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Martin-Torres, JavierORCID iD iconorcid.org/0000-0001-6479-2236
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Publications (10 of 164) Show all publications
Webster, C. R., Martin-Torres, J., Zorzano, M.-P. & Vasavada, A. R. (2018). Background levels of methane in Mars' atmosphere show strong seasonal variations. Science, 360(6393), 1093-1096
Open this publication in new window or tab >>Background levels of methane in Mars' atmosphere show strong seasonal variations
2018 (English)In: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 360, no 6393, p. 1093-1096Article in journal (Refereed) Published
Abstract [en]

Variable levels of methane in the martian atmosphere have eluded explanation partly because the measurements are not repeatable in time or location. We report in situ measurements at Gale crater made over a 5-year period by the Tunable Laser Spectrometer on the Curiosity rover. The background levels of methane have a mean value 0.41 ± 0.16 parts per billion by volume (ppbv) (95% confidence interval) and exhibit a strong, repeatable seasonal variation (0.24 to 0.65 ppbv). This variation is greater than that predicted from either ultraviolet degradation of impact-delivered organics on the surface or from the annual surface pressure cycle. The large seasonal variation in the background and occurrences of higher temporary spikes (~7 ppbv) are consistent with small localized sources of methane released from martian surface or subsurface reservoirs.

Place, publisher, year, edition, pages
American Association for the Advancement of Science, 2018
National Category
Aerospace Engineering
Research subject
Atmospheric science
Identifiers
urn:nbn:se:ltu:diva-69292 (URN)10.1126/science.aaq0131 (DOI)000434635500039 ()29880682 (PubMedID)2-s2.0-85048593070 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-06-11 (andbra)

Available from: 2018-06-11 Created: 2018-06-11 Last updated: 2018-11-20Bibliographically approved
Sam, L., Bhardwaj, A., Kumar, R., Buchroithner, M. F. & Martin-Torres, J. (2018). Heterogeneity in topographic control on velocities of Western Himalayan glaciers. Scientific Reports, 8(1), Article ID 12843.
Open this publication in new window or tab >>Heterogeneity in topographic control on velocities of Western Himalayan glaciers
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2018 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, no 1, article id 12843Article in journal (Refereed) Published
Abstract [en]

Studies of the seasonal and annual patterns of glacier velocities improve our understanding of the ice volume, topography, responses to climate change, and surge events of glaciers. Such studies are especially relevant and equally rare for the Himalayan glaciers, which supply many rivers that sustain some of the most heavily populated mountainous regions in the world. In particular, the control of the hypsometric distribution of geomorphometric parameters, such as slope, aspect, and curvature, on the dynamics of Himalayan glaciers have never been studied so far, at the river basin scale. Here, we present the degree to which topographic and hypsometric parameters affect the seasonal and annual average flow velocities of 112 glaciers in the Baspa River basin in the Western Indian Himalaya by analysing Global Land Ice Velocity Extraction from Landsat 8 (GoLIVE) datasets for the years 2013–2017. We observe, (i) significant heterogeneity in topographic controls on the velocities of these glaciers, (ii) elevation and the seasons play important roles in regulating the degree to which morphometric parameters (slope, aspect, and curvature) affect these velocities, (iii) a possible polythermal regime promoting both sliding and deformational forms of motion in a majority of these glaciers, and (iv) a detailed analysis of complex topographic controls within various elevation zones using a novel hypso-morphometric approach. These findings can help us to better model the dynamics of Himalayan glaciers and their responses to the future climatic scenarios. The inferences also suggest the need to incorporate dynamic topography in glacio-hydrological models in the wake of constant glacial evolutions.

Place, publisher, year, edition, pages
Nature Publishing Group, 2018
National Category
Aerospace Engineering
Research subject
Atmospheric science
Identifiers
urn:nbn:se:ltu:diva-70625 (URN)10.1038/s41598-018-31310-y (DOI)30150785 (PubMedID)2-s2.0-85052300710 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-08-28 (andbra)

Available from: 2018-08-28 Created: 2018-08-28 Last updated: 2018-09-07Bibliographically approved
Lasue, J., Cousin, A., Meslin, P., Mangold, N., Wiens, R., Berger, G., . . . Zorzano Mier, M.-P. (2018). Martian Eolian Dust Probed by ChemCam. Geophysical Research Letters, 45(20), 10968-10977
Open this publication in new window or tab >>Martian Eolian Dust Probed by ChemCam
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2018 (English)In: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 45, no 20, p. 10968-10977Article in journal (Refereed) Published
Abstract [en]

The ubiquitous eolian dust on Mars plays important roles in the current sedimentary and atmospheric processes of the planet. The ChemCam instrument retrieves a consistent eolian dust composition at the submillimeter scale from every first laser shot on Mars targets. Its composition presents significant differences with the Aeolis Palus soils and the Bagnold dunes as it contains lower CaO and higher SiO2. The dust FeO and TiO2contents are also higher, probably associated with nanophase oxide components. The dust spectra show the presence of volatile elements (S and Cl), and the hydrogen content is similar to Bagnold sands but lower than Aeolis Palus soils. Consequently, the dust may be a contributor to the amorphous component of soils, but differences in composition indicate that the two materials are not equivalent.

Place, publisher, year, edition, pages
John Wiley & Sons, 2018
Keywords
Mars, dust, ChemCam
National Category
Aerospace Engineering
Research subject
Atmospheric science
Identifiers
urn:nbn:se:ltu:diva-71898 (URN)10.1029/2018GL079210 (DOI)2-s2.0-85054722874 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-12-05 (johcin)

Available from: 2018-12-05 Created: 2018-12-05 Last updated: 2018-12-10Bibliographically approved
Fonseca, R., Zorzano Mier, M.-P. & Martín-Torres, J. (2018). Planetary Boundary Layer and Circulation Dynamics at Gale Crater, Mars. Icarus (New York, N.Y. 1962), 302, 537-559
Open this publication in new window or tab >>Planetary Boundary Layer and Circulation Dynamics at Gale Crater, Mars
2018 (English)In: Icarus (New York, N.Y. 1962), ISSN 0019-1035, E-ISSN 1090-2643, Vol. 302, p. 537-559Article in journal (Refereed) Published
Abstract [en]

The Mars implementation of the Planet Weather Research and Forecasting (PlanetWRF) model, MarsWRF, is used here to simulate the atmospheric conditions at Gale Crater for different seasons during a period coincident with the Curiosity rover operations. The model is first evaluated with the existing single-point observations from the Rover Environmental Monitoring Station (REMS), and is then used to provide a larger scale interpretation of these unique measurements as well as to give complementary information where there are gaps in the measurements.

The variability of the planetary boundary layer depth may be a driver of the changes in the local dust and trace gas content within the crater. Our results show that the average time when the PBL height is deeper than the crater rim increases and decreases with the same rate and pattern as Curiosity's observations of the line-of-sight of dust within the crater and that the season when maximal (minimal) mixing is produced is Ls 225°-315° (Ls 90°-110°). Thus the diurnal and seasonal variability of the PBL depth seems to be the driver of the changes in the local dust content within the crater. A comparison with the available methane measurements suggests that changes in the PBL depth may also be one of the factors that accounts for the observed variability, with the model results pointing towards a local source to the north of the MSL site.

The interaction between regional and local flows at Gale crater is also investigated assuming that the meridional wind, the dynamically important component of the horizontal wind at Gale, anomalies with respect to the daily mean can be approximated by a sinusoidal function as they typically oscillate between positive (south to north) and negative (north to south) values that correspond to upslope/downslope or downslope/upslope regimes along the crater rim and Mount Sharp slopes and the dichotomy boundary. The smallest magnitudes are found in the northern crater floor in a region that comprises Bradbury Landing, in particular at Ls 90° when they are less than 1 m s−1, indicating very little lateral mixing with outside air. The largest amplitudes occur in the south-western portions of the crater where they can exceed 20 m s−1. Should the slope flows along the crater rims interact with the dichotomy boundary flow, which is more likely at Ls 270° and very unlikely at Ls 90°, they are likely to interact constructively for a few hours from late evening to nighttime (∼17-23 LMST) and from pre-dawn early morning (∼5-11 LMST) hours at the norther crater rim and destructively at night (∼22-23 LMST) and in the morning (∼10-11 LMST) at the southern crater rim.

We conclude that a better understanding of the PBL and circulation dynamics has important implications for the variability of the concentration of dust, non-condensable and trace gases at the bottom of other craters on Mars as mixing with outside air can be achieved vertically, through changes in the PBL depth, and laterally, by the transport of air into and out of the crater.

Place, publisher, year, edition, pages
Elsevier, 2018
National Category
Aerospace Engineering
Research subject
Atmospheric science
Identifiers
urn:nbn:se:ltu:diva-67009 (URN)10.1016/j.icarus.2017.11.036 (DOI)000423779600038 ()2-s2.0-85037838111 (Scopus ID)
Note

Validerad;2018;Nivå 2;2017-12-21 (andbra)

Available from: 2017-12-14 Created: 2017-12-14 Last updated: 2018-06-13Bibliographically approved
Cockell, C. S., Martin-Torres, J., Zorzano, M.-P., Bhardwaj, A., Soria-Salinas, Á., Mathanla, T., . . . Suckling, B. (2018). Subsurface scientific exploration of extraterrestrial environments (MINAR 5):: analogue science, technology and education inthe Boulby Mine, UK. International Journal of Astrobiology
Open this publication in new window or tab >>Subsurface scientific exploration of extraterrestrial environments (MINAR 5):: analogue science, technology and education inthe Boulby Mine, UK
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2018 (English)In: International Journal of Astrobiology, ISSN 1473-5504, E-ISSN 1475-3006Article in journal (Refereed) Epub ahead of print
Abstract [en]

The deep subsurface of other planetary bodies is of special interest for robotic and human exploration. The subsurface provides access to planetary interior processes, thus yielding insights into planetary formation and evolution. On Mars, the subsurface might harbour the most habitable conditions. In the context of human exploration, the subsurface can provide refugia for habitation from extreme surface conditions. We describe the fifth Mine Analogue Research (MINAR 5) programme at 1 km depth in the Boulby Mine, UK in collaboration with Spaceward Bound NASA and the Kalam Centre, India, to test instruments and methods for the robotic and human exploration of deep environments on the Moon and Mars. The geological context in Permian evaporites provides an analogue to evaporitic materials on other planetary bodies such as Mars. A wide range of sample acquisition instruments (NASA drills, Small Planetary Impulse Tool (SPLIT) robotic hammer, universal sampling bags), analytical instruments (Raman spectroscopy, Close-Up Imager, Minion DNA sequencing technology, methane stable isotope analysis, biomolecule and metabolic life detection instruments) and environmental monitoring equipment (passive air particle sampler, particle detectors and environmental monitoring equipment) was deployed in an integrated campaign. Investigations included studying the geochemical signatures of chloride and sulphate evaporitic minerals, testing methods for life detection and planetary protection around human-tended operations, and investigations on the radiation environment of the deep subsurface. The MINAR analogue activity occurs in an active mine, showing how the development of space exploration technology can be used to contribute to addressing immediate Earth-based challenges. During the campaign, in collaboration with European Space Agency (ESA), MINAR was used for astronaut familiarization with future exploration tools and techniques. The campaign was used to develop primary and secondary school and primary to secondary transition curriculum materials on-site during the campaign which was focused on a classroom extra vehicular activity simulation.

Place, publisher, year, edition, pages
Cambridges Institutes Press, 2018
National Category
Geochemistry Astronomy, Astrophysics and Cosmology Aerospace Engineering
Research subject
Atmospheric science
Identifiers
urn:nbn:se:ltu:diva-70069 (URN)10.1017/S1473550418000186 (DOI)
Available from: 2018-07-04 Created: 2018-07-04 Last updated: 2018-08-02
Dirri, F., Palomba, E., Longobardo, A., Biondi, D., Boccaccini, A., Galiano, A., . . . Martin-Torres, J. (2018). VISTA instrument: a PCM-based sensor for organics and volatiles characterization by using Thermogravimetric technique. In: : . Paper presented at 2018 5th IEEE International Workshop on Metrology for AeroSpace (MetroAeroSpace), 20-22 June 2018, Rome, Italy (pp. 150-154). IEEE, Article ID 8453532.
Open this publication in new window or tab >>VISTA instrument: a PCM-based sensor for organics and volatiles characterization by using Thermogravimetric technique
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2018 (English)Conference paper, Published paper (Refereed)
Abstract [en]

VISTA (Volatile In Situ Thermogravimetry Analyser) is a µ-Thermogravimeter sensor developed by Consortium of Italian Institutes. ThermoGravimetric Analysis (TGA) is a widely used technique to monitor thermal processes involving volatile compounds, e.g. deposition/sublimation and absorption/ desorption. The instrument core is composed by a Piezoelectric Crystal Microbalance (PCM), equipped with built-in heater and built-in temperature sensor, and provided of its own Proximity Electronics (PE). The PCM oscillation frequency linearly depends on the mass deposited on its sensible area (according to Sauerbrey equation) while the PCM temperature can be increased by means of integrated heaters. Thus, mass and volatile composition can be inferred by the frequency change and by desorption temperature, respectively. The instrument is divided in two sensor heads: VISTA1, able to monitor outgassing processes in space, and VISTA2, able to reach higher temperatures, studying the dehydration and organics decomposition in minerals in different environmental conditions. An Engineering Model of VISTA1 and a laboratory breadboard of VISTA2 have been developed. Pure organic compounds and contaminant have been characterized by using deposition processes and TGA cycles obtaining some physical-chemical parameters, i.e. enthalpy of sublimation/evaporation, ΔHHsub,evap , deposition rates, kk and vapor pressures, Pvap . The instrument concept, the scientific objectives and the laboratory measurements are explained in this work.

Place, publisher, year, edition, pages
IEEE, 2018
National Category
Aerospace Engineering
Research subject
Atmospheric science
Identifiers
urn:nbn:se:ltu:diva-71018 (URN)10.1109/MetroAeroSpace.2018.8453532 (DOI)2-s2.0-85053898913 (Scopus ID)978-1-5386-2474-6 (ISBN)
Conference
2018 5th IEEE International Workshop on Metrology for AeroSpace (MetroAeroSpace), 20-22 June 2018, Rome, Italy
Available from: 2018-10-01 Created: 2018-10-01 Last updated: 2018-10-12Bibliographically approved
Fonseca, R., Martin-Torres, J. & Andersson, K. (2018). Wind Forecasts for Rocket and Balloon Launches at the Esrange Space Center Using the WRF Model. Weather and forecasting, 33(3), 813-833
Open this publication in new window or tab >>Wind Forecasts for Rocket and Balloon Launches at the Esrange Space Center Using the WRF Model
2018 (English)In: Weather and forecasting, ISSN 0882-8156, E-ISSN 1520-0434, Vol. 33, no 3, p. 813-833Article in journal (Refereed) Published
Abstract [en]

High-altitude balloons and rockets are regularly launched at the Esrange Space Center (ESC) in Kiruna, Sweden, with the aim of retrieving atmospheric data for meteorological and space studies in the Arctic region. Meteorological conditions, particularly wind direction and speed, play a critical role in the decision of whether to go ahead with or postpone a planned launch. Given the lack of high-resolution wind forecasts for this remote region, the Weather Research and Forecasting (WRF) Model is used to downscale short-term forecasts given by the Global Forecast System (GFS) for the ESC for six 5-day periods in the warm, cold, and transition seasons. Three planetary boundary layer (PBL) schemes are considered: the local Mellor-Yamada-Janjic' (MYJ), the nonlocal Yonsei University (YSU), and the hybrid local-nonlocal Asymmetric Convective Model 2 (ACM2). The ACM2 scheme is found to provide the most skillful forecasts. An analysis of the WRF Model output against the launch criteria for two of the most commonly launched vehicles, the sounding rockets Veículo de Sondagem Booster-30 (VSB-30) and Improved Orion, reveals probability of detection (POD) values that always exceeds 60% with the false alarm rate (FAR) generally below 50%. It is concluded that the WRF Model, in its present configuration, can be used to generate useful 5-day wind forecasts for the launches of these two rockets. The conclusions reached here are applicable to similar sites in the Arctic and Antarctic regions.

Place, publisher, year, edition, pages
American Meteorological Society, 2018
National Category
Aerospace Engineering
Research subject
Atmospheric science
Identifiers
urn:nbn:se:ltu:diva-69940 (URN)10.1175/WAF-D-18-0031.1 (DOI)000437098000001 ()2-s2.0-85048660164& (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-06-27 (andbra)

Available from: 2018-06-27 Created: 2018-06-27 Last updated: 2018-08-10Bibliographically approved
Bhardwaj, A., Singh, S., Sam, L., Joshi, P., Bhardwaj, A., Martín-Torres, J. F. & Kumar, R. (2017). A review on remotely sensed land surface temperature anomaly as an earthquake precursor. International Journal of Applied Earth Observation and Geoinformation, 63, 158-166
Open this publication in new window or tab >>A review on remotely sensed land surface temperature anomaly as an earthquake precursor
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2017 (English)In: International Journal of Applied Earth Observation and Geoinformation, ISSN 0303-2434, Vol. 63, p. 158-166Article in journal (Refereed) Published
Abstract [en]

The low predictability of earthquakes and the high uncertainty associated with their forecasts make earthquakes one of the worst natural calamities, capable of causing instant loss of life and property. Here, we discuss the studies reporting the observed anomalies in the satellite-derived Land Surface Temperature (LST) before an earthquake. We compile the conclusions of these studies and evaluate the use of remotely sensed LST anomalies as precursors of earthquakes. The arrival times and the amplitudes of the anomalies vary widely, thus making it difficult to consider them as universal markers to issue earthquake warnings. Based on the randomness in the observations of these precursors, we support employing a global-scale monitoring system to detect statistically robust anomalous geophysical signals prior to earthquakes before considering them as definite precursors.

Place, publisher, year, edition, pages
Elsevier, 2017
National Category
Geosciences, Multidisciplinary Aerospace Engineering
Research subject
Atmospheric science
Identifiers
urn:nbn:se:ltu:diva-64993 (URN)10.1016/j.jag.2017.08.002 (DOI)000411848500015 ()2-s2.0-85032462154 (Scopus ID)
Note

Validerad;2017;Nivå 2;2017-08-15 (rokbeg)

Available from: 2017-08-10 Created: 2017-08-10 Last updated: 2017-11-24Bibliographically approved
Martín-Torres, J. (2017). A space rose by another name smells sweeter [Letter to the editor]. New scientist (1971), 233(3116), 52-54
Open this publication in new window or tab >>A space rose by another name smells sweeter
2017 (English)In: New scientist (1971), ISSN 0262-4079, Vol. 233, no 3116, p. 52-54Article in journal, Letter (Refereed) Published
Place, publisher, year, edition, pages
Elsevier, 2017
National Category
Aerospace Engineering
Research subject
Atmospheric science
Identifiers
urn:nbn:se:ltu:diva-63163 (URN)10.1016/S0262-4079(17)30484-0 (DOI)
Available from: 2017-04-26 Created: 2017-04-26 Last updated: 2018-09-13Bibliographically approved
Soria-Salinas, Á., Zorzano Mier, M.-P., Martin-Torres, J., Sánchez-García-Casarrubios, J., Pérez-Díaz, J.-L. & Vakkada Ramachandran, A. (2017). A Xenon Mass Gauging through Heat Transfer Modeling for Electric Propulsion Thrusters. World Academy of Science, Engineering and Technology: An International Journal of Science, Engineering and Technology, 11(1), 94-105
Open this publication in new window or tab >>A Xenon Mass Gauging through Heat Transfer Modeling for Electric Propulsion Thrusters
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2017 (English)In: World Academy of Science, Engineering and Technology: An International Journal of Science, Engineering and Technology, ISSN 2010-376X, E-ISSN 2070-3740, Vol. 11, no 1, p. 94-105Article in journal (Refereed) Published
Abstract [en]

The current state-of-the-art methods of mass gauging of Electric Propulsion (EP) propellants in microgravity conditions rely on external measurements that are taken at the surface of the tank. The tanks are operated under a constant thermal duty cycle to store the propellant within a pre-defined temperature and pressure range. We demonstrate using computational fluid dynamics (CFD) simulations that the heat-transfer within the pressurized propellant generates temperature and density anisotropies. This challenges the standard mass gauging methods that rely on the use of time changing skin-temperatures and pressures. We observe that the domes of the tanks are prone to be overheated, and that a long time after the heaters of the thermal cycle are switched off, the system reaches a quasi-equilibrium state with a more uniform density. We propose a new gauging method, which we call the Improved PVT method, based on universal physics and thermodynamics principles, existing TRL-9 technology and telemetry data. This method only uses as inputs the temperature and pressure readings of sensors externally attached to the tank. These sensors can operate during the nominal thermal duty cycle. The improved PVT method shows little sensitivity to the pressure sensor drifts which are critical towards the end-of-life of the missions, as well as little sensitivity to systematic temperature errors. The retrieval method has been validated experimentally with CO2 in gas and fluid state in a chamber that operates up to 82 bar within a nominal thermal cycle of 38 °C to 42 °C. The mass gauging error is shown to be lower than 1% the mass at the beginning of life, assuming an initial tank load at 100 bar. In particular, for a pressure of about 70 bar, just below the critical pressure of CO2, the error of the mass gauging in gas phase goes down to 0.1% and for 77 bar, just above the critical point, the error of the mass gauging of the liquid phase is 0.6% of initial tank load. This gauging method improves by a factor of 8 the accuracy of the standard PVT retrievals using look-up tables with tabulated data from the National Institute of Standards and Technology.

Place, publisher, year, edition, pages
World Academy of Science, Engineering and Technology, 2017
Keywords
Electric propulsion, mass gauging, propellant, PVT, xenon.
National Category
Aerospace Engineering
Research subject
Atmospheric science
Identifiers
urn:nbn:se:ltu:diva-61373 (URN)10.5281/zenodo.1339694 (DOI)
Funder
Swedish National Space Board
Available from: 2017-01-10 Created: 2017-01-10 Last updated: 2018-11-19Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0001-6479-2236

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