Mapping New Zealand and Antarctic snowpack from LANDSAT

Ther are no author-identified significant results in this report

Cold-regions river flow observed from space

Knowledge of water-surface velocities in rivers is useful for understanding a wide range of lotic processes and systems, such as water and ice fluxes and forces, mixing, solute and sediment transport, bed and bank stability, aquatic and riparian ecology, and extreme hydrologic events. In cold regions, river-ice break up and the associated downstream transport of ice debris is often the most important hydrological event of the year, producing flood levels that commonly exceed those for the open-water period and dramatic consequences for river infrastructure and ecology. Quantification of river surface velocity and currents has relied mostly on very scarce in situ measurements or particle tracking in laboratory models, with few attempts to cover entire river reaches. Accurate and complete surface-velocity fields on rivers have rarely been produced. Here, we use river-ice debris as an index of surface water velocity, and track it over a time period of about one minute, which is the typical time lapse between the two or more images that form a stereo data set in spaceborne, alongtrack optical-stereo mapping. In this way, we measure and visualize for the first time, the almost complete surface velocity field of a river. Examples are used from approximately 80 km and 40 km long reaches of the St. Lawrence and Mackenzie rivers, respectively. The methodology and results will be valuable to a number of disciplines requiring detailed information about river flow, such as hydraulics, hydrology, river ecology and natural-hazard management

Where did all the pangolins go? International CITES trade in pangolin species

Available online 24 October 2016The pangolin is greatly sought after for its various body parts, largely driven by demand from China. The mammal has been driven to the edge of extinction in Asia, with two Asian species listed as Critically Endangered in the International Union for Conservation of Nature Red List. With declining Asian pangolin populations, a shift in trade from Asian to African pangolin species has been suggested. The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) Trade Database provides a unique opportunity to investigate global trends in pangolin trade at the species level, across a broad temporal scale (1977–2014). We found that CITES trade in Asian pangolin species decreased through time, whilst trade in African species increased post 2000. The total number of incidents involving Asian species declined since 2000, yet they were still being traded in large volumes (more than 17,500 estimated whole Asian pangolins were traded from 2001 to 2014) despite a zero export quota for all wild sourced Asian species, traded for primarily commercial purposes. In 2014 all eight pangolin species were recorded in the CITES trade for the first time. An increasingly complex international network was identified through time, with the United States of America (US) being the dominant player in the global pangolin trade that was reported to CITES. The US was the most frequent trade country throughout the entire period and was the greatest importer of pangolins, and their products; measured both in volume as well as frequency. We hope that identifying these global trade network characteristics, and pangolin trade dynamics will help to inform pangolin conservation efforts, and guide enforcement and legislative changes in the future.Sarah Heinrich, Talia A. Wittmann, Thomas A.A. Prowse, Joshua V. Ross, Steven Delean, Chris R. Shepherd, Phillip Casse

Temporal modelling of ballast water discharge and ship-mediated invasion risk to Australia

Biological invasions have the potential to cause extensive ecological and economic damage. Maritime trade facilitates biological invasions by transferring species in ballast water, and on ships' hulls. With volumes of maritime trade increasing globally, efforts to prevent these biological invasions are of significant importance. Both the International Maritime Organization and the Australian government have developed policy seeking to reduce the risk of these invasions. In this study, we constructed models for the transfer of ballast water into Australian waters, based on historic ballast survey data. We used these models to hindcast ballast water discharge over all vessels that arrived in Australian waters between 1999 and 2012. We used models for propagule survival to compare the risk of ballast-mediated propagule transport between ecoregions. We found that total annual ballast discharge volume into Australia more than doubled over the study period, with the vast majority of ballast water discharge and propagule pressure associated with bulk carrier traffic. As such, the ecoregions suffering the greatest risk are those associated with the export of mining commodities. As global marine trade continues to increase, effective monitoring and biosecurity policy will remain necessary to combat the risk of future marine invasion events.Robert C. Cope, Thomas A. A. Prowse, Joshua V. Ross, Talia A. Wittmann, Phillip Casse

Integrative analysis of the physical transport network into Australia

Effective biosecurity is necessary to protect nations and their citizens from a variety of threats, including emerging infectious diseases, agricultural or environmental pests and pathogens, and illegal wildlife trade. The physical pathways by which these threats are transported internationally, predominantly shipping and air traffic, have undergone significant growth and changes in spatial distributions in recent decades. An understanding of the specific pathways and donor-traffic hotspots created by this integrated physical transport network is vital for the development of effective biosecurity strategies into the future. In this study, we analysed the physical transport network into Australia over the period 1999-2012. Seaborne and air traffic were weighted to calculate a "weighted cumulative impact" score for each source region worldwide, each year. High risk source regions, and those source regions that underwent substantial changes in risk over the study period, were determined. An overall risk ranking was calculated by integrating across all possible weighting combinations. The source regions having greatest overall physical connectedness with Australia were Singapore, which is a global transport hub, and the North Island of New Zealand, a close regional trading partner with Australia. Both those regions with large amounts of traffic across multiple vectors (e.g., Hong Kong), and those with high levels of traffic of only one type (e.g., Bali, Indonesia with respect to passenger flights), were represented among high risk source regions. These data provide a baseline model for the transport of individuals and commodities against which the effectiveness of biosecurity controls may be assessed, and are a valuable tool in the development of future biosecurity policy.Robert C. Cope, Joshua V. Ross, Talia A. Wittmann, Thomas A. A. Prowse, Phillip Casse

What Does Free Space Lambda-Lambda Interaction Predict for Lambda-Lambda Hypernuclei?

Data on Lambda-Lambda hypernuclei provide a unique method to learn details on the strangeness S =-2 sector of the baryon-baryon interaction. From the free space Bonn-Julich potentials, determined from data on baryon-baryon scattering in the S=0,-1 channels, we construct an interaction in the S =-2 sector to describe the experimentally known Lambda-Lambda hypernuclei. After including short--range (Jastrow) and RPA correlations, we find masses for these Lambda-Lambda hypernuclei in a reasonable agreement with data, taking into account theoretical and experimental uncertainties. Thus, we provide a natural extension, at low energies, of the Bonn-Julich OBE potentials to the S =-2 channel.Comment: 4 pages, 2 figures, revtex4 style. Minor changes in conclusions. References updated. Accepted in Phys. Rev. Let

The Lambda-Lambda Interaction and ^{6}_{Lambda Lambda}He

An OBE potential model for the ^{1}S_0 S = -2 interaction is analyzed with emphasis on the role of coupling between the Lambda Lambda, N Xi, and Sigma Sigma channels. Singlet scalar exchange, an approximation to two-pion exchange, is significant in all channels; surprisingly, the one-pion exchange component is almost negligible. The size of the channel coupling as a function of the overall strength of the OBE model potential is examined. Implications of the analysis for the binding energy of ^{6}_{Lambda Lambda}He are considered; the new experimental datum may suggest a consistency between the extracted Lambda Lambda matrix element and the relation implied by SU(3) among OBE baryon-baryon interactions. \\Comment: 4 pages brief report to Physical Review

Arctic system on trajectory to new state

The Arctic system is moving toward a new state that falls outside the envelope of glacial-interglacial fluctuations that prevailed during recent Earth history. This future Arctic is likely to have dramatically less permanent ice than exists at present. At the present rate of change, a summer ice-free Arctic Ocean within a century is a real possibility, a state not witnessed for at least a million years. The change appears to be driven largely by feedback-enhanced global climate warming, and there seem to be few, if any processes or feedbacks within the Arctic system that are capable of altering the trajectory toward this “super interglacial” state