The targets of management rules for marine mammal populations require justification: A reply to

The management of anthropogenic impacts on marine mammal populations involves the setting of targets that are built on assumptions and choices. Scientific methods can be used to investigate the implications of management actions, but the choice of overall objectives and priorities lies outside science. A recent paper (Potential biological removal and other currently used management rules for marine mammal populations: A comparison in Marine Policy), summarised the characteristics of the main approaches currently used to set conservation management targets for marine mammal populations in order to provide a basis for discussion of the targets they contain. Cooke et al. (Management rules for marine mammal populations: A response to Lonergan in Marine Policy) responded, giving some important additional information about these management rules. However most of that paper's criticisms were incorrect or misplaced. Specifically, it erroneously treated an example of how PBR could be reworked, to make its abundance explicit, as a proposal to ignore uncertainty in managing populations. This paper addresses Cooke's main criticisms, and suggests that explicit justifications should be an important part of the process of setting targets for the management of marine mammal populations.     

Fluxes of Sr into the headwaters of the Ganges

Himalayan weathering is recognized as an important agent in modifying sea water chemistry, but there are significant uncertainties in our understanding of Himalayan riverine fluxes. This paper examines causes of the variability, including that of the seasons, by analysis of downstream variations in Sr, ⁸⁷Sr, and major ions in the mainstream, in relation to the composition of tributary streams from subcatchments with differing geologic substrates.Water samples were collected over four periods spanning the premonsoon, monsoon, and postmonsoon seasons. Uncertainties in the relative fluxes have been estimated, using Monte Carlo techniques, from the short-term variability of mainstream chemistry and the scatter of tributary compositions. The results show marked seasonal variations in the relative inputs related to high monsoon rainfall in the High and Lesser Himalaya, contrasting with the major contribution from glacial melt waters from the Tibetan Sedimentary Series (TSS) at times of low rainfall. Much of the spread in previously published estimates of the sources of Sr in Himalayan rivers may result from these seasonal variations in Sr fluxes.The annual fluxes of Sr into the headwaters of the Ganges are derived from the three main tectonic units in the proportions 35 ± 1% from the TSS, 27 ± 3% from the High Himalayan Crystalline Series (HHCS), and 38 ± 8% from the Lesser Himalaya. The particularly elevated ⁸⁷Sr/⁸⁶Sr ratios characteristic of the HHCS and the Lesser Himalaya enhance their influence on seawater Sr-isotope composition. The TSS contributes 13 ± 1%, the HHCS 30 ± 3%, and the Lesser Himalaya 57 ± 11% of the ⁸⁷Sr flux in excess of the seawater ⁸⁷Sr/⁸⁶Sr ratio of 0.709.     

Does risk communication really decrease cooperation in climate change mitigation?

Effective communication of risks involved in the climate change discussion is crucial and despite ambitious protection policies, the possibility of irreversible consequences actually occurring can only be diminished but never ruled out completely. We present a laboratory experiment that studies how residual risk of failure of climate change policies affects willingness to contribute to such policies. Despite prevailing views on people’s risk aversion, we found that contributions were higher at least in the final part of treatments including a residual risk. We interpret this as the product of a psychological process where residual risk puts participants into an ”alarm mode,” keeping their contributions high. We discuss the broad practical implications this might have on the real-world communication of climate change.     

Fine-Scale Measurements Of Turbulence In The Lower Troposphere: An Intercomparison Between A Kite- And Balloon-Borne, And A Helicopter-Borne Measurement System

Two state-of-the-art, high-resolution, in situ turbulence measurement systems, which can be deployed at altitudes well above the atmospheric surface layer, are compared: the Tethered Lifting System (TLS) of the Cooperative Institute for Research in Environmental Sciences (CIRES)at the University of Colorado, Boulder, Colorado, and the helicopter-borneturbulence measurement system HELIPOD of the Technical UniversityBraunschweig, Germany, and the University of Hanover, Germany. Whilethe CIRES TLS is a fixed-point platform, HELIPOD is a moving platform.On the basis of data taken with the two systems in separate field campaigns,the system capabilities are quantified and discussed. Criteria for instrumentalrequirements are presented. It is shown that both the CIRES TLS and HELIPODare well suited for measuring fine-scale turbulence that is characterized by very small temperature structure parameters 10⁶ K² m^–2/3 and smaller) and very small energy dissipation rates (10^-7 m² s^-3 and smaller). The authors are not aware of any other turbulence measurement systems that have similar capabilities and can be deployed at altitudes of up to several kilometres. The HELIPOD is ideal for high-resolution horizontal measurements while the TLS is ideal for high-resolution vertical measurements using multiple sensors attached to a suspended line.     

Mean flux estimation and cospectra of airborne carbon dioxide and water vapour eddy flux measurements in the planetary surface layer

CO₂ and H₂O eddy-flux measurements derived from airborne vertical wind and concentration data are examined to determine the accuracy of the eddy-flux estimate in moderately unstable conditions within the surface layer. Integral scale estimation is used to determine the minimum length of a sample required to achieve a given accuracy. Cospectral analysis is used to examine the scales responsible for the transport of water vapour and carbon dioxide in the surface layer. Cospectra are found to broaden as the sampling altitude increases, a well known result. At low altitudes, the cospectrum is found to become negative for large scales. A significant fraction of the flux is carried by this range of scales, which suggests that scales larger than the boundary-layer height may play an important role in the transport at low altitudes.     

Membrane Interface Probe Protocol for Contaminants in Low‐Permeability Zones

Accurate characterization of contaminant mass in zones of low hydraulic conductivity (low k) is essential for site management because this difficult‐to‐treat mass can be a long‐term secondary source. This study developed a protocol for the membrane interface probe (MIP) as a low‐cost, rapid data‐acquisition tool for qualitatively evaluating the location and relative distribution of mass in low‐k zones. MIP operating parameters were varied systematically at high and low concentration locations at a contaminated site to evaluate the impact of the parameters on data quality relative to a detailed adjacent profile of soil concentrations. Evaluation of the relative location of maximum concentrations and the shape of the MIP vs. soil profiles led to a standard operating procedure (SOP) for the MIP to delineate contamination in low‐k zones. This includes recommendations for: (1) preferred detector (ECD for low concentration zones, PID or ECD for higher concentration zones); (2) combining downlogged and uplogged data to reduce carryover; and (3) higher carrier gas flow rate in high concentration zones. Linear regression indicated scatter in all MIP‐to‐soil comparisons, including R² values using the SOP of 0.32 in the low concentration boring and 0.49 in the high concentration boring. In contrast, a control dataset with soil‐to‐soil correlations from borings 1‐m apart exhibited an R² of ≥0.88, highlighting the uncertainty in predicting soil concentrations using MIP data. This study demonstrates that the MIP provides lower‐precision contaminant distribution and heterogeneity data compared to more intensive high‐resolution characterization methods. This is consistent with its use as a complementary screening tool.     

Alma and E-merlin Data Transmission Systems: Lessons for Ska

ALMA, EVLA and e-MERLIN use high data rate optical fibre links based on commercially available 10 Gbps opto-electronics. This paper describes the systems designed by NRAO and JBO staff to be used in ALMA and e-MERLIN. ALMA has a requirement for a 120 Gbps data rate per telescope, requiring the use of 12 lasers in the 1550 nm telecommunication band, with maximum link lengths around 20 km. e-MERLIN has a lower bandwidth and requires 30 Gbps links per telescope and therefore three lasers per telescope; however, the link lengths reach up to around 400 km, and amplification, de-dispersion and regeneration are required. Dense wavelength division multiplexing is used to avoid fibre management problems and save fibre costs. The design criteria and experience gained in these projects is very relevant to SKA as the proposed configuration of the antenna elements maps well to the link lengths used here. The chosen data rate will be a major cost driver.     

Predicting phosphorus dynamics in complex terrains using a variable source area hydrology model

Phosphorus (P) loss from agricultural watersheds has long been a critical water quality problem, the control of which has been the focus of considerable research and investment. Preventing P loss depends on accurately representing the hydrological and chemical processes governing P mobilization and transport. The Soil and Water Assessment Tool (SWAT) is a watershed model commonly used to predict run‐off and non‐point source pollution transport. SWAT simulates run‐off employing either the curve number (CN) or the Green and Ampt methods, both assume infiltration‐excess run‐off, although shallow soils underlain by a restricting layer commonly generate saturation‐excess run‐off from variable source areas (VSA). In this study, we compared traditional SWAT with a re‐conceptualized version, SWAT‐VSA, that represents VSA hydrology, in a complex agricultural watershed in east central Pennsylvania. The objectives of this research were to provide further evidence of SWAT‐VSA's integrated and distributed predictive capabilities against measured surface run‐off and stream P loads and to highlight the model's ability to drive sub‐field management of P. Thus, we relied on a detailed field management database to parameterize the models. SWAT and SWAT‐VSA predicted discharge similarly well (daily Nash–Sutcliffe efficiencies of 0.61 and 0.66, respectively), but SWAT‐VSA outperformed SWAT in predicting P export from the watershed. SWAT estimated lower P loss (0.0–0.25 kg ha^?1) from agricultural fields than SWAT‐VSA (0.0–1.0+ kg ha^?1), which also identified critical source areas – those areas generating large run‐off and P losses at the sub‐field level. These results support the use of SWAT‐VSA in predicting watershed‐scale P losses and identifying critical source areas of P loss in landscapes with VSA hydrology. Copyright © 2014 John Wiley & Sons, Ltd.     

An Assessment of Surface and Atmospheric Conditions Associated with the Extreme 2014 Wildfire Season in Canada’s Northwest Territories

Weather and climate are major factors influencing worldwide wildfire activity. This study assesses surface and atmospheric conditions associated with the 2014 extreme wildfires in the Northwest Territories (NWT) of Canada. Hot and dry conditions led to the NWT experiencing the most severe wildfire season in its recorded history. The season included a record number of cloud-to-ground lightning flashes and set a record for area burned. Lightning was the dominant ignition source and accounted for about 95% of the wildfires. Prolonged periods of smoke led to dramatic reductions in visibility, frequent road closures, and reduced air quality resulting in numerous health alerts. Temporal and spatial patterns of lightning characteristics in 2014, derived from Canadian Lightning Detection Network data, were different from those in other years with, for example, far more positive flashes from 0600 to 1200?utc (midnight to 6:00 am local time). The highest fraction of positive cloud-to-ground flashes (43.1%) occurred in the smoke-dominated North Slave region, which was more than in the Dehcho, South Slave, or Sahtu regions. Mid-tropospheric atmospheric circulation over a large region that included the NWT was classified into the six most common summer patterns. Results showed that ridging and ridge displacements occurred more frequently during 2014 although lightning was associated with all circulation patterns. This study has advanced the understanding of the roles of weather, lightning, and mid-tropospheric circulation patterns associated with extreme wildfires in northwestern Canada.