The Euskadi Research Prize 2016 has been given to Agustin Sánchez Lavega, Astrophysicist and Full Professor of Physics at the Applied Physics Department at the School of Engeenering (UPV/EHU) in Bilbao. The Euskadi Research Prize has a main goal to promote the scientific activities and stimalute the efforts in scientific innovation of scientists and research teams in the Basque Country or to researchers whose works has been a positive influence to the Basque Country.Press release: (Spanish or Basque only)
UPV/EHU researchers continue to enlarge the Cassini Mission Legacy. High-resolution images of Saturn's polar region observed in limb geometry in 2015 revealed a complex system of hazes southwards of the planet's hexagonal wave. However, the geometry of the observations and the faint structure in some of these hazes made the images to remain archived for a long time without an in depth analyses. A thorough analysis of these observations show that at least six stacked above the upper clouds pressure level and extending from 500 to 10 mbar with an upper layer of aerosols reaching altitudes of 340 km above the clouds (0.4 mbar). Their optical properties were studied with numerical models of radiative transfer stablishing particle sizes of 0.07-1.4 microns with densities of 100-500 particles per cubic centimeter (these values are typical of hazes). These hazes are possibly hydrocarbon condensates at temperatures of -120 to -180ºC (acetylene, benzene and others) formed by methane photolysis and electron deposition in the nearby auroras. However, the latitudinal location of this complex haze system close to the hexagon suggests that they could be due to gravity waves generated by the interaction of the hexagon atmospheric wave and the associated eastward jet.Reference: Multilayer hazes over Saturn's hexagon from Cassini ISS limb images.
Saturn is home to the largest and most intense convective storms in the Solar System. The so-called Great White Spots (GWS) develop approximately every 30 years and can grow to sizes of 20,000 km to expand later covering a complete latitudinal band of the planet. These rare storms are giants that dwarf the most common storms in Saturn: small-scale (3,000 km) seasonal storms appearing in the mid-latitudes. In 2018 however, a series of storms initiated in the North polar atmosphere. Their growth was much smaller than those of a GWS but their longevity was similar. Up to 4 storms developed over months at different latitudes and being drifted by the winds. Their interactions produced larger amounts of cloud material and modified the polar atmosphere almost to the latitude of the famous north polar hexagon. An analysis made by our research group of the existing observations including Hubble Space Telescope images, observations with the PlanetCam instrument at Calar Alto Observatory and a multitude of high-resolution observations obtained by amateur astronomers has been published in the journal Nature Astronomy. From a comparison of the observations with numerical models of the atmosphere we clonclude that these polar storms represent an intermediate type of storms in Saturn not observed before.Reference: A complex storm system in Saturn's north polar atmosphere in 2018.
Venus atmospheric superrotation has been one key mistery of planetary science for the last five decades. While the planet rotates extremely slowly requiring 243 days to complete a rotation about its axis, its atmosphere acquires fast velocities that reach more than 360 km/h at the cloud tops at an altitude of about 70 km requiring only four days to circulate around the planet. This superrotation has been known for long from the motions of cloud features on images of the day-side of the planet, however their rotation at night had not been studied before. Now an international team lead by Javier Peralta (formerly a Ph.D. student at the Grupo de Ciencias Planetarias in the UPV/EHU and now a post-doc at the Japanese Space Agency JAXA) and with members of the GCP, unveils the night-side motions from observations obtained by the VIRTIS instrument onboard the European mission Venus Express with additional observations obtained at an Infrared Telescope in Hawaii. The result: a more impredictible wind pattern with large variations, different cloud shapes and a wealth of stationary waves above high-land regions in the planet. The study, published in the journal Nature Astronomy, opens new doors to investigate the origin and maintenance of Venus superrotation from the new data of Venus night-side clouds and waves.Reference: Stationary waves and slowly moving features in the night upper clouds of Venus. J. Peralta, R. Hueso, A. Sánchez-Lavega, Y. J. Lee, A. García Muñoz, T. Kouyama, H. Sagawa, T. M. Sato, G. Piccioni, S. Tellmann, T. Imamura & T. Satoh
The equatorial jet stream in Saturn's atmosphere is one of the most interesting global wind systems in Solar System planets. The jet is home to an eastward intense wind of 450 ms-1 that encompasses a broad region of the equatorial atmosphere with a complex three-dimensional structure mixed with time variability. The variability of the jet has been studied since early wind measurements from Voyager data obtained in 1980 and 1981 together with more recent data from Cassini (years 2004-2015). However, up to now this variability has been clouded by the intriguing three-dimensional structure of the jet and lack of knowledge of the precise vertical cloud structure. The equatorial region is also affected by seasonal insolation cycles and ring shadow effects and is home to the development of half of the known giant planetary-scale storms that have developed in it. In this paper we present recent data from Cassini, Hubble Space Telescope and ground-based observations from 2014 and 2015 addresing the temporal changes in the wind and the vertical cloud structure revealing the true magnitude of the velocity changes and disentangling the effects of time variation in the jet speeds and the vertical cloud structure of the equatorial atmosphere.Reference: An enduring rapidly moving storm as a guide to Saturn's Equatorial jet's complex structure. A. Sánchez-Lavega, E. García-Melendo, S. Pérez-Hoyos, R. Hueso, M. H. Wong, A. Simon, J. F. Sanz-Requena, A. Antuñano, N. Barrado-Izagirre, I. Garate-Lopez, J. F. Rojas, T. del Río-Gaztelurrutia, J. M. Gómez-Forrellad, I. de Pater, L. Li & T. Barry. Nature Communications, 7: 13262, doi:10.1038/ncomms13262 (2016).
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We are a group of planetary scientists working at the University of the Basque Country in Bilbao (Spain).
Our main research line is the study of the dynamics of the atmospheres of the planets of the Solar System.
Currently we are involved in the analysis of data from the VIRTIS instrument onboard the European space mission Venus Express.
We also serve the planetary sciences community coordinating the IOPW (International Outer Planets Watch) and the software tool PVOL (Planetary Virtual Observatory & Laboratory) which you can access from these webpages.