Manuel de la Torre Juárez

Curiosity's rover environmental monitoring station: Overview of the first 100 sols

In the first 100 Martian solar days (sols) of the Mars Science Laboratory mission, the Rover Environmental Monitoring Station (REMS) measured the seasonally evolving diurnal cycles of ultraviolet radiation, atmospheric pressure, air temperature, ground temperature, relative humidity, and wind within Gale Crater on Mars. As an introduction to several REMS-based articles in this issue, we provide an overview of the design and performance of the REMS sensors and discuss our approach to mitigating some of the difficulties we encountered following landing, including the loss of one of the two wind sensors. We discuss the REMS data set in the context of other Mars Science Laboratory instruments and observations and describe how an enhanced observing strategy greatly increased the amount of REMS data returned in the first 100 sols, providing complete coverage of the diurnal cycle every 4 to 6 sols. Finally, we provide a brief overview of key science results from the first 100 sols. We found Gale to be very dry, never reaching saturation relative humidities, subject to larger diurnal surface pressure variations than seen by any previous lander on Mars, air temperatures consistent with model predictions and abundant short timescale variability, and surface temperatures responsive to changes in surface properties and suggestive of subsurface layering.

Observations and preliminary science results from the first 100 sols of MSL Rover Environmental Monitoring Station ground temperature sensor measurements at Gale Crater

We describe preliminary results from the first 100 sols of ground temperature measurements along the Mars Science Laboratorys traverse from Bradbury Landing to Rocknest in Gale. The ground temperature data show long-term increases in mean temperature that are consistent with seasonal evolution. Deviations from expected temperature trends within the diurnal cycle are observed and may be attributed to rover and environmental effects. Fits to measured diurnal temperature amplitudes using a thermal model suggest that the observed surfaces have thermal inertias in the range of 265–375 J m−2 K−1 s−1/2, which are within the range of values determined from orbital measurements and are consistent with the inertias predicted from the observed particle sizes on the uppermost surface near the rover. Ground temperatures at Gale Crater appear to warm earlier and cool later than predicted by the model, suggesting that there are multiple unaccounted for physical conditions or processes in our models. Where the Mars Science Laboratory (MSL) descent engines removed a mobile layer of dust and fine sediments from over rockier material, the diurnal temperature profile is closer to that expected for a homogeneous surface, suggesting that the mobile materials on the uppermost surface may be partially responsible for the mismatch between observed temperatures and those predicted for materials having a single thermal inertia. Models of local stratigraphy also implicate thermophysical heterogeneity at the uppermost surface as a potential contributor to the observed diurnal temperature cycle.

The three-dimensional vortical nature of atmospheric and oceanic turbulent flows

Using a novel numerical method at unprecedented resolution, we demonstrate that structures of small to intermediate scale in rotating, stratified flows are intrinsically three-dimensional. Such flows are characterized by vortices (spinning volumes of fluid), regions of large vorticity gradients, and filamentary structures at all scales. It is found that such structures have predominantly three-dimensional dynamics below a horizontal scale L≈12LR, where LR is the so-called Rossby radius of deformation, equal to the characteristic vertical scale of the fluid H divided by the ratio of the rotational and buoyancy frequencies f/N. The breakdown of two-dimensional dynamics at these scales is attributed to the so-called “tall-column instability” [D. G. Dritschel and M. de la Torre Juarez, J. Fluid. Mech. 328, 129 (1996)], which is active on columnar vortices that are tall after scaling by f/N, or, equivalently, that are narrow compared with LR. Moreover, this instability eventually leads to a simple relationship...

Muscle and genotype effects on fatty acid composition of goat kid intramuscular fat

Little is known about the fatty acid composition of the major muscles in goats from different breeds. Forty entire male suckling kids, 20 Criollo Cordobes and 20 Anglo Nubian, were slaughtered at 75 days of age and the fatty acid composition of their longissimus thoracis (LT) and semitendinosus (ST) muscles was analysed to clarify the effects of genotype and muscle type on goat kid meat. Genotype had a great influence on the fatty acid composition of goat kid meat. Meat from Criollo Cordobes had greater saturated (P<0.001) and lower monounsaturated (P<0.001) and polyunsaturated fatty acids (P=0.002) concentration than meat from Anglo Nubian, showing higher saturated fatty acids (SFA). On the other hand, intramuscular fat content from both genotypes was higher (P=0.042) in ST muscle, while the lowest cholesterol levels were observed in ST of Criollo Cordobes (P=0.038). That higher fat content resulted in lower relative contents of total polyunsaturated (P<0.001) and n-3 (P=0.002) fatty acids due to the lower contribution of the membrane phospholipids.

The NASA Mars 2020 Rover Mission and the Search for Extraterrestrial Life

Abstract The NASA Mars 2020 rover mission will explore an astrobiologically relevant martian site to investigate regional geology, evaluate past habitability, seek signs of ancient life, and assemble a returnable cache of samples. The spacecraft is based on successful heritage design of the Mars Science Laboratory Curiosity rover, but includes a new scientific payload and other advanced capabilities. The Mars 2020 science payload features the first two Raman spectrometers on Mars, the first microfocus X-ray fluorescence instrument, the first ground-penetrating radar, an infrared spectrometer, an upgraded microscopic and stereo context cameras and weather station, and a demonstration unit for oxygen production on Mars. The instrument suite combines visible and multispectral imaging with coordinated measurements of chemistry and mineralogy, from the submillimeter to the regional scale. Using the data acquired by the science instruments as a guide, the team will collect core samples of rock and regolith selected to represent the geologic diversity of the landing site and maximize the potential for future Earth-based analyses to answer fundamental questions in astrobiology and planetary science. These samples will be drilled, hermetically sealed, and cached on the martian surface for possible retrieval and return to Earth by future missions. The Mars 2020 spacecraft is designed and built according to an unprecedented set of biological, organic, and inorganic cleanliness requirements to maximize the scientific value of this sample suite. Here, we present the scientific vision for the Mars 2020 mission, provide an overview of the analytic capabilities of the science payload, and discuss how Mars 2020 seeks to further our understanding of habitability, biosignatures, and possibility of life beyond Earth.

Guaranteeing Canadian lamb meat quality using near-infrared spectroscopy on intact rack

Abstract: Lamb racks from commercial carcasses were scanned using near-infrared spectroscopy. The prediction accuracies (R 2) for meat quality traits were assessed. Prediction accuracy ranged between 0.40 and 0.94. When predicted values were used to classify meat based on quality, 88.7%–95.2% of samples were correctly classified as quality guaranteed.

Effects of electrical stimulation on meat quality of bison striploin steaks and ground patties

Abstract: As bison is characteristically dark in colour, this study was conducted to determine if high-voltage electrical stimulation (HVES) could improve the colour and other quality characteristics in bison, similar to positive effects of HVES previously observed in beef. Forty bison bull carcasses were split and HVES (400 V peak, 5 ms pulses at 15 pulses s-1 for 30 s) was applied to the right sides and subsequently evaluated for grade characteristics, metabolic activity, and quality characteristics. The bison carcasses used in this study had a wide range of lean and fat, with minimal marbling. In the present study, HVES had no effect on bison quality traits, sensory attributes, retail display characteristics, nor the glycolytic metabolites (P > 0.05) except lactate. Inherent differences in muscle fibre type or physical carcass differences may have influenced the response to the electrical parameters used in the present study and merits further investigation.

Generalized procrustes analysis (GPA) as a tool to discriminate among sheep breeds

Abstract. Forty male lambs of five Southern Spanish breeds were used to study the effects of the breed in their sensorial characteristics. The used breeds were: Segurena, Spanish Merino, Grazalema Merino, Churra Lebrijana and Montesina breeds. Milk lambs were slaughtered at 12 kg of live weight. A descriptive sensory evaluation was developed using the longissimus lumborum from each animal by a panel of 12 experts and a Generalized Procrustes Analysis (GPA) was used to discriminate among them. Generalized Procrustes Analysis clearly differentiated Churra Lebrijana of out the rest breeds. Churra Lebrijana was defined as more tender, juicier and with less lamb odour than the rest of the Southern Spanish lamb breeds. Thus, GPA is able to discriminate among breeds.

Remote Sensing of Fine-Scale Vertical Structures in the Atmosphere with GPS Occultations

Recent advances of inversion techniques in processing GPS radio occultation (RO) measurements have resulted in more accurate atmospheric retrievals of temperature and water vapor. Furthermore, the new techniques can overcome the resolution limit imposed by Fresnel diffraction. Fine-scale atmospheric structures with vertical extent of less than 100 m are now formally resolvable. This allows GPS RO to capture very sharp tropopause heretofore only revealed by in-situ measurements such as radiosonde soundings. Moreover, GPS RO are well suited to probing planetary boundary layer tops as well as sub-km thin moisture layers that, based on analysis of aircraft measurements, appear to be ubiquitous in the troposphere. In this work, we present the theoretical estimate and observational evidence of the high vertical resolution achievable with GPS RO measurements from CHAMP and SAC-C. In addition, since GPS RO is a limb sounding measurement, we consider the interpretation and representation of the retrieved fine-scale vertical structures in the presence of horizontal inhomogeneity.

Geostrophic Thermal Winds with a Full Coriolis Force: Response to "Thermal Wind Balance with Full Geostrophy" By J.-I. Yano

This paper gives the expressions for the synoptic scale thermal winds when a full Coriolis force is considered. The atmosphere is assumed stratified with a steady density profile. It is also argued that the resulting expressions can be applied to atmospheric temperature maps obtained by standard infrared methods only if approximations are made. This paper augments the interpretation of the results obtained in a previous paper by the author and addresses comments made by J.-I. Yano in another paper of this journal.This paper gives the expressions for the synoptic scale thermal winds when a full Coriolis force is considered. The atmosphere is assumed stratified with a steady density profile. It is also argued that the resulting expressions can be applied to atmospheric temperature maps obtained by standard infrared methods only if approximations are made. This paper augments the interpretation of the results obtained in a previous paper by the author and addresses comments made by J.-I. Yano in another paper of this journal.