Will drought events become more frequent and severe in Europe?

As a result of climate change in recent past and unsustainable land management, drought became one of the most impacting disasters and, with the projected global warming, it is expected to progressively cause more damages by the end of the 21st century. This study investigates changes in drought occurrence, frequency, and severity in Europe in the next decades. A combined indicator based on the predominance of the drought signal over normal/wet conditions has been used. The indicator, which combines the standardized precipitation index (SPI, which accounts for anomalous low rainfall), the standardized precipitation evapotranspiration index (SPEI, which accounts for high temperatures and scarce precipitations), and the reconnaissance drought indicator (RDI, similar to SPEI but more affected by extreme events), has been computed at 3- and 12-month accumulation scales to characterize trends in seasonal and annual events from 1981 to 2100. Climate data from 11 bias-adjusted high-resolution (0.11°) simulations from the EURO-CORDEX (coordinated regional climate downscaling experiment) have been used in the analyses. For each simulation, the frequency and severity of drought and extreme drought events for 1981–2010, 2041–2070, and 2071–2100 have been analysed. Under the moderate emission scenario (RCP4.5), droughts are projected to become increasingly more frequent and severe in the Mediterranean area, western Europe, and Northern Scandinavia, whereas the whole European continent, with the exception of Iceland, will be affected by more frequent and severe extreme droughts under the most severe emission scenario (RCP8.5), especially after 2070. Seasonally, drought frequency is projected to increase everywhere in Europe for both scenarios in spring and summer, especially over southern Europe, and less intensely in autumn; on the contrary, winter shows a decrease in drought frequency over northern Europe.Fil: Spinoni, Jonathan. European Commission Joint Research Centre; ItaliaFil: Vogt, Jürgen V.. European Commission Joint Research Centre; ItaliaFil: Naumann, Gustavo. European Commission Joint Research Centre; Italia. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Barbosa, Paulo. European Commission Joint Research Centre; ItaliaFil: Dosio, Alessandro. European Commission Joint Research Centre; Itali

Fractionated Space Architectures: Tracing the Path to Reality

In an effort to achieve responsiveness, increase effectiveness, and reduce the uncertainty involved in maintaining a space architecture dependent on a few high-capacity, high-cost satellites, the Defense Advanced Research Projects Agency (DARPA) has proposed the concept of fractionated spacecraft. DARPA plans to compress spacecraft development timelines, enable launch with smaller, more responsive vehicles, and make the spacecraft architecture fundamentally flexible and robust. DARPA’s System F6 (Future Fast, Flexible, Free-Flying, Fractionated Spacecraft united by Information eXchange) is a technological and paradigmatic demonstrator of this concept.While fractionated architecture is likely to significantly transform the technology base, as well as the development and operational concept for delivering on-orbit capability, this disruptive concept arose from a substantial and rather distinguished pedigree of foundational thoughts, concepts, and demonstrators developed throughout the Space Age as designers have explored satellite constellations, cooperative spacecraft, distributed systems, and miniaturization. Concepts or programs ranging from pioneers like the Transit navigation and IDSCP/DSCS-I communications satellite efforts through the Air Force’s XSS series, NASA’s New Millennium, DART, and TPF programs, Orbcomm, ANTS, TechSat-21, GPS, and many others have contributed to the stream of innovation leading to the architectural paradigm shift of the F6 program.It was not just the promise of new technologies and operational concepts that led to the genesis of F6, but also the deficiencies of the conventional, monolithic approach to space systems that largely pervades the industry today. This paper traces the development of the intellectual, technological, and policy foundations of the fractionated spacecraft concept throughout the preceding decades. We conclude with an assessment of future hurdles to its proliferation and make some projections about its likely applicability to various space missions in the years to come