ALBERT

Description / Table of Contents: This volume of IOP Conference Series: Earth and Environmental Science presents a selection of papers that were given at the WMO/GEO Expert Meeting on an International Sand and Dust Storm Warning System hosted by the Barcelona Supercomputing Center – Centro Nacional de Supercomputación in Barcelona (Spain) on 7-9 November 2007 (http://www.bsc.es/wmo). A sand and dust storm (SDS) is a meteorological phenomenon common in arid and semi-arid regions and arises when a gust front passes or when the wind force exceeds the threshold value where loose sand and dust are removed from the dry surface. After aeolian uptake, SDS reduce visibility to a few meters in and near source regions, and dust plumes are transported over distances as long as thousands of kilometres. Aeolian dust is unique among aerosol phenomena: (1) with the possible exception of sea-salt aerosol, it is globally the most abundant of all aerosol species, (2) it appears as the dominating component of atmospheric aerosol over large areas of the Earth, (3) it represents a serious hazard for life, health, property, environment and economy (occasionally reaching the grade of disaster or catastrophic event) and (4) its influence, impacts, complex interactions and feedbacks within the Earth System span a wide range of spatial and temporal scales. From a political and societal point of view, the concern for SDS and the need for international cooperation were reflected after a survey conducted in 2005 by the World Meteorological Organization (WMO) in which more than forty WMO Member countries expressed their interest for creating or improving capacities for SDS warning advisory and assessment. In this context, recent major advances in research – including, for example, the development and implementation of advanced observing systems, the theoretical understanding of the mechanisms responsible for sand and dust storm generation and the development of global and regional dust models – represent the basis for developing applications focusing on societal benefit and risk reduction. However, at present there are interdisciplinary research challenges to overwhelm current uncertainties in order to reach full potential. Furthermore, the community of practice for SDS observations, forecasts and analyses is mainly scientifically based and rather disconnected from potential users. This requires the development of interfaces with operational communities at international and national levels, strongly focusing on the needs of people and factors at risk ... The general objective of the WMO/GEO Expert Meeting on an International Sand and Dust Storm Warning System was to discuss and recommend actions needed to develop a global routine SDS-WAS based on integrating numerical SDS prediction and observing systems, and on establishing effective cooperation between data producers and user communities in order to provide SDS-WAS products capable of contributing to the reduction of risks from SDS. The specific objectives were: to identify, present and suggest future real-time observations for forecast verification and dust surveillance: satellite, ground-based remote sensing (passive and active) and in-situ monitoring; to present ongoing forecasting activities; to discuss and identify user needs: health, air quality, air transport operations, ocean, and others; to identify and discuss dust research issues relevant for operational forecast applications; to present the concept of SDS-WAS and Regional Centers...

Description / Table of Contents: Assessments of stratospheric ozone have been conducted for nearly two decades and have evolved from describing ozone morphology to estimating ozone trends, and then to attribution of those trends. Stratospheric aerosol has only been integrated in assessments in the context of their effects on ozone chemistry and has not been critically evaluated itself. As a result, the Assessment of Stratospheric Aerosol Properties (ASAP) has been carried out by the WCRP project on Stratospheric Process and their Role in Climate (SPARC). The objective of this report is to present a systematic analysis of the state of knowledge of stratospheric aerosols including their precursors. It includes an examination of precursor concentrations and trends, measurements of stratospheric aerosol properties, trends in those properties, and modeling of aerosol formation, transport, and distribution in both background and volcanic conditions. The scope of this report is extensive; however, some aspects of stratospheric aerosol science have been deliberately excluded. For instance, we have not attempted to include an examination of polar stratospheric clouds (PSCs) or other clouds (such as cirrus clouds) occurring at or above the tropopause except in as much as they influence aerosol observations. Polar stratospheric clouds are the subject of a separate SPARC activity. We have produced a gap-free aerosol data base for use beyond this report. This required some new analysis that has not previously appeared in the technical literature. Similarly, the trend analysis required the development of a new analysis technique that is the subject of an article published in the Journal of Geophysical Research. New work is clearly identified in the present report. ASAP began with a general kick-off meeting in November 2001 at CNES in Paris, France. There were also three chapter lead meetings in Nice, France (April 2003), in Frankfurt, Germany (July 2003) and in Lexington, Massachusetts, USA (January 2004). The final report is the result of concerted effort by scientists world-wide who continue to work toward understanding the measurements and processes controlling stratospheric aerosol. Their work was supported by their host institutions and funding agencies that include the WCRP and the SPARC Office (in Paris and Toronto), as well as Atmospheric and Environmental Research, Inc., NASA, the Universities of Frankfurt and Wyoming, and ETH Zurich. An initial overview of ASAP appeared in the SPARC Newsletter No. 23 in July 2004.