USGS 30 ARC-second Global Elevation Data, GTOPO30

The Scientific Committee on Antarctic Research (SCAR) had its antecedents in the Special Committee on Antarctic Research of the International Geophysical Year, and thus its establishment in 1958 predates the Antarctic Treaty. As a body of the International Council for Science (ICSU, formerly the International Council of Scientific Unions) it is a nongovernmental organization, yet it has been intimately linked to the governmental discussions at the Antarctic Treaty since the first Antarctic Treaty meeting in 1961. Its primary role has always been to develop and coordinate international scientific research, but it has also provided independent advice to Treaty Parties on many scientific and environmental questions, initially through national government delegations. Only in 1987 was SCAR itself granted the status of observer and the right to attend Antarctic Treaty Consultative Meetings (ATCMs) and to submit information and working papers. This paper looks at the changing relationship between SCAR and the Treaty Parties, at some of its most important science inputs to the ATCM, and at the way SCAR itself has changed. Its earliest input to governance was advice on conservation that became the Agreed Measures for the Conservation of Antarctic Fauna and Flora of 1964, and for the first 40 years of the Antarctic Treaty, SCAR provided major input on protected areas and protected species, as well as environmental impact and monitoring. Its proposals for seal conservation and management gave it a specific role in the Convention for the Conservation of Antarctic Seals, and its Biological Investigations of Marine Antarctic Systems and Stocks (BIOMASS) programme laid the foundations for the Convention for the Conservation of Antarctic Marine Living Resources (CCAMLR). Its nonpolitical stance has allowed it to provide the only unified gazetteer for the Antarctic. The organization of SCAR remained virtually unchanged for around 30 years until the logisticians split to form the Council of Managers of National Antarctic Programs (COMNAP) in 1989. The organization was languishing, but a major review of structure and function changed that in 2000, resulting in the establishment of Open Science Conferences, major new international programmes, increased educational outreach, and a greater input to the annual Antarctic Treaty meetings, often on controversial subjects like marine acoustics or specially protected species. There are currently 31 full members with 4 associate members and 9 ICSU union members.

Projections of global sea-level rise into the future have become more pessimistic over the past five years or so. A global rise by more than one metre by the year 2100 is now widely accepted as a serious possibility if greenhouse gas emissions continue unabated. That is witnessed by the scientific assessments that were made since the last IPCC report was published in 2007. The Delta Commission of the Dutch government projected up to 1.10 m as a 'high-end' scenario (Vellinga et al 2009). The Scientific Committee on Antarctic Research (SCAR) projected up to 1.40 m (Scientific Committee on Antarctic Research 2009), and the Arctic Monitoring and Assessment Programme (AMAP) gives a range of 0.90–1.60 m in its 2011 report (Arctic Monitoring and Assessment Programme 2011). And recently the US Army Corps of Engineers recommends using a 'low', an 'intermediate' and a 'high' scenario for global sea-level rise when planning civil works programmes, with the high one corresponding to a 1.50 m rise by 2100 (US Army Corps of Engineers 2011).

D. Walton and P. Clarkson present a history of the last 50 years of international collaborations stimulated by the presence and flexibility inherent in the Scientific Committee on Antarctic Research (SCAR) in their new book Science in the snow. As aptly portrayed in the acknowledgements that precede the book, SCAR has been both an important umbrella for drawing attention to the Antarctic and a virtual and real (meeting rooms to pubs) venue for Antarctic scientists to discuss their scientific findings, their experiences, and their dreams for understanding a place that - with the exception of the impact of iconic expeditions of the early explorers - was barely on the world’s collective mind until about 50 years ago.(Published: 3 September 2012)Citation: Polar Research 2012, 31, 19275, http://dx.doi.org/10.3402/polar.v31i0.19275

Black CarbonThe Dark Horse of Climate Change Drivers F or decades, efforts to slow global warming have mostly aimed to limit heat-trapping emissions of carbon dioxide (CO 2 ).Now scientists are pointing to a different class of warming agents they say also must be targeted to keep global temperatures in check.Dubbed "shortlived climate forcings" (SLCFs), these other emissionsnamely, black carbon particles, methane, hydrofluorocarbons, and tropospheric ozone-are even more powerful than CO 2 in terms of their warming potential.But they persist in the atmosphere for much shorter durations than CO 2 , which can linger airborne for hundreds to thousands of years. 1 Steve Seidel, vice president for policy analysis at the Pew Center on Global Climate Change, says the recent emphasis on SLCFs represents new policy thinking on climate change."We thought the Kyoto Protocol and its follow-on agreements would get us to where we need to be, but that's not working out the way we hoped it would," he says."So, we're broadening the discussion and opening up new pathways for going forward."More than three-quarters of the world's black carbon is thought to come from developing countries, discharged from cookstoves, open burning, and older diesel engines.This data visualization uses data from NASA's GEOS-5 Goddard Chemistry Aerosol and Transport (GOCART) climate model to show atmospheric concentrations of black carbon on 26 September 2009.Aerosol optical thickness ranges nonlinearly from 0.002 (transparent) to 0.02 (purple) to 0.2 (white).Animations of global black soot transport are available at

Urban flood models that use Digital Elevation Models (DEMs) to simulate extent and depth of flood inundation rely on the accuracy of DEMs for predicting flood events. Despite recent advances in developing vegetation corrected DEMs, the effect of building height and density errors in global DEMs in urban areas are still poorly understood, and their correction remains a challenge. In this research we developed a methodology for building error correction that can be applied to any other case study, where building density data and a local reference DEM data are available. This methodology was applied to Nairobi, Kenya using six global DEMs (SRTM, MERIT, ALOS, NASADEM, TanDEM-X 12 m, and TanDEM-X 90 m DEM). Our results show building error at highest building density varying between 1.25 m and 5.07 m for the DEMs used, with the MERIT DEM showing the smallest vertical height error from the reference DEM. The six DEMs were corrected by deriving a linear relationship between building density and DEM error. Our findings show that the removal of building density error resulted in the improvement of the vertical height accuracy of the global DEMs of up to 45% for MERIT and 40% for ALOS. This methodology was also applied to the Central Business District (CBD) area of Nairobi, characterized by taller buildings and high building density. The error parameters in the CBD area resulted to be between 15 to 45% higher than those of the Nairobi city wide area for the six global DEMs, thus providing further insights into the contribution of building heights to errors in global DEMs. Building height data is still unavailable on a global scale and our results show that global DEMs can be usefully corrected for building density errors in urban areas, even where specific building height data are not available.

The advent of the Landsat Data Continuity Mission (LDCM), currently with a launch readiness date of December, 2012, will see evolutionary changes in the Landsat data products available from the U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center. The USGS initiated a revolution in 2009 when EROS began distributing Landsat data products at no cost to requestors in contrast to the past practice of charging the cost of fulfilling a request; that is, charging $600 per Landsat scene. To implement this drastic change, EROS terminated data processing options for requestors and began to produce all data products using a consistent processing recipe. EROS plans to continue this practice for the LDCM and will required new algorithms to process data from the LDCM sensors. All previous Landsat satellites flew multispectral scanners to collect image data of the global land surface. Additionally, Landsats 4, 5, and 7 flew sensors that acquired imagery for both reflective spectral bands and a single thermal band. In contrast, the LDCM will carry two pushbroom sensors; the Operational Land Imager (OLI) for reflective spectral bands and the Thermal InfraRed Sensor (TIRS) for two thermal bands. EROS is developing the ground data processing system that will both calibrate and correct the data from the thousands of detectors employed by the pushbroom sensors and that will also combine the data from the two sensors to create a single data product with registered data for all of the OLI and TIRS bands.

The early national expeditions to Antarctica were short-term, with science usually driven by the interests and opportunities of those scientists who were taken along. Some expeditions made important collections of both data and specimens that proved crucial in establishing why more research should be funded. However, in those early days, there was little coordination other than attempts to use similar instruments and protocols for collecting physical data such as magnetic and meteorological records. With our present-day sophisticated communications, aerial and oceanic surveys, regular access to scientific stations and ships across Antarctica and the Southern Ocean, and research on and around the continent by many nations, collaboration is essential to make the most of the resources. Establishing the Scientific Committee on Antarctic Research (SCAR) in 1958 proved to be a crucial step in developing the Antarctic scientific community and maximising the value of research across all scientific fields. In parallel to this, SCAR has also developed a major role as the primary scientific advisor to the Antarctic Treaty Parties on scientific and environmental matters.

The Antarctic digital topographic database is the outcome of a truly international collaborative project between 11 nations. Data capture was co-ordinated in the UK, under the auspices of the Scientific Committee on Antarctic Research (SCAR), during a two-year period. Over 200 maps, at scales ranging from 1:200 000 to 1:5 000 000, were digitized for the project and reference was made to a similar number of satellite images (mostly Landsat photographic products). Editing and harmonization of the data derived from the different sources has produced a seamless map of Antarctica which has the most up-to-date coastline now available. The topographic database created, to be published on one CD-ROM, will form the foundation for future GIS needs in Antarctic research. Products already derived from the database include digital elevation models and customized maps; the latter can be reproduced by research groups to meet their own mapping needs.

The U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center has legislative charters to preserve and make accessible land remote sensing records important to the United States. This essay explains the appraisal process developed by EROS to ensure the science records it holds and those offered to it align with those charters. The justifications behind the questions employed to weed and to complement the EROS archive are explained along with the literature reviewed supporting their inclusion. Appraisal results are listed by individual collection and include the recommendations accepted by EROS management.

Formulation of the problem. Water erosion of soils is the most widespread and dangerous soil degradation process in Ukraine. The development of an effective system of soil protection measures requires the use of spatially distributed mathematical models of soil erosion losses. This, in turn, highlights the problem of spatially distributed source data, which adequately reflect the spatial differentiation of factors of the erosion process, among which the main one is the relief. The purpose of the article. Assessing the adequacy of available spatially distributed source data, including cartographic and freely distributed global digital elevation models (DEMs), for spatially distributed quantitative assessment of soil erosion losses at the local level of territorial coverage is the aim of the article. Assessing from this point of view the scale of the original cartographic data, different global DEMs and their spatial resolution, as well as the degree of spatial generalization of the original data. Materials and methods. The solution of the set tasks was performed by the method of simulation modeling with the use of physical-statistical GIS-realized mathematical model of soil erosion-accumulation, developed at Odessa I. I. Mechnikov National University. Source data arrays were tested with DEMs SRTM90 and SRTM30 with a spatial resolution of 3 and 1 angular seconds, respectively, and AW3D30 with a spatial resolution of 1 angular second, as well as with cartographic DEMs based on topographic maps of scale 1:10000 and 1:25000. For testing the initial data, three test plots with an area of 2.67, 0.59 and 0.21 km2 were selected. The plots are located in the Balta district of Odessa region on the southern spurs of the Podolska upland. Results. It is established that freely distributed global digital elevation models SRTM and AW3D30 in the conditions of flat terrain do not always allow to adequately display the structure of slope runoff and, accordingly, to correctly perform calculations of soil erosion losses. The maximum deviation of the average soil erosion losses calculated for the test plots using global DEMs from the soil losses calculated using the reference DEM for SRTM30 and AW3D30 was 27%, for SRTM90 – almost 70%. The distribution of soil losses over the area of test plots obtained using different global DEMs differs even more. When using DEM based on topographic maps, reducing the scale of the original maps from 1: 10000 to 1: 25000 leads to a decrease in the average value of soil erosion losses by about 20% due mainly to reducing the magnitude and area of distribution of maximum soil losses, and on slopes of complex shape also due to changes in the area of accumulation zones. The degree of spatial generalization of the initial data significantly affects the results of the assessment of soil erosion losses both in relation to the average values and their distribution over the area. For small areas, the use of raster cells larger than 50 m is impractical. Scientific novelty and practical significance. It has been shown for the first time that in the conditions of flat terrain at the local level of spatial coverage, the freely distributed global DEM SRTM and AW3D30 are not always hydrologically correct. The reasons and conditions of violation of this correctness are specified. It has been established that the global DEM AW3D30 has local instrumental errors that may make it impossible to use it. The most realistic values of soil erosion losses are provided by DEM SRTM with a spatial resolution of 1 angular second.

This paper is motivated by a global online satellite images distribution system operated at the Earth Resources Observation and Science (EROS) center of the U.S Geological Survey. Fundamental objectives of EROS include, but are not limited to, building high-speed and cost-effective massive data processing and storage systems to support online satellite images distribution. Hybrid storage systems -- containing solid-state drives (SSD), hard disks (HDD), and tapes -- can provide an ideal data storage solution for a wide variety of data processing centers like EROS. Large-scale hybrid storage systems will become increasingly popular in the next few years for the following two reasons. First, highly accessed storage objects in a hybrid storage system can be prefetched and cached to high-speed storage components such as solid-state drives. SSD-based hybrid storage system can provide large storage capacity, high I/O performance and data reliability. Second, hybrid storage systems are cost-effective, because inexpensive tapes help in increasing storage capacities at very low cost. Transferring data back and forth among SSDs, HDDs, and tapes plays a critical role in achieving high I/O performance. Thus, we proposed data mining algorithms that can judiciously prefetch data. Our analytical model and the experimental results reveals that our data mining prefetching algorithm increase the performance of the hybrid storage systems.

Antarctica has become a topical news item in many countries. TV programs, radio reportage and popular journals portray its harsh beauty, unique wildlife and the growing impact of tourism. The number of scientific specialties in which this cold continent has become an important aspect has increased steadily, especially during the last twenty years. Since 1961 a treaty drafted by 12 nations has been in force, regulating relationships between countries involved in Antarctic affairs. Today there are twenty-six so-called Consultative Parties to the Antarctic Treaty (Table I). These make up the “club” of nations that hold decision-making powers over the continent’s future. An additional 13 countries are acceding members, or affiliates with observer status. Full membership comes only after a country has passed the test of science. According to the treaty the prior requirement for admission to the Antarctic club is the display of substantial research in the region. This has usually meant that a country has to place a research station there. The responsibility for overseeing science belongs to a non-governmental organization, the Scientific Committee for Antarctic Research (SCAR), under the International Council of Scientific Unions (ICSU). SCAR also responds to requests for advice from the treaty members, a function that has taken on increasing proportions during the past decade.KeywordsPolar ResearchAntarctic ResearchCommon HeritageTerritorial ClaimAntarctic TreatyThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

TanDEM-X (TerraSAR-X add-on for Digital Elevation Measurements) is an Earth observation radar mission that consists of a SAR interferometer built by two almost identical satellites flying in close formation [1]–[4]. With a typical separation between the satellites of 120 to 500 m a global Digital Elevation Model (DEM) with 2 m relative height accuracy at 12 m posting is being generated. While the main mission phase for DEM data acquisition has been finished in 2014, the processing of the global TanDEM-X DEM will be concluded in autumn 2016. Final DEMs are well within specifications and feature a low percentage of void areas. Following the DEM data acquisition the capabilities of this unique mission for new scientific application have been demonstrated. In the meantime the continuation of the joint TerraSAR-X/TanDEM-X mission was approved and will be dedicated to the generation of DEMs with even higher accuracy for selected areas and further scientific experiments.

South Georgia and the South Sandwich archipelagoes fall within the scope of SCAR (Scientific Committee on Antarctic Research) and CCAMLR (Convention for the Conservation of Antarctic Marine Living Resources). From the early twentieth century to the present Argentina has proposed and supported intemational agreements and conventions to regulate the harvesting of marine biota, and to promote marine conservation. Adherence to CCAMLR is required by Argentine law.

The history and behavior of Antarctic ice sheets over millions of years is increasingly of interest as the rising carbon dioxide levels of today exceed any in the ice core record of the last 0.4 m.y. Yet the changes and events that formed these ancient ice sheets are not well understood. A record of these changes lies in sedimentary strata around the Antarctic margin, and such changes have been the focus of a coordinated effort at the Antarctic margin to acquire seismic and drill core data that are needed to derive and model paleoenvironments of the past 65 m.y. The effort is being led by the Antarctic Offshore Stratigraphy Project (ANTOSTRAT), a group that works under the aegis of the Scientific Committee on Antarctic Research (SCAR).