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The development of liveable space made from shipping containers becomes a trend even in Malaysia with the hot and humid climate persisting throughout the year. For sustaining the indoor comfort, building insulation is well adapted to increase thermal resistance and reduce the dependency on the mechanical cooling systems. The prospective of a shippingcontainer as an efficient construction material and bamboo as a sustainableinsulation material is well documented but basic information on the internal environment that has an impact on a person, particularly risk potential towards sick building syndrome (SBS) has been absent. Therefore, the measurements of both indoor and outdoor temperatures, relative humidity and CO2concentration with two different conditions were done by using different sets of dataloggers for at least 70 days under each condition. The firstcondition is a bareunit of the shippingcontainer and followed by the installation of untreated bamboo as insulation for the secondcondition. This research reveals that high temperatures were recorded up to 40°C in both conditions and untreated bamboo as insulation increased the relative humidity levels up to the maximum, 100%. The mean values of CO2concentration are in the range of 1,869 ppm to 2,938 ppm and they reach up to 5,000 ppm at the most of the intervals, indicating a significantcontribution to SBS. The condition of the equatorial climate denies the compatibility of the shipping container to be used as the building material of liveable space. The quality and treatment of the bamboo must be the ultimate priority

Soiling, particulate accumulation on photovoltaic (PV) module surfaces, reduces the available solar resource and the resulting generated device power. In regions where the installation of PV technology is advantageous because of high irradiance areas, in many cases, also possess arid or desert climates that inherently exhibit greater surface soiling. Because of the energy production and associated maintenance-cost factors, it is advantageous to evaluate environmental factors (meteorological variables, climate, and geographical features) as early as possible in developing a PV installation. Alternatively, the determination of the soiling rates (SRate), even after system commissioning can aid in the optimization of maintenance and cleaning-cycle requirements. Significant research has been reported addressing these critical factors through determining local soiling losses. This article presents, evaluates, and compares methodologies to accurately determine and compare SRate and losses from soiling monitoring stations and installed PV systems operating in Belo Horizonte, Brazil (latitude-19.92°, longitude-43.99°). Specifically, data collected from soiling stations were used to estimate the soiling ratio (SRatio) and SRate. A related process is applied to the PV system, using the performance ratio. The methodology incorporates several key refinements. These include normalization and adjustment for the meteorological parameters (temperature and irradiance). Additionally, the differences between the measured global horizontal irradiance (GHI), the plane-of-array irradiance ( G POA) obtained through the application of a transposition model, and the plane-of-array measured by reference cell ( G ref) are presented and compared. The results demonstrate that the transposition model is an acceptable option for cases in which only GHI measurements are available.

The experience of organizing a system of anti-epidemic measures in the Russian military medical group operating on the territory of the island of Sumatra during the humanitarian operation to eliminate the effects of the tsunami in 2005 is presented. A characteristic of the consequences of a natural disaster, a climatogeographic description of the region is presented. The natural-climatic and socio-economic conditions for the spread of malaria infection in the coverage area of the Russian military medical group are analyzed. Russian military physicians acted in an equatorial climate in a zone of tropical rainforest in a highly endemic area for tropical (P. falciparum) and three-day (P. vivax) malaria, as well as for vector-borne tropical infections such as dengue fever, vuhereriosis, and brugiosis. Among the carriers of malaria parasites and other tropical infections on the territory of about. Sumatra mosquitoes Anopheles sundaicus are of the greatest epidemic importance. In 2005, their mass breeding occurred in late January - early February (1,5-2 months earlier than usual). A system of anti-malarial protection of personnel is described, aimed at reducing the risk of infection of military personnel, preventing the development of the disease and its malignant course, early detection of patients and their effective treatment. There were no cases of malaria among the Russian military personnel during their entire stay in the endemic territory. At the same time, the incidence rate among Indonesian soldiers and local residents was constantly increasing. In hospitals, the number of patients with severe forms of tropical malaria increased. Thus, the effectiveness of the developed system of anti- malarial measures among the military personnel involved in peacekeeping and humanitarian operations in the territory with a continuous season of transmission of malaria infection has been confirmed.

The storage of water in the plant and its impacts on eco-hydrological processes are not commonly considered in the models for estimating plant transpiration and evapotranspiration. The high costs required for a wide monitoring network are major obstacles to obtain more consistent results. The aim of the present study is to build and evaluate a low-cost system for the continuous monitoring of stem moisture content (SM). After constructing and calibrating the stem moisture sensors, they were used to monitor plants of the parica (Schizolobium amazonicum) and catingueira (Caesalpinia pyramidalis Tul.). The parica was studied in equatorial climate conditions while the study with the catingueira was carried out in a tropical semiarid condition. Three individuals of the parica and four of the catingueira were selected for monitoring the SM. The stem moisture sensor probe that was developed showed a small error (less than 4.8% in 95% of measurements) compared to the gravimetric method, and can be used to monitor SM in other species as well as those under study, as long as prior calibration is carried out. In a field experiment, the probe enabled the SM response to be studied in two species with fairly different wood densities and moisture content, in environments of contrasting soil and climate characteristics.

Data on droughts and floods and their impacts on croplands and production are important for policy makers and the scientific community. This dataset was developed to provide data of the impacts of droughts and floods on agriculture in the Monsoon Climate Region and Equatorial Climate Region of Southeast Asia during the crop growing seasons over a 40-year period between 1980 and 2019. The data were generated using the TerraClimate global high-resolution gridded Palmer Drought Severity Index (PDSI) datasets in Google Earth Engine along with a set of algorithms. Datasets were available on 47,192 grid points of a 10 × 10 km resolution containing PDSI, their latitude longitude between 1980 and 2019 with five years interval, monthly temporal PDSI data, cropland drought and flood intensity data between 1980 and 2019., Graphical abstract Image, graphical abstract

Aerosol optical depth (AOD) is a highly influential variable in solar resource assessment and clear-sky radiation modelling. Hence, the accuracy of solar energy estimates ultimately depends on the accuracy of the measured or assumed AOD. Gridded satellite information is often used for solar modelling due to its geographical coverage, and so a global validation of commonly utilised AOD products is imperative. Here, all Level-3 Moderate Resolution Imaging Spectroradiometer (MODIS) daily observations of AOD (at 470, 550 and 660 nm, noted AOD470, AOD550 and AOD660, respectively) from the Aqua and Terra satellites (of 1° × 1° spatial resolution) from 2000 to 02/2018 are compared and validated against all of NASA’s ground sensing Aerosol Robotic NETwork (AERONET) V3 Level 2 AOD daily averages from sites that reported at least one year of observations during 2000–2018 (452 sites representing at least 653,000 observations per variable). Furthermore, sub-categorisation by Koppen-Geiger climate regions enables a novel climate-specific validation to ascertain any distinct climatic influence. The results demonstrate significant climatological influences that impact the derived AOD product at all three wavelengths. It is found that blending the two Aqua and Terra products results in a higher accuracy of daily estimates of all AOD products. Each AOD product is validated similarly and separately. AOD550, which is most commonly used in solar resource assessment, is found worst in the equatorial climate (absolute root mean square error (RMSE) of 0.194) and best in the temperate climate (RMSE of 0.126). Globally, the combined Aqua + Terra AOD550 experiences an absolute RMSE of 0.106 and a mean absolute error of 0.109. The most common MODIS AOD retrievals are between 0.01 and 0.25, suggesting that the MODIS daily AOD products may introduce a significant source of uncertainty in modelled irradiance estimates, and that other sources of input data should be used instead whenever their applications demand high accuracy.

While droughts and floods have intensified in recent years, only a handful of studies have assessed their impacts on croplands and production in Southeast Asia. Here, we used the Google Earth Engine to assess the droughts and floods and their impacts on croplands and crop production over 40 years from 1980 to 2019. Using the Palmer Drought Severity Index (PDSI) as the basis for determining the drought and flood levels, and crop damage levels, crop production loss in both the Monsoon Climate Region (MCR) and the Equatorial Climate Region (ECR) of Southeast Asia was assessed over 47,192 grid points with 10 × 10-kilometer resolution. We found that rainfed crops were severely affected by droughts in the MCR and floods in the ECR. About 9.42 million ha and 3.72 million ha of cropland was damaged by droughts and floods, respectively. We estimated a total loss of 20.64 million tons of crop production between 2015 and 2019. Rainfed crops in Thailand, Cambodia, and Myanmar were strongly affected by droughts, whereas Indonesia, the Philippines, and Malaysia were more affected by floods over the same period. Accordingly, four levels of policy interventions were prioritized by considering the geolocated crop damage levels.

Climate change has had adverse impacts on agriculture, but only a handful of studies exist on this phenomenon in South-East Asia. To help provide better-informed policy interventions, in this study, the Google Earth Engine (GEE) cloud-computing platform was used to assess the temporal and spatial changes of drought conditions and related impacts on crops in the Association of Southeast Asian Nations (ASEAN) region from 1980 to 2019. To assess drought intensity and to identify its impact on irrigated and rain-fed agriculture land, 47,192 grid points with 10 × 10 km (km) resolution were created. It found that the Monsoon Climate Region had more droughts with higher intensity, while the Equatorial Climate Region experienced more wet conditions with a lower intensity of drought conditions in irrigated and rain-fed agriculture lands. Still, about 19.9 million hectares (ha) of croplands in the ASEAN region faced severe drought conditions, while 3.6 million ha of croplands faced wet conditions and possible flood damage. Accordingly, the loss of production of irrigated and rain-fed croplands in Cambodia, Indonesia, the Lao People’s Democratic Republic, Myanmar, Thailand, and Viet Nam was estimated at about 21.9 million tons during 2015–2019. To address drought impacts, four levels of policy interventions for ASEAN are suggested—low, medium, high, and business-as-usual—depending on the level of drought conditions in a particular country.

West Africa is characterised by diverse hydro-climatic divisions ranging from the humid equatorial climate to the semi-arid and arid climates that manifest in high space–time variability in rainfall. In this study, drought and floods in six delineated domains (Northern Sahel, Southern Sahel, Sudanian, Western Guinea Coast, Central Guinea Coast and Eastern Guinea Coast) of West Africa were illustrated using the Standardized Precipitation Index (SPI 3 months and 9 months) calculated from global CPC Merged Analysis of precipitation (CMAP 2.5° by 2.5° resolution) data from 1980 to 2017. The trend analysis shows that none of the domains exhibits a significant trend in the computed SPI. However, there is a significant trend in the annual rainfall rate for all the domains except the Eastern Guinea Coast. Again, there is a likelihood of an increasing trend of SPI-3 but a decreasing trend for the SPI-9. The drier areas have significant increasing rainfall trend while the highly humid regions show significant negative trend except for the Eastern Guinea Coast that shows a non-significant very weak positive trend. The most exposed area to extreme drought conditions occurs over the northern Sahel domain at SPI-3 though the frequency of occurrence is very low. The Western Guinea coast experiences the highest number of dry events of about 32% of the time followed by the Northern Sahel domain. Under SPI-9, the following domains: Eastern Guinea coast, Sudanian, Northern Sahel and Western Guinea coast are prone to flooding incidence as they had 40%, 37%, 29% and 26% of wet events, respectively. The study recommends apt and timely climate service delivery, adoption of ecosystem-based adaptation strategies that promote apt and sustainable water management practices in the region.

Many factors can influence the spread of viruses and respiratory infections. Studies have suggested that there is a direct relationship between environmental issues and population density with cases of COVID-19. In this sense, this research aims to analyze, through correlational study and Krigagem, the relationship of meteorological and demographic variables with cases of COVID-19 in regions of subtropical climate in Brazil. The results suggest that population and demographic density (hab/km2) are risk factors for the spread of SAR-Cov-2 and an increase in the daily case record of COVID-19. The distribution of cases according to age group did not present a significant disparity between men and women. Relative humidity (RH)%, average temperature °C, minimum temperature °C, maximum temperature °C, wind speed m/s and daily precipitation (rain) mm show negative relationships with cases of COVID-19 in regions of humid equatorial climate. Analysis between associations of environmental factors, wind, temperature and HR in a region is extremely important to understand the dynamics of SARS-Cov-2 in the environment. In the northern region of Brazil, low wind speed, high temperatures and high RH are observed, environmental factors that, when associated, reduce the transmission process because it hinders the movement of the virus in the environment. In this sense, it is suggested that the transmission of SARS-CoV-2 in this region is disseminated through fluids in the air between man/man and by contact between objects/men. Therefore, strategic public policies to combat the pandemic must consider the environmental factors of the regions involved and control and/or blocking the transit of people.

We develop a new algorithm, the simplified urban-extent (SUE) algorithm, to estimate the surface urban heat island (UHI) intensity at a global scale. We implement the SUE algorithm on the Google Earth Engine platform using Moderate Resolution Imaging Spectroradiometer (MODIS) images to calculate the UHI intensity for over 9500 urban clusters using over 15 years of data, making this one of the most comprehensive characterizations of the surface UHI to date. The results from this algorithm are validated against previous multi-city studies to demonstrate the suitability of the method. The dataset created is then filtered for elevation differentials and percentage of urban area and used to estimate the diurnal, monthly, and long-term variability in the surface UHI in different climate zones. The global mean surface UHI intensity is 0.85 °C during daytime and 0.55 °C at night. Cities in arid climate show distinct diurnal and seasonal patterns, with higher surface UHI during nighttime (compared to daytime) and two peaks throughout the year. The diurnal variability in surface UHI is highest for equatorial climate zone (0.88 °C) and lowest for arid zone (0.53 °C). The seasonality is highest in the snow climate zone and lowest for equatorial climate zone. While investigating the change in the surface UHI over a decade and a half, we find a consistent increase in the daytime surface UHI in the urban clusters of the warm temperate climate zone (0.04 °C/decade) and snow climate zone (0.05 °C/decade). Only arid climate zones show a statistically significant increase in the nighttime surface UHI intensity (0.03 °C/decade). Globally, the change is mainly seen during the daytime (0.03 °C/decade). Finally, the importance of vegetation differential between urban and rural areas on the spatiotemporal variability is examined. Vegetation has a strong control on the seasonal variability of the surface UHI and may also partly control the long-term variability. The complete UHI data are available through this website ( https://yceo.yale.edu/research/global-surface-uhi-explorer ) and allows the user to query the UHI of urban clusters using a simple interface.

This summary looks at the southern hemisphere and equatorial climate patterns for spring 2016, with particular attention given to the Australasian and equatorial regions of the Pacific and Indian Ocean basins. Spring 2016 was marked by the later part of a strong negative phase of the Indian Ocean Dipole, alongside cool neutral El Niño–Southern Oscillation conditions. September was exceptionally wet over much of Australia, contributing to a wet spring with near-average temperatures. The spring was one of the warmest on record over the southern hemisphere as a whole, with Antarctic Sea ice extent dropping to record low levels for the season.

A avaliação da sensação térmica em Santarém é importante, devido à recente expansão física e populacional da cidade. Santarém é a terceira maior cidade do Pará, tanto em tamanho, quanto em população. O clima Equatorial, caracterizado com temperatura do ar e umidade relativa do ar elevadas ao longo do ano, associado a variações diurnas de temperatura, mesmo que pequenas, podem representar alterações importantes no conforto/desconforto térmico do ambiente urbano. Neste sentido, o conforto térmico horário foi testado por meio de quatro modelos capazes de retorna a resposta térmica local, focados neste estudo na estação seca de 2016 (julho a novembro), utilizando dados da estação meteorológica automática de superfície de Santarém. Entre os resultados encontrados podemos destacar que, no intervalo de 11 às 18h, em ambiente aberto, a sensação térmica varia de desconfortável a extremante desconfortável. Entre 14 e 17h, os índices apontam sensação muito quente com falha na termorregulação do corpo e cautela extrema, estas sensações térmicas estão associadas aos valores máximos de temperatura ar em torno de 31°C e umidade relativa inferior a 60%. A compreensão acerca da sensação térmica atual em Santarém e dos horários mais críticos, servem como subsidio para medidas de prevenção a exposição a ambientes abertos, além de possibilidade de emissão de alertas a sociedade e poder público.

One of the effective measures to save cooling energy in countries with an equatorial climate like Malaysia is through the use of roof thermal insulation. This paper focuses on the economic evaluation of commonly used thermal insulation solutions for a typical hypermarket roof in Malaysia. Eight commonly used thermal insulation systems have been identified and evaluated. In order to find the most cost-effective thermal insulation measure, three types of economic evaluation methods i.e. life-cycle savings, discounted payback period and internal rate of return have been used. All the eight thermal insulation systems were ranked accordingly to these three methods It has been found that insulation system using small bubble aluminium foil ranked first with the highest life-cycle savings, internal rate of return and the shortest payback period. Sensitivity analyses have also been carried out to identify the effects of changes in the key parameters for example cost of capital and lifetime period have on the evaluation results. The analyses show that small bubble aluminium foil is least susceptible to fluctuation of these two parameters relative to other examined insulation materials.

An analysis is made of the volcanic landscape structure of Mount Kerinci, the highest volcano in South-East Asia. Field observations, remote sensing methods, and also cartographic material were used in obtaining new evidence to gain a more penetrating insight into the characteristics of structure and altitudinal zonation of the landscapes along the equatorial belt that have shaped themselves and are evolving in conditions of intense volcanic activity, equatorial climate and heavy anthropogenic load. The analysis revealed natural and anthropogenic landscape-forming factors that determined the present-day landscape appearance of the Kerinci volcano. Within the boundaries of the volcanic structure, landscapes of the mountain class show the highest diversity of landscape taxa. They are represented largely by slope units. With an increase in altitude, there is an increase in the proportion of landscapes of steep and vertical slopes as well as moderately steep slopes, along with the disappearance of landscapes of smart slopes and valley bottoms. A less diverse landscape structure is characteristic for subclasses of aggraded-denudation plains where there occur only landscapes with bogs and waterlogged meadows predominating. Anthropogenic modifications of landscapes occur mostly within subclasses of smart slopes and aggraded-denudation plains. They are characterized by a predominance of agricultural plants.

The spatial and temporal characteristics of rainfall and raindrop size distribution for terrestrial or space to earth communication link affects the perfromace of radio and radar communication system operating above 10 GHz in the temperate climate and above 7 GHz in tropical and equatorial climate. The rain drop size distribution plays an important role for limiting the performance of communiation system due to different rain attenuation and polarization of radio signals at mm wave rfequuencies. The single point measurement of rainfall rate as well as rain drop distribution, and non-uniform rainfall rate characteristics of terrestrial radio link causes difference in the rain attenuation measured value at mm wave frequencies from the rain attenuation based on raindrop size distribution or rainfall rate. In this paper, model for cross-polarisation discrimination (XPD) due to rain rate at 20 GHz and 30 GHz have been developed based on rain attenuation measurement of LOS link for vertical and horizontal polarisation signals. The variation of XPD with rain rate and co-polar attenuation have been discussed for understanding the effect of rain drop size distribution at 20/ 30 GHz.

Flash floods are one of the most widespread and dangerous phenomenon on our planet. They are characterized by fast speed of development and short duration. However their study just begins because there is no one opinion what flash flood is, and there is no special term in many countries. The key reasons of their formation are intensive rainfall of short duration, location of river basin in mountain areas, and small catchment area, providing fast concentration of the runoff in river channel. Another significant factor is antecedent soil moisture. Flash floods are mostly spread in zones of subtropic, tropic and equatorial climate in the northern hemisphere. The study of flash floods is implemented in various fields of science due to hydrometeorological and lythogeomorphological causes of their formation. The important task is the differentiation of flash floods and debris flows. It can be based on the relations between sediment yield and sediments grain size and runoff characteristics with a glance of sediments concentration. The scheme of natural factors of flash floods formation is suggested with their differentiation from debris flows and floods of other types. The main issues of flash floods research and forecast are connected with small spatio-temporal scale of phenomenon and remoteness of river basins.

O objetivo da pesquisa foi analisar o campo térmico e as ilhas de calor em uma cidade de clima equatorial na Amazônica brasileira. O recorte espacial foi a cidade de Tefé, localizada na região do Médio Solimões no interior do estado do Amazonas. Foram realizados transectos móveis em dias representativos do mês de outubro que se insere no período sazonal menos chuvoso denominado de verão amazônico, para coleta dos dados da temperatura do ar em 37 pontos na cidade de Tefé. Os dados foram tabulados e interpolados pelo método IDW no software QGIS. Posteriormente, geraram-se as cartas da temperatura da superfície e o NDVI para análise da estrutura térmica e da densidade de vegetação na área. As diferenças térmicas entre os pontos variaram em até 4,6°C, sendo que na área central da cidade, com ocupação mais antiga, densidade construtiva e arborização urbana esparsa, configurou-se a ilha de calor de forte magnitude. As temperaturas da superfície variaram de 25°C a 30°C e também indicaram a concentração do aquecimento na parte central, derivada da ampla cobertura de materiais construtivos inapropriados para o clima equatorial. Além disso, constatou-se que a alta densidade de vegetação arbórea associou-se a configuração da ilha de frescor. Conclui-se que os estudos de clima urbano devem ser articulados ao planejamento e (re) produção do espaço urbano, uma vez que mesmo localizada em meio a Amazônia profunda a produção social do clima urbano de forma desigual pode potencializar problemas relacionados ao desconforto térmico e a saúde de parte da população. The aim of the research was to analyze the thermal field and the heat islands in a city of equatorial climate in the Brazilian Amazon. The spatial clipping was the city of Tefé, located in the region of the Middle Solimões in the interior of the state of Amazonas. For this, mobile transects were performed on representative days of the month of October, which is inserted in the less rainy seasonal period called the Amazonian summer, to collect air temperature data in 37 points of the city. The data were tabulated and interpolated by the IDW method in the QGIS software. The surface temperature chart and the NDVI were also generated for analysis of the thermal structure and soil occupation. The thermal differences between the points varied up to 4.6 ° C, and in the central part of the city of the oldest occupation, construction density and sparse urban afforestation, the island of heat was of great magnitude. Surface temperatures varied from 25°C to 30°C and also indicated the concentration of heating in the central part, derived from the wide coverage of constructive materials inappropriate for the equatorial climate. In addition, it was verified that the high density of arboreal vegetation was associated to the configuration of the island of freshness. It is concluded that the urban climate studies should be articulated to the planning and (re) production of the urban space, since even located in the middle of the deep Amazon the social production of the urban climate in an unequal way can potentiate problems related to thermal discomfort and the health of part of the population.

The measurement of the fine dead fuel moisture content (FDFMC) is extremely important for forest fire prevention and suppression activities, as it has a great influence on the ignition probability and fire behavior. The Fine Fuel Moisture Code (FFMC) from the Fire Weather Index (FWI), is one of the most used models to estimate the FDFMC. Nevertheless, studies that assess the efficiency of this model in Brazil or in low latitude regions are rare. The present study aimed to evaluate the efficiency of the FFMC in an equatorial climate area and to develop a new model capable of estimating the FDFMC with greater precision. For this purpose, 861 random samples of fine dead fuel had their moisture content determined through oven drying. The obtained values were compared with those estimated by the FFMC and correlated with meteorological parameters to build a regression model. The results obtained show that the FDFMC was overestimated by the FFMC. The independent variables with the greatest influence on the FDFMC were, in decreasing order of significance: air relative humidity, air temperature, amount of rainfall in the last 24 hours and number of days without rainfall. The developed model presented good statistical parameters (r2 = 0.86; p

Dendroclimatology can be used to better understand past climate in regions such as Australia where instrumental and historical climate records are sparse and rarely extend beyond 100 years. Here we review 36 Australian dendroclimatic studies which cover the four major climate zones of Australia; temperate, arid, subtropical and tropical. We show that all of these zones contain tree and shrub species which have the potential to provide high quality records of past climate. Despite this potential only four dendroclimatic reconstructions have been published for Australia, one from each of the climate zones: A 3592 year temperature record for the SE-temperate zone, a 350 year rainfall record for the Western arid zone, a 140 year rainfall record for the northern tropics and a 146 year rainfall record for SE-subtropics. We report on the spatial distribution of tree-ring studies, the environmental variables identified as limiting tree growth in each study, and identify the key challenges in using tree-ring records for climate reconstruction in Australia. We show that many Australian species have yet to be tested for dendroclimatological potential, and that the application of newer techniques including isotopic analysis, carbon dating, wood density measurements, and anatomical analysis, combined with traditional ring-width measurements should enable more species in each of the climate zones to be used, and long-term climate records to be developed across the entire continent.

The effects of climate change on marine ecosystems are accelerating. Identifying and protecting areas of the ocean where conditions are most stable may provide another tool for adaptation to climate change. To date, research on potential marine climate refugia has focused on tropical systems, particularly coral reefs. We examined a northeast Pacific temperate region – Canada’s Pacific – toidentify areas where physical conditions are stable or changing slowly. We analyzed the rate and consistency of change for climatic variables where recent historical data were available for the whole region, which included sea surface temperature, sea surface height, and chlorophyll a . We found that some regions have been relatively stable with respect to these variables. In discussions with experts in the oceanography of this region, we identified general characteristics that may limit exposure to climate change. We used climate models for sea surface temperature and sea surface height to assess projected future changes. Climate projections indicate that large or moderate changes will occur throughout virtually the entire area and that small changes will occur in only limited portions of the coast. Combining past and future areas of stability in all three examined variables to identify potential climate refugia indicates that only 0.27% of the study region may be insulated from current and projected future change. A greater proportion of the study region (11%) was stable in two of the three variables. Some of these areas overlap with oceanographic features that are thought to limit climate change exposure. This approach allowed for an assessment of potential climate refugia that could also have applications in other regions and systems, but revealed that there are unlikely to be many areas unaffected by climate change.

We examine the “tropical storm” hypothesis that precipitation variability in the Yucatan Peninsula (YP) was linked to the frequency of tropical cyclones during the demise of the Classic Maya civilization, in the Terminal Classic Period (TCP, AD 750—950). Evidence that supports the hypothesis includes: (1) a positive relationship between tropical storm frequency and precipitation amount over the YP today (proof of feasibility), (2) a statistically significant correlation between a stalagmite (Chaac) quantitative precipitation record from the YP and the number of named tropical cyclones affecting this region today (1852—2004) (calibration sensu lato), and, (3) correlations between the stalagmite Chaac precipitation record and an Atlantic basin tropical cyclone count record and two proxy records of shifts in macroscale climate and ocean states that influence Atlantic tropical cyclongenesis. At face value, regional paleotempestology proxy records suggest that tropical storm activity in the YP was either similar or significantly lower than today during the TCP. The “tropical storm” hypothesis has implications for our understanding of the role the hydrological cycle played in the collapse of Classic Maya polities and the role of tropical storms in possibly ameliorating future drought in the YP and other tropical regions.

El Nino exhibits distinct Eastern Pacific (EP) and Central Pacific (CP) types which are commonly, but not always consistently, distinguished from each other by different signatures in equatorial climate variability. Here we propose an index based on evolving climate networks to objectively discriminate between both flavors by utilizing a scalar-valued measure that quantifies spatial localization and dispersion in global teleconnections of surface air temperature. Our index displays a sharp peak (high localization) during EP events, whereas during CP events (larger dispersion) it remains close to the values observed during normal periods. In contrast to previous classification schemes, our approach specifically accounts for El Nino's global impacts. We confirm recent El Nino classifications for the years 1951 to 2014 and assign types to those cases where former works yielded ambiguous results. Ultimately, we demonstrate that our index provides a similar discrimination of La Nina episodes into two distinct types.

Temperate rainforest is restricted to a globally rare set of climatic conditions. Scotland has among the best remaining examples of intact temperate rainforest in Europe, characterised ecologically by a unique assemblage of epiphytic bryophytes and lichens. Given climatic control on rainforest distribution and ecology, climate change is a probable risk to Scotland’s rainforest. This study investigated climate change impacts for 20 target sites, classified based on (i) bioclimatic conditions, and (ii) epiphytic diversity, into contrasting rainforest and more continental (non-rainforest) examples. Space-for-time matching identified climate analogues within the European conservation forest network, which at present have a climate similar to that expected of the target sites during the 2080s (WorldClim datasets). The results show that 2080s analogues for sites in more continental north-eastern Scotland occur in Wales and southern England. However, Scottish rainforest sites were their own ‘best analogu...

Even if an external forcing that will drive a climate change is given uniformly over the globe, the corresponding climate change and the feedbacks by the climate system differ by region. Thus the detection of global warming signal has been made on a regional scale as well as on a global average against the internal variabilities and other noises involved in the climate change. The purpose of this study is to estimate a timing of unprecedented climate due to global warming and to analyze the regional differences in the estimated results. For this purpose, unlike previous studies that used climate simulation data, we used an observational dataset to estimate a magnitude of internal variability and a future temperature change. We calculated a linear trend in surface temperature using a historical temperature record from 1880 to 2014 and a magnitude of internal variability as the largest temperature displacement from the linear trend. A timing of unprecedented climate was defined as the first year when a predicted minimum temperature exceeds the maximum temperature record in a historical data and remains as such since then. Presumed that the linear trend and the maximum displacement will be maintained in the future, an unprecedented climate over the land would come within 200 years from now in the western area of Africa, the low latitudes including India and the southern part of Arabian Peninsula in Eurasia, the high latitudes including Greenland and the mid-western part of Canada in North America, the low latitudes including Amazon in South America, the areas surrounding the Ross Sea in Antarctica, and parts of East Asia including Korean Peninsula. On the other hand, an unprecedented climate would come later after 400 years in the high latitudes of Eurasia including the northern Europe, the middle and southern parts of North America including the U.S.A. and Mexico. For the ocean, an unprecedented climate would come within 200 years over the Indian Ocean, the middle latitudes of the North Atlantic and the South Atlantic, parts of the Southern Ocean, the Antarctic Ross Sea, and parts of the Arctic Sea. In the meantime, an unprecedented climate would come even after thousands of years over some other regions of ocean including the eastern tropical Pacific and the North Pacific middle latitudes where an internal variability is large. In summary, spatial pattern in timing of unprecedented climate are different for each continent. For the ocean, it is highly affected by large internal variability except for the high-latitude regions with a significant warming trend. As such, a timing of an unprecedented climate would not be uniform over the globe but considerably different by region. Our results suggest that it is necessary to consider an internal variability as well as a regional warming rate when planning a climate change mitigation and adaption policy.

This research presents Koppen–Geiger (K-G) climate type maps of the Last Glacial Maximum (LGM) of 21,000 years ago (21 ka), the mid-Holocene (MH) of 6 ka, and the present (1976–2005). Data used to calculate and map the K-G climate type are-year monthly mean 2-m air temperature and precipitation from the National Center for Atmospheric Research (NCAR) Community Climate System Model version 4 (CCSM4)—Community Atmosphere Model version 4 (CAM4) as part of the Coupled Model Intercomparison Project Phase 5 (CMIP5). Results suggest that the model depicts similar modern climate distributions as in data-based research, excepting a larger distribution of tropical wet–dry and humid subtropical types, and a smaller distribution of hot arid and hot semi-arid types. The modeled modern K-G climate types cover similar percentages of Earth's terrestrial and marine surface as during the MH, with slight enlargement of the tropical wet–dry and decreased area of mesothermal monsoonal hot summer type in the modern period. At the LGM, the K-G Polar (E) climate was far more extensive than in modern times, with concurrent decreases in area of the Tropical (A) climates. Because Koppen-type classifications are intended to mimic the biome distributions, these results may be helpful in identifying biotic realms from the geologic past and the potential vegetative response to future climate changes.

Unsustainable anthropogenic activities such as indiscriminate logging of trees, mineral exploitation, conversion of forest into agricultural lands are known to cause major environmental changes, thereby triggering a chain of irreversible forest depletion. This has called an urgent need by government and private agencies to institute policies and programs to curtail the destruction of the ecosystem due to the pressure on the available land. In this study, the Land use/land cover changes between the period of 1986 and 2020 in the tropical rainforest of Ghana was considered. A combination of machine learning and Markov chain approach was adopted to project future LULC for 2040 and 2060.The results showed that area covered by Open Forest declined from 21,531.87 km2 to 14,518.82 km2 and Dense Forest also declined from 14,313 km2 to 8202.98 km2 over a period of 34 years. The CA-Markov model was used to predict the future land use land cover, and it was observed that the total forest cover could decline to 15,551.79 km2 in 2040 and further decrease to 13,401.79 km2 in 2060. It was also found that settlement, mining and agricultural land, which is be driven by rapid population increase, has contributed significantly to the rapid declining forest cover. The results of this study have demonstrated the impact of unsustainable use of natural resources in these three regions. It also highlights the need for concerted effort to develop comprehensive environmental policies to encapsulate sustainable conversion and utilisation of natural resources by focusing on water-energy-food nexus.

Rapid urbanization, population explosion and climate change have threatened water security globally, regionally and locally. While there are many ways of addressing these problems, one of the innovative techniques is the recent employment of Sustainable Urban Drainage Systems (SUDS) which include rainwater harvesting systems (RWHS). Therefore, this paper reviews the design and component of two types of RWHS, the namely roof harvesting system (RHS) and the pond harvesting system (PHS). The performance in terms of quantity and quality of collected rainwater and energy consumption for RWHS with different capacities were evaluated, as well as the benefits and challenges particularly in environmental, economic and social aspects. Presently, the RHS is more commonly applied but its effectiveness is limited by its small scale. The PHS is of larger scale and has greater potentials and effectiveness as an alternative water supply system. Results also indicate the many advantages of the PHS especially in terms of economics, environmental aspects and volume of water harvested. While the RHS may be suited to individual or existing buildings, the PHS has greater potentials and should be applied in newly developed urban areas with wet equatorial climate.

Apart from in deep and mainly enclosed systems, the occurrence of hypoxic conditions in coastal seas is generally only a seasonal phenomenon. Despite this, we observed quasi-persistent hypoxia in an equatorial shallow open bay (Jakarta Bay, Indonesia) between 2015 and 2018. There are 3 reasons for the persistence of this hypoxic water mass, namely 1) This bay tends to be stratified due to weak tidal mixing and high river discharge; 2) Due to the lack of continuous vertical convection caused by surface cooling in an equatorial climate, here the water column tends to remain stratified; 3) The oxygen demand in the water is high. Recovery from hypoxia in Sep. 2017 followed the intrusion of offshore water induced by wind. In this study it is suggested that estuaries and ROFIs (Region of Fresh Water Influence) in equatorial regions are susceptible to hypoxia under increasing anthropogenic impacts.

Whether pessimistic believing that overpopulation is the ultimate cause of many environmental problems or optimistic arguing for social justice and technological development, studying human population dynamics and their impacts on the environment is an important and ongoing field of study. This type of research should take advantage of the many benefits offered by indirect remote sensing, geographic information systems, and other related disciplines data that are based on relationships developed at the field. Nevertheless, many facets of the subject including the relationship between human population distribution (HPD) and land surface temperature (LST) in areas that have different climatic classifications are still lacking attention. Hence, this study focused on bridging this gap in order to provide supporting scientific evidence for planners and decision makers all over the globe. Four areas that represent the four main populated climate zones were randomly selected. They are: (1) El-Salvador for equatorial climate, (2) Kuwait for arid climate, (3) Lebanon for warm temperate climate, and (4) New Hampshire for boreal climate. For the years 2001, 2009, and 2017 for the four areas, HPD data were obtained from LandScan project while LST data were derived from MOD11C3 product. An integrated framework approach was implemented. This approach included: (1) basic descriptive non-spatial statistics, (2) spatial Global Moran's I Index and Anselin Local Moran's I Index, (3) non-spatial Pearson correlation coefficient (r) and ordinary least squares (OLS) regression, and (4) spatial lag model (SLM) and spatial error model (SEM) regressions. It has been observed that the strength and direction of the relationship between HPD and LST do not vary from time to time but vary from climate zone to another. The strongest relationship can be found in boreal climates, followed by warm temperate climates, and then arid and equatorial climates. In boreal, warm temperate, and equatorial climates the relationship is positive while in arid climates the relationship is negative providing indirect supporting evidence for the inversion of surface urban heat islands phenomenon in arid climates. Furthermore, it has been noticed that the relationship between HPD and LST is highly spatially dependent regardless the time and climate zone where some type of spatial diffusion or spillover processes might be present. Still, it is clear that this relationship is complex and not amenable to direct explanation and needs further investigation in order to be explained.

The best knowledge of physico-geochemical content of water helps to cope with adequacy between water availability and its importance. Thus, in BAFIA where groundwater is used in households, it is mandatory to evaluate and characterize the quality of that water. BAFIA is an important area of Cameroon due to its geographical position, growing population and associated needs. Located between an equatorial climate in the western region and a humid tropical climate in the eastern region, this area contains an aquifer system that represents sequences of shales, mica quarry, biotite gneiss, post-tectonic granites, and ortho-amphibolite. Groundwater flows aquifers recharge areas and provides base flows to supply drinking water to study area. The objective of this work was to assess the physicochemical and bacteriological quality of groundwater, to explain the phenomena that cause its mineralization in and around the BAFIA area and to correlate these different ions. We only included boreholes that had a good flow rate to meet the need to supply a large number of populations with water for domestic use. We conducted an analytical study of the physicochemical and bacteriological parameters of the elements collected from the water samples. The results were processed using hydro-chemical methods (Piper diagram, distribution maps of chemical elements) for a study of water typology and multivariate statistical analysis techniques. Principal component analysis (PCR) and ascending hierarchical classification (CHA) analysis were used to determine the phenomena causing water mineralization and the links between these waters, respectively. Our results showed that: the waters analyzed in the study area were slightly basic and moderately mineralized. Chemical parameter grades were below the world health organization (WHO) standard; except for iron. Most of the water was chlorinated and sulfated calsic and magnesic. Three phenomena have been at the origin of water mineralization: anthropogenic activity, recharge of groundwater (soil infiltration) and water-rock contact (main ion production mechanism).

The Edea-Eseka region (EER), a portion of West African Margin located in SW Cameroon between 3°30′—4°00′ N and 10°00′—10°55′ E and submitted to equatorial climate since early Miocene is used here as a proxy for climatic conditions. Geomorphological analysis based on morphometric parameters computed from DEM (30 m) combined with geological maps and field observations were used to constrain geomorphic evolution and landscape adjustment to tectonic processes in this humid zone. Three types of geomorphic indices reflecting specially patterns of differential uplift, those efficient in detecting tilting, and those revealing interactions between erosion and tectonics. - The obtained results show that lithological boundaries and base level controls on landscape are very limited. Tectonic processes, peculiarly uplift induced by faults or tilting at local scale and by mantle dynamics at large scale coupled with climate condition, represent the main factors that drove the geomorphic evolution of this area discriminating three main morphotectonic provinces different by their geomorphic characteristics, uplift and degree of incision. There are, from West to East: (1) the coastal province (CP), deeply incised and built on Douala-Kribi/Campo basin ( - Several geomorphic indices used to evaluate tectonic activities and their average the index of relative active tectonics (IAT) show that tectonic activity differs from one province to another and within each province. Generally, it increases from coast (coastal province) to hinterland (UP). EER are represented by classes 2 and 3 of IAT indicating moderate to high active tectonics. Class 1 revealing the highest tectonic activity, occurs exclusively in the UP. Class 2 corresponding to high tectonic activity happens largely in the south of the IP along the Nyong Fault and the UP where relief are particularly high. Class 3 indicates the moderate relative tectonic in the IP. Class 4 mainly takes place in tectonically low to inactive Douala-Kribi/Campo basin, except along the South part of Sanaga Fault. The development and the evolution of Edea-Eseka region landscape is then acted by a dominant high-uplift rate in SW Cameroon. This tectonic activity apparently incompatible with the passive margin context is however realistic in this area, on one hand justified by the numerous reactivations over time of faults crossing the region that generate earthquakes in some places and on the other hand, by the activity of the Cameroon Volcanic Line, and particularly that of the Mount Cameroon located near the study area. It appears at the end that, due to mantle dynamics, the EER has been rejuvenated under the tectonics and climate forcings, returning to a transient stage of its geomorphic evolution.

Earth-to-satellite links are highly affected by propagation impairments especially by rain that operate at frequencies higher than 10 GHz. Therefore, the satellite communication system performance suffers from severe degradation at high frequencies in tropical and equatorial climate. Time diversity is one of the workable technique with suitable time delay between successive transmissions which is proposed by many researchers to mitigate rain fade. However, time diversity analysis requires measured rain attenuation data. For future high frequency link design those data are not available at most of the places. This paper proposes a method to utilize 1-minute rain rate to analyse time diversity gain at any desirable frequency. In proposed method, it is assumed that rain rate with delay can represent rain attenuation with delay for same period of time at same location. This assumption is valid as long as the attenuation causes due to rain. One year measured rain rate in Malaysia is used to predict rain attenuation gain. The measured gain at 12.225 GHz signal is compared with that predicted by ITU-R based on rain rate measurement and is found good agreement. Hence it is recommended that the time diversity gain can be predicted using measured rain rate for any desired frequencies.

The Malaysian International Seminar on Antarctica (MISA) is a series of the biennial event, which gathers researchers from various countries across the globe to share findings and experiences in polar research and also provides a platform for our scientists to strengthen existing and forge new collaborations. MISA also provides opportunities for local researchers and students who are interested in pursuing their career in polar sciences especially global sciences. The theme of MISA7 is “Connectivity between Polar and Equatorial Climate and Biosphere: from the Poles to the Tropics”. The theme is in line with the rationale that the Poles are an integral part of the global Earth system and as the origin of important climatic, biological, and physical processes that can influence the tropics. Conversely, processes in the tropics could also influence the polar region. This connectivity issue becomes critical in the Anthropocene Era where climate change and anthropogenic activities have significant impacts on the environment. This crucial topic requires attention and collaboration between various disciplines and field of research. The link between polar process and tropics may reveal results that may provide an early warning precursor of important global changes that may affect both regions. This Special Issue of Polar Science is a collection of selected papers delivered at this seminar.

Species inhabiting tropical mountaintops may be most at risk from the detrimental effects of climate change. Yet few regional assessments have critically assessed the degree of threat to species in these habitats. Here we model under three climate scenarios the current and future suitable climate niche of 19 plant species endemic to tropical mountaintops in northeast Queensland, Australia. The suitable climate niche for each of the 19 species is predicted to decline by a minimum of 17% and maximum of 100% by 2040 (mean for all species of 81%) and minimum of 46% (mean for all species of 95%) by 2080. Seven species are predicted to have some suitable climate niche space reductions (ranging from 1 to 54% of their current suitable area) by 2080 under all three climate scenarios. Three additional species are projected to retain between 0.1 and 9% of their current distribution under one or two of the climate scenarios. In addition to these declines, which are predicted to occur over the next 30 years in northeast Queensland, we discuss and outline pressing research priorities that may be relevant for the conservation of biodiversity on tropical mountaintop environments across the globe. Specifically, further research is needed on thermal tolerances, acclimation potentials, and physiological constraints of tropical mountaintop taxa as current species distributions are primarily determined by climatic factors.

The width of the tropical belt affects the subtropical dry zones and has expanded since 1980. Analyses of observations and climate–chemistry model simulations suggest that the northern tropical edge retracted between 1945 and 1980.

This selective review of the Quaternary paleoclimate of the South American summer monsoon (SASM) domain presents viewpoints regarding a range of key issues in the field, many of which are unresolved and some of which are controversial. (1) El Nino-Southern Oscillation variability, while the most important global-scale mode of interannual climate variation, is insufficient to explain most of the variation of tropical South American climate observed in both the instrumental and the paleoclimate records. (2) Significant climate variation in tropical South America occurs on seasonal to orbital (i.e. multi-millennial) time scales as a result of sea-surface temperature (SST) variation and ocean–atmosphere interactions of the tropical Atlantic. (3) Decadal-scale climate variability, linked with this tropical Atlantic variability, has been a persistent characteristic of climate in tropical South America for at least the past half millennium, and likely, far beyond. (4) Centennial-to-millennial climate events in tropical South America were of longer duration and, perhaps, larger amplitude than any observed in the instrumental period, which is little more than a century long in tropical South America. These were superimposed upon both precession-paced insolation changes that caused significant variation in SASM precipitation and eccentricity-paced global glacial boundary conditions that caused significant changes in the tropical South American moisture balance. As a result, river sediment and water discharge increased and decreased across tropical South America, lake levels rose and fell, paleolakes arose and disappeared on the Altiplano, glaciers waxed and waned in the tropical Andes, and the tropical rainforest underwent significant changes in composition and extent. To further evaluate climate forcing over the last glacial cycle (∼125 ka), we developed a climate forcing model that combines summer insolation forcing and a proxy for North Atlantic SST forcing to reconstruct long-term precipitation variation in the SASM domain. The success of this model reinforces our confidence in assigning causation to observed reconstructions of precipitation. In addition, we propose a critical correction for speleothem stable oxygen isotopic ratios, which are among the most significant of paleoclimate proxies in tropical South America for reconstruction of variation of paleo-precipitation (or SASM intensity). However, it is already well known that any particular δ18O value observed in speleothem carbonate is affected by two processes that have nothing to do with changes in precipitation amount—the influence of temperature on carbonate-water isotopic fractionation in the cave and the influence of changing δ18O of seawater. Quantitatively accounting for both “artifacts” can significantly alter the interpretations of speleothem records. In tropical South America, both adjustments act in the same direction and have the tendency to increase the true amplitude of the paleo-hydrologic signal (but by different amounts in glacial and inter-glacial stages). These corrections have even graver implications for the interpretation of tropical Northern Hemisphere speleothem records (e.g. Chinese speleothems) where the combined adjustments tend to decrease or even eliminate the “true” signal amplitude.

Observations show that cloud feedback over the Namibian stratocumulus region is positive because cloud cover is anticorrelated with local sea surface temperature (SST) anomalies. Moreover, regressions of observed atmospheric fields on equatorial Atlantic SST anomalies indicate that cloud feedbacks over the Namibian stratocumulus region covary with Atlantic Niño. However, from observations alone, it is not possible to quantify the influence of regional cloud feedbacks on equatorial climate variability. To address this question, a set of sensitivity experiments are conducted using an atmospheric general circulation model (ECHAM6) coupled to a slab ocean in which the strength of positive cloud feedback is enhanced over several regions in the South Atlantic basin. Enhanced positive cloud feedback over the Namibian stratocumulus region increases local as well as equatorial SST variability, whereas enhanced cloud feedback over other regions in the South Atlantic increases local SST variability but exhibits negligible responses at the equator. The authors’ results indicate that the Namibian region plays a central role in enhancing equatorial SST variability because it is located where the SST anomalies associated with the simulated Atlantic Niño in the slab-ocean model develop. These results highlight the important role of the regional coupling of cloud cover over the Namibian region with local SSTs and its effects on equatorial Atlantic climate variability.

Using precipitation data from the Climatic Research Unit and the cluster analysis method, the northern Africa (0–30°N; 20°W–40°E) was sub-divided into four homogenous climatic zones for the base period (P0) 1901–1940. The four climatic zones were distributed into Saharan, Sahelian, wet tropical and equatorial climate types. The application of a segment of 15 years with overlap going from 1901–1940 (P0) and 1961 to 2000 (P4) throughout the periods 1916–1955 (P1), 1931–1970 (P2) and 1946–1985 (P3), shows important spatio-temporal modifications of rainfall zones south of 15°N . The semiarid lands (Sahelian) which govern the dynamics of this zone doubled at the end of the twentieth century, while the wet tropical and equatorial zones decreased at the half. Temperature trends have a magnitude of up to 1.5 K per century in all the four climatic zones. This warming was mainly observed during the last three decades. During these same three decades, regional precipitation trends were less significant. The extreme conditions in temperature and the precipitation were analysed in terms of their persistence. The sporadic long-lasting extreme conditions appear for several years to over 10 years during the last century.

Droughts can cause dry-season productivity to decline in tropical forests. This decline occurs when precipitation is below 2,000 mm yr−1, resulting in insufficient subsurface water storage to maintain constant production through the dry season.

Increasing awareness of the impacts of global climate change on marine ecosystems and concerns about shifting bioclimatic and agricultural zones necessitate a reassessment of the geographical distribution of Earth’s climate types. In recent years, the availability of truly global data-sets has allowed for the application of climatic types, including the Kӧppen–Geiger system, over the oceans. This research uses NCAR Reanalysis data to create a global ‘Extended Kӧppen–Geiger climate classification’, including the world ocean, for the 1981−2010 averaging period. The percentages of Earth’s surface covered by tropical rainforest (Af), tropical monsoon (Am), and (especially) the mesothermal– mild summer (Cfc) climate types are much larger than in the terrestrial only analysis. Expanding and contracting terrestrial climate zones are also identified based on the differences in the total area through comparison with maps produced for 1901−1925, 1926−1950, 1951−1975, 1976−2000 and model-output-based predicted Kӧppe...

Most annually resolved climate reconstructions of the Common Era are based on terrestrial data, making it a challenge to independently assess how recent climate changes have affected the oceans. Here as part of the Past Global Changes Ocean2K project, we present four regionally calibrated and validated reconstructions of sea surface temperatures in the tropics, based on 57 published and publicly archived marine paleoclimate data sets derived exclusively from tropical coral archives. Validation exercises suggest that our reconstructions are interpretable for much of the past 400 years, depending on the availability of paleoclimate data within, and the reconstruction validation statistics for, each target region. Analysis of the trends in the data suggests that the Indian, western Pacific, and western Atlantic Ocean regions were cooling until modern warming began around the 1830s. The early 1800s were an exceptionally cool period in the Indo-Pacific region, likely due to multiple large tropical volcanic eruptions occurring in the early nineteenth century. Decadal-scale variability is a quasi-persistent feature of all basins. Twentieth century warming associated with greenhouse gas emissions is apparent in the Indian, West Pacific, and western Atlantic Oceans, but we find no evidence that either natural or anthropogenic forcings have altered El Nino–Southern Oscillation-related variance in tropical sea surface temperatures. Our marine-based regional paleoclimate reconstructions serve as benchmarks against which terrestrial reconstructions as well as climate model simulations can be compared and as a basis for studying the processes by which the tropical oceans mediate climate variability and change.

Eastern Africa, classically presented as a major dry climate anomaly region in the otherwise wet equatorial belt, is a transition zone between the monsoon domains of West Africa and the Indian Ocean. Its complex terrain, unequaled in the rest of Africa, results in a huge diversity of climatic conditions that steer a wide range of vegetation landscapes, biodiversity and human occupations. Meridional rainfall gradients dominate in the west along the Nile valley and its surroundings, where a single boreal summer peak is mostly observed. Bimodal regimes (generally peaking in April and November) prevail in the east, gradually shifting to a single austral summer peak to the south. The swift seasonal shift of the Intertropical Convergence Zone and its replacement in January–February and June–September by strong meridional, generally diverging low-level winds (e.g., the Somali Jet), account for the low rainfall. These large-scale flows interact with topography and lakes, which have their own local circulation in the form of mountain and lake breezes. This results in complex rainfall patterns, with a strong diurnal component, and a frequent asymmetry in the rainfall distribution with respect to the major relief features. Whereas highly organized rain-producing systems are uncommon, convection is partly modulated at intra-seasonal (about 30–60-day) timescales. Interannual variability shows a fair level of spatial coherence in the region, at least in July–September in the west (Ethiopia and Nile Valley) and October–December in the east along the Indian Ocean. This is associated with a strong forcing from sea-surface temperatures in the Pacific and Indian Oceans, and to a lesser extent the Atlantic Ocean. As a result, Eastern Africa shows some of the largest interannual rainfall variations in the world. Some decadal-scale variations are also found, including a drying trend of the March–May rainy season since the 1980s in the eastern part of the region. Eastern Africa overall mean temperature increased by 0.7 to 1 °C from 1973 to 2013, depending on the season. The strong, sometimes non-linear altitudinal gradients of temperature and moisture regimes, also contribute to the climate diversity of Eastern Africa.

The relationships between tropical cyclones in the South Pacific Ocean basin and the two major modes of natural climate variability (i.e., El Nino–Southern Oscillation and the Madden–Julian Oscillation) are reviewed. Main focus is on how tropical cyclone genesis location, frequency, track, and intensity are influenced by these modes of natural variability. The impact of climate change on tropical cyclone characteristic in the South Pacific is also reviewed with particular emphasis on climate model projections.

The performance of improved versions of the four earth system models (ESMs) CNRM, EC-Earth, HadGEM, and MPI-ESM is assessed in comparison to their predecessor versions used in Phase 5 of the Coupled Model Intercomparison Project. The earth System Model Evaluation Tool (ESMValTool) is applied to evaluate selected climate phenomena in the models against observations. This is the first systematic application of the ESMValTool to assess and document the progress made during an extensive model development and improvement project. This study focuses on the South Asian (SAM) and West African (WAM) monsoons, the coupled equatorial climate, and Southern Ocean clouds and radiation, which are known to exhibit systematic biases in present-day ESMs. The analysis shows that the tropical precipitation in three out of four models is significantly improved. Two of three updated coupled models show an improved representation of tropical sea surface temperatures with one coupled model not exhibiting a double Inter-Tropical Convergence Zone. Simulated cloud amounts and cloud-radiation interactions are improved over the Southern Ocean. Improvements are also seen in the simulation of the SAM and WAM, although systematic biases remain in regional details and the timing of monsoon rainfall. Analysis of simulations with EC-Earth at different horizontal resolutions from T159 up to T1279 shows that the synoptic-scale variability of precipitation over the SAM and WAM regions improves with higher model resolution. The results suggest the reasonably good agreement of modeled and observed mean WAM and SAM rainfall in lower resolution models may be a result of unrealistic intensity distributions.

Southern Africa extends from the equator to about 34°S and is essentially a narrow, peninsular land mass bordered to its south, west, and east by oceans. Its termination in the mid-ocean subtropics has important consequences for regional climate, since it allows the strongest western boundary current in the world ocean (warm Agulhas Current) to be in close proximity to an intense eastern boundary upwelling current (cold Benguela Current). Unlike other western boundary currents, the Agulhas retroflects south of the land mass and flows back into the South Indian Ocean, thereby leading to a large area of anomalously warm water south of South Africa which may influence storm development over the southern part of the land mass. Two other unique regional ocean features imprint on the climate of southern Africa—the Angola-Benguela Frontal Zone (ABFZ) and the Seychelles-Chagos thermocline ridge (SCTR). The former is important for the development of Benguela Niños and flood events over southwestern Africa, while the SCTR influences Madden-Julian Oscillation and tropical cyclone activity in the western Indian Ocean. In addition to South Atlantic and South Indian Ocean influences, there are climatic implications of the neighboring Southern Ocean. Along with Benguela Niños, the southern African climate is strongly impacted by ENSO and to lesser extent by the Southern Annular Mode (SAM) and sea-surface temperature (SST) dipole events in the Indian and South Atlantic Oceans. The regional land–sea distribution leads to a highly variable climate on a range of scales that is still not well understood due to its complexity and its sensitivity to a number of different drivers. Strong and variable gradients in surface characteristics exist not only in the neighboring oceans but also in several aspects of the land mass, and these all influence the regional climate and its interactions with climate modes of variability. Much of the interior of southern Africa consists of a plateau 1 to 1.5 km high and a narrow coastal belt that is particularly mountainous in South Africa, leading to sharp topographic gradients. The topography is able to influence the track and development of many weather systems, leading to marked gradients in rainfall and vegetation across southern Africa. The presence of the large island of Madagascar, itself a region of strong topographic and rainfall gradients, has consequences for the climate of the mainland by reducing the impact of the moist trade winds on the Mozambique coast and the likelihood of tropical cyclone landfall there. It is also likely that at least some of the relativity aridity of the Limpopo region in northern South Africa/southern Zimbabwe results from the location of Madagascar in the southwestern Indian Ocean. While leading to challenges in understanding its climate variability and change, the complex geography of southern Africa offers a very useful test bed for improving the global models used in many institutions for climate prediction. Thus, research into the relative shortcomings of the models in the southern African region may lead not only to better understanding of southern African climate but also to enhanced capability to predict climate globally.