Examinando por Autor "Bhardwaj, A."

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Acceso Abierto
Quantifying the Congruence between Air and Land Surface Temperatures for Various Climatic and Elevation Zones of Western Himalaya
(Multidisciplinary Digital Publishing Institute (MDPI), 2019-12-04) Singh, S.; Bhardwaj, A.; Singh, A.; Sam, L.; Shekhar, M.; Martín Torres, Javier; Zorzano, María Paz; Martín Torres, J. [0000-0001-6479-2236]; Shingh, S. [0000-0003-4304-388X]; Zorzano, M. P. [0000-0002-4492-9650]; Sam, L. [0000-0003-3181-2960]; Bhardwaj, A. [0000-0002-2502-6384]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
The surface and near-surface air temperature observations are primary data for glacio-hydro-climatological studies. The in situ air temperature (T-a) observations require intense logistic and financial investments, making it sparse and fragmented particularly in remote and extreme environments. The temperatures in Himalaya are controlled by a complex system driven by topography, seasons, and cryosphere which further makes it difficult to record or predict its spatial heterogeneity. In this regard, finding a way to fill the observational spatiotemporal gaps in data becomes more crucial. Here, we show the comparison of T-a recorded at 11 high altitude stations in Western Himalaya with their respective land surface temperatures (T-s) recorded by Moderate Resolution Imagining Spectroradiometer (MODIS) Aqua and Terra satellites in cloud-free conditions. We found remarkable seasonal and spatial trends in the T-a vs. T-s relationship: (i) T-s are strongly correlated with T-a (R-2 = 0.77, root mean square difference (RMSD) = 5.9 degrees C, n = 11,101 at daily scale and R-2 = 0.80, RMSD = 5.7 degrees C, n = 3552 at 8-day scale); (ii) in general, the RMSD is lower for the winter months in comparison to summer months for all the stations, (iii) the RMSD is directly proportional to the elevations; (iv) the RMSD is inversely proportional to the annual precipitation. Our results demonstrate the statistically strong and previously unreported T-a vs. T-s relationship and spatial and seasonal variations in its intensity at daily resolution for the Western Himalaya. We anticipate that our results will provide the scientists in Himalaya or similar data-deficient extreme environments with an option to use freely available remotely observed T-s products in their models to fill-up the spatiotemporal data gaps related to in situ monitoring at daily resolution. Substituting T-a by T-s as input in various geophysical models can even improve the model accuracy as using spatially continuous satellite derived T-s in place of discrete in situ T-a extrapolated to different elevations using a constant lapse rate can provide more realistic estimates.
Acceso Abierto
Subsurface robotic exploration for geomorphology, astrobiology and mining during MINAR6 campaign, Boulby Mine, UK: part I (Rover development).
(Cambridge University Press, 2020-04-05) Mathanlal, Thasshwin; Bhardwaj, A.; Vakkada Ramachandran, A.; Zorzano, María Paz; Martín Torres, Javier; Cockell, C. S.; Edwards, T.; Martín Torres, J. [0000-0001-6479-2236]; Zorzano, M. P. [0000-0002-4492-9650]; Bhardwaj, A. [0000-0002-2502-6384]; Vakkada Ramachandran, A. [0000-0003-0499-6370]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Autonomous exploration requires the use of movable platforms that carry a payload of instruments with a certain level of autonomy and communication with the operators. This is particularly challenging in subsurface environments, which may be more dangerous for human access and where communication with the surface is limited. Subsurface robotic exploration, which has been to date very limited, is interesting not only for science but also for cost-effective industrial exploitation of resources and safety assessments in mines. Furthermore, it has a direct application to exploration of extra-terrestrial subsurface environments of astrobiological and geological significance such as caves, lava tubes, impact or volcanic craters and subglacial conduits, for deriving in-situ mineralogical resources and establishing preliminary settlements. However, the technological solutions are generally tailor-made and are therefore considered as costly, fragile and environment-specific, further hindering their extensive and effective applications. To demonstrate the advantages of rover exploration for a broad-community, we have developed KORE (KOmpact Rover for Exploration); a low-cost, re-usable, rover multi-purpose platform. The rover platform has been developed as a technological demonstration for extra-terrestrial subsurface exploration and terrestrial mining operations pertaining to geomorphological mapping, environmental monitoring, gas leak detections and search and rescue operations in case of an accident. The present paper, the first part of a series of two, focuses on describing the development of a robust rover platform to perform dedicated geomorphological, astrobiological and mining tasks. KORE was further tested in the Mine Analogue Research 6 (MINAR6) campaign during September 2018 in the Boulby mine (UK), the second deepest potash mine in Europe at a subsurface depth of 1.1 km, the results of which will be presented in the second paper of this series. KORE is a large, semi-autonomous rover weighing 160 kg with L x W x H dimensions 1.2 m x 0.8 m x 1 m and a payload carrying capacity of 100 kg using 800 W traction power that can power to a maximum speed of 8.4 km h(-1). The rover can be easily dismantled in three parts facilitating its transportation to any chosen site of exploration. Presently, the main scientific payloads on KORE are: (1) a three-dimensional mapping camera, (2) a methane detection system, (3) an environmental station capable of monitoring temperature, relative humidity, pressure and gases such as NO2, SO2, H2S, formaldehyde, CO, CO2, O-3, O(2,)volatile organic compounds and particulates and (4) a robotic arm. Moreover, the design of the rover allows for integration of more sensors as per the scientific requirements in future expeditions. At the MINAR6 campaign, the technical readiness of KORE was demonstrated during 6 days of scientific research in the mine, with a total of 22 h of operation.