Global change and the intensification of agriculture in the tropics

Bridging understanding of local environmental change with regional and global patterns of land-use and land-cover change (LUCC) remains a key goal and challenge for our understanding of global environmental change. This meta-analysis attempts to bridge local and regional scales of LUCC by demonstrating the ways in which previously published case studies can be compared and used for a broader regional synthesis in the tropics. In addition to providing results from a meta-analysis, this paper suggests ways to make future case studies more widely comparable.     

Origin of crystalline,cold desert salts in the McMurdo region,Antarctica

The distribution of crystalline salt minerals in deposits in the McMurdo region of Antarctica has been examined to study the origin of these salts. Sulphate, chloride, sodium and calcium salts are most frequently encountered. Salts containing chloride and sodium ions become less common away from the coast. Sulphate salts are more regularly distributed but tend to be related isotopically to sea water sulphate. Salts containing magnesium ion tend to exist mainly on substrates composed of basic igneous rocks, whereas calcium and carbonate salts are present on all rock types in the region.These distributions show that salts of marine origin are regionally and quantitatively most important but that chemical weathering of mafic materials in rocks and soils is also significant. However, biological, volcanic and hydrothermal processes are or have been active contributing to salts in local areas, that include penguin rookeries and eastern Taylor Valley, the summit area of Erebus Volcano, and subsurface rocks, respectively.     

Uncertainties in Solar Synoptic Magnetic Flux Maps

Magnetic flux synoptic charts are critical for a reliable modeling of the corona and heliosphere. Until now, however, these charts were provided without uncertainty estimates. The uncertainties are due to instrumental noise in the measurements and to the spatial variance of the magnetic flux distribution that contributes to each bin in the synoptic chart. We describe here a simple method to compute synoptic magnetic flux maps and their corresponding magnetic flux spatial variance charts that can be used to estimate the uncertainty in the results of coronal models. We have tested this approach by computing a potential-field source-surface model of the coronal field for a Monte Carlo simulation of Carrington synoptic magnetic flux maps generated from the variance map. We show that these uncertainties affect both the locations of source-surface neutral lines and the distributions of coronal holes in the models.     

Gravity wave and sporadic-E echo signatures on VHF backscatter radar systems

Wave-like features in range seen on the range/time/intensity (RTI) records of VHF backscatter radars operating in the South of New Zealand are interpreted as being the signature of gravity waves propagating in an ionospheric sporadic-E layer. The data show that, during midsummer in particular, sporadic-E ionisation which has been modified by the passage of a gravity wave can produce two distinct echo types : backscatter from field-aligned irregularities within the sporadic-E layer, probably generated by plasma waves, and a second type of echo resulting from energy backscattered from the surface of the sea after specular reflection in the ionosphere. The backscattering and reflecting region can exist at latitudes at least as low as 49° geographic (57° geomagnetic) latitude during quiet magnetic conditions. We confirm the patchiness of dense sporadic-E, and conclude that gravity waves at sporadic-E heights have amplitudes of the order of several tenths of a kilometre.     

Preparing for climate change in Washington State

Climate change is expected to bring potentially significant changes to Washington State’s natural, institutional, cultural, and economic landscape. Addressing climate change impacts will require a sustained commitment to integrating climate information into the day-to-day governance and management of infrastructure, programs, and services that may be affected by climate change. This paper discusses fundamental concepts for planning for climate change and identifies options for adapting to the climate impacts evaluated in the Washington Climate Change Impacts Assessment. Additionally, the paper highlights potential avenues for increasing flexibility in the policies and regulations used to govern human and natural systems in Washington.     

Food security,remoteness and consolidation of supermarket distribution centres: Factors contributing to food pricing inequalities across Queensland,Australia

There is a clear association between food prices, affordability and issues of food security. Australian food supply chains have lengthened in recent years in response to consolidation policies of the dominant supermarkets, which have reduced the number of distribution centres in order to maximise economic efficiencies. This study presents a spatial analysis of a healthy food basket survey undertaken across Queensland, Australia in order to identify the primary determinants of food pricing. Ambiguity in the academic literature on this subject is largely due to limitations of the utilised methods. Our results indicate that food price variability is directly related to the type of store surveyed, and the distance of the surveyed store to the supermarket distribution centres in Brisbane, or urban centres on the east coast of Australia. Population size of towns and the level of social disadvantage observed in communities were indirect determinants of food prices. Therefore, in order to lessen the disadvantage already encountered by communities located in outer regional and remote areas who pay increasingly more for food than their urban counterparts, policy interventions need to move beyond subsiding food costs and consider the relationship between fuel prices and the lengthening of dominant food supply chains, in addition to the capacity of local supply chains.     

Precipitation extremes and the impacts of climate change on stormwater infrastructure in Washington State

The design of stormwater infrastructure is based on an underlying assumption that the probability distribution of precipitation extremes is statistically stationary. This assumption is called into question by climate change, resulting in uncertainty about the future performance of systems constructed under this paradigm. We therefore examined both historical precipitation records and simulations of future rainfall to evaluate past and prospective changes in the probability distributions of precipitation extremes across Washington State. Our historical analyses were based on hourly precipitation records for the time period 1949–2007 from weather stations in and near the state’s three major metropolitan areas: the Puget Sound region, Vancouver (WA), and Spokane. Changes in future precipitation were evaluated using two runs of the Weather Research and Forecast (WRF) regional climate model (RCM) for the time periods 1970–2000 and 2020–2050, dynamically downscaled from the ECHAM5 and CCSM3 global climate models. Bias-corrected and statistically downscaled hourly precipitation sequences were then used as input to the HSPF hydrologic model to simulate streamflow in two urban watersheds in central Puget Sound. Few statistically significant changes were observed in the historical records, with the possible exception of the Puget Sound region. Although RCM simulations generally predict increases in extreme rainfall magnitudes, the range of these projections is too large at present to provide a basis for engineering design, and can only be narrowed through consideration of a larger sample of simulated climate data. Nonetheless, the evidence suggests that drainage infrastructure designed using mid-20th century rainfall records may be subject to a future rainfall regime that differs from current design standards.