Mostrando entradas con la etiqueta Antarctic ozone hole. Mostrar todas las entradas
Mostrando entradas con la etiqueta Antarctic ozone hole. Mostrar todas las entradas

domingo, 27 de octubre de 2013

CURIOSIDADES: La NASA quiere más mujeres en la ciencia


La NASA quiere más mujeres en la ciencia
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La NASA quiere más mujeres en la ciencia
Por Agencia EFE – 22/11/2011 
Washington, 22 nov (EFE).- La NASA quiere más mujeres en la ciencia y con el fin de animar a las jóvenes estudiantes a que encaminen sus carreras hacia las ramas de ingeniería, matemáticas y tecnología ha creado una nueva web que fue presentada hoy.
La página women.nasa.gov/a2i/ contiene vídeos en los que pueden saber más sobre las mujeres que trabajan en la NASA, sus carreras, su formación y cómo comenzaron a trabajar para la agencia espacial estadounidense.
Como la matemática Carolina Restrepo, quien creció en Colombia y Bolivia, y a los 18 años no dudó en marcharse a Estados Unidos para estudiar ingeniería, con la ilusión de poder diseñar, construir y hacer volar un aeroplano radiocontrolado.
Fue lo que vio en la televisión sobre la NASA lo que le impulsó a querer trabajar en la agencia espacial. "Nunca había tenido la oportunidad de conocer o hablar con alguien que había trabajado en el campo del espacio, pero no me importó, me concentré para que cuando creciera sucediera", cuenta en su relato.
Pocas semanas después de comenzar su primer semestre en la Universidad de Texas A&M, leyó que la NASA estaba contratando gente de su edad y ese se convirtió en su nuevo objetivo. Un año más tarde estaba trabajando en el Centro Espacial Johnson de Houston algo que siempre ha disfrutado desde entonces.
Como estudiante trabajó en varios proyectos, pero cuenta que sus favoritos eran los que estaban relacionados con diseñar algoritmos sobre el vuelo de las naves espaciales, un trabajo que requirió una base sólida en Matemáticas y en Física para poder simular el vuelo del vehículo espacial.
Ahora forma parte del equipo de diseño de la cápsula Orion, el nuevo vehículo de la NASA con el que espera poder enviar al hombre a Marte.
"Trabajar en la NASA hace que todos esos años de trabajo duro y las largas noches de estudio hayan merecido la pena. No cambiaría esto por nada en el mundo", añadió.
Con esta herramienta "tenemos la oportunidad de llegar a la próxima generación e inspirar a las jóvenes de hoy a perseguir una carrera en la ciencia y la tecnología", señaló Rebecca Keiser, directora adjunta de políticas de integración y representante de la NASA ante la Casa Blanca del consejo de políticas para mujeres y niñas.
La web incluye cuatro cuentas de Twitter, una por cada uno de los temas, en las que las estudiantes pueden interactuar enviando sus preguntas a las científicas.
La NASA ya contaba con una página web women.nasa.gov, en la que se incluyen el testimonio de mujeres en puestos destacados en la agencia, entre otras, la subdirectora Lori Garver, con el mismo objetivo de llevar la ciencia a la nueva generación.
Según datos de la NASA, de los 18.544 empleados que tiene la agencia espacial en todos sus centros, 6.539 son mujeres, de las que 417 son hispanas.
EFE
 
Antarctic Ozone Hole Slightly Smaller than Average This Year
The Antarctic ozone hole reached its maximum single-day area for 2013 on Sept. 16, 2013.
The Antarctic ozone hole reached its maximum single-day area for 2013 on Sept. 16. The ozone hole (purple and blue) is the region over Antarctica with total ozone at or below 220 Dobson units (a common unit for measuring ozone concentration).
Image Credit: NASA's Goddard Space Flight Center
The ozone hole that forms each year in the stratosphere over Antarctica was slightly smaller in 2013 than average in recent decades, according to NASA satellite data.
The ozone hole is a seasonal phenomenon that starts to form during the Antarctic spring (August and September). The September-October 2013 average size of the hole was 8.1 million square miles (21 million square kilometers). For comparison, the average size measured since the mid-1990s when the annual maximum size stopped growing is 8.7 million square miles (22.5 million square kilometers). However, the size of the hole in any particular year is not enough information for scientists to determine whether a healing of the hole has begun.
"There was a lot of Antarctic ozone depletion in 2013, but because of above average temperatures in the Antarctic lower stratosphere, the ozone hole was a bit below average compared to ozone holes observed since 1990," said Paul Newman, an atmospheric scientist and ozone expert at NASA's Goddard Space Flight Center in Greenbelt, Md.
The ozone hole forms when the sun begins rising again after several months of winter darkness. Polar-circling winds keep cold air trapped above the continent, and sunlight-sparked reactions involving ice clouds and chlorine from manmade chemicals begin eating away at the ozone. Most years, the conditions for ozone depletion ease before early December when the seasonal hole closes.
Levels of most ozone-depleting chemicals in the atmosphere have gradually declined as the result of the 1987 Montreal Protocol, an international treaty to protect the ozone layer by phasing out production of ozone-depleting chemicals. As a result, the size of the hole has stabilized, with variation from year to year driven by changing meteorological conditions.
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Daily images from Jul. 1 to Oct. 15 show the evolution of the 2013 ozone hole. The ozone hole maximum occurred on Sept. 16, 2013.
Image Credit: NASA/Robert Simmon/Ozone Hole Watch
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The single-day maximum area this year was reached on Sept. 16 when the maximum area reached 9.3 million square miles (24 million square kilometers), about equal to the size of North America. The largest single-day ozone hole since the mid-1990s was 11.5 million square miles (29.9 million square kilometers) on Sept. 9, 2000.
Science teams from NASA and the National Oceanic and Atmospheric Administration (NOAA) have been monitoring the ozone layer from the ground and with a variety of instruments on satellites and balloons since the 1970s. These ozone instruments capture different aspects of ozone depletion. The independent analyses ensure that the international community understands the trends in this critical part of Earth's atmosphere. The resulting views of the ozone hole have differences in the computation of the size of the ozone hole, its depth, and record dates.
NASA observations of the ozone hole during 2013 were produced from data supplied by the Ozone Monitoring Instrument on NASA's Aura satellite and the Ozone Monitoring and Profiler Suite instrument on the NASA-NOAA Suomi National Polar-orbiting Partnership satellite. Long-term satellite ozone-monitoring instruments have included the Total Ozone Mapping Spectrometer, the second generation Solar Backscatter Ultraviolet Instrument, the Stratospheric Aerosol and Gas Experiment series of instruments, and the Microwave Limb Sounder.
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NASA
Guillermo Gonzalo Sánchez Achutegui

domingo, 14 de octubre de 2012

ESA: Focus on space debris: Envisat


http://www.esa.int/images/globcover_poster2010_H.jpg
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ESA’s 2009 global land cover map was generated using 12 months worth of data, collected from 1 January-31 December 2009, from Envisat’s Medium Resolution Imaging Spectrometer (MERIS) instrument. GlobCover 2009 proves the sharpest possible global land cover map can be created within a year.
The map’s legend uses the UN Food and Agriculture Organisation’s Land Cover Classification System. Credits: ESA 2010 and Université Catholique de Louvain.

 Space debris came into focus last week at the International Astronautical Congress in Naples, Italy. Envisat, ESA’s largest Earth observation satellite, ended its mission last spring and was a subject of major interest in the Space Debris and Legal session.

Envisat was planned and designed in 1987–1990, a time when space debris was not considered to be a serious problem and before the existence of mitigation guidelines, established by the UN in 2007 and adopted the next year by ESA for all of its projects.
Only later, during the post-launch operational phase, did Envisat’s orbit of about 780 km become a risky debris environment, particularly following the Chinese antisatellite missile test in 2007 and the collision between the Iridium and the Cosmos satellites in 2009.
Lowering Envisat to an orbit that would allow reentry within 25 years, however, was never an option because of its design and limited amount of fuel.
Even if controllers had lowered the satellite immediately after launch in 2002, there would not have been enough fuel to bring it down low enough – to around 600 km – where it could reenter within 25 years.  
http://www.esa.int/images/ARIA_Env_D347_50cm_cycle_ifg_ge.jpg
Envisat Advanced Synthetic Aperture Radar coseismic interferogram from descending track 347, processed by JPL/Caltech ARIA project. Data acquired on 19 February and 21 March 2011, spanning the main shock of the magnitude 9 earthquake and several aftershocks that occurred in Japan on 11 March 2011 and the following days (until 21 March). One colour cycle represents 50 cm of motion in the satellite line of sight (approximately east at 41 degrees from the vertical), i.e. about 35 cm of motion on the ground. The seismicity plot is from the US Geological Survey.
Credits: Based on ESA data - JPL/Caltech ARIA project (E. Fielding, Principal Scientist JPL/Caltech; S. Yun, Research Scientist JPL/Caltech; P. Agram, KISS Postdoctoral Fellow Caltech).

 In 2010, part of the remaining fuel was used to lower the satellite slightly into a less crowded orbit at 768 km, while keeping enough reserve to provide collision avoidance for several years.
The lower orbit also ensured continuity of crucial Earth-observation data until the next generation of satellites – the Sentinels – are fully operational in 2013.
In April 2012, however, contact with Envisat was suddenly lost, preventing ESA from controlling the spacecraft and disrupting data provision to the international Earth observation user community.
ESA is strongly committed to reducing space debris. Today, the deorbiting of missions is taken into consideration during the development of future satellites, and during the operations of current satellites when technically feasible.
Indeed, ESA decided to terminate operations of the 16-year-old ERS-2 satellite in 2011 because there was still enough fuel to lower its orbit to about 570 km, allowing it to reenter well within 25 years.

The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) aboard Envisat can map the atmospheric concentrations of more than 20 trace gases, including ozone, as well as the pollutants that attack it. This animation shows the ozone hole over the Antarctic during 13–20 September 2011.
Credits: ESA
During the last years of Envisat, ESA began to investigate new technology to deorbit space debris in a controlled fashion.
The problem of debris in low orbits is of paramount importance. ESA space debris represent about 0.5% of the more than 16 000 objects catalogued by the US surveillance network.
ESA is working together with other agencies to reinforce international cooperation in monitoring space debris and to study mitigation and remediation measures that will ensure the future of space endeavours.
During its extended operational lifetime, Envisat provided crucial Earth observation data not only to scientists, but also to many operational services, such as monitoring floods and oil spills.
Its data supported civil protection authorities in managing natural and man-made disasters.
An estimated 2500 scientific publications so far have been based on the data provided by the satellite during its ten-year life.
ESA
Guillermo Gonzalo Sánchez Achutegui
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