High-latitude Locations Research Articles

Self-reported discomfort associated with Daylight Saving Time in Brazilian tropical and subtropical zones

Background: Daylight Saving Time (DST) annually moves clocks 1 hour forward, when daytime is longer than night. Previous studies from medium and high latitude locations have pointed to a disruptive effect of DST on human circadian rhythms. Since Brazil is an equatorial country implementing DST, a different relationship between photic and social synchronisers may interfere with DST effects.Aim: To explore the prevalence and duration of self-reported discomfort related to DST among Brazilian residents (latitude 12–33° S, longditude 39–57° W). It was hypothesised that an elevated prevalence of self-reported discomfort would be found in Brazil, due to the pronounced uncoupling between social and geophysical synchronisers.Subjects and methods: In total, 12 467 volunteers completed a web-based, Brazilian version of Horne-Östberg Morningness-Eveningness Questionnaire, provided demographic information, and answered questions related to DST complaints (discomfort, duration of discomfort).Results: Of the total sample, 45.43% reported no discomfort related to DST, with meaningful proportions for all chronotypes. However, eveningness was most associated with discomfort. About one fourth of the total sample reported discomfort over the whole DST period. Gender interaction is largely supported by these results.Conclusions: DST at low latitude locations may be disruptive for circadian rhythms, since seasonality of sunrise near the equator is negligible or very mild.

Design of an innovative linear Fresnel collector by means of optical performance optimization: A comparison with parabolic trough collectors for different latitudes

Different innovative linear Fresnel field designs are obtained for two locations of latitudes 37° N and 24° N. This designs are the result of the exergy efficiency optimization by means of a validated Monte Carlo Ray Trace code and analytic methods. From the results obtained it is concluded that, whereas for high latitude locations East-West orientation achieves higher efficiencies with lower cost, when the solar field is located in latitudes closer to the tropics NS orientation is a better solution. From the performance comparison between Fresnel and trough collectors it results that, although the latter always achieves higher exergy efficiencies, differences are importantly reduced for low latitudes.

Probing the infrared counterparts of diffuse far-ultraviolet sources in the Galaxy

Recent availability of high quality infrared (IR) data for diffuse regions in the Galaxy and external galaxies have added to our understanding of interstellar dust. A comparison of ultraviolet (UV) and IR observations may be used to estimate absorption, scattering and thermal emission from interstellar dust. In this paper, we report IR and UV observations for selective diffuse sources in the Galaxy. Using archival mid-infrared (MIR) and far-infrared (FIR) observations from Spitzer Space Telescope, we look for counterparts of diffuse far-ultraviolet (FUV) sources observed by the Voyager, Far Ultraviolet Spectroscopic Explorer (FUSE) and Galaxy Evolution Explorer (GALEX) telescopes in the Galaxy. IR emission features at 8µm are generally attributed to Polycyclic Aromatic Hydrocarbon (PAH) molecules, while emission at 24µm are attributed to Very Small Grains (VSGs). The data presented here is unique and our study tries to establish a relation between various dust populations. By studying the FUV-IR correlations separately at low and high latitude locations, we have identified the grain component responsible for the diffuse FUV emission.

Cyphastrea salae, a new species of hard coral from Lord Howe Island, Australia (Scleractinia, Merulinidae).

A new zooxanthellate reef-dwelling scleractinian coral species, Cyphastrea salae sp. n. (Scleractinia, Merulinidae), is described from Lord Howe Island Australia. The new species can be distinguished morphologically from the only other congeneric species on Lord Howe Island, C. microphthalma, by the number of primary septa (12 vs. 10) and the much taller corallites (mean ± SE: 1.0 ± 0.07 mm v 0.4 ± 0.04 mm). The relationship of C. salae to four of the other eleven currently accepted species in the genus was explored through analyses of nuclear (28S rDNA) and mitochondrial (noncoding intergenic region) gene sequences. Cyphastrea salae sp. n. forms a strongly supported clade that is distinct from a clade containing three species found commonly in Australia, C. chalcidicum, C. serailia, and C. microphthalma. One specimen was also found in the Solitary Islands, another high latitude location in south-eastern Australia. The discovery of a new species in the genus Cyphastrea on high latitude reefs in south-eastern Australia suggests that other new species might be found among more diverse genera represented here and that the scleractinian fauna of these isolated locations is more distinct than previously recognised.

Calibration of the physiological equivalent temperature index for three different climatic regions.

In human biometeorology, the integration of several microclimatic variables as a combined index facilitates the understanding of how users perceive thermal environments. Indices, such as the physiological equivalent temperature (PET) index, translate the combined effects of meteorological variables on humans in terms of thermal stress or comfort and serve as important aids to climate-responsive urban and regional planning as well as heat stress and thermal comfort analyses. However, there is a need for adjusting proposed comfort/stress ranges of a given index when using it in different climatic contexts. The purpose of this study is to present a preliminary calibration procedure for the PET index for three different climatic regions: Curitiba, Brazil, a subtropical location; Rio de Janeiro, Brazil, a tropical city; and Glasgow, UK, a high-latitude location. Field studies have been carried out by the authors according to a similar protocol and using similar equipment, yielding actual thermal sensation votes and microclimate data, post-processed as PET data. The calibration procedure uses exclusively thermal sensation data as reported by pedestrians during outdoor comfort campaigns and concurrent microclimatic data recorded during the interviews. PET comfort/stress classes differ among the three locations and, in general, are less restrictive as in the original ranges proposed by the index developers.

Greater temperature sensitivity of plant phenology at colder sites: implications for convergence across northern latitudes.

Warmer temperatures are accelerating the phenology of organisms around the world. Temperature sensitivity of phenology might be greater in colder, higher latitude sites than in warmer regions, in part because small changes in temperature constitute greater relative changes in thermal balance at colder sites. To test this hypothesis, we examined up to 20years of phenology data for 47 tundra plant species at 18 high-latitude sites along a climatic gradient. Across all species, the timing of leaf emergence and flowering was more sensitive to a given increase in summer temperature at colder than warmer high-latitude locations. A similar pattern was seen over time for the flowering phenology of a widespread species, Cassiope tetragona. These are among the first results highlighting differential phenological responses of plants across a climatic gradient and suggest the possibility of convergence in flowering times and therefore an increase in gene flow across latitudes as the climate warms.

Bergmann's Body Size Rule Operates in Facultatively Endothermic Insects: Evidence from a Complex of Cryptic Bumblebee Species.

According to Bergmann’s rule we expect species with larger body size to inhabit locations with a cooler climate, where they may be well adapted to conserve heat and resist starvation. This rule is generally applied to endotherms. In contrast, body size in ectothermic invertebrates has been suggested to follow the reverse ecogeographic trend: these converse Bergmann’s patterns may be driven by the ecological constraints of shorter season length and lower food availability in cooler high latitude locations. Such patterns are particularly common in large insects due to their longer development times. As large and facultatively endothermic insects, bumblebees could thus be expected to follow either trend. In this investigation, we studied body size of three bumblebee species over a large spatial area and investigated whether interspecific trends in body size correspond to differences in their distribution consistent with either Bergmann’s or a converse Bergmann’s rule. We examined the body size of queens, males and workers of the Bombus lucorum complex of cryptic bumblebee species from across the whole of Great Britain. We found interspecific differences in body size corresponding to Bergmann’s rule: queens and males of the more northerly distributed, cool-adapted, species were largest. In contrast, the mean body size of the worker caste did not vary between the three species. These differences in body size may have evolved under selection pressures for thermoregulation or starvation resistance. We suggest that this case study in facultatively endothermic insects may help clarify the selection pressures governing Bergmann rule trends more generally.

Assessing Climate Change Impacts on Water Resources in the Songhua River Basin

The Songhua River Basin (SRB) in Northeast China is one of the areas most sensitive to global climate change because of its high-latitude location. In this study, we conducted a modeling assessment on the potential change of water resources in this region for the coming three decades using the Soil and Water Assessment Tool (SWAT). First, we calibrated and validated the model with historical streamflow records in this basin. Then, we applied the calibrated model for the period from 2020 to 2049 with the projected and downscaled climatic data under two emission scenarios (RCP 4.5 and RCP 8.5). The study results show: (1) The SWAT model performed very well for both the calibration and validation periods in the SRB; (2) The projected temperatures showed a steady, significant increase across the SRB under both scenarios, especially in two sub-basins, the Nenjiang River Basin (NRB) and the Lower SRB (LSRB). With regard to precipitation, both scenarios showed a decreasing trend in the NRB and LSRB but an increasing trend in the Upper Songhua River Basin (USRB); and (3), generally, the hydrologic modeling suggested a decreasing trend of streamflow for 2020–2049. Compared to baseline conditions (1980–2009), the streamflow in the NRB and LSRB would decrease by 20.3%–37.8%, while streamflow in the USRB would experience an increase of 9.68%–17.7%. These findings provide relevant insights into future surface water resources, and such information can be helpful for resource managers and policymakers to develop effective eco-environment management plans and strategies in the face of climate change.

Comparison of MODIS and VIIRS cloud properties with ARM ground-based observations over Finland

Abstract. Cloud retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments aboard the satellites Terra and Aqua and the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard the Suomi-NPP satellite are evaluated using a combination of ground-based instruments providing vertical profiles of clouds. The ground-based measurements are obtained from the Atmospheric Radiation Measurement (ARM) programme mobile facility, which was deployed in Hyytiälä, Finland, between February and September 2014 for the Biogenic Aerosols – Effects on Clouds and Climate (BAECC) campaign. The satellite cloud parameters cloud top height (CTH) and liquid water path (LWP) are compared with ground-based CTH obtained from a cloud mask created using lidar and radar data and LWP acquired from a multi-channel microwave radiometer. Clouds from all altitudes in the atmosphere are investigated. The clouds are diagnosed as single or multiple layer using the ground-based cloud mask. For single-layer clouds, satellites overestimated CTH by 326 m (14 %) on average. When including multilayer clouds, satellites underestimated CTH by on average 169 m (5.8 %). MODIS collection 6 overestimated LWP by on average 13 g m−2 (11 %). Interestingly, LWP for MODIS collection 5.1 is slightly overestimated by Aqua (4.56 %) but is underestimated by Terra (14.3 %). This underestimation may be attributed to a known issue with a drift in the reflectance bands of the MODIS instrument on Terra. This evaluation indicates that the satellite cloud parameters selected show reasonable agreement with their ground-based counterparts over Finland, with minimal influence from the large solar zenith angle experienced by the satellites in this high-latitude location.

In Situ Balloon-Borne Ice Particle Imaging in High-Latitude Cirrus

Cirrus clouds reflect incoming solar radiation, creating a cooling effect. At the same time, these clouds absorb the infrared radiation from the Earth, creating a greenhouse effect. The net effect, crucial for radiative transfer, depends on the cirrus microphysical properties, such as particle size distributions and particle shapes. Knowledge of these cloud properties is also needed for calibrating and validating passive and active remote sensors. Ice particles of sizes below 100 µm are inherently difficult to measure with aircraft-mounted probes due to issues with resolution, sizing, and size-dependent sampling volume. Furthermore, artefacts are produced by shattering of particles on the leading surfaces of the aircraft probes when particles several hundred microns or larger are present. Here, we report on a series of balloon-borne in situ measurements that were carried out at a high-latitude location, Kiruna in northern Sweden (68N 21E). The method used here avoids these issues experienced with the aircraft probes. Furthermore, with a balloon-borne instrument, data are collected as vertical profiles, more useful for calibrating or evaluating remote sensing measurements than data collected along horizontal traverses. Particles are collected on an oil-coated film at a sampling speed given directly by the ascending rate of the balloon, 4 m s−1. The collecting film is advanced uniformly inside the instrument so that an always unused section of the film is exposed to ice particles, which are measured by imaging shortly after sampling. The high optical resolution of about 4 µm together with a pixel resolution of 1.65 µm allows particle detection at sizes of 10 µm and larger. For particles that are 20 µm (12 pixel) in size or larger, the shape can be recognized. The sampling volume, 130 cm3 s−1, is well defined and independent of particle size. With the encountered number concentrations of between 4 and 400 L−1, this required about 90- to 4-s sampling times to determine particle size distributions of cloud layers. Depending on how ice particles vary through the cloud, several layers per cloud with relatively uniform properties have been analysed. Preliminary results of the balloon campaign, targeting upper tropospheric, cold cirrus clouds, are presented here. Ice particles in these clouds were predominantly very small, with a median size of measured particles of around 50 µm and about 80 % of all particles below 100 µm in size. The properties of the particle size distributions at temperatures between −36 and −67 °C have been studied, as well as particle areas, extinction coefficients, and their shapes (area ratios). Gamma and log-normal distribution functions could be fitted to all measured particle size distributions achieving very good correlation with coefficients R of up to 0.95. Each distribution features one distinct mode. With decreasing temperature, the mode diameter decreases exponentially, whereas the total number concentration increases by two orders of magnitude with decreasing temperature in the same range. The high concentrations at cold temperatures also caused larger extinction coefficients, directly determined from cross-sectional areas of single ice particles, than at warmer temperatures. The mass of particles has been estimated from area and size. Ice water content (IWC) and effective diameters are then determined from the data. IWC did vary only between 1 × 10−3 and 5 × 10−3 g m−3 at temperatures below −40 °C and did not show a clear temperature trend. These measurements are part of an ongoing study.

The role of vitamin D in muscle strength among the elderly

Vitamin D deficiency is a common condition among the elderly and it is associated with an increased risk of fractures. The condition is common among elderly at higher latitude locations and very common among the institutionalized. Currently there is also evidence that low levels of vitamin D are associated with multiple disorders such as cardiovascular diseases, inflammation, and infectious diseases, among other things. In addition, clinical studies on the elderly have shown that the low vitamin D levels correlate with reduced muscle strength in the lower limbs and poor physical performance. However, suitable levels for maintaining proper muscle function and strength have not yet been established. Objective: To verify recent evidence of the effects of vitamin D on muscle strength in the elderly. Method: A survey of studies published between 2010 and 2014 in Pubmed, Medline, and Scopus using the terms “cholecalciferol”, “muscle strength,” and “elderly.” Results: Seven studies were selected. The results suggest a positive influence of vitamin D on muscle strength in the elderly. Conclusion: This review showed that despite the action of vitamin D on the musculoskeletal system, there is still uncertainty; there tended to be a greater benefit with vitamin D supplementation at higher doses. However, additional studies are needed to define the best therapeutic profile

The role of vitamin D in muscle strength among the elderly

Vitamin D deficiency is a common condition among the elderly and it is associated with an increased risk of fractures. The condition is common among elderly at higher latitude locations and very common among the institutionalized. Currently there is also evidence that low levels of vitamin D are associated with multiple disorders such as cardiovascular diseases, inflammation, and infectious diseases, among other things. In addition, clinical studies on the elderly have shown that the low vitamin D levels correlate with reduced muscle strength in the lower limbs and poor physical performance. However, suitable levels for maintaining proper muscle function and strength have not yet been established. Objective: To verify recent evidence of the effects of vitamin D on muscle strength in the elderly. Method: A survey of studies published between 2010 and 2014 in Pubmed, Medline, and Scopus using the terms “cholecalciferol”, “muscle strength,” and “elderly.” Results: Seven studies were selected. The results suggest a positive influence of vitamin D on muscle strength in the elderly. Conclusion: This review showed that despite the action of vitamin D on the musculoskeletal system, there is still uncertainty; there tended to be a greater benefit with vitamin D supplementation at higher doses. However, additional studies are needed to define the best therapeutic profile

The pulsed-flow design: A new low-cost solar collector

A new pulsed-flow design of hose-based solar collector is presented, which uses a long hose connected to district-grid water in the same way that the basic hose design does. But on contrary that this last, here the exit is not connected directly to consumption and instead the hot water flow is controlled by a thermostat that purges the hose to an insulated tank every time it reaches the desired temperature. So, this water-pond collector works close its maximum efficiency along the day and minimizes nocturnal cooling effect, improving noticeably the performance of the original hose design. As was demonstrated by thermal modeling, this new pulsed-flow design could satisfy the domestic demand of sanitary hot water even in high-latitude locations and furthermore, its performance could be noticeably improved by adding a smart microcontroller. The economic analysis shows this design could be highly competitive applied to large hot-water demands and relatively good for single family demands.

The Effect of Elevated CO2 and Increased Temperature on in Vitro Fertilization Success and Initial Embryonic Development of Single Male:Female Crosses of Broad-Cast Spawning Corals at Mid- and High-Latitude Locations

The impact of global climate change on coral reefs is expected to be most profound at the sea surface, where fertilization and embryonic development of broadcast-spawning corals takes place. We examined the effect of increased temperature and elevated CO2 levels on the in vitro fertilization success and initial embryonic development of broadcast-spawning corals using a single male:female cross of three different species from mid- and high-latitude locations: Lyudao, Taiwan (22° N) and Kochi, Japan (32° N). Eggs were fertilized under ambient conditions (27 °C and 500 μatm CO2) and under conditions predicted for 2100 (IPCC worst case scenario, 31 °C and 1000 μatm CO2). Fertilization success, abnormal development and early developmental success were determined for each sample. Increased temperature had a more profound influence than elevated CO2. In most cases, near-future warming caused a significant drop in early developmental success as a result of decreased fertilization success and/or increased abnormal development. The embryonic development of the male:female cross of A. hyacinthus from the high-latitude location was more sensitive to the increased temperature (+4 °C) than the male:female cross of A. hyacinthus from the mid-latitude location. The response to the elevated CO2 level was small and highly variable, ranging from positive to negative responses. These results suggest that global warming is a more significant and universal stressor than ocean acidification on the early embryonic development of corals from mid- and high-latitude locations.

Perennial growth of hermatypic corals at Rottnest Island, Western Australia (32°S).

To assess the viability of high latitude environments as coral refugia, we report measurements of seasonal changes in seawater parameters (temperature, light, and carbonate chemistry) together with calcification rates for two coral species, Acropora yongei and Pocillopora damicornis from the southernmost geographical limit of these species at Salmon Bay, Rottnest Island (32°S) in Western Australia. Changes in buoyant weight were normalised to colony surface areas as determined from both X-ray computed tomography and geometric estimation. Extension rates for A. yongei averaged 51 ± 4 mm y−1 and were comparable to rates reported for Acroporid coral at other tropical and high latitude locations. Mean rates of calcification for both A. yongei and P. damicornis in winter were comparable to both the preceding and following summers despite a mean seasonal temperature range of ∼6 °C (18.2°–24.3 °C) and more than two-fold changes in the intensity of downwelling light. Seasonal calcification rates for A. yongei (1.31–2.02 mg CaCO3 cm−2 d−1) and P. damicornis (0.34–0.90 mg CaCO3 cm−2 d−1) at Salmon Bay, Rottnest Island were comparable to rates from similar taxa in more tropical environments; however, they appeared to decline sharply once summer temperatures exceeded 23 °C. A coral bleaching event observed in December 2013 provided further evidence of how coral at Rottnest Island are still vulnerable to the deleterious effects of episodic warming despite its high latitude location. Thus, while corals at Rottnest Island can sustain robust year-round rates of coral growth, even over cool winter temperatures of 18°–19 °C, there may be limits on the extent that such environments can provide refuge against the longer term impacts of anthropogenic climate change.

Global warming impact on floral phenology of fruit trees species in Mediterranean region

This study was carried out in three geographically contrasting countries of the Mediterranean region. It aims to understand the impact of climate change, particularly the temperature increases, on phenological stage of three taxonomically different species (early and late-spring-flowering species). Three species, namely olive (Olea europaea), apple (Malus domestica Borkh.) and almond (Prunus dulcis (Mill.)) were investigated to highlight the phenological behavior of one species at different locations and different species at one location. Climatic and phenological data were collected from Morocco, France and Italy over the last 40 years. Analysis of data on temperature showed a strong warming in the northern locations (coldest areas), particularly in Nîmes, compared to the southern ones (warmer locations) during the period October to May. The marked spring warming in all locations since the end of 1980s in France (the beginning of 1990s in Italy and Morocco) resulted in blooming earliness, with regional patterns in terms of impact. The late-spring-flowering species (olive and apple) showed a remarkable sensitivity to continuous warming in different areas. No flowering earliness was observed in early-spring-flowering species (almond), due to the stability of mean temperature during February. Thus, a strong control of mean temperature during the forcing period on flowering earliness of apple was found in all areas. Physiological processes (dormancy and dormancy release) of trees during the dormant and growth period explain, in part, the regional differences observed in flowering dates among sites and species. Overall, the pronounced warming in the southern France reflects a relative trend toward aridity of climate at this site, and consequently some vulnerability of fruit trees. As result, the process of flowering in a high latitude locations (northern areas) in the future can be represented by that in a low latitude locations at present (southern areas), particularly for apple.

Effect of temperature on the structure and activity of a methanogenic archaeal community during rice straw decomposition

In recent years, the rice fields in Sanjiang Plain of Northeast China have drawn more and more attention because of the unique high-latitude location and the important contributions to rice production and methane emission. In the present study, a rice field soil in Sanjiang Plain was anaerobically incubated in presence and absence of rice straw at three temperatures (10 °C, 30 °C and 45 °C). The community structure and activity dynamics of methanogenic archaea were investigated by the terminal restriction fragment length polymorphism analyses in combination with cloning and sequencing of mcrA genes and transcripts and archaeal 16S rRNA genes. We found rice straw addition significantly shortened the lag phase of methanogenesis and enhanced the production of CH4 and the accumulation of methanogenic precursors (CO2, H2 and acetate). The T-RFLP analysis of mcrA gene revealed that structure of methanogenic archaeal community was relatively stable during the anoxic incubation. By contrast, analysis at the transcript level showed a highly dynamic composition of the active methanogens. In the beginning and early stages of incubation, Methanosarcinaceae actively utilized the accumulated acetate and H2/CO2 for CH4 production. Then the different methanogenic community developed along with the incubation time, and each representative methanogen group became predominant in different temperatures and treatments. At 10 °C, Methanobacteriales became more abundant in the soil without straw, while Methanosarcinaceae dominated in the soil with straw. The acetoclastic Methanosaetaceae, in particular, appeared to be active at 30 °C, probably due to the low concentration of acetate. High temperature of 45 °C significantly favored the hydrogenotrophic methanogens, with the increasing abundance of Methanobacteriales early and then the Methanocellales in the later stages.

Contrasting patterns of peptidase activities in seawater and sediments: An example from Arctic fjords of Svalbard

The structural specificities and activities of microbial extracellular enzymes help determine the nature and quantity of substrates available for microbial uptake, and therefore the rate and location of organic matter transformation in the ocean. Previous work has demonstrated major differences in the spectrum of enzymes hydrolyzing polysaccharides in the water column and sediments, particularly in high-latitude locations. To determine whether pelagic–benthic contrasts in enzyme activities extend to other classes of organic matter, the hydrolysis of five peptide substrates was investigated in two Arctic fjords of Svalbard. Substrates were intended to measure leucine aminopeptidase activity (exo-acting; terminal-unit cleaving), plus chymotrypsin and trypsin activities (endo-acting; mid-chain cleaving). All substrates were readily hydrolyzed in surface sediments. In contrast, only two to four of the peptide substrates were hydrolyzed in the water column of both fjords. Chymotrypsin activities were undetectable or were far lower than trypsin and leucine aminopeptidase activities in the water column, but were comparable to the activities of other enzymes in sediments. The pelagic–benthic contrast in the spectrum of peptide substrates hydrolyzed in these fjords parallels patterns of hydrolysis previously observed for polysaccharides. Some organic matter may pass untouched through the water column due to a lack of the specific enzymes required for hydrolysis; these substrates could then selectively fuel benthic metabolism. Pelagic–benthic contrasts in enzymatic capabilities may be widespread in the ocean, and thus affect the processing of a significant fraction of marine organic matter.

Reduced calcification in Western Australian corals during anomalously high summer water temperatures

Here we report the seasonal response of calcification rates over two years, for three coral species (Acropora pulchra, Pocillopora damicornis and Goniastrea aspera), to anomalously warm summer water temperatures (2012 and 2013), following the most severe marine heat wave on record (2010–2011). The study sites at Coral Bay (Ningaloo Reef), the Houtman Abrolhos Islands and Marmion Reef (Perth) spanned over 10° of latitude and ranged from tropical to temperate habitats. Calcification rates were determined using repeated measurements of buoyant weight normalized to surface area and rates were monitored over two winters and two summers from 2011 to 2013. Average growth rates followed predicted latitudinal trends, with the fastest growth in the tropics (Coral Bay) and slowest growth rates in the temperate zone (Marmion). However, calcification rates did not show the expected seasonality (higher in summer, lower in winter), even at high latitude locations. Instead, there was either little difference between summer and winter growth or growth was slower in the summer (on average, a reduction of ~40% across locations and species). Additionally, differences in species growth rates did not follow expected trends, with usually fast growing branching corals not calcifying much faster than the normally slower growing massive corals (A. pulchra, grew ~40% faster than G. aspera, which grew ~6% faster than P. damicornis across all latitudes and seasons). Survival rates were also reduced in the summer months, while among species, P. damicornis had the lowest survival and G. aspera the highest. We conclude that high temperature stress through the summers of 2011 to 2013 was the most likely cause for the lack of seasonality in calcification rates, the similarity in calcification rates among species and the increased mortality of susceptible species in the summer months. The effect of prolonged elevated temperature anomalies (1.5 to 3°C) on the growth and survival of colonies over consecutive years was often greater than the fundamental influences of season and species, highlighting the extent to which climate change could now be re-structuring the life histories of corals on Western Australian reefs.

The Vertical-Tube Solar Collector: A Low-Cost Design Suitable for Temperate High-Latitude Locations

A new low-cost solar collector based on thick (4.5′′) vertical tubes related to the previous design based on long 1.5′′ plastic hoses connected directly between water-grid supply and consumption is presented. This novel design could noticeably improve its performance for temperate locations mid and high latitudes, as was demonstrated by dynamic thermal modeling. This tool has been useful for understanding the particular characteristics of this kind of water-pond collector and besides, for noticeably improving its performance by optimizing its parameters, like tube diameter and number of glazing layers. By this way, the optimized design could fully satisfy the household demand up to midnight along the whole year for Buenos Aires (35°S) and during summers (remaining as a useful preheater for the whole year) for Ushuaia (55°S). Besides, its high simplicity makes it available for user’s own construction, costing down 50 dollars for a single-family unit.