Humid Climate Research Articles

Comparative analysis of geochemical peculiarities of pleistocene sediments from Indian and Atlantic oceans

We have compared the arithmetic average chemical composition of main types of Pleistocene sediments in the Indian and Atlantic oceans, and average chemical composition of the Pleistocene in both oceans as well. As the base for comparison we have used data from International project of deep-sea drilling reports (phases DSDP, ODP, IODP) and other references. It was revealed that results of comparative analyses of meanweighted chemical composition have been determined by masses of dry sediment matter. Domination of Atlantic mass accumulation rates over the Indian Ocean ones was due to larger ratio of watershed areas to areas of basin accumulation, more significant role of humid climate and enhanced primary production.

Numerical Analysis of the Heat and Mass Transfer in a Ventilated Cavity for Turbulent Convective Flow With Extreme Hot and Humid Climate Conditions

ABSTRACTTo analyze the temperature and relative humidity (RH) in a room located in the Lacandona jungle in Chiapas, Mexico, a numerical heat and mass transfer study was performed. The study was carried out in a ventilated cavity, by introducing air flow into user‐occupied spaces. The study analyzed the combination of temperature and humidity percentage to create thermal comfort conditions. The finite volume method was used to solve the governing equations, while pressure–velocity coupling was done with the SIMPLEC algorithm. Turbulent airflow was considered, and modeled using the k–ε turbulence model, with Reynolds numbers (Re) in the range from 100 to 5000. Seven sets of weather conditions were considered for a warm April day with solar radiation values that ranged from 0 to 981 W/m², outdoor temperatures between 19.9°C and 35.3°C, as well as RH from 42% up to 100%. The study analyzed temperature, RH, distribution efficiencies, and heat fluxes. It was found that the average temperature closest to thermal comfort was 25.8°C. This corresponds to an Re = 5000, being the best hygrothermal conditions with an average RH of 50%. However, this level of RH is unattainable by many air conditioning systems.

The Influence of Age, Sex, and Season on Hematological Parameters in a Captive Population of Former Laboratory Chimpanzees (Pan troglodytes).

This study aimed to establish a baseline hematological profile and examine the influence of age, sex, and season on hematological parameters in captive chimpanzees (Pan troglodytes) living in a humid tropical climate. Hematological parameters are a useful tool for assessing health status and diagnosing diseases in animals. We analyzed 473 blood samples collected from 84 chimpanzees (43 females and 41 males) during annual health checks, conducted under anesthesia for a routine physical examination. The main findings revealed significant sex differences in some hematological parameters: males had higher hematocrit and red blood cell counts than females. Age-related variations have also been noted, with adolescents and adults having lower lymphocyte counts but higher neutrophil and monocyte counts than infants. Adults, in particular, had significantly lower platelet counts compared to other age classes. Seasonal fluctuations were also observed: lymphocyte counts were higher in the rainy season, while neutrophil counts were higher in the dry season. In addition, the general trends in hematological parameters for this captive population of chimpanzees were similar to those reported in captive chimpanzees living in the United States. These results should provide animal health professionals, particularly those working with nonhuman primates, with data to compare and interpret. They will help improve practices for monitoring and managing the health of nonhuman primates in captivity.

Effects of urbanization on the ephemeral lake flood risks under subtropical humid monsoon climate

Study regionPoyang Lake region, China. Study focusThis study focuses on addressing severe summer monsoon floods in the Poyang Lake region under subtropical monsoon climate conditions. Employing the Seasonal Water Yield analysis within the Integrated Valuation of Ecosystem Services and Tradeoffs framework to investigate and assess the impacts of subtropical monsoon climate and urban dynamics on regional flood risk. By combining simulation results with analysis of regional urban distribution, the study aims to identify sensitive changes in flood hazard characteristics. Ultimately, the research seeks to enhance regional flood resilience to address climate change and urban development challenges. New hydrological insights for the regionUpon analyzing the model simulation results, we discovered that the subtropical humid monsoon climate contributes significantly, accounting for 35.98 % of surface runoff variability during the ephemeral lake region's flood season. Rapid urbanization amplifies the negative impact of land use change on surface runoff (with a contribution rate of 26.00 %). In urban agglomeration areas, surface runoff increased by 30 mm, and the area with surface runoff production of 60–90 mm increased by 120.33 km2. Implementing proactive ecological management measures around lakes and riverbanks has mitigated flood risks across 22 administrative regions, reducing high-risk flood areas by 92.15 km². Restoration of lake flood storage capacity has significantly bolstered resilience against flood disasters.

Air Conditioning Energy Efficiency and Thermal Comfort in Hotel Buildings in Hot and Humid Tropical Climates

The objective of this research is to examine energy consumption efficiency strategies with respect to the type of dwelling unit, cooling load, and thermal comfort. This can be evaluated through the study of the hotel building air system, with the aim of ensuring the thermal comfort of its occupants. This research employs a quantitative methodology, using observation, measurement, and experimental techniques. The case study is situated within the context of hotels in Makassar City, South Sulawesi Province, Indonesia. The subject of this study is the Swissbel Hotel building, located in the coastal area of Makassar City. The data are analyzed in order to determine the Energy Consumption Intensity (IKE), Room Energy Intensity (REI), and occupancy rate based on the heat load inside and outside the building. The data are then processed using a parametric statistical approach. Subsequently, the building envelope is analyzed through the calculation of the Overall Thermal Transfer Value (OTTV) in accordance with the standards set out in SNI 6390: 2011. The cooling load and a thermal comfort assessment, in line with the Predicted Mean Vote (PMV) index, Predicted Percentage of Dissatisfaction (PPD) index, and effective temperature according to the ASHRAE 55-2022 standard, are then calculated, and a simulation is performed to determine the most efficient strategy for the use of air conditioning energy. The findings indicated that alterations in the dimensions of the facade (sun shading) resulted in a 16% reduction in the cooling load, with the incorporation of horizontal and vertical shading sizes of 4 m × 2.5 m, square glass openings, and 8 mm heat-absorbing glass. This led to a PMV value of 0.40, a PPD of 8%, and an effective temperature value of 26.8°C. The modification resulted in a percentage gain of 20.08%, at 10-60% occupancy load with a cooling load reduction rate of 1,912,071 kW and a thermal comfort index within the comfortable range.

R744 heat pump driven liquid desiccant air conditioning system for hot and humid climates

Heat pump-driven liquid desiccant air conditioning systems are energy-efficient for hot and humid climates. The synthetic refrigerants (high GWP) currently used in heat pumps must be phased down/out sooner or later to mitigate the rising environmental problems. Being a natural and eco-friendly refrigerant, R744 (carbon dioxide) is a promising alternative for heat pumps. R744 heat pump-driven liquid desiccant air conditioning system (hybrid system) is not only a clean system but also yields better performance in hot and humid climates. However, its potential for air conditioning systems has yet to be thoroughly investigated. The present study compares the performance and emissions of an R744 hybrid system (HS) with a conventional R134a system (CS) for two cases: 100 % fresh air (HS-1 vs CS-1) and 30 % fresh air recirculation (HS-2 vs CS-2) in hot and humid conditions like those in Chennai. For the 100 % fresh air case, the hybrid system (HS-1) reduces energy consumption at peak ambient conditions by 36% and annual operating costs by 22% compared to the conventional system (CS-1), making it highly competitive in extreme climates. For the recirculation case while energy use is 16 % lower for HS-2 compared to CS-2 during peak summer, there is no annual cost difference. However, HS-2 remains cleaner and more eco-friendly due to negligible direct emissions.

Benefits of Irrigation or Fertigation on Early Growth and Yield of a High-density Apple Planting in a Humid Climate

The success of a new high-density apple planting depends on how fast the grower can recoup the high investment that these systems require. The right balance between vegetative growth and cropping during the early life of the planting is where tree growth is sufficient to rapidly fill the allotted space while at the same time producing high early yields. In this study we evaluated irrigation or fertigation as strategies compared with the traditional nonirrigated control to improve growth and yield of five apple scion cultivars (Mutsu, Gala, Honeycrisp, Jonagold, and Macoun) on M.9 or B.9 rootstocks over the first 5 years at Geneva, NY. Calcium nitrate at the rate of 113 kg·ha−1 N was applied to all three irrigation treatments (dissolved in water for the fertigation treatment, broadcast dry with the irrigation treatment, or broadcast dry with the nonirrigated control). Our results showed that fertigation with dissolved N and irrigation with dry broadcast N increased yield and tree growth similarly and significantly over the first 5 years of orchard establishment compared with the nonirrigated treatment with dry broadcast N. There was a significant economic benefit of irrigation or fertigation in the humid climate of New York State.

Optimizing active chilled beam systems in the South Korean Climate: Comparative analysis of cooling energy and thermal comfort by set-point temperature

In this study, the feasibility of implementing the active chilled beam system (ACBS) in South Korea has been analyzed, and an appropriate control strategy has been proposed. While ACBS is increasingly adopted in North America and Europe, its spread in South Korea has been slow due to different climatic characteristics and a lack of diverse understanding and analysis. Furthermore, research discussing the effects of key system parameters on ACBS is notably scarce. Therefore, this study aims to assess the impact of air handling unit discharge air temperature (AHU DAT) and ACBS entering chilled water temperature (ACBS ECWT) on ACBS and propose a control strategy suitable for the South Korean climate. The applicability of ACBS, compared with existing HVAC systems using this control strategy, has been evaluated. The study incorporates two methodologies: firstly, the impact of control variables has been assessed, and a suitable control strategy has been proposed through a sensitivity analysis of these variables. Secondly, the feasibility of applying ACBS, in comparison with conventional HVAC systems, has been evaluated from the perspectives of energy and thermal comfort. It has been found that system parameters, tailored for the South Korean climate, can maintain a level of thermal comfort like existing HVAC systems while achieving up to 18% in energy savings. Overall, this research not only demonstrates the potential applicability of ACBS in hot and humid climates like South Korea but also emphasizes the need for controlling key system parameters

Energy-saving and carbon reduction analysis of series/parallel combination for heat pump and chiller in a hotel building

Taiwan is known for its hot and humid climate, where buildings rely on air conditioning systems to provide comfortable conditions. Specifically in commercial buildings such as hotels, apart from being required to provide comfortable indoor conditions, they need to provide hot water 24 h for guests, leading to the common application of chiller and heat pump systems in hotels. With the rise of the Taiwanese tourism industry, many hotels have been newly built or renovated. However, during the planning and construction stages, considerations may be limited by personnel experience, operational difficulties, installation costs, or the desire to simplify operations. This often results in the separate consideration of heat pump systems and chiller systems, leading to unnecessary resource and energy waste. Therefore, this study takes place at a hotel building in Taichung located in Central Taiwan. Designing a series/parallel system between the heat pump and chiller systems. Through a control system and a real-time recording system, controllable factors were analyzed, such as system equipment supply/return water temperature, outdoor relative and enthalpy, and occupancy rate change. Additionally, energy-saving potential was evaluated from the collected data through linear regression. The results show that when the outdoor air temperature, outdoor enthalpy, and occupancy rate are low, the parallel system is more energy-efficient due to the higher energy consumption of the chiller under low load conditions, which is suitable for winter. Conversely, the series system is more energy-efficient than under hot weather and high indoor load conditions, making it suitable for use in the summer.

Manganese Cycling Driven by Fluctuating Redox Chemocline in the Ediacaran Ocean

AbstractThe Ediacaran Period, immediately following the Neoproterozoic Cryogenian glaciations, marked a crucial phase in the Earth's evolutionary history. The paleo‐oceanic environment helped shape the habitability, yet the links between oceanic redox state, hydrochemistry, biological activity, and elemental cycling during this time remain poorly understood. Here, we address this scientific issue based on high‐resolution geochemical data from black shale‐hosted, manganese (Mn)‐rich carbonates within the upper Ediacaran Doushantuo Formation, located on the northern margin of the Yangtze Block, South China. Multiple redox proxies indicate that while the open ocean may have been intermittently oxygenated during the late Ediacaran glaciation, the continental margin slope was characterized by redox stratified conditions with a fluctuating redox interface. These fluctuations were driven by climatic shifts. During the deposition of black shales, a relatively warm and humid climate caused a notable increase in freshwater runoff and glacial meltwater, raising water levels and lowering salinity. The influx of bioessential elements carried by terrestrial runoff promoted primary productivity. By contrast, the deposition of the Mn(II) carbonates occurred under colder, more arid conditions, with limited terrigenous nutrient input, leading to lower organic carbon production. This resulted in the deepening of the redox chemocline over the continental shelf, promoting Mn(II) oxidation and subsequent mineralization. Paleoclimate‐driven redox fluctuations were key in controlling elemental cycling during the late Ediacaran. This may offer insights into similar processes throughout Earth's history.

Thermal Comfort–Based Differential Pricing for High-Rise Apartments in Hot and Humid Climates: A Multicriteria Decision-Making Approach

Thermal Comfort–Based Differential Pricing for High-Rise Apartments in Hot and Humid Climates: A Multicriteria Decision-Making Approach

Sedimentary provenance and paleogeographic environment of a Mississippian coal-bearing unit in South China: Constraints from detrital zircon U-Pb ages and sedimentologic and geochemical evidence

The Mississippian Xiangbai Formation in South China is one of the oldest coal-bearing sedimentary units in China. However, the sedimentary provenance, paleogeography, and coal formation patterns of the coal-bearing strata are not well constrained. We address this key issue by using a combination of detrital zircon U-Pb data, geochemical analyses of mudstone and shale, drilling data, and geologic field observations. With the exception of the early Paleozoic orogenic events (ca. 440–420 Ma) in the eastern part of the study area, the samples from the Xiangbai Formation exhibit similar detrital zircon U-Pb age distribution with major age peaks at ca. 980–960 Ma and several subordinate age peaks at ca. 800–780 and 600–500 Ma. These detrital zircon grains mainly originated from recycled sedimentary units. Field and drilling data reveal that the Xiangbai Formation was formed in a tidal flat environment with water depth gradually increasing from the bottom to the top, indicating an overall trend of transgression. The Mississippian Xiangbai Formation was deposited in an interglacial period. The Lower Xiangbai Formation was deposited in a relatively cold paleoclimate, gradually transitioning upwards to a warm and humid climate, creating favorable conditions for coal formation. The alternation of warming and cooling climates triggered high-frequency eustatic fluctuations, which led to multiple sedimentary cycles and resulted in thin, unstable coal seams within the Xiangbai Formation. Mississippian sedimentary paleogeography, palaeoclimate, and sedimentary provenance together dominate the coal-bearing clastic sediments in southwestern South China.

Urban green spaces enhanced human thermal comfort through dual pathways of cooling and humidifying

The severe heat stress caused by climate change and urbanization has become an urgent issue for sustainable development, and urban green spaces can effectively mitigate heat stress. However, traditional heat stress assessments based solely on temperature do not fully capture human thermal perception, which also hinders the understanding of the multiple pathways through which green spaces regulate thermal comfort, potentially underestimating their ecological benefits. This study used the universal thermal climate index (UTCI) to assess heat stress in Shanxi. Structural equation modeling was to quantify the contribution of green spaces in regulating UTCI through dual pathways of cooling and humidifying. In the summer of 2019, the average UTCI was 30.87°C, indicating moderate thermal stress, with 27.90% of the area experiencing strong thermal stress. Green spaces reduced UTCI by cooling and humidifying, with respective contributions of 78.02% and 21.98%. In more humid Cold climate zones, the green space humidifying pathway accounted for as much as 63.75%, underscoring the significant role of humidification in reducing UTCI. By quantifying the contribution of the dual pathways through which green spaces regulate UTCI and comprehensively understanding their mechanisms, this study highlighted the importance of vegetation configuration of green spaces in enhancing urban climate resilience.

Automatic Detection of Skin Diseases Using Convolutional Neural Network Algorithms

Skin diseases are a major health concern in Indone sia and they can seriously impact a patient’s quality of life. The problem is aggravated by humid tropical climate, limited access to healthcare facilities, and a lack of trained dermatology personnel. The cases in Indonesia are many, and the diagnosis and treatment of skin diseases are delayed, which makes the patient's condition worse. Based on data from the Ministry of Health (Kemenkes), the prevalence of skin disease in Indonesia is 0.62 cases per 10,000 population with the highest prevalence in Eastern Indonesia. Developing a Skin Disease Detection System Based on Convolutional Neural Network (CNN) algorithms. However, CNN algorithms are widely used in image recognition and classification, and can act as an automatic diagnostic system. This system has been developed to aid in diagnosis and improve patient access to dermatological care, especially for remote communities. Users can reach out for services at any time and any location, a practical solution for treating skin health problems. This study's results are anticipated to lower the diagnostic delays and improve the treatment outcomes while offering quick access to reliable dermatological service. This is a great effort on global level for any skin disease supporting to improve life of human lives from skin health issues.

Observed determinants of urban outdoor thermal exposure during hot summer and snowy winter periods in a humid continental climate

Many cities in the midlatitudes experience both extreme heat and cold, and pedestrians are exposed to thermal extremes that cause bodily stress. With growing urban populations, city design that contributes to mitigating summer heat while reducing winter cold exposure is increasingly important. Pedestrian thermal exposure depends on several microclimatic factors, including shortwave and longwave radiation absorption, which can be quantified by the mean radiant temperature (Tmrt). Limited research has been conducted on the radiative components of thermal exposure in hot, humid summers and cold, snowy winters. We gathered micrometeorological data from diverse urban sites and in multiple seasons in Guelph, Canada, using a mobile human-biometeorological weather station (MaRTy cart) that applies the six-directional method to determine Tmrt. Seasonal datasets were analysed and compared to examine the drivers of thermal exposure and recommend strategies for mitigating heat and cold stress. In summer, shade is the primary factor that reduces daytime heat exposure and it slightly increases nighttime heat exposure. Enhanced pervious ground cover is a secondary factor day and night. In winter, reduced shade alleviated daytime cold exposure, while snow cover provided daytime benefits from increased solar reflections and post-sunset penalties associated with reduced longwave radiation from low snow surface temperatures.

Enhancing Paddy Rice Drying Quality with Non-Destructive LPG Refrigeration System in a Fixed-Bed Dryer

High relative air humidity in humid climates slows the process of paddy drying and leads to rehydration. The use of a liquefied petroleum gas (LPG) refrigeration system for dehumidifying ambient air effectively reduces drying time and improves product quality in a non-destructive manner. This environmentally friendly method enhances both the quality of the rice samples and the efficiency of the drying process. This study examined the impact of dehumidification on Hashemi rice quality and moisture reduction, using the Response Surface Method to optimize drying conditions at three levels of temperature (40, 45, and 50 °C), air velocity (1.7, 2.2, and 2.7 m/s), and relative humidity (70, 80, and 90%). The results showed that dehumidification led to a moisture content of 6% and the lowest cracking rate of 2%. Temperature was the most influential factor, affecting responses by 73.09% under dehumidified conditions. Optimal conditions of 40 °C, 80% RH, and 1.7 m/s air velocity resulted in a cracking rate of 2% and a desirability index of 0.958. The Response Surface Method showed an excellent fit for the cracking index (R² = 0.98). These results highlight the LPG refrigeration system as an effective, non-destructive, and environmentally friendly method for drying paddy in humid regions, making it suitable for industrial applications.

Observations on palynology of the Tukau Formation in northwest Sarawak, Malaysia

This palynological study analysed 15 samples of the Tukau Formation, comprising intensely bioturbated sandy mudstone and organic-rich mudstones. Diverse vegetation types, including hinterland, mangroves, back mangroves, and montane regions, characterise the landscape of the region during the Tukau sediment deposition. Certain palynomorph types, such as Rhizophora type, Laevigatosporites sp., Elaeocarpus type, Euphorbiaceae, and Verrucatosporites usmensis (Stenochlaena), dominated the pollen assemblage, which represents the ancient landscape at that time. The influx of non-mangrove palynomorphs from the hinterland, likely transported by water, underscores the role of fluvial processes in controlling pollen distribution. Notably, the presence of age-specific marker pollen, such as Florschuetzia levipoli, Florschuetzia meridionalis, and Florschuetzia trilobata, confirms the age of the formation as Middle Miocene or younger. The presence of Acrostichum aureum pollen suggests a warm and humid tropical climate. Recognition of mangrove pollen from both front and back mangrove vegetation suggests deposition in the seaward region of the coast with significant tidal influences.

Classrooms and comfort temperature in South East Nigeria

A field study was conducted in naturally ventilated public-school buildings located in the warm and humid climate of Imo State in Nigeria, to determine the comfort temperature of the schoolchildren. The survey took place from October 2017 to May 2018, covering rainy season and dry season, where objective and subjective approaches to data collection were employed. Results of the fieldwork of the 330 surveyed children (aged 7-12 years) revealed that the maximum comfort temperature derived from their responses corresponding to mean thermal sensations of +0.85, is 31.6oC for the combined classrooms. This is about 4.9oC higher than the ASHRAE upper 80% acceptability limit. Furthermore, when categorized according to season and time of day, the comfort temperature were also found to be higher than the ASHRAE upper limit. The study shows that respondents in a tropical country, such as in Nigeria, can be comfortable at high temperatures. The information on comfort temperature is important as that may guide professionals in the building industry to achieve eco-friendly and sustainable classrooms that use less energy and at the same time provide thermal comfort to the occupants.

Palynology of Late Oligocene to Pliocene succession in Temana Field of Balingian Province, offshore Sarawak

Palynological records in Late Cenozoic succession from two Temana wells were reviewed and investigated for palynomorph assemblages, biostratigraphic correlation and age dating, as well as for paleoenvironment and paleoclimate interpretation. The data indicates abundant and diverse pollen and spores deposited in marginal marine with tidal influence setting. Three main palynomorph assemblages were identified from the Temana wells: (1) Zone-1 (dated as Late Oligocene), characterized by abundant Florschuetzia trilobata and dominant montane and seasonal elements such as Picea, Tsuga and Pinus, (2) Zone-2 (Early to Middle Miocene), dominated by Kerapah Casuarina-type pollen and characterized by increasing abundance of Rhizophoraceae mangrove pollen. Zone-2 can be further differentiated into Subzone-2a and Subzone-2b based on later appearance of Florschuetzia levipoli, and (3) Zone-3 (Late Miocene to Pliocene) occurring above a major angular unconformity is marked by a high percentage of the rainforest pollen Rubiaceae and a minor increase in seasonal elements. The interpreted paleoclimate inferred from temporal variations in hinterland-derived pollen shows cyclical pattern from seasonally dry climate in the Oligocene to warm and ever-wet climate, marked by the growth of Kerapah peat swamp during Early to Middle Miocene, and finally a prolong humid climate characterized by rainforest vegetation with minor intermittent seasonality since Late Miocene/Pliocene.

Global Terrestrial Water–Energy Coupling Across Scales

ABSTRACTTerrestrial water–energy coupling (WEC), in the form of a non‐linear relationship between Soil Moisture (SM) and evaporative fraction (EF, ratio of actual and potential evapotranspiration), controls critical ecohydrological processes. We investigate and parameterize the evolution of global SM–EF coupling from the field to remote‐sensing (RS)‐pixel. The field‐scale EF and SM were obtained from eddy covariance (EC) and SM sensors at the global FLUXNET and Texas Water Observatory sites. RS‐pixel‐scale EF and SM estimates were obtained from Moderate‐resolution Imaging Spectroradiometer (MODIS) and Soil Moisture Active Passive (SMAP) sensors, respectively. We estimate the effective thresholds of the WEC regimes from both EC and satellite datasets to highlight the influence of sub‐pixel‐scale heterogeneity, and, scaling and observational constraints on the evolution of WEC regimes from the field to RS‐pixel scale. We argue that the changes in land surface conditions add a temporal variability in the critical thresholds of terrestrial WEC at RS pixel scale. We compare the critical WEC thresholds of the water‐ and energy‐limited regimes with a SM drydown‐based approach and highlight the similarities between both methods in partitioning dominant WEC regimes. EF and SM are strongly coupled in dryland arid and semi‐arid regions compared to humid climates. WEC regimes and thresholds have strong interseason variability due to dynamic interactions between soil, vegetation and atmosphere at the RS‐pixel scale. In contrast, field‐scale SM‐EF coupling is influenced predominantly by soil conditions and land‐use/management practices. Hence, future development of Earth‐system/Land‐surface models must account for the inter‐scale differences in the coupling between terrestrial water and energy fluxes representative of the ‘effective’ processes at large spatial scales.