Essentials of Mineral Exploration and Evaluation

Gandhi, S.M.; Sarkar, B. C.

doi:10.1016/c2015-0-04648-2

Cited by 10 publications

(6 citation statements)

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“…Our SST results under 4 × CO 2 qualitatively agree with previous studies (Liu et al, 2005;Collins et al, 2010;Vecchi and Wittenberg, 2010;Cai et al, 2015a;Huang and Ying, 2015;Luo et al, 2015;Kohyama et al, 2017;Nowack et al, 2017). Overcooling of the tropics (and as such, the tropical Pacific) is a robust signal in G1 simulations, even short ones, simply due to the different meridional distribution of shortwave and longwave forcing (Govindasamy and Caldeira, 2000;Lunt et al, 2008;Kravitz et al, 2013b;Curry et al, 2014;Nowack et al, 2016). The results presented here based on a long simulation not only corroborate previously published findings but also statistically demonstrate that under G1, the warm pool and SPCZ cool faster than the cold tongue.…”

Section: Sea Surface Temperaturesupporting

confidence: 92%

“…We present climatologies for SSTs, rainfall, Intertropical Convergence Zone (ITCZ), vertical velocity averaged between 500 and 100 hPa ( 500-100), PWC, zonal wind stress, zonal and meridional SST gradients (ZSSTG and MSSTG, respectively), and thermocline depth. We calculate mean climatological differences for all these variables simulated under 4 × CO 2 and G1 relative to piControl and assess their statistical significance using non-parametric Wilcoxon signed-rank and Wilcoxon ranksum tests (Hollander et al, 2014;Gibbons and Chakraborti, 2011). All analyses are performed on re-gridded (2 • longitude × 2.5 • latitude) HadCM3L output for model years 11 to 1000 unless otherwise stated.…”

Section: Definitions and Statistical Testsmentioning

confidence: 99%

“…S1). Positive skewness means that in a given data distribution, the tail of the distribution is spread out towards high positive values and vice versa (Gandhi and Sarkar, 2016). The skewness criterion is used to exclude climate models simulating overly wet or dry conditions over the Niño3 region (Cai et al, 2017).…”

Section: Enso Representation In Hadcm3lmentioning

confidence: 99%

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Tropical Pacific climate variability under solar geoengineering: impacts on ENSO extremes

et al. 2020

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Abstract. Many modelling studies suggest that the El Niño–Southern Oscillation (ENSO), in interaction with the tropical Pacific background climate, will change with rising atmospheric greenhouse gas concentrations. Solar geoengineering (reducing the solar flux from outer space) has been proposed as a means to counteract anthropogenic climate change. However, the effectiveness of solar geoengineering concerning a variety of aspects of Earth's climate is uncertain. Robust results are particularly challenging to obtain for ENSO because existing geoengineering simulations are too short (typically ∼ 50 years) to detect statistically significant changes in the highly variable tropical Pacific background climate. We here present results from a 1000-year-long solar-geoengineering simulation, G1, carried out with the coupled atmosphere–ocean general circulation model HadCM3L. In agreement with previous studies, reducing the solar irradiance (4 %) to offset global mean surface warming in the model more than compensates the warming in the tropical Pacific that develops in the 4 × CO2 scenario. We see an overcooling of 0.3 ∘C and a 0.23 mm d−1 (5 %) reduction in mean rainfall over the tropical Pacific relative to preindustrial conditions in the G1 simulation, owing to the different latitudinal distributions of the shortwave (solar) and longwave (CO2) forcings. The location of the Intertropical Convergence Zone (ITCZ) in the tropical Pacific, which moved 7.5∘ southwards under 4 × CO2, is restored to its preindustrial position. However, other aspects of the tropical Pacific mean climate are not reset as effectively. Relative to preindustrial conditions, in G1 the time-averaged zonal wind stress, zonal sea surface temperature (SST) gradient, and meridional SST gradient are each statistically significantly reduced by around 10 %, and the Pacific Walker Circulation (PWC) is consistently weakened, resulting in conditions conducive to increased frequency of El Niño events. The overall amplitude of ENSO strengthens by 9 %–10 % in G1, but there is a 65 % reduction in the asymmetry between cold and warm events: cold events intensify more than warm events. Notably, the frequency of extreme El Niño and La Niña events increases by ca. 60 % and 30 %, respectively, while the total number of El Niño events increases by around 10 %. All of these changes are statistically significant at either 95 or 99 % confidence level. Somewhat paradoxically, while the number of total and extreme events increases, the extreme El Niño events become weaker relative to the preindustrial state, while the extreme La Niña events become even stronger. That is, such extreme El Niño events in G1 become less intense than under preindustrial conditions but also more frequent. In contrast, extreme La Niña events become stronger in G1, which is in agreement with the general overcooling of the tropical Pacific in G1 relative to preindustrial conditions.

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Section: Sea Surface Temperaturesupporting

confidence: 92%

Section: Definitions and Statistical Testsmentioning

confidence: 99%

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Tropical Pacific climate variability under solar geoengineering: impacts on ENSO extremes

et al. 2020

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“…The digital elevation models can be represented as a raster image or as a vector data such as TIN (Triangulated Irregular Network). The DEMs can be generated using photogrammetry, IfSAR, LiDAR, land surveying techniques [1,7].…”

Section: Digital Elevation Modelmentioning

confidence: 99%

An Extraction and Analysis of Land Elevation and Coastal Area using Spatial Data Mining Techniques in DEMs

Kodge¹

2023

Advances in Intelligent Systems Research

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The earth's land surface is always changing its morphology and characteristics due to its inside and outside movements/activities like earthquakes, volcanic eruptions, tsunamis, cyclones, avalanches, asteroid hits, floods, land sliding, and so on. All these earth's movements/activities are the natural phenomenon and not affected the earth's atmosphere that much which is affecting more than the man made things or global warming. The main causes of increase in the earth's temperature are the industrialization, deforestation, and pollutions which are generating more and more artificial disasters. The melting of land ice such as glaciers and ice sheets are the main reasons of increase in global sea levels and is become a big challenge to the people of cities/villages which are located on the sea coasts. Therefore an attempt is made in this paper to extract and analyse the land elevation data, elevation statistics, number of cities/villages located near the sea coasts in India within a specific distance and elevation classes using spatial data mining techniques in DEMs (Digital Elevation Models). The states wise extracted results of this paper are visualized geographically for better understanding and will be useful to plan, monitor and control the by local administrative of that concern province.

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“…Estimasi sumberdaya dilakukan bedasarkan informasi geoscientific dengan menggunakan pendekatan matematis. [4] Metode yang paling sering digunakan saat ini adalah metode dengan analisis geostatistik yaitu ordinary kriging [5]- [7]. Estimasi sumberdaya endapan nikel laterit pada penelitian ini didasarkan pada data hasil kegiatan pemboran yang kemudian dianalisis untuk mengetahui dimensi endapan dan persebaran kadar Ni di daerah penelitian.…”

Section: Pendahuluanunclassified

Estimasi Sumberdaya Endapan Nikel Laterit Sulawesi Tenggara dengan Metode Ordinary Kriging

Khaq

Bargawa

Winarno

2022

SEMITAN

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Estimasi sumberdaya merupakan salah satu bagian penting dalam industri pertambangan yang secara kolektif menghasilkan model deposit mineral. Metode estimasi yang paling optimal dan sering digunakan saat ini adalah metode ordinary kriging. Estimasi sumberdaya endapan nikel laterit pada penelitian ini didasarkan pada data hasil kegiatan pemboran yang kemudian dianalisis dengan metode geostatistik ordinary kriging. Tahapan dalam penelitian ini, yaitu melakukan pengumpulan dan validasi data, analisis geostatistik dan estimasi sumberdaya. Penelitian ini bertujuan untuk memberikan gambaran taksiran kuantitas dan kualitas dari endapan nikel laterit, yang pada akhirnya dapat digunakan sebagai dasar dalam menentukan perencanaan penambangan yang tepat.

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Essentials of Mineral Exploration and Evaluation

Cited by 10 publications

References 0 publications

Tropical Pacific climate variability under solar geoengineering: impacts on ENSO extremes

Tropical Pacific climate variability under solar geoengineering: impacts on ENSO extremes

An Extraction and Analysis of Land Elevation and Coastal Area using Spatial Data Mining Techniques in DEMs

Estimasi Sumberdaya Endapan Nikel Laterit Sulawesi Tenggara dengan Metode Ordinary Kriging

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