Quantification of cloud water interception in the canopy vegetation from fog gauge measurements

With changes in climate looming, quantifying often‐overlooked components of the canopy water budget, such as cloud water interception (CWI), is increasingly important. Commonly, CWI quantification requires detailed continuous measurements, which is extremely challenging, especially when throughfall is included. In this study, we propose a simplified approach to estimate CWI using the Rutter‐type interception model, where CWI inputs in the canopy vegetation are proportional to fog interception measured by an artificial fog gauge. The model requires the continuous acquisition of meteorological variables as input and calibration datasets. Throughfall measurements below the forest are used only for calibration and validation of the model; thus, CWI estimates can be provided even after the cessation of throughfall monitoring. This approach provides an indirect and undemanding way to quantify CWI by vegetation and allows the identification of its controlling factors, which could be useful to the comparison of CWI in contrasting land covers. The method is applied on a 2‐year dataset collected in an endemic highland forest of San Cristobal Island (Galapagos). Our results show that CWI reaches 21% ± 6% of the total water input during the first year, and 9% ± 2% during the second one. These values represent 32% ± 10% and 17% ± 5% of water inputs during the cool foggy season of the first and second year, respectively. The difference between seasons is attributed to a lower fog liquid water during the second season.     

Lower and Middle Pleistocene human settlements recorded in fluvial deposits of the middle Loire River Basin,Centre Region,France

This paper records the findings from c. 80 prehistoric sites that have been discovered in the alluvial deposits of the rivers Creuse, Cher, and Loir, tributaries of the middle Loire River, over the period since 1981. These deposits comprise river terrace aggradations formed during successive glacial–interglacial cycles which have recorded climate and environment during Quaternary time. The systematic dating of these river deposits by Electron Spin Resonance (ESR) applied to optically bleached sedimentary quartz has resulted in the establishment of a chronological framework for the evolution of these rivers during Lower and Middle Pleistocene (between 1.7 Ma and 130 ka). Evidence for Early Palaeolithic (Mode 1) industries with an in situ context (workshops, soils) in the highest aggradations indicates that Hominins were present in the study area, near the geographical centre of France (47°N), around 1.1 Ma. Examination of the sites indicates that Human occupations were located along valley bottom sites during temperate episodes. Subsequently, after a gap of several hundred thousand years industries with handaxes appear in the Middle Loire Basin in the interval between 700 and 600 ka, and then continuously from 400 ka. These two phases of settlement produced industrial assemblages with clear differences in their responses to the supplies of raw materials and in the modes of making flakes.     

Comparing the atmosphere to a bathtub: effectiveness of analogy for reasoning about accumulation

Understanding the process of accumulation is fundamental to recognising the magnitude and speed of emissions reduction required to stabilise atmospheric CO₂ and, hence, global temperature. This research investigated the effectiveness of analogy for building understanding of accumulation among non-experts. Two studies tested the effects of analogy and graphical information on: (1) performance on a CO₂ stabilisation task; and (2) preferred level of action on climate change. Study 1 was conducted with a sample of undergraduate students and Study 2, with a sample of the Australian public. In the student sample, analogical processing significantly improved task performance when information about emission rates was presented in text but not when it was presented in graph format. It was also associated with greater preference for strong action on climate change. When tested with the public, analogy and information format independently influenced task performance. Furthermore, there was a marginal effect of education such that the analogy especially might have helped those with at least high school attainment. Our results show that analogy can improve non-experts’ understanding of CO₂ accumulation but that using graphs to convey emissions rate information is detrimental to such improvements. The results should be of interest to climate change communicators, advocates, and policy-makers.     

On the use of imagery for climate change engagement

This article answers calls from scholars to attend to a research gap concerning the visual representation of climate change. We present results from three Q-methodology workshops held in Melbourne (Australia), Norwich (UK) and Boulder (USA) investigating engagement with climate change imagery drawn from mass media sources. Participants were provided with a concourse of climate change images drawn from a newspaper content analysis carried out across all three countries, and asked to carry out two Q-sorts: first, for salience (‘this image makes me feel climate change is important’) and second, for efficacy (‘this image makes me feel I can do something about climate change’). We found results remarkably consistent both across and within country cohorts. This may indicate the presence of a dominant, mainstream discourse around climate imagery. We found that imagery of climate impacts promotes feelings of salience, but undermines self-efficacy; that imagery of energy futures imagery promotes self-efficacy; and that images of politicians and celebrities strongly undermine saliency, and undermine self-efficacy for the Australian cohort. These results, if widely replicable, have implications for climate change communication and engagement. Our results suggest that imagery plays a role in either increasing the sense of importance of the issue of climate change (saliency), or in promoting feelings of being able to do something about climate change (efficacy) – but few, if any, images seem to do both. Communications strategies should assess the purpose of their messages, considering these findings regarding salience and efficacy in this study, and choose to employ images accordingly.     

Diurnal and tidal patterns of carbon uptake and calcification in geniculate inter‐tidal coralline algae

Research on coralline algal responses to ocean acidification and other environmental stressors has increased in recent years as coralline algae is thought to stand a higher chance of being affected by acidification stress than other macroalgae. To provide context and enhance the existing eco‐physiological framework for climate change studies, it is important to understand the effects of non‐extreme stressors experienced regularly by inter‐tidal coralline algae. In this study, we tested the potentially interacting effects of diurnal and tidal treatments on calcification in the geniculate coralline algae Corallina frondescens and Corallina vancouveriensis using ¹³C‐labeled bicarbonate. Both species deposited more calcium carbonate during the day than at night, and also when submerged (high tide) compared with when emerged (low tide) in their apical and mature segments (intergenicula). These results indicate that inter‐tidal coralline algae do in fact pay a cost for living inter‐tidally at the edge of an adaptive zone.     

Spatial Variability of Sampling: Grid Size Impact on Atmospheric Metals and Trace Elements Deposition Mapping with Mosses

This paper deals with the spatial heterogeneity structure and the influence of the precision of moss data on results interpretation as real spatial variations of atmospheric heavy metal deposition. Different sizes of map mesh net (unit I of 30 × 30 km, unit II of 10 × 10 km, unit III of 3 × 3 km) have divided an area of 90 × 90 km. The protocol used is a nested design with three levels and random draws. The statistical method of components of variance analysis estimates the associated variability for each mesh size. Our results show the poor precision of this biological tool for map purposes on a little scale (unit III). Furthermore, the high residual variance of As, Ba, Cd, Co, Cu, La, Ti, and U hides the spatial variations associated with mesh sizes. In order to obtain useful maps, it should be reasonable to use a 30 × 30 km mesh size, or even larger, to build spatial variation maps of Pb, Sb and with more caution for Cu, Sr, Rb and Zn. For V, As and Cd, the residual variability of moss data was too important to guarantee any spatial origin to the mapped variations. The cost–benefit study shows that the sampling effort has to be concentrated on unit I of 30 × 30 km to optimize future campaigns, and with a particular stress on the sampling repetitions for Cu, Pb, and Sb.     

High resolution simulation of recent Arctic and Antarctic stratospheric chemical ozone loss compared to observations

Simulations of polar ozone losses were performed using the three-dimensional high-resolution (1^∘ × 1^∘) chemical transport model MIMOSA-CHIM. Three Arctic winters 1999–2000, 2001–2002, 2002–2003 and three Antarctic winters 2001, 2002, and 2003 were considered for the study. The cumulative ozone loss in the Arctic winter 2002–2003 reached around 35% at 475 K inside the vortex, as compared to more than 60% in 1999–2000. During 1999–2000, denitrification induces a maximum of about 23% extra ozone loss at 475 K as compared to 17% in 2002–2003. Unlike these two colder Arctic winters, the 2001–2002 Arctic was warmer and did not experience much ozone loss. Sensitivity tests showed that the chosen resolution of 1^∘ × 1^∘ provides a better evaluation of ozone loss at the edge of the polar vortex in high solar zenith angle conditions. The simulation results for ozone, ClO, HNO₃, N₂O, and NO _y for winters 1999–2000 and 2002–2003 were compared with measurements on board ER-2 and Geophysica aircraft respectively. Sensitivity tests showed that increasing heating rates calculated by the model by 50% and doubling the PSC (Polar Stratospheric Clouds) particle density (from 5 × 10⁻³ to 10⁻² cm⁻³) refines the agreement with in situ ozone, N₂O and NO _y levels. In this configuration, simulated ClO levels are increased and are in better agreement with observations in January but are overestimated by about 20% in March. The use of the Burkholder et al. (1990) Cl₂O₂ absorption cross-sections slightly increases further ClO levels especially in high solar zenith angle conditions. Comparisons of the modelled ozone values with ozonesonde measurement in the Antarctic winter 2003 and with Polar Ozone and Aerosol Measurement III (POAM III) measurements in the Antarctic winters 2001 and 2002, shows that the simulations underestimate the ozone loss rate at the end of the ozone destruction period. A slightly better agreement is obtained with the use of Burkholder et al. (1990) Cl₂O₂ absorption cross-sections.     

An intercomparison study of luminescence dating protocols and techniques applied to medieval brick samples from Normandy (France)

A luminescence dating study has been applied to inform the history and archaeology of two early medieval buildings in north western France. Five bricks were sampled from the medieval churches (10th–11th centuries A.D.) of Rugles and Condé-sur-Risle in Normandy. The samples were divided and tested in the luminescence laboratories of the University of Durham (UK) and of Iramat-CRP2A, University of Bordeaux 3 (France). The fine grain and quartz inclusion techniques were applied, and tests included an examination of the anomalous fading of the luminescence signal from fine grain samples and coarse grains of feldspar. With one exception, the dates produced using the fine grain technique, although corrected for fading, were significantly younger than those produced with quartz inclusions. Although most of the corrected fine grain dates were consistent with the medieval construction of the churches, the brick fabric is of Roman type by archaeological assessment, and this is supported by the quartz coarse grain dates. We conclude that the bricks sampled are re-used, likely to be of Roman origin, and that the reliability of measurements with feldspars in brick fabrics requires wider investigation.