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Publicación Acceso Abierto Mid-winter lower stratosphere temperatures in the Antarctic vortex: comparison between observations and ECMWF and NCEP operational models(EGU European Geosciences Union, 2007-01-24) Parrondo, María Concepción; Yela González, Margarita; Gil, M.; Von der Gathen, P.; Ochoa, H.Radiosonde temperature profiles from Belgrano (78° S) and other Antarctic stations have been compared with European Centre for Medium-Range Weather Forecasting (ECMWF) and National Centers for Environmental Prediction (NCEP) operational analyses during the winter of 2003. Results show good agreement between radiosondes and NCEP and a bias in the ECMWF model which is height and temperature dependent, being up to 3°C too cold at 80 and 25–30 hPa, and hence resulting in an overestimation of the predicted potential PSC areas. Here we show the results of the comparison and discuss the potential implications that this bias might have on the ozone depletion computed by Chemical Transport Models based on ECMWF temperature fields, after rejecting the possibility of a bias in the sondes at extreme low temperatures.Publicación Acceso Abierto A trajectory-based estimate of the tropospheric ozone column using the residual method(AGU Publishing, 2007-12-19) Schoeberl, M. R.; Ziemke, J. R.; Bojkov, B.; Livesey, N.; Duncan, B.; Strahan, S.; Froidevaux, L.; Kulawik, S.; Bhartia, P. K.; Chandra, S.; Levelt, P. F.; Witte, J. C.; Thompson, A. M.; Cuevas, E.; Redondas, A.; Tarasick, D. W.; Davies, J.; Bodeker, G.; Hansen, G.; Johnson, B. J.; Oltmans, S. J.; Vömel, H.; Allaart, M.; Kelder, H.; Newchurch, M.; Godin Beekmann, S.; Ancellet, G.; Claude, H.; Andersen, S. B.; Kyrö, E.; Parrondo, María Concepción; Yela González, Margarita; Zablocki, G.; Moore, D.; Dier, H.; Von der Gathen, P.; Viatte, P.; Stübi, R.; Calpini, B.; Skrivankova, P.; Dorokhov, V.; De Backer, H.; Schmidlin, F. J.; Coetzee, G.; Fujiwara, M.; Thouret, V.; Posny, F.; Morris, G.; Merrill, J.; Leong, C. P.; Koenig Langlo, G.; Joseph, E.[1] We estimate the tropospheric column ozone using a forward trajectory model to increase the horizontal resolution of the Aura Microwave Limb Sounder (MLS) derived stratospheric column ozone. Subtracting the MLS stratospheric column from Ozone Monitoring Instrument total column measurements gives the trajectory enhanced tropospheric ozone residual (TTOR). Because of different tropopause definitions, we validate the basic residual technique by computing the 200-hPa-to-surface column and comparing it to the same product from ozonesondes and Tropospheric Emission Spectrometer measurements. Comparisons show good agreement in the tropics and reasonable agreement at middle latitudes, but there is a persistent low bias in the TTOR that may be due to a slight high bias in MLS stratospheric column. With the improved stratospheric column resolution, we note a strong correlation of extratropical tropospheric ozone column anomalies with probable troposphere-stratosphere exchange events or folds. The folds can be identified by their colocation with strong horizontal tropopause gradients. TTOR anomalies due to folds may be mistaken for pollution events since folds often occur in the Atlantic and Pacific pollution corridors. We also compare the 200-hPa-to-surface column with Global Modeling Initiative chemical model estimates of the same quantity. While the tropical comparisons are good, we note that chemical model variations in 200-hPa-to-surface column at middle latitudes are much smaller than seen in the TTOR.Publicación Acceso Abierto Arctic winter 2005: Implications for stratospheric ozone loss and climate change(AGU Publishing, 2006-12-08) Rex, M.; Salawitch, R. J.; Deckelmann, H.; Von der Gathen, P.; Harris, N. R. P.; Chipperfield, M. P.; Naujokat, B.; Reimer, E.; Allaart, M.; Andersen, S. B.; Bevilacqua, R.; Braathen, G. O.; Claude, H.; Davies, J.; De Backer, H.; Dier, H.; Dorokhov, V.; Fast, H.; Gerding, M.; Godin Beekmann, S.; Hoppel, K.; Johnson, B.; Kyrö, E.; Litynska, Z.; Moore, D.; Nakane, H.; Parrondo, María Concepción; Risley, A. D.; Skrivankova, P.; Stübi, R.; Viatte, P.; Yushkov, V.; Zerefos, C.[1] The Arctic polar vortex exhibited widespread regions of low temperatures during the winter of 2005, resulting in significant ozone depletion by chlorine and bromine species. We show that chemical loss of column ozone (ΔO3) and the volume of Arctic vortex air cold enough to support the existence of polar stratospheric clouds (VPSC) both exceed levels found for any other Arctic winter during the past 40 years. Cold conditions and ozone loss in the lowermost Arctic stratosphere (e.g., between potential temperatures of 360 to 400 K) were particularly unusual compared to previous years. Measurements indicate ΔO3 = 121 ± 20 DU and that ΔO3 versus VPSC lies along an extension of the compact, near linear relation observed for previous Arctic winters. The maximum value of VPSC during five to ten year intervals exhibits a steady, monotonic increase over the past four decades, indicating that the coldest Arctic winters have become significantly colder, and hence are more conducive to ozone depletion by anthropogenic halogens.Publicación Acceso Abierto Chemical ozone loss in the Arctic winter 2002/2003 determined with Match(EGU European Geosciences Union, 2006-07-10) Streibel, M.; Rex, M.; Von der Gathen, P.; Lehmann, R.; Harris, N. R. P.; Braathen, G. O.; Reimer, E.; Deckelmann, H.; Chipperfield, M.; Millard, G.; Allaart, M.; Andersen, S. B.; Claude, H.; Davies, J.; De Backer, H.; Dier, H.; Dorokov, V.; Fast, H.; Gerding, M.; Kyrö, E.; Litynska, Z.; Moore, D.; Moran, E.; Nagai, T.; Nakane, H.; Parrondo, María Concepción; Skrivankova, P.; Stübi, R.; Vaughan, G.; Viatte, P.; Yushkov, V.The Match technique was used to determine chemically induced ozone loss inside the stratospheric vortex during the Arctic winter 2002/2003. From end of November 2002, which is the earliest start of a Match campaign ever, until end of March 2003 approximately 800 ozonesondes were launched from 34 stations in the Arctic and mid latitudes. Ozone loss rates were quantified from the beginning of December until mid-March in the vertical region of 400–550 K potential temperature. In accordance with the occurrence of a large area of conditions favourable for the formation of polar stratospheric clouds in December ozone destruction rates varied between 10–15 ppbv/day depending on height. Maximum loss rates around 35 ppbv/day were reached during late January. Afterwards ozone loss rates decreased until mid-March when the final warming of the vortex began. In the period from 2 December 2002 to 16 March 2003 the accumulated ozone loss reduced the partial ozone column of 400–500 K potential temperature by 56±4 DU. This value is in good agreement with that inferred from the empirical relation of ozone loss against the volume of potential polar stratospheric clouds within the northern hemisphere. The sensitivity of the results on recent improvements of the approach has been tested.Publicación Restringido OClO, NO2 and O3 total column observations over Iceland during the winter 1993/94(AGU Publishing, 1996-11-15) Gil, M.; Puentedura, O.; Yela González, Margarita; Parrondo, María Concepción; Jadhav, D. B.; Thorkelsson, B.Ground-based observation of OClO, NO2, and O3 columns by differential UV-Visible spectroscopy at twilight during the fall winter of 1993/94 at the sub-Arctic station of Reykjavik (64°N, 23°W) are presented. Results show no direct evidence of ozone depletion during the period but significant amounts of OClO were observed in December and January when NO2 abundances were at the annual minimum. NO2 columns are found to be controlled by the hours of light available but highly modulated by the lower stratosphere temperature. OClO was observed outside the vortex as well, but only at times when NO2 was low.Publicación Acceso Abierto Evaluation of a liquid crystal based polarization modulator for a space mission thermal environment(Elsevier, 2017-09-21) Silva-López, Manuel; Bastide, L.; Restrepo, R.; García Parejo, Pilar; Álvarez-Herrrero, AlbertoThe Multi Element Telescope for Imaging and Spectroscopy (METIS) is one of the remote sensing instruments to be onboard the future NASA/ESA Solar Orbiter mission. The science nominal mission orbit will take the spacecraft from 0.28 to 0.95 astronomical units from the Sun, setting challenging and variable thermal conditions to its payload. METIS is an inverted-occultation coronagraph that will image the solar corona in the visible and UV wavelength range. In the visible light path a Polarization Modulation Package (PMP) performs a polarimetric analysis of the incoming solar light. This PMP is based on liquid crystal variable retarders (LCVR) and works under a temporal modulation scheme. The LCVRs behavior has a dependence on temperature and, as a consequence, it is critical to guarantee the PMP performance in the mission thermal environment. Key system specifications are the optical quality and the optical retardance homogeneity. Moreover, the thermally induced elastic deformations of the mechanical mounts and the LCVRs shall not produce any performance degradation. A suitable thermal control is hence required to maintain the system within its allowed limits at any time. The PMP shall also be able to reach specific set-points with the power budget allocated. Consequently, and in order to verify the PMP thermal design, we have experimentally reproduced the expected thermal flight environment. Specifically, a thermal-vacuum cycle test campaign is run at the different mission operational conditions. The purpose is both to check the stability of the thermal conditions and to study the optical quality evolution/degradation. Within this test transmitted wavefront measurements and functional verification tests have been carried out. To do that we adapted an optical interrogation scheme, based on a phase shifting interferometric technique, that allows for inspection of the PMP optical aperture. Finally, measurements obtained at non-operational temperature conditions are also shown. These results demonstrate that the device meets the specifications required to perform its operational role in the space mission environment.Publicación Acceso Abierto Fine tuning method for optimization of liquid crystal based polarimeters(Optica Publishing Group, 2018-04-18) Álvarez-Herrrero, Alberto; García Parejo, Pilar; Silva-López, Manuel; Ministerio de Economía y Competitividad (MINECO)Liquid crystal variable retarders (LCVR) based polarimeters perform temporal polarization modulation by applying a sequence of driving voltages to introduce different optical retardances. However, even after a careful design and fabrication, manufacturing tolerances (i.e., slight optical axis misalignments, instrument residual polarization, optical activity in the LCVRs...) or the final system configuration (i.e., LCVRs in a convergent optical beam, thermal gradient across the clear aperture...) produce deviations from the ideal setup. As a consequence, all of these effects can reduce the polarimetric modulation efficiency of the device and, therefore, its signal-to-noise ratio. Hence, the voltage sequence applied according to the LCVR calibration curves may not be suitable to reach the optimal theoretical polarimetric efficiencies. In this work, a systematic fine tuning method for the LCVRs driving voltages is described an experimentally demonstrated.Publicación Acceso Abierto Advanced iterative algorithm for phase calibration of spatial light modulators integrated in optical instrumentation in a vibration environment(Optica Publishing Group, 2020-07-30) Silva-López, Manuel; Uribe Patarroyo, Néstor; Álvarez-Herrrero, Alberto; Agencia Estatal de Investigación (España)We present a method to obtain the phase modulation characteristic curve of a spatial light modulator (SLM) under severe vibration conditions. The procedure is based on the well-known advanced iterative algorithm (AIA), which allows wavefront extraction from unknown phase-shifted interferograms. Generally, AIA is used to determine the wavefront and the determined phase shifts are of little interest. In contrast, in our method, the main goal of using AIA is to determine the unknown phase shifts induced by an SLM during the calibration procedure. Using a segmented approach to calibration, AIA enables successful calibration even in the presence of additional random phase shifts due to environmental changes. This method has the potential to calibrate SLMs integrated in complex optical instruments with little to no modifications to the optical setup, no matter the environmental conditions. We demonstrate our technique by calibrating an SLM under vacuum conditions (10−5 mbar) in a common-path configuration compatible with usage of an SLM as a wavefront modulator at the pupil plane of an instrument. Our technique compensates for the vibrations produced by the vacuum pumps and reduces an order of magnitude the root-mean-squared error of the calibration curve evaluated with vibration errors. Our technique enhances the potential use of SLMs in complex optical systems, including aerospace optical instrumentation.Publicación Acceso Abierto Magnetoelastic Anisotropy Drives Localized Magnetization Reversal in 3D Nanowire Networks(Royal Society of Chemistry, 2025-01) Vivas, Laura G.; Ruiz Clavijo, Alejandra; Caballero Calero, Olga; Navas, David; Ordoñez Cencerrado, Amanda A.; Manzano, Cristina V.; Sanz, Ruy; Martín-González, Marisol; Agencia Estatal de Investigación (España)Three-dimensional magnetic nanowire networks (3DNNs) have shown promise for applications beyond those of their linear counterparts. However, understanding the underlying magnetization reversal mechanisms has been limited. In this study, we present a combined experimental and computational investigation on simplified 3DNNs to address this gap. Our findings reveal a previously unidentified in-plane magnetoelastic anisotropy, validated through comparisons between experimental and simulated magnetic data. Notably, we discovered that magnetization reversal in 3DNNs is driven by highly localized magnetic states, arising from the interplay of exchange and dipolar interactions, magnetoelastic anisotropy, and nanowire microstructure. This discovery challenges the prevailing understanding of magnetization reversal in nickel nanowires. Our work provides critical insights into the magnetic behavior of 3DNNs, opening doors for their tailored design and optimization.Publicación Restringido Design of a Portable Susceptometer With No Electromagnets(Institute of Electrical and Electronics Engineers (IEEE), 2023-12-04) Rivelles García, Alejandro; Sanz Lluch, María del Mar; Maicas, Marco; Mesa, José Luis; Díaz Michelena, Marina; Aroca, Claudio; Ministerio de Ciencia e Innovación (MICINN); European Research Council (ERC)Magnetic materials characterization usually requires heavy equipment based on electromagnets, which limits their use to the laboratory. The volume of the typical samples is small in order to keep a good uniformity of the applied magnetic field in the sample. This kind of equipment is not appropriate for geological measurements in the field, where portable systems are required and samples have typically a higher volume. Here, we study the limits and applicability of a portable susceptometer device based on strong magnets potentially applicable in geological prospections. A new prototype has been built and tested. The device makes use of Nd–Fe–B magnets and an iron magnetic circuit (MC) to apply the magnetic field to the sample. A quasi-spherical geometry of the MC provides good uniformity of the magnetic field while keeping a moderate measuring volume. The equipment is powered by a 12-V battery and a mechanical design allows the control of the magnetic flux density in the range of approximately 30–130 mT.Publicación Acceso Abierto Constraints on the Spatial Distribution of Lunar Crustal Magnetic Sources From Orbital Magnetic Field Data(Advancing Earth and Space Science (AGU), 2024-02-14) Oliveira, Joana S.; Vervelidou, Foteini; Wieczorek, Mark A.; Díaz Michelena, Marina; Ministerio de Ciencia e Innovación (MICINN); European Research Council (ERC)Spacecraft measurements show that the crust of the Moon is heterogeneously magnetized. The sources of these magnetic anomalies are yet not fully understood, with most not being related to known geological structures or processes. Here, we use an inversion methodology that relies on the assumption of unidirectional magnetization, commonly referred to as Parker's method, to elucidate the origin of the magnetic sources by constraining the location and geometry of the underlying magnetization. This method has been used previously to infer the direction of the underlying magnetization but it has not been tested as to whether it can infer the geometry of the source. The performance of the method is here assessed by conducting a variety of tests, using synthetic magnetized bodies of different geometries mimicking the main geological structures potentially magnetized within the lunar crust. Results from our tests show that this method successfully localizes and delineates the two-dimensional surface projection of subsurface three-dimensional magnetized bodies, provided their magnetization is close to unidirectional and the magnetic field data are of sufficient spatial resolution and reasonable signal-to-noise ratio. We applied this inversion method to two different lunar magnetic anomalies, the Mendel-Rydberg impact basin and the Reiner Gamma swirl. For Mendel-Rydberg, our analysis shows that the strongest magnetic sources are located within the basin's inner ring, whereas for Reiner Gamma, the strongest magnetic sources form a narrow dike-like body that emanates from the center of the Marius Hills volcanic complex.Publicación Acceso Abierto Vector magnetometry to analyse the Caldereta volcano in the canary islands as a possible terrestrial analogue of mars(Elsevier, 2025-04-07) Díaz Michelena, Marina; Losantos, Emma; Rivero Rodríguez, Miguel Ángel; Oliveira, Joana S.; García Monasterio, Óscar; Mansilla, Federico; Melguizo, Ángel; García Bueno, Jose Luis; Salamanca, David; Fernández Romero, S.; Ministerio de Ciencia e Innovación (MICINN); European Research Council (ERC)Volcanoes are typical features of terrestrial planets' surfaces. Among the different geological processes which give rise to volcanoes, hydromagmatic eruptions are of particular importance for the search of extraterrestrial life since they require the presence of water. Phreatomagmatic eruptions on Mars shall resemble those of the Earth. The possibility to perform magnetic surveys on Mars with magnetometers carried by helicopters opens a new scenario to gain more insights on such features. As a natural first step, gathering a database of terrestrial analogue magnetic signatures is desired, prior to magnetic surveys on the Martian surface. In this work we have selected the Caldereta volcano, a phreatomagmatic edifice in Lanzarote Island (Canary Islands), to perform a magnetic survey using on board drones magnetometry. The acquired data will allow to compare future measurements from other similar structures of the “Red Planet”. The survey casts vector magnetic field data generated by the volcanic edifice. Additionally, we suggest a simplified structure that mimics the geomorphology observed, we attribute a magnetization to such structure and develop a mathematical model that computes its sourced magnetic field. Finally, we develop synthetic models of a volcano on Mars which have been preliminarily classified as hydromagmatic taking Caldereta simulated structure as a reference.Publicación Acceso Abierto Future space experiment platforms for astrobiology and astrochemistry research(npj Microgravity, 2023-06-12) Elsaesser, Andreas; Burr, David J.; Mabey, Paul; Urso, Riccardo Giovanni; Billi, Daniela; Cockell, Charles S.; Cottin, Hervé; Kish, Adrienne; Leys, Natalie; Van Loon, Jack J. W. A.; Mateo Marti, Eva; Moissl-Eichinger, Christine; Onofri, Silvano; Quinn, Richard C.; Rabbow, Elke; Rettberg, Petra; de la Torre Noetzel, Maria Rosa; Slenzka, Klaus; Ricco, Antonio J.; De Vera, Jean Pierre; Westall, Frances; European Space Agency (ESA)Space experiments are a technically challenging but a scientifically important part of astrobiology and astrochemistry research. The International Space Station (ISS) is an excellent example of a highly successful and long-lasting research platform for experiments in space, that has provided a wealth of scientific data over the last two decades. However, future space platforms present new opportunities to conduct experiments with the potential to address key topics in astrobiology and astrochemistry. In this perspective, the European Space Agency (ESA) Topical Team Astrobiology and Astrochemistry (with feedback from the wider scientific community) identifies a number of key topics and summarizes the 2021 “ESA SciSpacE Science Community White Paper” for astrobiology and astrochemistry. We highlight recommendations for the development and implementation of future experiments, discuss types of in situ measurements, experimental parameters, exposure scenarios and orbits, and identify knowledge gaps and how to advance scientific utilization of future space-exposure platforms that are either currently under development or in an advanced planning stage. In addition to the ISS, these platforms include CubeSats and SmallSats, as well as larger platforms such as the Lunar Orbital Gateway. We also provide an outlook for in situ experiments on the Moon and Mars, and welcome new possibilities to support the search for exoplanets and potential biosignatures within and beyond our solar system.Publicación Acceso Abierto The September 2002 Antarctic vortex major warming as observed by visible spectroscopy and ozone soundings(Taylor & Francis Ltd, 2005-08) Yela González, Margarita; Parrondo, María Concepción; Gil Moulet, Manuel; Rodríguez, S.; Araujo, J.; Ochoa, H.; Deferrari, Guillermo Alejandro; Diaz, Susana BeatrizThe record of O3 total column and NO2 obtained by visible spectroscopy at Ushuaia (55° S), Marambio (64° S) and Belgrano (78° S) and vertical ozone profiles from the latter station provide insight into the unprecedented major warming observed above Antarctica in the last week of September 2002. From 18 September to 25 September the temperature increased 54°C at the isentropic level of 700 K. The temperature anomaly was observed down to the level of 300 K in which a well-defined tropopause was established. From comparison of the ozone profiles before and during the event, it can be seen that a fast increase in O3 took place basically above 500 K, but the layer where the ozone hole occurs was barely affected. Low potential vorticity values above Belgrano occurred only at levels above 500 K, confirming that the vortex split was confined to heights above the layer of the Antarctic spring depletion. The signature of poleward-transported air is clearly visible from the NO2 column departure from the envelope of the previous years in all three stations. NO2 columns larger than typical for ozone hole conditions by 400% were observed at Belgrano. Diurnal variations provide evidence of non-denitrified extra-vortex air.Publicación Acceso Abierto Chemical depletion of Arctic ozone in winter 1999/2000(American Geophysical Union, 2002-09-20) Rex, Markus; Salawitch, R. J.; Harris, Neil R. P.; Gathen, Peter von der; Braathen, Geir O.; Schulz, Astrid; Deckelmann, H.; Chipperfield, M.; Sinnhuber, B. M.; Reimer, E.; Alfier, R.; Bevilacqua, R.; Hoppel, K.; Fromm, M.; Lumpe, J.; Küllmann, H.; Kleinböhl, A.; Bremer, H.; Von König, M.; Künzi, K.; Toohey, D.; Vömel, H.; Richard, E.; Aikin, K.; Jost, H.; Greenblatt, J. B.; Loewenstein, M.; Podolske, J. R.; Webster, Christopher R.; Flesch, Gregory J.; Scott, D. C.; Herman, R. L.; Elkins, J. W.; Ray, E. A.; Moore, F. L.; Hurst, D. F.; Romashkin, P.; Toon, G. C.; Sen, B.; Margitan, J. J.; Wennberg, P.; Neuber, R.; Allart, M.; Bojkov, B. R.; Claude, H.; Davies, Jonathan; Davies, W.; De Backer, H.; Dier, Horst; Dorokhov, Valery; Fast, H.; Kondo, Yutaka; Kyrö, E.; Litynska, Z.; Mikkelsen, I. S.; Molyneux, M. J.; Moran, E.; Nagai, T.; H. Nakane; Parrondo, María Concepción; Ravegnani, Fabrizio; Skrivánková, Pavla; Viatte, P.; Yushkov, Vladimir; European Commission (EC); National Aeronautics and Space Administration (NASA)[1] During Arctic winters with a cold, stable stratospheric circulation, reactions on the surface of polar stratospheric clouds (PSCs) lead to elevated abundances of chlorine monoxide (ClO) that, in the presence of sunlight, destroy ozone. Here we show that PSCs were more widespread during the 1999/2000 Arctic winter than for any other Arctic winter in the past two decades. We have used three fundamentally different approaches to derive the degree of chemical ozone loss from ozonesonde, balloon, aircraft, and satellite instruments. We show that the ozone losses derived from these different instruments and approaches agree very well, resulting in a high level of confidence in the results. Chemical processes led to a 70% reduction of ozone for a region ∼1 km thick of the lower stratosphere, the largest degree of local loss ever reported for the Arctic. The Match analysis of ozonesonde data shows that the accumulated chemical loss of ozone inside the Arctic vortex totaled 117 ± 14 Dobson units (DU) by the end of winter. This loss, combined with dynamical redistribution of air parcels, resulted in a 88 ± 13 DU reduction in total column ozone compared to the amount that would have been present in the absence of any chemical loss. The chemical loss of ozone throughout the winter was nearly balanced by dynamical resupply of ozone to the vortex, resulting in a relatively constant value of total ozone of 340 ± 50 DU between early January and late March. This observation of nearly constant total ozone in the Arctic vortex is in contrast to the increase of total column ozone between January and March that is observed during most years.Publicación Acceso Abierto Arctic ozone loss in threshold conditions: Match observations in 1997/1998 and 1998/1999(American Geophysical Union, 2001-04-01) Schulz, Astrid; Rex, Markus; Harris, Neil R. P.; Braathen, Geir O.; Reimer, E.; Alfier, R.; Kilbane Dawe, Iarla; Eckermann, Stephen; Allaart, Marc; Alpers, Matthias; Bojkov, B; Cisneros Sanchiz, Juan María; Claude, H.; Cuevas Agulló, Emilio; Davies, Jonathan; Backer, Hugo de; Dier, Horst; Dorokhov, Valery; Fast, Hans; Godin, Sophie; Johnson, B. J.; Kois, Bogumil; Kondo, Yutaka; Kosmidis, Evangelos; Kyrö, Esko; Litynska, Z.; Mikkelsen, I. S.; Molyneux, M. J.; Murphy, Gerry; Nagai, T.; Nakane, Hideaki; O'Connor, Fiona M.; Parrondo, María Concepción; Schmidlin, Frank J.; Skrivánková, Pavla; Varotsos, Costas; Vialle, C.; Viatte, P.; Yushkov, Vladimir; Zerefos, Christos S.; Gathen, Peter von der; European Commission (EC)Chemical ozone loss rates inside the Arctic polar vortex were determined in early 1998 and early 1999 by using the Match technique based on coordinated ozonesonde measurements. These two winters provide the only opportunities in recent years to investigate chemical ozone loss in a warm Arctic vortex under threshold conditions, i.e., where the preconditions for chlorine activation, and hence ozone destruction, only occurred occasionally. In 1998, results were obtained in January and February between 410 and 520 K. The overall ozone loss was observed to be largely insignificant, with the exception of late February, when those air parcels exposed to temperatures below 195 K were affected by chemical ozone loss. In 1999, results are confined to the 475 K isentropic level, where no significant ozone loss was observed. Average temperatures were some 8°–10° higher than those in 1995, 1996, and 1997, when substantial chemical ozone loss occurred. The results underline the strong dependence of the chemical ozone loss on the stratospheric temperatures. This study shows that enhanced chlorine alone does not provide a sufficient condition for ozone loss. The evolution of stratospheric temperatures over the next decade will be the determining factor for the amount of wintertime chemical ozone loss in the Arctic stratosphere.Publicación Acceso Abierto Match observations in the Arctic winter 1996/97: High stratospheric ozone loss rates correlate with low temperatures deep inside the polar vortex(American Geophysical Union, 2020-01-15) Schulz, Astrid; Rex, Markus; Steger, J.; Harris, Neil R. P.; Braathen, Geir O.; Reimer, E.; Alfier, R.; Beck, A.; Alpers, Matthias; Cisneros Sanchiz, Juan María; Claude, H.; De Backer, Hugo; Dier, Horst; Dorokhov, Valery; Fast, Hans; Godin, Sophie; Hansen, Georg; Kanzawa, Hiroshi; Kois, Bogumil; Kondo, Yutaka; Kosmidis, Evangelos; Kyrö, Esko; Litynska, Z.; Molyneux, M. J.; Murphy, Gerry; Nakane, Hideaki; Parrondo, María Concepción; Ravegnani, Fabrizio; Varotsos, Costas; Vialle, C.; Viatte, P.; Yushkov, Vladimir; Zerefos, Christos S.; Gathen, Peter von derWith the Match technique, which is based on the coordinated release of ozonesondes, chemical ozone loss rates in the Arctic stratospheric vortex in early 1997 have been quantified in a vertical region between 400 K and 550 K. Ozone destruction was observed from mid February to mid March in most of these levels, with maximum loss rates between 25 and 45ppbv/day. The vortex averaged loss rates and the accumulated vertically integrated ozone loss have been smaller than in the previous two winters, indicating that the record low ozone columns observed in spring 1997 were partly caused by dynamical effects. The observed ozone loss is inhomogeneous through the vortex with the highest loss rates located in the vortex centre, coinciding with the lowest temperatures. Here the loss rates per sunlit hour reached 6 ppbv/h, while the corresponding vortex averaged rates did not exceed 3.9 ppbv/h.Publicación Acceso Abierto Drying of the Martian mesosphere during aphelion induced by lower temperatures(Springer Nature, 2024-11-20) Toledo, D.; Rannou, P.; Apéstigue, Víctor; Rodríguez Veloso, Raúl; Rodríguez Manfredi, J. A.; Arruego, Ignacio; Martínez, Germán M.; Tamppari, L. K.; Munguira, A.; Lorenz, Ralph; Stcherbinine, Aurélien; Montmessin, F.; Sánchez Lavega, Agustín; Patel, P.; Smith, Michael D.; Lemmon, M. T.; Vicente Retortillo, Álvaro; Newman, C. E.; Viúdez Moreiras, Daniel; Hueso, R.; Bertrand, T.; Pla García, J.; Yela González, Margarita; De la Torre Juárez, M.; Ministerio de Ciencia e Innovación (MICINN); Jet Propulsion Laboratory (JPL); National Aeronautics and Space Administration (NASA); Gobierno Vasco; Agencia Estatal de Investigación (AEI); Unidad de Excelencia Científica María de Maeztu Instituto de Astrofísica de Cantabria, MDM-2017-0765The formation of water ice clouds or hazes on Mars imposes substantial limitations on the vertical transport of water into the middle-upper atmosphere, impacting the planet’s hydrogen loss. Recent observations made by the Mars Environmental Dynamics Analyzer instrument onboard Mars 2020 Perseverance rover have shown a marked decline in water ice abundance within the mesosphere (above 35-40 km) when Mars is near its aphelion (near the northern summer solstice), notably occurring during solar longitudes (Ls) between Ls 70∘ and 80∘. Orbital observations around the same latitudes indicate that temperatures between ~ 30-40 km reach a minimum during the same period. Using cloud microphysics simulations, we demonstrate that this decrease in temperature effectively increases the amount of water cold-trapped at those altitudes, confining water ice condensation to lower altitudes. Similarly, the reinforcement of the cold trap induced by the lower temperatures results in significant reductions in the water vapor mixing ratio above 35–40 km, explaining the confinement of water vapor observed around aphelion from orbiters.Publicación Acceso Abierto Ozone Detector Based on Ultraviolet Observations on the Martian Surface(Multidisciplinary Digital Publishing Institute, 2024-10-21) Viúdez Moreiras, Daniel; Saiz López, A.; Smith, Michael D.; Apéstigue, Víctor; Arruego, Ignacio; García-Menéndez, Elisa; Jiménez Martín, Juan José; Rodríguez Manfredi, J. A.; Toledo, D.; Wolff, Michael; Zorzano, María-Paz; Ministerio de Ciencia e Innovación (MICINN); Agencia Estatal de Investigación (AEI); Ministerio de Economía y Competitividad (MINECO)Ozone plays a key role in both atmospheric chemistry and UV absorption in planetary atmospheres. On Mars, upper-tropospheric ozone has been widely characterized by space-based instruments. However, surface ozone remains poorly characterized, hindered by the limited sensitivity of orbiters to the lowest scale height of the atmosphere and challenges in delivering payloads to the surface of Mars, which have prevented, to date, the measurement of ozone from the surface of Mars. Systematic measurements from the Martian surface could advance our knowledge of the atmospheric chemistry and habitability potential of this planet. NASA’s Mars 2020 mission includes the first ozone detector deployed on the Martian surface, which is based on discrete photometric observations in the ultraviolet band, a simple technology that could obtain the first insights into total ozone abundance in preparation for more sophisticated measurement techniques. This paper describes the Mars 2020 ozone detector and its retrieval algorithm, including its performance under different sources of uncertainty and the potential application of the retrieval algorithm on other missions, such as NASA’s Mars Science Laboratory. Pre-landing simulations using the UVISMART radiative transfer model suggest that the retrieval is robust and that it can deal with common issues affecting surface operations in Martian missions, although the expected low ozone abundance and instrument uncertainties could challenge its characterization in tropical latitudes of the planet. Other space missions will potentially include sensors of similar technology.Publicación Restringido Magnetic Characterization of Permalloy Nanodome Surfaces on Flexible PEEK/TiO2 Vertical Nanotubes Composites(IEEE, 2022-10-10) Martín Rubio, C.; Rivelles García, Alejandro; Schneider, Marc; Del Hoyo, J. C.; Privitera, V.; Worgull, M.; del Hoyo Gordillo, Juan CarlosPoly-ether-ether-ketone (PEEK) composites present outstanding physical and chemical properties, including radiation tolerance and compatibility with vacuum and additive manufacturing processing. Applications of PEEK range from biomedical to aerospace. Controlled 3-D nanostructuring arises as a powerful approach to generate new phenomena suitable for technological applications. In this sense, we target to synthesize robust and shapeable magnetic nanocomposites (NCs) for sensing and electromagnetic shielding applications. For this aim, we synthesized and characterized Permalloy (Py, Ni80Fe20) nanostructured surfaces on PEEK/TiO2. These NCs were synthesized by scalable and high throughput compatible fabrication approaches: anodization (TiO2 nanotubes) and hot embossing (thermal nanoimprint). The resulting NCs are shapeable, stable below 300 °C, and vacuum compatible. Their surfaces compose TiO2 nanodomes filled by PEEK. Py layers (15 nm) were sputtered on NC and flat PEEK films. The characterization included SEM, AFM, ISO-2409 Adhesion Tests, hysteresis loops, and first-order reversal curves (FORCs). The results revealed that both types of films keep stable characteristics after bending cycles, and noticeable modifications of the magnetic global response and local interactions generated due to the 3-D nanostructure.
