects of hourly and daily thermal behaviors, and providing valuable insights for optimizing AGHE systems in similar climates.

Estimación de la erosión en un área de deforestación en la cuenca amazónica del bajo río Acre

The Lower Acre River Basin is located in an area of deforestation with the implementation of pastures for beef cattle ranching in soils susceptible to erosion and equatorial climate. The existence of slaughterhouses and beef cattle in the municipality of Boca do Acre, in the state of Amazonas, is one of the problems linked to deforestation in the Brazilian Amazon. Given this scenario, an estimate of soil losses was presented with the application of the Universal Equation in a geographic information system. In the methodology, a database was elaborated with vectorized information for the extraction of the areas of the types of soils and land cover, including the spatial analysis of slopes extracted from the digital elevation model. Due to the analysis of the areas by geoprocessing occurring by vectorization, the calculations of the erosion plots were obtained through tables with the parameters adopted by the scientific references. It was found that 60% of the soil loss occurs in the area of agriculture in 11% of the territory of the watershed, being predominantly in areas of rural settlements of the state of Acre. As a result of the estimate, soil loss in the Lower Acre River Basin was 386,422 t/ha/year, with a production of 46 million tons of sediment per year.

Nickel enrichment during lateritization of ophiolitic ultramafic rocks: A case study from the Kelurahan Pondidrha laterite profile in Sulawesi, Indonesia

The Southeast Asia is one of the most important producers of Ni-laterite deposits in the world, attracting more and more attentions in recent years. However, the lateritization processes as well as the enrichment mechanisms of Ni have not been well constrained. Recently, a Ni-rich laterite profile (KPP) was newly found in the Kelurahan Pondidrha area, Sulawesi island, Indonesia. To better understand the lateritization and Ni enrichment mechanisms, in this study, detailed mineralogical and geochemical analyses were conducted on the KPP. The KPP can be divided into bedrock, saprolitic and lateritic layers from bottom to top. The bedrock is serpentinized harzburgite mainly composed of olivine, serpentine and pyroxene, while the saprolitic layer mainly consists of Fe oxides, olivine, serpentine and pyroxene, and the lateritic layer is dominated by quartz and Fe oxy-hydroxides. Nickel is mainly hosted by serpentine in the bedrock and saprolitic layers, but by oxy-hydroxides in the lateritic layer. From the bedrock to the lateritic layer, whole-rock MgO and CaO contents decrease continuously while TFe2O3 contents increase, with TiO2/Al2O3, Zr/Hf and Pd/Pt ratios keeping stable. Combined with whole-rock pH value deceasing from the bedrock to the weathering products, the above results indicate the decomposition of silicate minerals and the formation of Fe oxides/oxy-hydroxides through hydrolysis during in-situ weathering. This led to the release of Ni and its adsorption by secondary minerals (e.g., Fe oxy-hydroxides in the lateritic layer and serpentine in the saprolitic layer). Nickel shows the highest contents in the saprolitic layer rather than the more weathered lateritic layer, indicating the decoupling between the lateritization and the Ni enrichment degrees. This could be due to the enhanced leaching of Ni from the surface under the tropical rainforest climate and the secondary adsorption in the deeper levels. These Ni enrichment features are commonly observed in the Mg-silicate type laterites, which are distinct from the oxide-type showing highest Ni enrichment in the lateritic layer, indicating that lithology played a critical role in controlling the lateritization and Ni enrichment.

Evaluation of oil palm (Elaeis guineensis Jacq.) productivity on peatlands based on DRIS analysis of leaf nutrient content in Siak District of Indonesia

Indonesia is the largest producer of oil palm in the world, with Riau Province particularly Siak District being the major contributor. The study focused on oil palm plantations within Siak District, characterized by a tropical rainforest climate of high humidity. The soil type in this area was a peatland with sapric and hemic maturity. The planting material used primarily consists of the DxP Marihat variety, which was planted between 1995-2005, with an average potential fresh fruit bunch productivity of 29.00 tons/ha/year. Variations in nutrient contents in oil palm leaf were observed across each block of the study location. Diagnosis and recommendation integrated system (DRIS) analysis was conducted on found number 17 to determine the key nutrients required to increase oil palm productivity. This method consists of several stages, including norm analysis, DRIS index, nutrient balance index (NBI), optimum leaf nutrient value, and leaf nutrient interval. Data was obtained from 312 leaf nutrient analyses and fresh fruit bunch productivity across 39 blocks for the period between 2015 and 2022. A value of 26.33 tons/ha/year, derived from DRIS norm calculation, indicated the border between high and low productivity blocks. The results showed that the order of macronutrient and micronutrient requirements in high productivity blocks was N>P>K>Ca>Mg and B>Cu>Zn, while in low productivity blocks, it was Ca>Mg>N>K>P and B>Cu>Zn. Regression of DRIS index and leaf nutrient content obtained optimum nutrient values of 2.78%, 0.16%, 1.02%, 0.66%, 0.35%, 29.51 ppm, 3.65 ppm, and 15.37 ppm for N, P, K, Ca, Mg, B, Cu, and Zn, respectively. Therefore, nutrients Ca and B were prioritized to increase the achievement of oil palm fresh fruit bunch productivity.

Renewable Energy Analysis and Evaluation with Economic Utilization of Solar Powered Air Conditioning System in Nigeria

This article focuses on the analysis and integration of PV systems to load ratio correlation and the economic importance of the left over to grid supply and integration. The paper focusses on the different methods of PV generation to load utilization using the solar powered air conditioner as the load while minimizing the use of fossil fuel (petroleum, natural gas and coal) which have serious environmental implications. Air conditioners are becoming more commonly used load power consumption metrics and are a major strain on energy demands especially in tropical rainforest climate countries like Nigeria. The photovoltaic electricity is a clean and sustainable energy. In this paper, we present a techno-economic feasibility study for solar powered air conditioning system in Nigeria. The method used made a correlation of four alternatives of PV to load ratio factor being investigated. In the first instance, the PV system supplied 50% of the energy to the loads. In the second method, the PV system supplied 75% of the energy to the loads. Thirdly, the PV system supplied 100% of the energy to the loads. Fourthly, on a final design, the PV system supplied 125% of the energy to the loads. In the first two case the PV energy generated is used solely to power the air conditioner system. In the last two design, there is excess electrical energy which is proposed to be sold to the Nigeria grid system especially if the grid system optimized and broken down into smaller grid array within 0.3$ feed-in tariff. The best alternative method is the grid-connected PV system with 125% capacity factor which is chosen due to its short payback time period as well as high profit rate over the lifetime of the project.

Advances in Retrofitting Strategies for Energy Efficiency in Tropical Climates: A Systematic Review and Analysis

The global construction industry significantly contributes to energy consumption and greenhouse gas emissions, necessitating immediate action for sustainable development. Recognizing the impact of buildings on emissions, the United Nations has set ambitious energy-related goals for 2030. Retrofitting buildings emerges as a strategic method for reducing energy consumption, offering lower environmental impact and life cycle costs. However, retrofitting is a complex process influenced by diverse factors such as policies, available resources, techniques, building-specific data, and uncertainties. Thus, this paper reviews the existing literature on retrofitting strategies for tropical and humid climates to identify effective approaches for enhancing energy efficiency, thermal comfort, and overall building performance in these regions. Through comprehensive analyses, including bibliometric analysis using VOSviewer version 1.6.18 and systematic assessments, this study investigates various retrofitting strategies. This study categorizes tropical climates into Af (Tropical Rainforest Climate) and Aw (Tropical Savanna Climate) based on the Köppen climate classification. It reveals distinct emphases, with Af climates concentrating on office buildings and Aw climates prioritizing residential structures. Passive strategies were predominantly favored in office buildings, with glazing being the most commonly implemented approach. Residential structures, on the other hand, adopted a combination of passive strategies such as phase change materials along with active methods like appliance replacement. Educational buildings tended to rely on passive strategies, including roof covers, shading, and glazing. The absence of specific cost values underscores the importance of establishing baseline metrics, revealing significant challenges in retrofit techniques. This study further highlights an opportunity to explore passive methods in educational buildings, stressing the need for comprehensive guidelines, especially in institutional settings. Moreover, it emphasizes the urgency for ambitious regulations to address carbon emissions and optimize energy efficiency in tropical climates.

Performance of grid-connected photovoltaic systems in Northern and Southern Hemispheres under equatorial climate

This work studied the actual and simulated technical performance between two grid-connected photovoltaic (GCPV) systems representing opposite latitudes. The system with a capacity of 5.4 kWp installed in Kelantan, Malaysia represents the northern equator, and the 183.6 kWp system installed in Cikarang, Indonesia, denotes the southern equator. The performance was simulated using PVsyst software, which included the energy output (E_outt), reference yield (Y_r), final yield 〖(Y〗_f), performance ratio (PR), and capacity factor (CF). The mean bias error (MBE) between the actual and simulated technical performance were as follows; for system A, the yearly MBE for the E_out, Y_r, Y_f, PR, and CF were -0.4%, 17.1%, -1.4%, -15.8%, and 1.4%, respectively, and for system B, the E_out, Y_r, 〖 Y〗_f, PR, and CF values were 9.80%, 18.3%, 10.0%, -7.2%, and 10.0% respectively. The results have proven that PVsyst has successfully simulated the yearly E_out, 〖 Y〗_f and CF for both systems including PR, for system B, with MBE less than 10%. However, it is noteworthy to highlight that PVsyst significantly overestimated the Y_r of both systems up to 18.3% and conversely underestimated the PR for system A by 15.8%, which highly likely caused by the Meteonorm imported weather data.

Soil erosion associated with roads—A global review and statistical analysis

AbstractGlobal soil degradation due to road erosion is an escalating concern. This study employed bibliometric analysis using the Science Citation Index‐Expanded dataset to gain insights into research trends in road erosion. It covered the years 2000–2021, revealing a steady increase in annual research publications, particularly after 2018. The United States and Catena was the leading contributor and the most popular journal, respectively. The primary research areas identified by keywords and statistical analysis are the forests and arid regions in the temperate climate zone (including temperate continental climate and temperate monsoon climate) and the tropical climate zone (including tropical rainforest climate and tropical monsoon climate). Since 2012, a noticeable shift from traditional methods to emerging technologies like isotope tracing (e.g., 137Cs, 210Pb) and machine learning (e.g., random forest) was observed, indicating evolving in methodologies with changes in research scales. The study emphasized the inevitability of road erosion, highlighting the crucial role of effective road management and restoration. It proposed integrating best management practices and ecosystem restoration strategies into watershed management, combined with advanced technological approaches, to foster sustainable watershed development.

Estudo de caso do projeto e execução do sistema de drenagem do gramado de futebol do Estádio Bezerrão

In soccer stadiums, every aspect is important. Infrastructure, stands, changing rooms, artificial lighting and, without a doubt, the pitch, which is vital if matches are to run smoothly and without risk. One of the problems that reduces playability is water puddles, i.e. the waterlogging of the pitch caused by rainwater. This problem is common in Brazil due to the equatorial tropical climate, which is characterized by high temperatures and intense rainfall, the latter causing, in some situations, cancellations of matches with inconvenience to fans and spectators and even delays in championships. Another problem caused by excessive accumulated water is damage to the health of the grass, as poor drainage prevents the correct development of the root system due to the lack of oxygen in the soil, limiting the absorption of nutrients, which are important for the development of the grass, and making the grass maintenance and mowing process more difficult. Within this context, the drainage system on a soccer pitch is essential. This system is divided into surface and subsurface. Therefore, this paper presents and discusses the drainage system of the Bezerrão Stadium soccer field, located in the Administrative Region of Gama, Federal District.

Palms of the past: can morphometric phytolith analysis inform deep time evolution and palaeoecology of Arecaceae?

Palm fossils are often used as evidence for warm and wet palaeoenvironments, reflecting the affinities of most modern palms. However, several extant palm lineages tolerate cool and/or arid climates, making a clear understanding of the taxonomic composition of ancient palm communities important for reliable palaeoenvironmental inference. However, taxonomically identifiable palm fossils are rare and often confined to specific facies. Although the resolution of taxonomic information they provide remains unclear, phytoliths (microscopic silica bodies) provide a possible solution because of their high preservation potential under conditions where other plant fossils are scarce. We thus evaluate the taxonomic and palaeoenvironmental utility of palm phytoliths. We quantified phytolith morphology of 97 modern palm and other monocot species. Using this dataset, we tested the ability of five common discriminant methods to identify nine major palm clades. We then compiled a dataset of species' climate preferences and tested if they were correlated with phytolith morphology using a phylogenetic comparative approach. Finally, we reconstructed palm communities and palaeoenvironmental conditions at six fossil sites. Best-performing models correctly identified phytoliths to their clade of origin only 59 % of the time. Although palms were generally distinguished from non-palms, few palm clades were highly distinct, and phytolith morphology was weakly correlated with species' environmental preferences. Reconstructions at all fossil sites suggested that palm communities were dominated by Trachycarpeae and Areceae, with warm, equable climates and high, potentially seasonal rainfall. However, fossil site reconstructions had high uncertainty and often conflicted with other climate proxies. While phytolith morphology provides some distinction among palm clades, caution is warranted. Unlike prior spatially restricted studies, our geographically and phylogenetically broad study indicates phytolith morphology may not reliably differentiate most palm taxa in deep time. Nevertheless, it reveals distinct clades, including some likely to be palaeoenvironmentally informative.

Robust Polar Amplification in Ice-Free Climates Relies on Ocean Heat Transport and Cloud Radiative Effects

Abstract A fundamental divide exists between previous studies that conclude that polar amplification does not occur without sea ice and studies that find that polar amplification is an inherent feature of the atmosphere independent of sea ice. We hypothesize that a representation of climatological ocean heat transport is key for simulating polar amplification in ice-free climates. To investigate this, we run a suite of targeted experiments in the slab ocean aquaplanet configuration of CESM2-CAM6 with different profiles of prescribed ocean heat transport, which are invariant under CO2 quadrupling. In simulations without climatological ocean heat transport, polar amplification does not occur. In contrast, in simulations with climatological ocean heat transport, robust polar amplification occurs in all seasons. What is causing this dependence of polar amplification on ocean heat transport? Energy-balance model theory is incapable of explaining our results and in fact would predict that introducing ocean heat transport leads to less polar amplification. We instead demonstrate that shortwave cloud radiative feedbacks can explain the divergent polar climate responses simulated by CESM2-CAM6. Targeted cloud locking experiments in the zero ocean heat transport simulations are able to reproduce the polar amplification of the climatological ocean heat transport simulations, solely by prescribing high-latitude cloud radiative feedbacks. We conclude that polar amplification in ice-free climates is underpinned by ocean–atmosphere coupling, through a less negative high latitude shortwave cloud radiative feedback that facilitates enhanced polar warming. In addition to reconciling previous disparities, these results have important implications for interpreting past equable climates and climate projections under high-emissions scenarios. Significance Statement Polar amplification is a robust feature of climate change in the modern-day climate. However, previous climate modeling studies fundamentally do not agree on whether polar amplification occurs in ice-free climates. In this study, we find in a state-of-the-art climate model that, if ocean heat transport is neglected, the response to an increase in CO2 is not polar amplified, whereas robust polar amplification occurs if ocean heat transport is included. Using targeted model experiments, we diagnose cloud radiative effects as the driver of this divergent behavior. We conclude that polar amplification is a robust feature of the atmosphere–ocean system. Our results have important implications for interpreting past warm climates and future projections under high-emissions scenarios.

Variable drivers trigger future change in water yield capacity of terrestrial ecosystems in Africa: An intensification of reduction and unevenness

Predicting the water-related services of terrestrial ecosystems in a changing climate is of great significance for managing rich ecosystems in water-scarce areas. Water yield capacity (WYC), which characterizes water resource availability, was thrown into sharp focus of this study. The spatiotemporal trends of WYC and their dynamics by potential climate shifts were evaluated based on calculative WYC and climate zones for historical period (2001–2018) and future scenarios (both 2050 and 2100 under SSP1-2.6 or SSP5-8.5 scenarios). The multiple factors affecting WYC in the recent past were identified as the basis for explaining the future tendency in WYC. All analyses were conducted from the perspective of holistic continental scale and specific basin scale so as to explore the contrast between various scales. The results showed that the total WYC both in whole Africa and the four major basins (the Congo, the Nile, the Niger and the Zambezi) are projected to decrease in 2050 and 2100 compared with that in 2018, under both SSP1-2.6 or SSP5-8.5 scenarios describing future pathways with low or high greenhouse gas emissions, respectively. The areas producing WYC will be more concentrated, suggesting that the proportion of areas contributing to the top 50% of this function across Africa will drop from current 10.5% to 4.94% in 2100 under SSP5-8.5 scenario. As climate zones are likely to shift in the future, the WYC will reduce most in the areas experiencing the conversion between tropical monsoon and tropical rainforest climates. In addition, WYC was driven by precipitation, temperature, net primary productivity (NPP) and landscape pattern (connectivity and diversity), which had spatial scale effect. The results add evidence for unstable availability of water resources provided by terrestrial ecosystems in a multi-scale manner.

Comparison of infiltration model performance based on basic infiltration rate for small watersheds in Papua region, Indonesia

Research on soil water infiltration in equatorial climates like Indonesia is limited. Despite Papua accounting for 29% of Indonesia’s surface water, there’s a shortage of hydrological data. This study aimed to identify the best infiltration model tailored to the characteristics of basic infiltration rates in Papua’s small watersheds. Observations were made at 95 points across 11 small watersheds in Papua. Based on equatorial basic infiltration rate theories, analysis classified infiltration values against observation time. The performance of four infiltration models — Horton, Philip, Kostiakov, and Green Ampt — were compared. The results indicated the Philip model as superior, with average scores of 0.901 (R), 0.814 (NSE), and 0.424 (RSR), followed by the Horton and Green Ampt models. These three models showed excellent performance. However, the Kostiakov model was found lacking and needs modification. Further research on rapid and very rapid classifications is vital for enhancing infiltration rate predictions in small equatorial watersheds.

Daytime Radiative Cooling under Extreme Weather Conditions

Radiative cooling, taking advantage of the coldness of the sky, has a potential to be a sustainable alternative to meet cooling needs. The performance of a radiative cooling device is fundamentally limited by the emissivity of the sky, therefore depends heavily on the regional weather conditions. Although the sky emissivity is known to increase with the dew point temperature, the feasibility of radiative cooling remains elusive in the equatorial tropical climate, where the weather is humid, cloudy, and constantly changing. It is pointed out that a high degree of thermal insulation of the radiative cooling system can be effective under such extreme weather conditions. A new method to characterize dynamic sky conditions is presented, namely to measure the sky window emissivity in the zenith direction. It is shown that a sub‐ambient cooling up to 8 °C is possible during daytime and that the cloud base is not a complete blackbody and can be used as a heat sink for radiative cooling.

Reconstruction of palaeoenvironmental conditions that led to the formation of Eocene sub-bituminous coal seams in the Hungarian Paleogene Basin

Although in the second half of the Eocene, thick sub-bituminous coal seams were deposited in the Hungarian Paleogene Basin, it is not known under what climatic conditions these strata were formed. To investigate this, the paleoenvironmental conditions were reconstructed for the upper Lutetian-middle Priabonian period. The reconstruction of paleoclimatic conditions was based on the Coexistence Approach, for which the climatic data of the extant relatives of 15 fossil plant genera provided the basis of the analysis. Most (87%) of the extant relatives of the studied fossil plant genera can be found most frequently in tropical climate regions. Plotting the reconstructed average mean annual temperature (23.4 ± 3.9 °C) and precipitation (2375 mm ± 964 mm) values to the Whittaker Plot and Peltier's plots it was found that the region had a tropical monsoon climate during the upper Lutetian- middle Priabonian period. At the same time, there was a great difference between the precipitation sums of the wettest and driest months (409 ± 178 mm and 59 ± 56 mm), indicating a tropical monsoon-like climate with strong chemical weathering conditions. Currently, in climatically similar regions, tropical rainforest and tropical moist deciduous forest vegetation grow under tropical rainforest and tropical monsoon climates, and lateritic soils are formed. Furthermore, relatively rich mangrove plant associations flourish along the coasts of these regions, indicating that a part of the peat may have been deposited in mangroves. The contemporary lateritic soils, which later became the protoliths of bauxites, provided a poor nutrient supply for coastal vegetation, likely due to peat accumulation.

Contribution of anthropogenic aerosols to persistent La Niña-like conditions in the early 21st century

The discrepancy between the observed lack of surface warming in the eastern equatorial Pacific and climate model projections of an El Niño-like warming pattern confronts the climate research community. While anthropogenic aerosols have been suggested as a cause, the prolonged cooling trend over the equatorial Pacific appears in conflict with Northern Hemisphere aerosol emission reduction since the 1980s. Here, using CESM, we show that the superposition of fast and slow responses to aerosol emission change-an increase followed by a decrease-can sustain the La Niña-like condition for a longer time than expected. The rapid adjustment of Hadley Cell to aerosol reduction triggers joint feedback between low clouds, wind, evaporation, and sea surface temperature in the Southeast Pacific, leading to a wedge-shaped cooling that extends to the central equatorial Pacific. Meanwhile, the northern subtropical cell gradually intensifies, resulting in equatorial subsurface cooling that lasts for decades.

Global prevalence of Plasmodium infection in wild birds: A systematic review and meta-analysis

Avian malaria is a vector-borne parasitic disease caused by Plasmodium infection transmitted to birds by mosquitoes. The aim of this systematic review was to analyze the global prevalence of malaria and risk factors associated with infection in wild birds. A systematic search of the databases CNKI, WanFang, VIP, PubMed, and ScienceDirect was performed from database inception to 24 February 2023. The search identified 3181 retrieved articles, of which 52 articles met predetermined inclusion criteria. Meta-analysis was performed using the random-effects model. The estimated pooled global prevalence of Plasmodium infection in wild birds was 16%.Sub-group analysis showed that the highest prevalence was associated with adult birds, migrant birds, North America, tropical rainforest climate, birds captured by mist nets, detection of infection by microscopy, medium quality studies, and studies published after 2016. Our study highlights the need for more understanding of Plasmodium prevalence in wild birds and identifying risk factors associated with infection to inform future infection control measures.

Determination of Onset and End of Growing Season in Nigeria using the Modified Dynamic (Optimal) Threshold Method and Satellite data

Understanding and accurately determining the onset and end of the growing season is essential for crop management, forecasting yields, and assessing the impacts of climate change, which are crucial for various sectors such as agriculture, ecology, and climate science. The study investigates the start and end of seasons using the optimal threshold method in different climate zones from 2001 to 2022. The climate zones include Tropical Rainforest (Af), Tropical Monsoon (Am), Tropical Wet (Aw), Hot Semi-Arid (BSh), Hot Arid (BWh), and Hot Summer Mediterranean climates. The relationship between climate parameters (temperature and precipitation) and phenology was examined using cross-correlation analysis. Furthermore, the research explores the annual distribution of precipitation and temperature, highlighting the variable nature of precipitation compared to temperature. Climate zone-specific analyses reveal trends in precipitation and temperature changes, indicating potential impacts on vegetation growth. The results show that the Af (BWh) climate zone indicated the longest (shortest) season length, and longer zones with a larger Length of Season (LOS) experienced delayed End of Season (EOS) and/or an early onset of the season. Moreover, Af climate seasons start earlier and finish later than those in the other climate zones. The findings have shown that season length (LOS) in Af, Aw, BSh, BWh, and Csb increased at 1.2, 0.4, 0.2, 0.9, and 0.5 days/yr, respectively. However, it is noteworthy that Am experiences a contraction at -0.6 days/yr. The study found that climatic fluctuation has an impact on vegetation phenology throughout all climate zones of Nigeria. Changes in agricultural growing seasons should be studied to maximize agricultural output.