Assessment of a 2016 mission concept: The search for trace gases in the atmosphere of Mars

The reported detection of methane in the atmosphere of Mars as well as its potentially large seasonal spatial variations challenge our understanding of both the sources and sinks of atmospheric trace gases. The presence of methane suggests ongoing exchange between the subsurface and the atmosphere of potentially biogenic trace gases, while the spatial and temporal variations cannot be accounted for with current knowledge of martian photochemistry. A Joint Instrument Definition Team (JIDT) was asked to assess concepts for a mission that might follow up on these discoveries within the framework of a series of joint missions being considered by ESA and NASA for possible future exploration of Mars. The following is based on the report of the JIDT to the space agencies (Zurek et al., 2009); a synopsis of the report was presented at the Workshop on Mars Methane held in Frascati, Italy, in November 2009. To summarize, the JIDT believed that a scientifically exciting and credible mission could be conducted within the evolving capabilities of the science/telecommunications orbiter being considered by ESA and NASA for possible launch in the 2016 opportunity for Mars.     

Evaluation of regional climate simulations for air quality modelling purposes

In order to evaluate the future potential benefits of emission regulation on regional air quality, while taking into account the effects of climate change, off-line air quality projection simulations are driven using weather forcing taken from regional climate models. These regional models are themselves driven by simulations carried out using global climate models (GCM) and economical scenarios. Uncertainties and biases in climate models introduce an additional “climate modeling” source of uncertainty that is to be added to all other types of uncertainties in air quality modeling for policy evaluation. In this article we evaluate the changes in air quality-related weather variables induced by replacing reanalyses-forced by GCM-forced regional climate simulations. As an example we use GCM simulations carried out in the framework of the ERA-interim programme and of the CMIP5 project using the Institut Pierre-Simon Laplace climate model (IPSLcm), driving regional simulations performed in the framework of the EURO-CORDEX programme. In summer, we found compensating deficiencies acting on photochemistry: an overestimation by GCM-driven weather due to a positive bias in short-wave radiation, a negative bias in wind speed, too many stagnant episodes, and a negative temperature bias. In winter, air quality is mostly driven by dispersion, and we could not identify significant differences in either wind or planetary boundary layer height statistics between GCM-driven and reanalyses-driven regional simulations. However, precipitation appears largely overestimated in GCM-driven simulations, which could significantly affect the simulation of aerosol concentrations. The identification of these biases will help interpreting results of future air quality simulations using these data. Despite these, we conclude that the identified differences should not lead to major difficulties in using GCM-driven regional climate simulations for air quality projections.     

A matter of tolerance: Distribution potential of scyphozoan polyps in a changing environment

Jellyfish blooms are unpredictable, unsustainable events, frequently affecting aquatic ecosystems severely. Of particular interest are the consequences of environmental change for jellyfish populations, especially in semi‐enclosed habitats. Regional and seasonal changes in water chemistry and physics may control the distribution of sessile polyps in the Baltic Sea, hence potentially driving the population dynamics of the two abundant medusa species Aurelia aurita and Cyanea capillata (Scyphozoa, Cnidaria). In laboratory experiments, settlement, growth, survival and physiological condition of A. aurita polyps were investigated at different levels of water temperature, pH and salinity. Survival and physiological condition of C. capillata polyps were examined after exposure to low salinity levels. Increased settlement of A. aurita planula larvae was observed on substrate plates at low temperature (4°C), low pH (7.4) and low salinity (7.5 psu), whereas early polyp growth was constrained by salinity ≤10 psu. Aurelia aurita polyps were in good physiological condition over the whole temperature range, while exposure to pH <6.5 led to stepwise tissue degradation. Salinity reduction to ≤5 and ≤8 psu caused irreversible degeneration of A. aurita and C. capillata polyps, respectively. Observed physiological limits suggest distribution of polyp populations of A. aurita in central and of C. capillata in western parts of the Baltic Sea, while future climate changes may particularly restrict occurrence of the less tolerant C. capillata.     

Offspring of Watsuji's theory of milieu (F^udo)

Watsuji Tetsurô (1889–1960), a Japanese philosopher, published in 1935 Fûdo: ningengakuteki kôsatsu, an essay on the relationship between the character of human societies and the natural conditions of their environment, mainly climate. This book has generally been understood as an illustration of geographical determinism, to which belong indeed some of the main supporters of Watsuji's theory. Yet Watsuji himself stated explicitly that his book was not about the influence of the natural environment on human life, but about ‘the structural moment of human existence’, in which the matter is milieu (fûdo) and mediance (fûdosei), not environment (kankyô), and which has much in common with Heidegger's Dasein, although Watsuji contests the Heideggerian precedence of temporality on spatiality. In this respect, Fûdo is the forerunner of a promising trend in cultural geography: studies on the geographical constitution of Being, opening the way to a recosmization of the human.     

Laboratory and numerical studies of wave damping by emergent and near-emergent wetland vegetation

Wetlands protect mainland areas from erosion and damage by damping waves. Yet, this critical role of wetland is not fully understood at present, and a means for reliably determining wave damping by vegetation in engineering practice is not yet available. Laboratory experiments were conducted to measure wave attenuation resulting from synthetic emergent and nearly emergent wetland vegetation under a range of wave conditions and plant stem densities. The laboratory data were analyzed using linear wave theory to quantify bulk drag coefficients and with a nonlinear Boussinesq model to determine numerical friction factors to better represent wetland vegetation in engineering analysis.     

Stakeholder participation in ecosystem-based approaches to fisheries management: A synthesis from European research projects

In this synthesis article, we claim that institutional innovation is required for ecosystem-based approaches to fisheries management (EBAFM), and that such innovation can best be achieved by engaging in a delicate process of societal decision making. Current instances of participation in fisheries shed light on the societal processes required for such institutional innovation. We apply the IBEFish analytical frame to examine findings from recent European research on participation in fisheries management at different jurisdictional levels. We distil several issues of major concern for institutional innovation towards EBAFM. These concern information management, legitimacy, social dynamics and costs, as well as aspects of cross-scale and cross-sector integration of fisheries governance.     

Control of the repeatability of high frequency multibeam echosounder backscatter by using natural reference areas

The increased use of backscatter measurements in time series for environmental monitoring necessitates the comparability of individual results. With the current lack of pre-calibrated multibeam echosounder systems for absolute backscatter measurement, a pragmatic solution is the use of natural reference areas for ensuring regular assessment of the backscatter measurement repeatability. This method mainly relies on the assumption of a sufficiently stable reference area regarding its backscatter signature. The aptitude of a natural area to provide a stable and uniform backscatter response must be carefully considered and demonstrated by a sufficiently long time-series of measurements. Furthermore, this approach requires a strict control of the acquisition and processing parameters. If all these conditions are met, stability check and relative calibration of a system are possible by comparison with the averaged backscatter values for the area. Based on a common multibeam echosounder and sampling campaign completed by available bathymetric and backscatter time series, the suitability as a backscatter reference area of three different candidates was evaluated. Two among them, Carré Renard and Kwinte, prove to be excellent choices, while the third one, Western Solent, lacks sufficient data over time, but remains a valuable candidate. The case studies and the available backscatter data on these areas prove the applicability of this method. The expansion of the number of commonly used reference areas and the growth of the number of multibeam echosounder controlled thereon could greatly contribute to the further development of quantitative applications based on multibeam echosounder backscatter measurements.     

Ground-based remote sensing observation of the complex behaviour of the Marseille boundary layer during ESCOMPTE

Ground-based remote sensing systems have been used during the ESCOMPTE campaign, to continuously characterize the boundary-layer behaviour through many atmospheric parameters (wind, extinction and ozone concentration distribution, reflectivity, turbulence). This analysis is focused on the comparison of the atmospheric stratification retrieved from a UV angular ozone lidar, an Ultra High Frequency wind profiler and a sodar, above the area of Marseille, on June 26th 2001 (Intensive Observation Period 2b). The atmospheric stratification is shown to be very complex including two superimposed sea breezes, with an important contribution of advection. The temporal and spatial evolution of the stratification observed by the UV lidar and by the UHF radar are in good agreement although the origin of the echoes of these systems is quite different. The complexity of the dynamic situation has only partially been retrieved by a non-hydrostatic mesoscale model used with a 3 km resolution.