Antonio Molina

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 265–375u2009J 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.

Surviving bad times: The role of citations, self-citations and numbers of citable items in recovery of the journal impact factor after at least four years of continuous decreases

We studied the influence of the number of citations, the number of citable items and the number of journal self-citations on increases in the impact factor (IF) in 123 journals from the Journal Citation Reports database in which this scientometric indicator had decreased during the previous four years. In general, we did not find evidence that abuse of journal self-citations contributed to the increase in the impact factor after several years of decreases.

Effect on the journal impact factor of the number and document type of citing records: a wide-scale study

We studied the effect on journal impact factors (JIF) of citations from documents labeled as articles and reviews (usually peer reviewed) versus citations coming from other documents. In addition, we studied the effect on JIF of the number of citing records. This number is usually different from the number of citations. We selected a set of 700 journals indexed in the SCI section of JCR that receive a low number of citations. The reason for this choice is that in these instances some citations may have a greater impact on the JIF than in more highly-cited journals. After excluding some journals for different reasons, our sample consisted of 674 journals. We obtained data on citations that contributed to the JIF for the years 1998–2006. In general, we found that most journals obtained citations that contribute to the impact factor from documents labeled as articles and reviews. In addition, in most of journals the ratio between citations that contributed to the impact factor and citing records was greater than 80% in all years. Thus, in general, we did not find evidence that citations that contributed to the impact factor were dependent on non-peer reviewed documents or only a few citing records.

Charge-coupled device spectral images of spatially resolved regions of Jupiter in the 6190- and 8900-Å methane and 6450-Å ammonia bands during the 1989 Opposition

High-quality charge-coupled device spectroscopic observations at different regions of Jupiter in the spectral regions λλ 6000–6600 and 8700–9200 A at a resolution of 1.2 A have been obtained. These spectra allowed us to obtain the center-to-limb curves of the equivalent widths of the CH4 6190-A band, the NH3 6450-A band, and the band depth of the 8900-A band, as well as their latitudinal distribution. Some asymmetries in the center-to-limb distribution of the equivalent widths of the CH4 6190-A and NH3 6450-A bands were detected, as well as a very prominent decrease toward the planetary limbs for the ammonia band. The latitudinal variations of the CH4 6190-A and NH3 6450-A equivalent widths were strongly correlated for fractional radii less than 0.4, with a maximum of absorption at the North Equatorial Belt. The South Equatorial Belt, undetectable at visible and near-infrared continuum wavelengths, was discernable at λ = 8900 A. Model computations for the Equatorial Region assuming three aerosol layer models gave some constraints on tropospheric atmospheric parameters during the 1989 Jupiter opposition date.

Absolutely calibrated CCD images of Saturn at methane band and continuum wavelengths during its 1991 opposition

Ground-based charge-coupled device images of Saturn were obtained at the Cassegrain focus of the 1.52-m telescope at the Calar Alto Observatory (Andalucia, Spain) during the 1991 opposition. The images were obtained in and out of the absorption methane bands at 6190, 7250, and 8900 A under very good seeing conditions. A Bayesian deconvolution technique was employed in the restoration procedure. The derived absolute reflectivities and band depths at some locations of the disk are provided in tables appropriate for analysis in terms of scattering models. Possible temporal variations between the reflectivities found here and those reported by West et al. (1982) are discussed. No longitudinal variations in reflectivity larger than a 4% level were found. Some images showed bright spot activity at the equatorial region.

Recent multispectral observations of Jupiter from 0.6 to 2.4 μm

Recent results obtained from observations of the Jovian atmosphere during the 1992 apparition are shown and discussed in a preliminary fashion. The observational data were acquired from two observing campaigns during very good seeing conditions. Charge-coupled device images were obtained on February 1992 at the Cassegrain focus of the 1.52-m telescope at Calar Alto Observatory, Spain. These images were taken using narrow-band interference filters in the 0.62- to 0.95-μm region. Also, we present images of Jupiter in the region 1.5–2.4 μm that were acquired on May 1992 using an InSb 58 × 62 array at the Cassegrain focus of the 4.2-m William Herschel telescope at La Palma, Spain. This work is intended to be a continuation of an extended program on ground-based observations of the Jovian planet atmospheres.

Thaw depth spatial and temporal variability at the Limnopolar Lake CALM-S site, Byers Peninsula, Livingston Island, Antarctica

A new Circumpolar Active Layer Monitoring (CALM) site was established in 2009 at the Limnopolar Lake watershed in Byers Peninsula, Livingston Island, Antarctica, to provide a node in the western Antarctic Peninsula, one of the regions that recorded the highest air temperature increase in the planet during the last decades. The first detailed analysis of the temporal and spatial evolution of the thaw depth at the Limnopolar Lake CALM-S site is presented here, after eight years of monitoring. The average values range between 48 and 29cm, decreasing at a ratio of 16cm/decade. The annual thaw depth observations in the 100×100 m CALM grid are variable (Variability Index of 34 to 51%), although both the Variance Coefficient and the Climate Matrix Analysis Residual point to the internal consistency of the data. Those differences could be explained then by the terrain complexity and node-specific variability due to the ground properties. The interannual variability was about 60% during 2009-2012, increasing to 124% due to the presence of snow in 2013, 2015 and 2016. The snow has been proposed here as one of the most important factors controlling the spatial variability of ground thaw depth, since its values correlate with the snow thickness but also with the ground surface temperature and unconfined compression resistance, as measured in 2010. The topography explains the thaw depth spatial distribution pattern, being related to snowmelt water and its accumulation in low-elevation areas (downslope-flow). Patterned grounds and other surface features correlate well with high thaw depth patterns as well. The edaphic factor (E=0.05842m2/°C·day; R2=0.63) is in agreement with other permafrost environments, since frozen index (F>0.67) and MAAT (<-2°C) denote a continuous permafrost existence in the area. All these characteristics provided the basis for further comparative analyses between others nearby CALM sites.

Active layer monitoring in Antarctica: an overview of results from 2006 to 2015

Monitoring of active layer thawing depth and active layer thickness (ALT), using mechanical pronging and continuous temperature data logging, has been undertaken under the Circumpolar Active Layer ...