scholarly journals Decomposing spatio-temporal seismicity patterns

2001 ◽  
Vol 1 (1/2) ◽  
pp. 83-92 ◽  
Author(s):  
C. Goltz
Keyword(s):  
Spatial And Temporal Variability ◽  
Seismicity Patterns ◽  
Seismicity Rate ◽  
Potential Applications ◽  
Time Series Approach ◽  
Distributed Process ◽  
Sample Application ◽  
Components Analysis ◽  
Spatio Temporal ◽  
Large Earthquakes

Abstract. Seismicity is a distributed process of great spatial and temporal variability and complexity. Efforts to characterise and describe the evolution of seismicity patterns have a long history. Today, the detection of changes in the spatial distribution of seismicity is still regarded as one of the most important approaches in monitoring and understanding seismicity. The problem of how to best describe these spatio-temporal changes remains, also in view of the detection of possible precursors for large earthquakes. In particular, it is difficult to separate the superimposed effects of different origin and to unveil the subtle (precursory) effects in the presence of stronger but irrelevant constituents. I present an approach to the latter two problems which relies on the Principal Components Analysis (PCA), a method based on eigen-structure analysis, by taking a time series approach and separating the seismicity rate patterns into a background component and components of change. I show a sample application to the Southern California area and discuss the promising results in view of their implications, potential applications and with respect to their possible precursory qualities.

scholarly journals Inter-comparison of daily precipitation products for large-scale hydro-climatic applications over Canada

2017 ◽  
Vol 21 (4) ◽  
pp. 2163-2185 ◽  
Author(s):  
Jefferson S. Wong ◽  
Saman Razavi ◽  
Barrie R. Bonsal ◽  
Howard S. Wheater ◽  
Zilefac E. Asong
Keyword(s):  
Large Scale ◽  
Spatial And Temporal Variability ◽  
The North ◽  
Global Precipitation Climatology Centre ◽  
Multiple Data ◽  
Geographical Regions ◽  
Central Canada ◽  
Different Seasons ◽  
Spatio Temporal ◽  
Global Precipitation

Abstract. A number of global and regional gridded climate products based on multiple data sources are available that can potentially provide reliable estimates of precipitation for climate and hydrological studies. However, research into the consistency of these products for various regions has been limited and in many cases non-existent. This study inter-compares several gridded precipitation products over 15 terrestrial ecozones in Canada for different seasons. The spatial and temporal variability of the errors (relative to station observations) was quantified over the period of 1979 to 2012 at a 0.5° and daily spatio-temporal resolution. These datasets were assessed in their ability to represent the daily variability of precipitation amounts by four performance measures: percentage of bias, root mean square error, correlation coefficient, and standard deviation ratio. Results showed that most of the datasets were relatively skilful in central Canada. However, they tended to overestimate precipitation amounts in the west and underestimate in the north and east, with the underestimation being particularly dominant in northern Canada (above 60° N). The global product by WATCH Forcing Data ERA-Interim (WFDEI) augmented by Global Precipitation Climatology Centre (GPCC) data (WFDEI [GPCC]) performed best with respect to different metrics. The Canadian Precipitation Analysis (CaPA) product performed comparably with WFDEI [GPCC]; however, it only provides data starting in 2002. All the datasets performed best in summer, followed by autumn, spring, and winter in order of decreasing quality. Findings from this study can provide guidance to potential users regarding the performance of different precipitation products for a range of geographical regions and time periods.

Crossmodal correspondences between chemosensory stimuli and musical notes

2012 ◽  
Vol 25 (0) ◽  
pp. 72
Author(s):  
Anne-Sylvie Crisinel ◽  
Charles Spence
Keyword(s):  
Musical Instruments ◽  
Crossmodal Correspondences ◽  
Musical Note ◽  
Water Based ◽  
Different Types ◽  
Potential Applications ◽  
Series Of Experiments ◽  
Components Analysis ◽  
Psychological Dimensions

We report a series of experiments investigating crossmodal correspondences between various food-related stimuli (water-based solutions, milk-based flavoured solutions, crisps, chocolate and odours) and sounds varying in pitch and played by four different types of musical instruments. Participants tasted or smelled stimuli before matching them to a musical note. Our results demonstrate that participants preferentially match certain stimuli to specific pitches and instrument types. Through participants’ ratings of the stimuli along a number of dimensions (e.g., pleasantness, complexity, familiarity or sweetness), we explore the psychological dimensions involved in these crossmodal correspondences, using principal components analysis (PCA). While pleasantness seems to play an important role in the choice of instrument associated with chemosensory stimuli, the pitch seems to also depend on the quality of the taste (bitter, salty, sour or sweet). The level at which such crossmodal correspondences might occur, as well as the potential applications of such results, will be discussed.

scholarly journals Versatile Layer-By-Layer Highly Stable Multilayer Films: Study of the Loading and Release of FITC-Labeled Short Peptide in the Drug Delivery Field

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1206 ◽  
Author(s):  
Kun Nie ◽  
Xiang Yu ◽  
Navnita Kumar ◽  
Yihe Zhang
Keyword(s):  
Drug Delivery ◽  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Mesoporous Silica Nanoparticles ◽  
Multilayer Films ◽  
Layer By Layer ◽  
Guest Molecules ◽  
Potential Applications ◽  
Spatio Temporal ◽  
Release Speed

A viable short FITC-peptide immobilization is the most essential step in the fabrication of multilayer films based on FITC-peptide. These functional multilayer films have potential applications in drug delivery, medical therapy, and so forth. These FITC-peptides films needed to be handled with a lot of care and precision due to their sensitive nature. In this study, a general immobilization method is reported for the purpose of stabilizing various kinds of peptides at the interfacial regions. Utilizing Mesoporous silica nanoparticles can help in the preservation of these FITC-peptides by embedding themselves into these covalently cross-linked multilayers. This basic outlook of the multilayer films is potent enough and could be reused as a positive substrate. The spatio-temporal retention property of peptides can be modulated by varying the number of capping layers. The release speed of guest molecules such as tyrosine within FITC-peptide or/and adamantane (Ad)-in short peptides could also be fine-tuned by the specific arrangements of the multilayers of mesoporous silica nanoparticles (MSNs) and hyaluronic acid- cyclodextrin (HA-CD) multilayer films.

scholarly journals Investigating the earthquake catalog of the National Observatory of Athens

2009 ◽  
Vol 9 (3) ◽  
pp. 905-912 ◽  
Author(s):  
G. Chouliaras
Keyword(s):  
B Value ◽  
Spatial And Temporal Variability ◽  
Earthquake Catalog ◽  
National Observatory ◽  
Data Set ◽  
Seismicity Rate ◽  
Earthquake Prediction Research ◽  
The Times ◽  
Seismicity Rate Changes ◽  
Selection Of

Abstract. The earthquake catalog of the National Observatory of Athens (NOA) since the beginning of the Greek National Seismological Network development in 1964, is compiled and analyzed in this study. The b-value and the spatial and temporal variability of the magnitude of completeness of the catalog is determined together with the times of significant seismicity rate changes. It is well known that man made inhomogeneities and artifacts exist in earthquake catalogs that are produced by changing seismological networks and in this study the chronological order of periods of network expansion, instrumental upgrades and practice and procedures changes at NOA are reported. The earthquake catalog of NOA is the most detailed data set available for the Greek area and the results of this study may be employed for the selection of trustworthy parts of the data in earthquake prediction research.

scholarly journals Spatio-Temporal Mapping of Multi-Satellite Observed Column Atmospheric CO2 Using Precision-Weighted Kriging Method

2020 ◽  
Vol 12 (3) ◽  
pp. 576 ◽  
Author(s):  
Zhonghua He ◽  
Liping Lei ◽  
Yuhui Zhang ◽  
Mengya Sheng ◽  
Changjiang Wu ◽  
...  
Keyword(s):  
Temporal Variations ◽  
Atmospheric Co2 ◽  
Total Carbon ◽  
Kriging Method ◽  
Good Reliability ◽  
Potential Applications ◽  
Satellite Sensors ◽  
Spatio Temporal ◽  
Atmospheric Co2 Concentrations

Column-averaged dry air mole fraction of atmospheric CO2 (XCO2), obtained by multiple satellite observations since 2003 such as ENVISAT/SCIAMACHY, GOSAT, and OCO-2 satellite, is valuable for understanding the spatio-temporal variations of atmospheric CO2 concentrations which are related to carbon uptake and emissions. In order to construct long-term spatio-temporal continuous XCO2 from multiple satellites with different temporal and spatial periods of observations, we developed a precision-weighted spatio-temporal kriging method for integrating and mapping multi-satellite observed XCO2. The approach integrated XCO2 from different sensors considering differences in vertical sensitivity, overpass time, the field of view, repeat cycle and measurement precision. We produced globally mapped XCO2 (GM-XCO2) with spatial/temporal resolution of 1 × 1 degree every eight days from 2003 to 2016 with corresponding data precision and interpolation uncertainty in each grid. The predicted GM-XCO2 precision improved in most grids compared with conventional spatio-temporal kriging results, especially during the satellites overlapping period (0.3–0.5 ppm). The method showed good reliability with R2 of 0.97 from cross-validation. GM-XCO2 showed good accuracy with a standard deviation of bias from total carbon column observing network (TCCON) measurements of 1.05 ppm. This method has potential applications for integrating and mapping XCO2 or other similar datasets observed from multiple satellite sensors. The resulting GM-XCO2 product may be also used in different carbon cycle research applications with different precision requirements.

Assessing spatio-temporal variability and biases of climate models

2020 ◽  
Author(s):  
Nedjeljka Žagar
Keyword(s):  
Temporal Variability ◽  
Prediction Models ◽  
Climate Model ◽  
Weather Prediction ◽  
Ocean Model ◽  
Spatial And Temporal Variability ◽  
Dynamical Regime ◽  
Temporal Variance ◽  
Slab Ocean ◽  
Spatio Temporal

<div>Atmospheric spatial and temporal variability are closely related with the former being relatively well observed compared to the latter. The former is also regularly assessed in the validation of numerical weather prediction models while the latter is more difficult to estimate. Likewise, thermodynamical fields and circulation are closely coupled calling for an approach that considers them simultaneously.  </div> <div>In this contribution, spatio-temporal variability spectra of the four major reanalysis datasets are discussed and applied for the validation of a climate model prototype.  A relationship between deficiencies in simulated variability and model biases is derived. The underlying method includes dynamical regime decomposition thereby providing a better understanding of the role of tropical variability in global circulation. </div> <div>Results of numerical simulations are validated by a 20th century reanalysis. A climate model was forced either with the prescribed SST or with a slab ocean model that updates SST in each forecast step.  Scale-dependent validation shows that missing temporal variance in the model relative to verifying reanalysis increases as the spatial scale reduces that appears associated with an increasing lack of spatial variance at smaller scales. Similar to variability, bias is strongly scale dependent; the larger the scale, the greater the bias. Biases present in the SST-forced simulation increase in the simulation using the slab ocean. The comparison of biases computed as a systematic difference between the model and reanalysis and between the SST-forced model and slab-ocean model (a perfect-model scenario) suggests that improving the atmospheric model increases the variance in the model on synoptic and subsynoptic scales but large biases associated with a poor SST remain at planetary scales.</div> <p> </p>

scholarly journals The Spatio-temporal Analysis of b-value in the Banda Arc, Indonesia

2021 ◽  
Vol 873 (1) ◽  
pp. 012010
Author(s):  
Muhammad Bani Al-Rasyid ◽  
Mira Nailufar Rusman ◽  
Daniel Hamonangan ◽  
Pepen Supendi ◽  
Kartika Hajar Kirana
Keyword(s):  
Temporal Variation ◽  
Temporal Analysis ◽  
B Value ◽  
Spatial And Temporal Variation ◽  
Tectonic Structure ◽  
Time Period ◽  
Banda Arc ◽  
Spatio Temporal ◽  
The Impact ◽  
Large Earthquakes

Abstract Banda arc is a complex tectonic structure manifests by high seismicity due to the collision of a continent and an intra-oceanic island arc. Using the relocated earthquakes data from ISC-EHB and BMKG catalogues from the time period of 1960 to 2018, we have conducted a spatial and temporal variation of b-value using the Guttenberg-Richter formula in the area. Our results show that the spatial distribution of low b-values located in the south of Ambon Island and southeast of Buru Island. On the other hand, the temporal variation of b-value shows a decrease in the northern part of the Banda sea probably high potential to produce large earthquakes in the future. Therefore, further mitigation is needed to minimize the impact of earthquakes in the area.

scholarly journals Spatio-temporal variations of HNO<sub>3</sub> total column from 9 years of IASI measurements – A driver study

2017 ◽  
Author(s):  
Gaétane Ronsmans ◽  
Catherine Wespes ◽  
Daniel Hurtmans ◽  
Cathy Clerbaux ◽  
Pierre-François Coheur
Keyword(s):  
Time Series ◽  
Polar Vortex ◽  
Temporal Variations ◽  
P Value ◽  
Spatial And Temporal Variability ◽  
Quasi Biennial Oscillation ◽  
Explanatory Variables ◽  
Multivariate Enso Index ◽  
Spatio Temporal ◽  
Stratospheric Clouds

Abstract. This study aims at understanding the spatial and temporal variability of HNO3 total columns in terms of explanatory variables. To achieve this, multiple linear regressions are used to fit satellite-derived time series of HNO3 daily averaged total columns. First, an analysis of the IASI 9-year time series (2008–2016) is conducted based on various equivalent latitude bands. The strong and systematic denitrification of the southern polar stratosphere is observed very clearly. It is also possible to distinguish, within the polar vortex, three regions wich are differently affected by the denitrification. Three exceptional denitrification episodes in 2011, 2014 and 2016 are also observed in the northern hemisphere, due to unusually low arctic temperatures. The time series are then fitted by multivariate regressions to identify what variables are responsible for HNO3 variability in global distributions and time series, and to quantify their respective influence. Out of an ensemble of proxies (annual cycle, solar flux, quasi-biennial oscillation, multivariate ENSO index, Arctic and Antarctic oscillations and volume of polar stratospheric clouds), only the ones defined as significant (p-value 

scholarly journals Spatial and temporal variability of snow depth and SWE in a small mountain catchment

2010 ◽  
Vol 4 (1) ◽  
pp. 1-30 ◽  
Author(s):  
T. Grünewald ◽  
M. Schirmer ◽  
R. Mott ◽  
M. Lehning
Keyword(s):  
Temporal Variability ◽  
Snow Depth ◽  
Energy Transport ◽  
Snow Water Equivalent ◽  
Laser Scanner ◽  
Ablation Rate ◽  
Spatial And Temporal Variability ◽  
M Cell ◽  
Snow Water ◽  
Spatio Temporal

Abstract. The spatio-temporal variability of the mountain snow cover determines the avalanche danger, snow water storage, permafrost distribution and the local distribution of fauna and flora. Using a new type of terrestrial laser scanner (TLS), which is particularly suited for measurements of snow covered surfaces, snow depth, snow water equivalent (SWE) and melt rates have been monitored in a high alpine catchment during an ablation period. This allowed for the first time to get a high resolution (2.5 m cell size) picture of spatial variability and its temporal development. A very high variability in which maximum snow depths between 0–9 m at the end of the accumulation season was found. This variability decreased during the ablation phase, although the dominant snow deposition features remained intact. The spatial patterns of calculated SWE were found to be similar to snow depth. Average daily melt rate was between 15 mm/d at the beginning of the ablation period and 30 mm/d at the end. The spatial variation of melt rates increased during the ablation rate and could not be explained in a simple manner by geographical or meteorological parameters, which suggests significant lateral energy fluxes contributing to observed melt. It could be qualitatively shown that the effect of the lateral energy transport must increase as the fraction of snow free surfaces increases during the ablation period.

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