Tropical Climate Variability

A three-moment modal parameterization scheme was developed for describing variations in the shape of cloud ice crystals during growth by vapor deposition. The shape of ice crystals is represented using the volume-weighted aspect ratio, while the size spectrum of the crystal population is described using a threeparameter gamma function. Verified with binned spectral calculations, the proposed modal scheme performed quite accurately in the evolution of the mass and shape of cloud ice crystals growing under idealized conditions. The associated error is within 1% in mass after 1000 s of growth under water saturation. When the ventilation effect is taken into account, the error remains within 5%. Error with regard to the bulk aspect ratio is generally about 3%. A failure to take into account the ice crystal shape led to a 45% underestimation in mass growth. Using only two moments to describe the gamma distribution led to a 37% underestimation in mass and 28% underestimation in the bulk aspect ratio of the ice crystals. The proposed scheme is able to capture the shape memory effect and the gradual adaptation of ice crystal aspect ratios to a new growth habit regime.

The Standardized Precipitation Index (SPI) is widely used to determine drought severity worldwide. However, inconsistencies exist regarding its application in warm, humid tropical climatic zones. Originally developed for temperate regions with a continental climate, the index may not adequately reflect drought conditions in tropical environments where rainfall regimes differ substantially. This study identifies the following two principal reasons why the traditional calculation method fails to characterize drought severity in tropical domains: first, the marked humidity contrast between the consistently humid rainy season and the rest of the year, and second, the diverse drought types in tropical regions, which include both long-term and short-term events. Using data from meteorological stations in Mexico’s humid tropics and comparing them with temperate regions, the study demonstrates significant discrepancies between SPI-based drought classifications and actual precipitation patterns. Our analysis shows that the abundant precipitation during the rainy season causes biases in longer time scales integrated into multivariate drought indices. Considerations are established for adapting the SPI for decision makers who monitor drought in humid tropics, with specific recommendations on time scale limits to avoid biases. This work contributes to more accurate drought monitoring in tropical regions by addressing the unique climatic characteristics of these environments.

In Colombia coffee production is facing risks due to an increase in the variability and amount of rainfall, which may alter hydrological cycles and negatively influence yield quality and quantity. Shade trees in coffee plantations, however, are known to produce ecological benefits, such as intercepting rainfall and lowering its velocity, resulting in a reduced net-rainfall and higher water infiltration. In this case study, we measured throughfall and soil hydrological properties in four land use systems in Cauca, Colombia, that differed in stand structural parameters: shaded coffee, unshaded coffee, secondary forest and pasture. We found that throughfall was rather influenced by stand structural characteristics than by rainfall intensity. Lower throughfall was recorded in the shaded coffee compared to the other systems when rain gauges were placed at a distance of 1.0 m to the shade tree. The variability of throughfall was high in the shaded coffee, which was due to different canopy characteristics and irregular arrangements of shade tree species. Shaded coffee and secondary forest resembled each other in soil structural parameters, with an increase in saturated hydraulic conductivity and microporosity, whereas bulk density and macroporosity decreased, compared to the unshaded coffee and pasture. In this context tree-covered systems indicate a stronger resilience towards changing rainfall patterns, especially in mountainous areas where coffee is cultivated.

Periphyton is a community of algae, fungi, microbes and associated plants and animals that grow in shallow water habitats. They are primary producers and an important foundation of many wetland food webs. These organisms stabilize substrata and serve as habitat for many other organisms. They are used as quantitative indicators of environmental quality in rivers and streams thus regarded as reliable monitoring tool of ecosystem integrity because attached algae form the autotrophic base of aquatic food webs. Benthic algae have short generation times and patchy microdistributions and so they respond rapidly to chemical and physical changes and can be used to detect impacts at localized spatial scales. Dense blooms of algae have long been associated with eutrophication through nutrient enrichment and organic sediment loading in lakes and rivers, so the abundance of algae has often been viewed as a sign of poor water quality and used as an indicator of impairment. Use of composite diatom community metrics for assessment of ecological conditions was first applied in classic pollution studies of rivers and has now been integrated into many programs of water quality testing, regulation and management. Because benthic algal assemblages are attached to substrate, their characteristics are affected by physical, chemical, and biological disturbances that occur in the stream reach during the time in which the assemblage developed. They are the major source of photosynthetic carbon fixation in shallow lakes and streams, which do not provide a favorable environment for plankton. These organisms traps nutrients from the water and transfer them to the sediment upon death, thus preventing nutrient loss from wetlands and streams into lakes. The periphyton species of Chilika lagoon indicated a wide diversity. During the period of investigation a total of 120 species belonging to cynophyaceae, chlorophyaceae, bacillariophyaceae, dinophyaceae, euglenophyaceae, xanthophyaceae and chrysophyaceae have been reported during 2010-2011. The numerical abundance fluctuates in ranged between 1541 nos/cm 2 and 2550 nos/cm 2 during 2010-2011.

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Complete removal of carbonates from calcareous soil samples is critical for accurate measurement of the quantity and isotopic signature (d 13 C) of soil organic carbon (SOC). Carbonates confound SOC and d 13 C measurements because they have d 13 C values ranging from (10 to '2, whereas those of soil organic carbon range from (27 to (13, depending on the source of plant residues. Commonly used methods for removing carbonates involve treatment with acid followed by repeated water washings; however, these methods are time consuming, labour-intensive and lead to losses of acid-and water-soluble organic carbon. Fumigation of soil samples with HCl was evaluated as an alternative method, and the time required for complete carbonate removal was determined in this study. Moistened soil samples, taken from 0-to 10-cm and 30-to 50-cm depths, were exposed to HCl vapours for periods of 0, 6, 12, 24, 48, 72, and 96 h, followed by measurements of total C and d 13 C using coupled elemental analyzer-isotope ratio mass spectrometry. The minimum time required to remove all carbonates was ca. 30 h and 56 h for surface and subsurface soils containing 0.80 and 1.94% inorganic C, respectively. Therefore, the fumigation period required is dependent on the total carbonate content of the sample and the nature of the carbonate (pedogenic vs lithogenic). In our study, the rate of removal of inorganic carbon was 0.08Á0.10 mg h (1 for soil samples sizes with 2.4 to 5.8 mg of carbonate-C, a rate similar to previous studies on acid fumigation. A ''correction factor'' was used to account for a change in sample mass due to fumigation and is necessary for accurate determination of SOC concentration using our proposed methodology.

Swale drainage is a broad and shallow drainage that is able to filter runoff before flowing to the main drain and river. This study is focused on the effectiveness of the swale drainage compared to concrete drainage, in terms of pollutant removal and its relationship with the infiltration rate. The chosen site is at Astaka field, in Selangor. The water quality of the outflow was tested to determine the water quality classes when compared to the Interim National Water Quality Standards (INWQS) for Malaysia. Chemical oxygen demand (COD), total suspended solid (TSS), ammonia nitrogen, pH and turbidity are the five parameters that were tested in the water quality test. The study of infiltration rate of swale outflow was done by using the Mini Disk Infiltrometer and was compared with that of the field without swale. Swale proved to be effective to remove about 40%-60% TSS, 10-70% COD and 30-80% ammonia nitrogen compared to the regular concrete drain. The water turbidity of the outlet is higher than that of the inlet for both types of drainage. Results show that swale has negligible effects towards the pH value. The pH value obtained shows signs of alkalinity of the water outflow. The water quality of the outflow at swale outlet achieved Class II according to the INWQS for Malaysia. Swale at Astaka field had a rate of infiltration of 1.8-2 cm/hour which indicates a smaller rate than the field without swale.

Reducing the role of the conventional cooling machines into the building to make the thermal comfort is so imperative as their massive energy consumption and their contribution to the global climate change. Shifting into less energy consumed cooling methods using the locally available vegetative sources as passive cooling, can be one of the appropriate methods. The aim of this study is to investigate the influence of trees to the thermal comfort performance in a building in Southeast Sulawesi, a region, geographically, located in the equator line with its high daily solar radiation intensity. It conducts an experiment on a small scale building with various tree configurations. The result shows that the trees provide the effect of lowering temperature and maintaining the relative humidity of air, contributing into making the thermal comfort-ability in the building. A comprehensive discussion, using the Psychometric chart, regarding to the reason for the phenomenon is also presented i...

Cloud seeding is a weather modification technique for enhancing precipitation in arid and semi-arid regions, including Western U.S. However, designing an optimal cloud seeding operation based on comprehensive evaluation metrics, such as seeding agent dispersion and atmospheric conditions, has yet to be thoroughly explored for this region. This study investigated the impacts of cloud seeding, particularly utilizing silver iodide, on ice particle growth within clouds through numerical modeling. By leveraging the Snow Growth Model for Rimed Snowfall (SGMR), the microphysical processes involved in cloud seeding across five distinct events were simulated. The events were in the Lake Tahoe region, nestled within the Sierra Nevada Mountain ranges in the western U.S. This model was executed based on six primary variables, including cloud top height, cloud base height, cloud top temperature, cloud base temperature, liquid water content, and ice water content. This study incorporated datasets from the Modern-Era Retrospective Analysis for Research and Applications Version 2 and the Clouds and the Earth Radiant Energy System. Findings revealed the importance of ice nucleation, aggregation, diffusion, and riming processes and highlighted the effectiveness of cloud seeding in enhancing ice particle number concentration, ice water content, and snowfall rates. However, event-specific analyses indicated diverse precipitation responses to cloud seeding based on initial atmospheric conditions. The SGMR modeling hints at the importance of improving ice microphysical processes and provides insights for future cloud seeding research using regional and global climate models.

The history of the Somali upwelling during the last 18.5 ka has been reconstructed using biogenic silica fluxes estimated from a sediment core retrieved from the western Arabian Sea. The reconstructed record demonstrates periodic weakening and strengthening of the Somali upwelling during the past 18.5 ka. Variations in biogenic silica fluxes suggest weak upwelling during the last glacial period (18.5-15 ka BP). Strengthened upwelling during the Bølling-Allerød period (15-10 13 ka BP) points to post-glacial onset of the southwest monsoon. The Younger Dryas (13-11 ka BP) is again marked by reduced upwelling strength. Intensification of the Somali upwelling at the beginning of the Holocene and a decline at 8 ka BP are observed. Increases in upwelling strength recorded since 8 ka BP suggest strengthening of the southwest monsoon during the latter part of the Holocene. Linking these upwelling variations with southwest monsoon precipitation, a major shift in the relationship between the strength of the Somali upwelling and southwest monsoon rainfall from positive to negative has 15 occurred during the pre-Holocene to the Holocene. The observed shift is attributed to the variation in the southwest monsoon strength due to the latitudinal shift of the Intertropical Convergence Zone (ITCZ) associated with changes in moisture sources. 1 Introduction The greater part of the world's population inhabits the tropical region, where climate is mainly controlled by monsoon rainfall. Understanding the causes of past changes thus plays a critical role in deciphering past, present and future monsoon variability. 20 The economy of India, which is a tropical country that contains a significant part of the world's population, is dependent to a large extent on the southwest monsoon (SWM) rainfall; hence, slight changes in SWM rainfall can lead to immense societal impacts. Several attempts have been made to identify the factors responsible for SWM rainfall variations. SWM rainfall variability is correlated with several global phenomena, such as ENSO (

Resumen:
Se determina el inicio y término de la estación lluviosa (IELL y TELL respectivamente), además
de la duración de la estación seca y lluviosa (DES y DELL respectivamente), con datos de
precipitación en rejilla sobre Guanacaste para el periodo 1950-2020 conformado por el
acople de dos conjuntos de datos, el primero es el conjunto Climate Hazards group Infrared
Precipitation with Stations (CHIRPS) y el segundo siendo el reanálisis ERA5 al que se le aplicó
un ajuste de escala para extender la cobertura temporal de los datos de CHIRPS. Se caracterizó
su IELL, TELL, DELL y DES con estadísticos como la mediana, desviación estándar, rango
inter cuartil y tendencias. Además, se relacionaron con fuentes de variabilidad climática como
El Niño-Oscilación del Sur (ENOS), la temperatura superficial del océano Atlántico Tropical
Norte (ATN) y la corriente en chorro de bajo nivel del Caribe (CLLJ, por sus siglas en inglés).
Los datos representan adecuadamente la climatología del IELL, TELL, DELL, DES y las
precipitaciones de la región, además de capturar la variabilidad asociada a la CLLJ y al acople
de los océanos (ATN-ENOS), pero no la asociada al ATN y ENOS individualmente. Aunque no
se pudo determinar si esto se debe a los datos de ERA5 o al método de reducción de escala
usado, por lo que se recomienda verificar si ERA5 captura tal variabilidad oceánica al realizar
el mismo análisis en un periodo de tiempo de 1980-2020 donde se tiene mayor disponibilidad
de observaciones como estaciones meteorológicas o CHIRPS que ya ha sido validada.

Abstract:
The onset and demise of the rainy season (IELL and TELL, respectively in Spanish), also the
duration of the dry and rainy seasons (DES and DELL, respectively in Spanish) are determined,
with gridded precipitation data on Guanacaste for the period 1950-2020 constructed by
coupling two data sets: 1) the dataset Climate Hazards group Infrared Precipitation with
Stations (CHIRPS), and 2) the ERA5 reanalysis to which a downscaling method was applied
to extend the data beyond the period covered by CHIRPS. Their IELL, TELL, DELL, and DES
were characterized with statistics such as the median, standard deviation, interquartile range,
and trends. In addition, were related to sources of climate variability such as El Niño Southern-
Oscillation (ENSO), the sea surface temperature of the tropical north Atlantic (TNA) and the
Caribbean Low-Level Jet (CLLJ). The dataset adequately represents the IELL, TELL, DELL, DES
and the precipitations of the region, in addition to capturing the variability associated with the
CLLJ and the coupling of the oceans (TNA-ENSO), but not that associated with the TNA and
ENSO individually. Although it could not be determined if this is due to the ERA5 dataset or
the downscaling method used, so it is recommended to verify if ERA5 captures such oceanic
variability when performing the same analysis in a period of time from 1980-2020 where there is
greater availability of observations such as meteorological gauge stations or CHIRPS that has
already been validated.

The sunflower genotypes viz., KBSH-1, TCSH-1, PKVSH-27, APSH-11 and DSH-1, their parental lines and the varieties, Morden, Surya, AKSF-9, CO-2, CO-3, CO-4, GAUSF-15, NDSH-15 and SS-56 were grouped on the basis of chemical tests (NaOH (2 &5%), KOH (2 &5%), GA 3 (25,50 &100 ppm), 2,4-D (5,10 & 15 ppm) and Metribuzin (0.03 ppm)) sensitivity test. The study revealed that these tests could be effectively used for varietal characterization and determining the varietal purity of sunflower in seed testing laboratories as the cultivars showed distinct response to these chemical tests.

Introducción: El Pacífico Norte de Costa Rica se caracteriza por presentar una variación de la temperatura subsuperficial del mar (TSSM) modulada por vientos superficiales de componente este, con variaciones estacionales e intra-estacional. La TSSM es fundamental para las interacciones de la interfase océano-atmósfera y de gran influencia en los procesos biológicos marinos. Los estudios de zooplancton en el Pacífico Norte son escasos y se han enfocado en la composición, abundancia y biomasa de macro y mesozooplanctonen en Bahía Culebra. No se han realizado trabajos sobre zooplancton al norte del Golfo de Papagayo. Objetivo: Analizar la variación del zooplancton de Bahía Salinas a diferentes escalas como respuesta a condiciones oceanográficas-atmosféricas. Métodos: durante algunos meses de los años 2011, 2012 y 2013, el mesozooplancton fue muestreado en siete estaciones siguiendo un gradiente costero-oceánico para determinar su abundancia, biomasa y composición de la comunidad. Se re...

Climate variability has a strong influence on disease prevalence and subsequently on economic wellbeing of the affected households. In this study, six regions were selected and clustered into three groups based on their climatic conditions as follows: areas prone to droughts, floods and those with relatively good weather. Respondents were interviewed and the effects of prevailing climatic conditions on the prevalence of diseases established. Malaria, respiratory tract infection, typhoid, pneumonia and diarrhoea were the major diseases among the Lake Victoria basin residents. The annual disease frequency per household was highest in Budalang'i, a flood prone region; and lowest in Bomet, a region with relatively good weather. The findings reveal the often unseen subtle effects of adverse climatic conditions on economically vulnerable communities in the Lake Victoria basin (LVB) and elsewhere, and recommends flood/drought prevention and mitigation strategies and awareness creation to better cope with the adverse climatic events.

Interception losses in stands of non-native trees in Hawaiian forests and their potential negative impacts on fresh water availability are poorly understood. In this study, a canopy water balance analysis was conducted to estimate interception losses using measurements of rainfall (RF), throughfall (TF), and stemflow (SF) at three locations, each dominated by one or more of the following non-native tree species: Psidium cattleianum Sabine (Strawberry guava), Schinus terebinthifolius Raddi (Christmas berry), Syzygium cumini (L.) Skeels (Java plum), and Coffea arabica L. (Coffee). Mean TF expressed as percentage of total RF was the lowest (43.3%) under a monotypic stand of P. cattleianum and the highest (56.5%) under mixture of S. terebinthifolius, P. cattleianum, and S. cumini. Observed SF was highest (33.9%) under P. cattleianum and lowest (3.6%) under a mixture of S. terebinthifolius, P. cattleianum, and S. cumini. The relatively high SF under P. cattleianum can be attributed to its smooth bark, stem density, and steep branching. The mean observed canopy interception varied between 23% under P. cattleianum and 45% at the site dominated by C. arabica. Mean direct TF coefficients from individual events at each location ranged from a low of 0.36 under the canopy dominated by C. arabica to a high of 0.51 under the canopy dominated by S. terebinthifolius, P. cattleianum, and S. cumini. In contrast, the mean SF partitioning coefficients from individual storm events at each location ranged from a low of 0.05 under the canopy dominated by S. terebinthifolius, P. cattleianum, and S. cumini to a high of 0.37 under P. cattleianum. Mean canopy storage capacity was highest (1.90) at the site dominated by S. terebinthifolius, P. cattleianum, and S. cumini whereas trunk storage capacity was highest (0.54) under the P. cattleianum.

We analyzed the documentation of leaf litter associated diatoms in streams of Palani hills, southern Western Ghats, India. A total of 2488 individual of diatoms were collected under five genera, three families and four orders in five streams of Palani hills, Southern Western Ghats, India. Of five genera observed, Tabellaria was occupied the highest percentage (86.4%). Diversity indices showed that the mid elevational stream of Moolayar had the highest diversity value. The correlation coefficient analysis revealed that pH and elevation were positively correlated with abundance of diatoms. The overall study indicate that leaf litter associated diatoms are related with anthropogenic impact. This study will envisage the water quality assessment by using leaf litter associated diatoms.

It is important and challenging to provide suitable thermal comfort conditions in hospital building due to widely varying conditions requirements by different types of occupants. The precise control of temperature and humidity is vital in hot-humid hospitals as these affect diseases, infections and allergies etc. indirectly. A field study comprising of thermal environment evaluation and thermal comfort survey, has been conducted in one Malaysian hospital in-patient wards with 315 respondents. Thermal comfort requirements of patients, visitors and nurses have been investigated. The patient rooms as well as nurse workstations were found bit overcooled by patients, visitors and nurses. Thermal preference of no change by patients and visitors whereas lower temperature was observed by nursing staff in wards. A bit humid air was preferred by all respondents as mean humidity sensation vote was bit drier for all of them. The air movement was acceptable for all respondents in wards as mean p...

Ice fragments are generated by sublimation of ice particles in subsaturated conditions in natural clouds. Conceivably, such sublimational breakup would be expected to cause ice multiplication in natural clouds. Any fragment that survives will grow to become ice precipitation that may sublimate and fragment further. As a first step toward assessing this overlooked process, a formulation is proposed for the number of ice fragments from sublimation of ice particles for an atmospheric model. This is done by amalgamating laboratory observations from previously published studies. The concept of a “sublimated mass activity spectrum” for the breakup is applied to the dataset. The number of ice fragments is determined by the relative humidity over ice and the initial size of the parent ice particles. The new formulation applies to dendritic crystals and heavily rimed particles only. Finally, a thought experiment is performed for an idealized scenario of subsaturation with in-cloud descent. S...

Land degradation affecting the livelihoods of people living in dryland areas, particularly the Sub-Saharan Africa countries like Ethiopia. Degraded land rehabilitation in dryland is a challenging task due to moisture limitation. This study was conducted to evaluate the effects of soil and water conservation structures on growth of planted tree and rehabilitation of indigenous plant species in West Guji Zone, Dugda Dawa District. Four multipurpose tree species (MPTs) namely Faidherbia albida, Melia azedarach, Moringa stenopetala, and Sesbania sesban were planted in four soil and moisture conservation structures (soil level bund, half-moon, trench and normal pit). Data of survival rate, height and diameter growth of planted tree species and, diversity and species richness of indigenous plant species were collected. The survival rate of all planted MPTs species were declining along the study years; however, the survival rate was better under soil level bund and half-moon. Under control treatments, all planted MPTs died at the end of the study period. The height and stem diameter of F. albida, M. azedarach and M. stenopetala were best in soil level bund and half-moon and followed by the trench. Whereas, the growth performance of Sesbania sesban was not significantly different among the three moisture conservation structures. Furthermore, soil moisture conservation structures significantly increased the indigenous plant species regeneration after the intervention. The mean indigenous plant species diversity and richness were significantly highest in half-moon and soil level bund followed by trench and, lowest in Control (normal pit). Thus, the results a potential for alternative forest and soil restoration in arid areas.

The modulation of the full-depth global integrated ocean heat content (GOHC) by El Niño–Southern Oscillation (ENSO) has been estimated in various studies. However, the quantitative results and the mechanisms at work remain uncertain. Here, a dynamically consistent ocean state estimate is utilized to study the large-scale integrated heat content variations during ENSO events for the global ocean. The full-depth GOHC exhibits a cooling tendency during the peak and decaying phases of El Niño, which is a result of the negative surface heat flux (SHF) anomaly in the tropics (30°S–30°N), partially offset by the positive SHF anomaly at higher latitudes. The tropical SHF anomaly acts as a lagged response to damp the convergence of oceanic heat transport, which redistributes heat from the extratropics and the subsurface layers (100–440 m) into the upper tropical oceans (0–100 m) during the onset and peak of El Niño. These results highlight the global nature of the oceanic heat redistribution...

Stemflow has a significant influence on hydrological and ecological processes within forests. However, research on stemflow is scant as stemflow comprises a very small volume compared to throughfall. In Japan, forest cover mainly distributed in mountainous areas occupies nearly 70% of the total land area and ranges from subalpine to subtropical zones. Many hydrological and agricultural studies have been conducted but a comprehensive literature review that summarizes the generation and chemical characteristics of stemflow is lacking. The purpose of this review is to interpret the results from Japanese forest stemflow papers and to propose objectives for future studies.

Al Ain, near Abu Dhabi, United Arab Emirates, is characterized by hot desert climate with high temperatures, aridity, and almost no rain. Several truncated earthen walls were discovered at the historic house of Sheikh Mohammed Bin Khalifa, a component of the World Heritage Cultural Sites. These remains are preserved in situ, outdoors, protected in glass showcases for public display. As this situation is not documented in the literature, the local Authority has requested to study the showcase environment to optimize conservation. The solar radiation and the projected shades have been modeled over one year; the temperature and humidity inside and outside the showcases, as well as the moisture content, have been measured to assess the potential preservation risks. The paper presents the results, i.e., the direct solar radiation generates extreme conditions of greenhouse effect with extremely high temperatures and forces evaporation from the remains. During the night, the excess moisture condenses on the inner surface of the glass panes, forming large drops that affect viewing and are dangerous for conservation. The repetition of evaporation–condensation cycles accumulates soluble salts on the remains. The paper discusses mitigation strategies (e.g., shading, ventilation, and cooling, to reduce the greenhouse effect) to improve conservation and fruition.

Fog water deposition is thought to influence the ecological function of many coastal ecosystems, including coast redwood forests. We examined cation and anion inputs from fog and rain, as well as the fate of these inputs, within a Sonoma County, California, coast redwood forest to elucidate the availability of these ions and some of the biotic and abiotic processes that may influence their relative abundance. At this site, the patterns of water and chemical inputs via fog and rain and their movement through the soil-plant ecosystem differed between the summer fog and winter rain seasons. Most (98 percent) of the annual water and more than three quarters of the total ionic load was delivered to the forest during the rain season. Soil water patterns followed those of throughfall. Water for plant use was most available in the rain season; however, after large fog events (fog season) plant-available soil water was also present at the forest edge. Differences between soil water and throughfall chemistry were a function of the mobility of each ion, whether or not an ion was a soil weathering product, and the likely biological demand for the ion. The impact of redwoods as fog catchers, transformers, and redistributors of both water and nutrients may extend all the way into the soil profile: in our plots, organic-rich soil horizons were thicker at the forest edge than in the forest interior. Our data show that, although total fog water inputs were small compared to inputs from rain, fog carried a large proportion of the total aqueous ionic inputs-inputs that, presumably, continued to be biologically available until their loss during the rain season. Cross-seasonal, functional coupling of aboveground (canopy) and belowground (soil) processes are likely to be prevalent in this redwood and other foginundated forests.

Developing a comprehensive understanding of what controls the mean state of the coupled ocean-atmosphere system in the Pacific, from the mean thermocline depth in the tropics, to the east-west SST gradient, to the position of ITCZ, is critical for understanding tropical climate and change (including El Nino). This problem is often treated as a local problem within the tropical band. However, inter-hemispheric asymmetries in extra-tropical atmospheric heating are communicated to the tropics affecting cross-equatorial heat transport and ITCZ position. Moreover, the strength of the cold tongue is ultimately controlled by the temperature of waters subducted in the extra-tropics and transported to the equator by the ocean subtropical cells (STC). Consequently, one needs to treat this problem in a broader geographical context and consider ocean-atmosphere coupling that goes beyond the tropics. Acknowledging from a fully coupled perspective the influence of both tropical and extra-tropical conditions, we are performing a suite of CESM experiments wherein: 1) we globally correct downward shortwave fluxes towards a CERES-EBAF climatology to investigate effects on climatological SSTs within the tropics, 2) in perturbed CO2 simulations, we alter the strength of convective and stratus cloud feedbacks respectively. By systematically exploring the sensitivity of the tropical coupled system to imposed changes in the strength of tropical and extra-tropical cloud feedbacks to CO2-induced warming this work aims to formalize our understanding of the controls exerted by cloud feedbacks on tropical climate.

The global, regional and local hydrological cycle is strongly linked to vegetation distribution. The hydrological cycle is composed by precipitation, infiltration, runoff, transpiration and evaporation. Evaporation is influenced by high temperatures, high winds and low relative humidity. This work is focused on the study of evapotranspiration (ET) as the main variable of water loss in the water balance in the central mountain region of Veracruz, Mexico. ET was estimated using the Penman-Monteith model, which requires environmental (net radiation, vapor pressure deficit, air temperature and wind intensity) and physiological (stomatal and canopy resistances and leaf area index) variables. These variables were measured in two sites within the region: La Joya and La Orduña, comparing different ecosystems: pine-oak, pine forests and grassland, and cloud forest and sugarcane crop, respectively. Results show that both, the estimated and real ET, are high; although, we found net surplus related to precipitation at both sites (533.8 and 526.5 mm) from September 2006 to August 2007. Apparently, no water deficits in either location were found; however, in the dry season water gain was very low, zero or negative. March and April were the months presenting the lowest water contribution to the system. The forests in the central mountain region of Veracruz can provide ecosystem services favoring evapotranspiration and regulating water balance, although the lack of information on the magnitude and value of this variable has hindered recognition and understanding of these forests.

Large variety of macro and micro algae in selected study area are described. In present investigation we reported 20 macro and micro algae belonging to six 6 classes of algae i.e. Chlorophyceae, Bacillariophyceae, Cyanophyceae, Charophyceae Xanthophyceae and Euglenoids. Chlorophyceae has 10 algae, Bacillariophyceae has 4, Cyanophyceae has 3, Charophyceae has 1, Xanthophyceae has 1, and Euglenoids has 1 in selected study area. The algae from class Chlorophyceae are Oedogonium, Chlorella, Volvox, Hydrodictyon (water net), spirogyra, Chlosterium, Ulthrox, Zygnema, Cosmarium and Chlymadonus species. The class Cyanophyceae reported Oscillatoria, Nostoc, and Anabaena species. And class Bacillariophyceae reported species pinnularia, Navicula, Frastulia and Didymonous. The class Charophyceae contains Chara, Xanthophyceae contain Vaucheria and Euglenoids contains Euglena. Existing of 20 algae's 15 algae's are dominant in the study area while 5 algae's are rare have been reported. There is an urgent need to evaluate this area for algal biodiversity.

In the present study, the PRECIS, a regional climate model, is employed to simulate the baseline (1970-2000) and future 2071-2100 (2080s) maximum, minimum and diurnal temperature range changes under SRES A1B scenario over the Kancheepuram district of Tamil Nadu, South India. A comparison of the simulated baseline results with observation data acquired from IMD show that PRECIS can well simulate the local distribution characteristics of diurnal temperature range over the study area with a correlation coefficient (R2) value of 0.948 with 1% significance level. Analyses of the simulated results in the 2080s under SRES A1B scenario relative to the baseline shows that there would be an overall increasing trend in the maximum and minimum temperatures over the study area and the warming amplitude in the north, west and interior parts are projected to be greater than in the east coastal areas. Sen's slope estimator supported by the Man Kendal test shows that the diurnal temperature range in the 2080s under SRES A1B scenario relative to the baseline are projected to decrease annually by-0.015°C and a statistically significant decrease of-0.029°C during the southwest monsoon season in the overall study area.

While CMIP5 models robustly project drying of the subtropics and more precipitation in the tropics and subpolar latitudes by the end of the century, the magnitude of these changes in precipitation varies widely across models: for example, some models simulate no drying in the eastern Mediterranean while others simulate more than a 50% reduction in precipitation relative to the model-simulated present-day value. Furthermore, the factors leading to changes in local subtropical precipitation remain unclear. The importance of zonal-mean changes in atmospheric structure for local precipitation changes is explored in 42 CMIP5 models. It is found that up to half of the local intermodel spread over the Mediterranean, northern Mexico, East Asia, southern Africa, southern Australia, and southern South America is related to the intermodel spread in large-scale processes such as the magnitude of globally averaged surface temperature increases, Hadley cell widening, polar amplification, stabiliz...

The hydrological performance of individual tree can be estimated by measuring the stem flow, throughfall and rainfall interception. Water distribution through tree canopy is affected by tree architectural model and another tree's morphology. This research was done in order to predict the most appropriate tree species that is suitable on soil and water conservation. This research was conducted in Purwodadi Botanic Garden during the rainy season on January 2014 to March 2015, in order to examine the interception rate, throughfall and stemflow on some selected local plants i.e Syzygium polyanthum, Diospyros blancoi, Schleichera oleosa, Madhuca longifolia, and Canarium vulgare. Other observation that support the data, was also measured i.e. Leaf Area Index (LAI), crown depth, leaf size, Diameter of Breast Height (DBH), and height of tree on each species. Results showed that Diospyros blancoi has the highest interception value, which is 53 %, followed by C. vulgare 47.4%, S. oleosa 46.9 %, M. longifolia 38.6%, and S. polyanthum 35.6% respectively. Under the heavy rain, D. blancoi, which has the highest LAI value, also showed the best performance in the rainfall interception value and showed significantly different among others. Canopy interception and stem flow is related to rainfall, the higher the rainfall, the higher the throughfall and the stemflow among species. Morphology on each species, gives the different effect on their partitioning rainfall value.

Sampling of urban stormwater runoff was carried out in a few small catchment area in UNITEN. The objectives of this study are to investigate the stormwater runoff quality in various location in UNITEN. The area represents different type of landuses such as residential (Cendekiawan Apartment), commercial (UNITEN's Cafe) and industrial (construction site near to College of Engineering (COE) parking area). Twelve runoff samples from three different location were analyzed. Stormwater runoff quality shows large variations in concentration during storms, especially for total suspended solid (TSS), BOD 5 , COD and turbidity. TSS for construction site was the highest which are 36123 mg/L. BOD 5 for UNITEN's Café was the highest with 165 mg/L. COD for both construction site and UNITEN's café were exceed the limit with 1421 mg/L and 989 mg/L respectively. pH measurement shows acceptable result for some locations. Event mean concentration (EMC) was evaluate and compared to mean EMC values by Department of Irrigation and Drainage (DID). Recommendation was made to improve the water quality in the future.

Atmospheric rivers (ARs) are well-known producers of precipitation along the U.S. West Coast. Depending on their intensity, orientation, and location of landfall, some ARs penetrate inland and cause heavy rainfall and flooding hundreds of miles from the coast. Climate change is projected to potentially alter a variety of AR characteristics and impacts. This study examines potential future changes in moisture transport and precipitation intensity, type, and distribution for a high-impact landfalling AR event in the U.S. Pacific Northwest using an ensemble of high-resolution numerical simulations produced under projected future thermodynamic changes. Results indicate increased total precipitation in all future simulations, although there is considerable model spread in both domain-averaged and localized inland precipitation totals. Notable precipitation enhancements across inland locations such as Idaho's Sawtooth Mountain Range are present in four out of six future simulations. The most marked inland precipitation increases are shown to occur by way of stronger and deeper moisture transport that more effectively crosses Oregon's Coastal and Cascade mountain ranges, essentially ''spilling over'' into the Snake River Valley and fueling orographic precipitation in the Sawtooth Mountains. Moisture transport enhancements are shown to have both thermodynamic and dynamic contributions, with both enhanced absolute environmental moisture and localized lower-and midlevel dynamics contributing to amplified inland moisture penetration. Precipitation that fell as snow in the present-day simulation becomes rain in the future simulations for many mid-and high-elevation locations, suggesting potential for enhanced flood risk for these regions in future climate instances of similar events.

Measurements from NASA's A‐train satellites indicate that spherical or quasi‐spherical particles may constitute up to 30% of the total cloud particles at temperatures below −30°C, and up to 10% even for temperatures below −40°C, the temperature range typically found in the upper troposphere and the lower stratosphere. Current climate models calculate cloud radiative forcing on the basis on an assumption that essentially no spherical or quasi‐spherical particles exist below −40°C (even below −15°C). The findings in this study show that this widely used assumption in climate models may need re‐examination. Further research is also needed to confirm and quantify these findings, especially improvements in the satellite retrievals of cloud particle shapes that, in the mean, currently contain about 10% uncertainties.

Highlights  The methodological caveats of OTC studies are addressed.  A holistic approach for future OTC assessment is proposed.  Multifactorial studies on ethnic disparities, adaptive thermal behaviour and health implications related to OTC in SEA are needed.

More than half the world's population lives in cities that were designed with a complete disregard for nature. Then, it is vital that nature should be present in these spaces to provide ecological support for urban areas. Natural elements that are in these spaces should be designed with people's comfort in mind. This research explores the application of the PET and UTCI biometeorological comfort indices in urban microspaces, where the general environmental parameters of the city are not valid and each space must be measured individually. The research looked into the influence of the design of natural elements on improving comfort. The results show that in the children's playing spaces, the absence of thermal comfort and considerable thermal stress were detected in summer. This effect is more easily seen in the PET values. The benefits to comfort of having double layers of vegetation in the gardens have also been shown. The micro-droplets of water from the jets in the fountains are carried by the breeze and modify the human-biometeorological conditions around the fountains and reduce thermal stress. This improvement needs an appropriate design of the fountains and an awareness of the breeze patterns in these spaces.

The climate change variables of temperature, relative humidity, rainfall and fire weather are used in conjunction with spatial methodologies to produce maps that overlay locations of Australian national, state and regional cultural heritage collections with climate change risks. The data analysis of these maps is evaluated in relation to the biological risks of insect pests and mould using published studies and recent observations. Mapping both the distribution of cultural heritage collections and potential environmental impacts allows for future risks to collections to be modelled, producing an evidence base for identifying future priorities for conservation. An historical study of the development of arts policy and conservation guidelines in Australia places the investigation of changing climate and risks within a broader national cultural heritage context. In understanding how Australian cultural heritage collections, and the conservation profession more broadly, might become more sustainable and resilient, the use of environmental guidelines in conjunction with predictive climate mapping resources is recommended.

El objetivo del trabajo fue obtener índices de fragilidad del paisaje  (IFP) como una forma de proporcionar datos confiables para el uso sostenible del suelo en la Cuenca Coatepec- La Antigua, Veracruz, México. Se incorporó un transecto altitudinal de colecta de datos de paisaje, desde los 3200 m en la cara oriental  del cofre de Perote, hasta el nivel de mar, cerca de la ciudad de Veracruz. Se utilizaron datos del inventario nacional forestal y cartas de uso del suelo para, con sistemas de información geográficos para generar imágenes que muestran la fragilidad de los paisajes por uso del suelo. Los datos geográficos fueron contrastados con las características socioeconómicas de la región y el valor social de los paisajes para la población que los habita. Los resultados muestran que los IFP altos (5), se localizan en el 2.8 % del paisaje, el 22.5 % se clasificaron como medio-alto (4), e inciden en zonas de bosque, selva mediana y selva alta, en la zona de montaña.  Las áreas más fr...

SUMMARY The objective of this study was to obtain landscape fragility indexes (LFI) as a way of acquiring trustworthy data for a sustainable use of soils in the Coatepec- La Antigua basin, in Veracruz, Mexico. For collecting landscape data, an altitude transect was done from 3200 m on the east side of the Cofre de Perote mountain, up to the sea level, close to the city of Veracruz. National forestry inventory data and soil use charts were used along with GIS techniques to generate images showing landscape fragility resulting from soil use. Geographical data were contrasted with socioeconomic characteristics in the region and with the social value of landscapes for the inhabitants. Results show that high LFI (grade 5) correspond to only 2.8% of the landscape; a 22.5% were classified as medium-high (grade 4), and are related to high and medium forest in the mountain range. The most fragile areas are located in the upper parts of the basin, which is coincidental with the highest margin...

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An improved understanding of present-day climate variability and change relies on high-quality data sets from the past 2 millennia. Global efforts to model regional climate modes are in the process of being validated against, and integrated with, records of past vegetation change. For South America, however, the full potential of vegetation records for evaluating and improving climate models has hitherto not been sufficiently acknowledged due to an absence of information on the spatial and temporal coverage of study sites. This paper therefore serves as a guide to highquality pollen records that capture environmental variability during the last 2 millennia. We identify 60 vegetation (pollen) records from across South America which satisfy geochrono-logical requirements set out for climate modelling, and we discuss their sensitivity to the spatial signature of climate modes throughout the continent. Diverse patterns of vegetation response to climate change are observed, with more similar patterns of change in the lowlands and varying intensity and direction of responses in the highlands. Pollen records display local-scale responses to climate modes; thus, it is necessary to understand how vegetation-climate interactions might diverge under variable settings. We provide a qualitative translation from pollen metrics to climate variables. Additionally, pollen is an excellent indicator of human impact through time. We discuss evidence for human land use in pollen records and provide an overview considered useful Published by Copernicus Publications on behalf of the European Geosciences Union. 484 S. G. A. Flantua et al.: Climate variability and human impact in South America during the last 2000 years for archaeological hypothesis testing and important in distinguishing natural from anthropogenically driven vegetation change. We stress the need for the palynological community to be more familiar with climate variability patterns to correctly attribute the potential causes of observed vegetation dynamics. This manuscript forms part of the wider LOng-Term multi-proxy climate REconstructions and Dynamics in South America-2k initiative that provides the ideal framework for the integration of the various palaeoclimatic subdisciplines and palaeo-science, thereby jump-starting and fostering multidisciplinary research into environmental change on centennial and millennial timescales.

Public spaces and green areas have been proven to influence people’s mental and physical health, thermal comfort being one of the main indicators. The growing trend of an ageing population globally led this research to analyse the outdoor thermal comfort of older adults in public spaces from two cities in Europe: Madrid in Spain and Newcastle upon Tyne in the United Kingdom during autumn. A mixed methodology through environmental measurements and surveys was performed in situ. In addition, the UTCI (Universal Thermal Climate Index) and PET (Physiological Equivalent Temperature) outdoor thermal comfort indices were applied. The results highlighted the risk of thermal stress and the vulnerability of this group of the population to the effects of climate on their health. Although most older people had ‘neutral’ thermal sensation, 86.3% of them would be at risk of cold stress in Newcastle, whilst in Madrid 31.5% would be at risk of cold stress and 35.7% of heat stress. Those results cou...

This work explores the maintenance of the stratospheric structure in a primitive equation model that is forced by a Newtonian cooling with a prescribed radiative equilibrium temperature field. Models such as this are well suited to analyze and address questions regarding the nature of wave propagation and tropospherestratosphere interactions. The focus lies on the lower to midstratosphere and the mean annual cycle, with its large interhemispheric variations in the radiative background state and forcing, is taken as a benchmark to be simulated with reasonable verisimilitude. A reasonably realistic basic stratospheric temperature structure is a necessary first step in understanding stratospheric dynamics. It is first shown that using a realistic radiative background temperature field based on radiative transfer calculations substantially improves the basic structure of the model stratosphere compared to previously used setups. Then, the physical processes that are needed to maintain the seasonal cycle of temperature in the lower stratosphere are explored. It is found that an improved stratosphere and seasonally varying topographically forced stationary waves are, in themselves, insufficient to produce a seasonal cycle of sufficient amplitude in the tropics, even if the topographic forcing is large. Upwelling associated with baroclinic wave activity is an important influence on the tropical lower stratosphere and the seasonal variation of tropospheric baroclinic activity contributes significantly to the seasonal cycle of the lower tropical stratosphere. Given a reasonably realistic basic stratospheric structure and a seasonal cycle in both stationary wave activity and tropospheric baroclinic instability, it is possible to obtain a seasonal cycle in the lower stratosphere of amplitude comparable to the observations.

Although the effects of land use changes on hydrological functioning are widely addressed, issues such as which components of the hydrological system are affected, how and on what time scales are still poorly understood. In this context, we evaluated whether forest restoration improves soil water conditions in a Cerrado area, and whether the combined effects of forest structure and hydrological variables influence soil attributes. For this, we monitored three areas in different stages of natural succession over seven months, and evaluated vegetation structure indicators, hydrological indicators and soil indicators. Vegetation structure variables were analyzed with Principal Components Analysis, and to evaluate the direct and indirect effects among the variables we used structural equations modelling. Each successional stage differed in relation to forest structure, affecting the hydrological processes and causing the improvement of soil attributes with forest development. In the ini...

While CMIP5 models robustly project drying of the subtropics and more precipitation in the tropics and subpolar latitudes by the end of the century, the magnitude of these changes in precipitation varies widely across models: for example, some models simulate no drying in the eastern Mediterranean while others simulate more than a 50% reduction in precipitation relative to the model-simulated present-day value. Furthermore, the factors leading to changes in local subtropical precipitation remain unclear. The importance of zonal-mean changes in atmospheric structure for local precipitation changes is explored in 42 CMIP5 models. It is found that up to half of the local intermodel spread over the Mediterranean, northern Mexico, East Asia, southern Africa, southern Australia, and southern South America is related to the intermodel spread in large-scale processes such as the magnitude of globally averaged surface temperature increases, Hadley cell widening, polar amplification, stabiliz...

Stormwater is a vital resource and dynamic driver of terrestrial ecosystem processes. However, processes controlling interactions during and shortly after storms are often poorly seen and poorly sensed when direct observations are substituted with technological ones. We discuss how human observations complement technological ones and the benefits of scientists spending more time in the storm. Human observation can reveal ephemeral storm-related phenomena such as biogeochemical hot moments, organismal responses, and sedimentary processes that can then be explored in greater resolution using sensors and virtual experiments. Storm-related phenomena trigger lasting, oversized impacts on hydrologic and biogeochemical processes, organismal traits or functions, and ecosystem services at all scales. We provide examples of phenomena in forests, across disciplines and scales, that have been overlooked in past research to inspire mindful, holistic observation of ecosystems during storms. We conclude that technological observations alone are insufficient to trace the process complexity and unpredictability of fleeting biogeochemical or ecological events without the shower thoughts produced by scientists' human sensory and cognitive systems during storms.

D. J. Nash et al.: Climate indices in historical climate reconstructions and Australia) as well as the world's oceans. We then outline the different methods by which indices are developed in each of these regions, including a discussion of the processes adopted to verify and calibrate index series, and the measures used to express confidence and uncertainty. We conclude with a series of recommendations to guide the development of future index-based climate reconstructions to maximise their effectiveness for use by climate modellers and in multiproxy climate reconstructions.

Land degradation affecting the livelihoods of people living in dryland areas, particularly the Sub-Saharan Africa countries like Ethiopia. Degraded land rehabilitation in dryland is a challenging task due to moisture limitation. This study was conducted to evaluate the effects of soil and water conservation structures on growth of planted tree and rehabilitation of indigenous plant species in West Guji Zone, Dugda Dawa District. Four multipurpose tree species (MPTs) namely Faidherbia albida, Melia azedarach, Moringa stenopetala, and Sesbania sesban were planted in four soil and moisture conservation structures (soil level bund, half-moon, trench and normal pit). Data of survival rate, height and diameter growth of planted tree species and, diversity and species richness of indigenous plant species were collected. The survival rate of all planted MPTs species were declining along the study years; however, the survival rate was better under soil level bund and half-moon. Under control treatments, all planted MPTs died at the end of the study period. The height and stem diameter of F. albida, M. azedarach and M. stenopetala were best in soil level bund and half-moon and followed by the trench. Whereas, the growth performance of Sesbania sesban was not significantly different among the three moisture conservation structures. Furthermore, soil moisture conservation structures significantly increased the indigenous plant species regeneration after the intervention. The mean indigenous plant species diversity and richness were significantly highest in half-moon and soil level bund followed by trench and, lowest in Control (normal pit). Thus, the results a potential for alternative forest and soil restoration in arid areas.