scholarly journals A Global Assessment of the Spatial Distribution of Precipitation Occurrence

2015 ◽  
Vol 54 (11) ◽  
pp. 2179-2197 ◽  
Author(s):  
Mark Smalley ◽  
Tristan L’Ecuyer
Keyword(s):  
Spatial Distribution ◽  
Shape Factor ◽  
Large Scale ◽  
High Sensitivity ◽  
Wet Season ◽  
Geographic Variations ◽  
Spatial Characteristics ◽  
Precipitation Occurrence ◽  
Stochastic Weather Generation ◽  
Scale Length

AbstractThe spatial distribution of precipitation occurrence has important implications for numerous applications ranging from defining cloud radiative effects to modeling hydrologic runoff, statistical downscaling, and stochastic weather generation. This paper introduces a new method of describing the spatial characteristics of rainfall and snowfall that takes advantage of the high sensitivity and high resolution of the W-band cloud precipitation radar aboard CloudSat. The resolution dependence of precipitation occurrence is described by a two-parameter exponential function defined by a shape factor that governs the variation in the distances between precipitation events and a scale length that represents the overall probability of precipitation and number density of distinct events.Geographic variations in the shape factor and scale length are consistent with large-scale circulation patterns and correlate with environmental conditions on local scales. For example, a large contrast in scale lengths between land and ocean areas reflects the more extensive, widespread nature of precipitation over land than over ocean. An analysis of warm rain in the southeast Pacific reveals a shift from frequent isolated systems to less frequent but more regularly spaced systems along a transect connecting stratocumulus and trade cumulus cloud regimes. A similar analysis during the Amazon wet season reveals a relationship between the size and frequency of convection and zonal wind direction with precipitation exhibiting a more oceanic character during periods of westerly winds. These select examples demonstrate the utility of this approach for capturing the sensitivity of the spatial characteristics of precipitation to environmental influences on both local and larger scales.

scholarly journals Large scale interaction of the outflow and quiescent gas in Orion

1991 ◽  
Vol 147 ◽  
pp. 456-457
Author(s):  
J. Martin-Pintado ◽  
A. Rodriguez-Franco ◽  
R. Bachiller
Keyword(s):  
Spatial Distribution ◽  
High Velocity ◽  
Large Scale ◽  
High Sensitivity ◽  
Molecular Flow ◽  
High Angular Resolution ◽  
Molecular Gas ◽  
Transition Analysis ◽  
Molecular Outflow ◽  
Hh Objects

The IRAM 30-m radiotelescope have been used to obtain, with high angular resolution, the spatial distribution and the physical conditions of the quiescent gas in Orion A, and to search for high velocity molecular gas far away from the well known molecular outflow around IRc2. To study the quiescent gas we mapped a region of 200″×300″ around IRc2 in the J=12-11 and J=16-15 lines of HC3N with angular resolutions of 22″ and 17″ respectively. The left panel of Fig. 1 shows the spatial distribution of the high density quiescent gas around IRc2 for different radial velocities. Beside the already known molecular ridge north of IRc2 (see e. g. Bartla et al. 1983), we find four very thin (nearly unresolved) and long filaments, like “fingers”, stretching from IRc2 to the north and west. The deconvolved size of the longest fingers is ≈180″×15″. From a multi-transition analysis of the HC3N emission we derive H2 densities of 1−8 105 cm−3, kinetic temperatures larger than 40 K and masses of ≈10 Mo. Our high sensitivity observations of the J=2-1 line of CO at selected positions (see right panel ib Fig. 1) show widespread molecular gas with high velocities wings over the region where the molecular fingers and the HH objects are observed (see Fig.1). The high velocity emission occurs over a range of ±40 kms−1. This high velocity gas is more extended (up to 150″ from IRc2) than the very compact (40″) and well studied molecular outflow around IRc2 (see e.g. Wilson et al. 1986). The terminal velocities of the CO wings decrease from 100 km s−1 (corresponding to the very fast molecular flow) to the typical terminal velocities of the extended high velocity gas when the distance to IRc2 changes from 40″ to 60″. The origin of the large scale high velocity gas is unknown, but it is very likely the link between the very compact (40″) and fast (±100 km s−1) molecular outflow around IRc2 and the ionized high velocity gas and the HH objects (Martín-Pintado et al. 1990). The mass, momentum and energy of the extended high velocity gas are crudely estimated to be ≈1 Mo, ≈20 Mo km s−1 and ≈2 1045 erg respectively (i.e. a factor of ≈10 smaller than those of the fast molecular outflow). The location, at the edges of the molecular fingers, and the proper motions of the HH objects (see Fig. 1) suggest the stellar wind is interacting with the molecular fingers. If this interpretation is correct, the influence of the molecular outflow in Orion on the surrounding molecular clouds must be revised.

scholarly journals Habitat suitability mapping of the black coral Leiopathes glaberrima to support conservation of vulnerable marine ecosystems

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
V. Lauria ◽  
D. Massi ◽  
F. Fiorentino ◽  
G. Milisenda ◽  
T. Cillari
Keyword(s):  
Spatial Distribution ◽  
Mediterranean Sea ◽  
Large Scale ◽  
High Sensitivity ◽  
Marine Ecosystems ◽  
Slope Aspect ◽  
Suitable Habitat ◽  
Environmental Predictors ◽  
Black Coral ◽  
The Mediterranean

AbstractThe black coral Leiopathes glaberrima is an important habitat forming species that supports benthic biodiversity. Due to its high sensitivity to fishing activities, it has been classified as indicator of Vulnerable Marine Ecosystems (VMEs). However, the information on its habitat selection and large-scale spatial distribution in the Mediterranean Sea is poor. In this study a thorough literature review on the occurrence of L. glaberrima across the Mediterranean Sea was undertaken. Predictive modelling was carried out to produce the first continuous map of L. glaberrima suitable habitat in the central sector of the Mediterranean Sea. MaxEnt modeling was used to predict L. glaberrima probability of presence as a function of seven environmental predictors (bathymetry, slope, aspect North–South and East–West, kinetic energy due to currents at the seabed, seabed habitat types and sea bottom temperature). Our results show that bathymetry, slope and aspect are the most important factors driving L. glaberrima spatial distribution, while in less extent the other environmental variables. This study adds relevant information on the spatial distribution of vulnerable deep water corals in relation to the environmental factors in the Mediterranean Sea. It provides an important background for marine spatial planning especially for prioritizing areas for the conservation of VMEs.

scholarly journals Large scale interaction of the outflow and quiescent gas in Orion

1991 ◽  
Vol 147 ◽  
pp. 456-457
Author(s):  
J. Martin-Pintado ◽  
A. Rodriguez-Franco ◽  
R. Bachiller
Keyword(s):  
Spatial Distribution ◽  
High Velocity ◽  
Large Scale ◽  
High Sensitivity ◽  
Molecular Flow ◽  
High Angular Resolution ◽  
Molecular Gas ◽  
Transition Analysis ◽  
Molecular Outflow ◽  
Hh Objects

The IRAM 30-m radiotelescope have been used to obtain, with high angular resolution, the spatial distribution and the physical conditions of the quiescent gas in Orion A, and to search for high velocity molecular gas far away from the well known molecular outflow around IRc2. To study the quiescent gas we mapped a region of 200″×300″ around IRc2 in the J=12-11 and J=16-15 lines of HC3N with angular resolutions of 22″ and 17″ respectively. The left panel of Fig. 1 shows the spatial distribution of the high density quiescent gas around IRc2 for different radial velocities. Beside the already known molecular ridge north of IRc2 (see e. g. Bartla et al. 1983), we find four very thin (nearly unresolved) and long filaments, like “fingers”, stretching from IRc2 to the north and west. The deconvolved size of the longest fingers is ≈180″×15″. From a multi-transition analysis of the HC3N emission we derive H2 densities of 1−8 105 cm−3, kinetic temperatures larger than 40 K and masses of ≈10 Mo. Our high sensitivity observations of the J=2-1 line of CO at selected positions (see right panel ib Fig. 1) show widespread molecular gas with high velocities wings over the region where the molecular fingers and the HH objects are observed (see Fig.1). The high velocity emission occurs over a range of ±40 kms−1. This high velocity gas is more extended (up to 150″ from IRc2) than the very compact (40″) and well studied molecular outflow around IRc2 (see e.g. Wilson et al. 1986). The terminal velocities of the CO wings decrease from 100 km s−1 (corresponding to the very fast molecular flow) to the typical terminal velocities of the extended high velocity gas when the distance to IRc2 changes from 40″ to 60″. The origin of the large scale high velocity gas is unknown, but it is very likely the link between the very compact (40″) and fast (±100 km s−1) molecular outflow around IRc2 and the ionized high velocity gas and the HH objects (Martín-Pintado et al. 1990). The mass, momentum and energy of the extended high velocity gas are crudely estimated to be ≈1 Mo, ≈20 Mo km s−1 and ≈2 1045 erg respectively (i.e. a factor of ≈10 smaller than those of the fast molecular outflow). The location, at the edges of the molecular fingers, and the proper motions of the HH objects (see Fig. 1) suggest the stellar wind is interacting with the molecular fingers. If this interpretation is correct, the influence of the molecular outflow in Orion on the surrounding molecular clouds must be revised.

Large-scale mapping of the catenas vegetation in Subarctic tundra

1995 ◽  
pp. 3-21
Author(s):  
S. S. Kholod
Keyword(s):  
Spatial Distribution ◽  
Vegetation Cover ◽  
Large Scale ◽  
Block Diagram ◽  
Abiotic Factors ◽  
Ecological Factors ◽  
Spatial Arrangement ◽  
Geological Time ◽  
Ecological Barriers ◽  
Functional Zones

One of the most difficult tasks in large-scale vegetation mapping is the clarification of mechanisms of the internal integration of vegetation cover territorial units. Traditional way of searching such mechanisms is the study of ecological factors controlling the space heterogeneity of vegetation cover. In essence, this is autecological analysis of vegetation. We propose another way of searching the mechanisms of territorial integration of vegetation. It is connected with intracoenotic interrelation, in particular, with the changing role of edificator synusium in a community along the altitudinal gradient. This way of searching is illustrated in the model-plot in subarctic tundra of Central Chukotka. Our further suggestion concerns the way of depicting these mechanisms on large-scale vegetation map. As a model object we chose the catena, that is the landscape formation including all geomorphjc positions of a slope, joint by the process of moving the material down the slope. The process of peneplanation of a mountain system for a long geological time favours to the levelling the lower (accumulative) parts of slopes. The colonization of these parts of the slope by the vegetation variants, corresponding to the lowest part of catena is the result of peneplanation. Vegetation of this part of catena makes a certain biogeocoenotic work which is the levelling of the small infralandscape limits and of the boundaries in vegetation cover. This process we name as the continualization on catena. In this process the variants of vegetation in the lower part of catena are being broken into separate synusiums. This is the process of decumbation of layers described by V. B. Sochava. Up to the slope the edificator power of the shrub synusiums sharply decreases. Moss and herb synusium have "to seek" the habitats similar to those under the shrub canopy. The competition between the synusium arises resulting in arrangement of a certain spatial assemblage of vegetation cover elements. In such assemblage the position of each element is determined by both biotic (interrelation with other coenotic elements) and abiotic (presence of appropriate habitats) factors. Taking into account the biogeocoenotic character of the process of continualization on catena we name such spatial assemblage an exolutionary-biogeocoenotic series. The space within each evolutionary-biogeocoenotic series is divided by ecological barriers into some functional zones. In each of the such zones the struggle between synusiums has its individual expression and direction. In the start zone of catena (extensive pediment) the interrelations of synusiums and layers control the mutual spatial arrangement of these elements at the largest extent. Here, as a rule, there predominate edificator synusiums of low and dwarfshrubs. In the first order limit zone (the bend of pediment to the above part of the slope) one-species herb and moss synusiums, oftenly substituting each other in similar habitats, get prevalence. In the zone of active colonization of slope (denudation slope) the coenotic factor has the least role in the spatial distribution of the vegetation cover elements. In particular, phytocoenotic interactions take place only within separate microcoenoses of herbs, mosses and lichens. In the zone of the attenuation of continualization process (the upper most parts of slope, crests) phytocoenotic interactions are almost absent and the spatial distribution of vegetation cover elements depends exclusively on the abiotic factors. The principal scheme of the distribution of vegetation cover elements and the disposition of functional zones on catena are shown on block-diagram (fig. 1).

Analysis and design of suitable model structures for activated sludge tanks with circulating flow

1999 ◽  
Vol 39 (4) ◽  
pp. 55-60 ◽  
Author(s):  
J. Alex ◽  
R. Tschepetzki ◽  
U. Jumar ◽  
F. Obenaus ◽  
K.-H. Rosenwinkel
Keyword(s):  
Activated Sludge ◽  
Large Scale ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
High Sensitivity ◽  
Suitable Model ◽  
Model Structure ◽  
Analysis And Design ◽  
Hydraulic Behaviour ◽  
Model Structures

Activated sludge models are widely used for planning and optimisation of wastewater treatment plants and on line applications are under development to support the operation of complex treatment plants. A proper model is crucial for all of these applications. The task of parameter calibration is focused in several papers and applications. An essential precondition for this task is an appropriately defined model structure, which is often given much less attention. Different model structures for a large scale treatment plant with circulation flow are discussed in this paper. A more systematic method to derive a suitable model structure is applied to this case. Results of a numerical hydraulic model are used for this purpose. The importance of these efforts are proven by a high sensitivity of the simulation results with respect to the selection of the model structure and the hydraulic conditions. Finally it is shown, that model calibration was possible only by adjusting to the hydraulic behaviour and without any changes of biological parameters.

scholarly journals Modeling Spatiotemporal Population Changes by Integrating DMSP-OLS and NPP-VIIRS Nighttime Light Data in Chongqing, China

2021 ◽  
Vol 13 (2) ◽  
pp. 284
Author(s):  
Dan Lu ◽  
Yahui Wang ◽  
Qingyuan Yang ◽  
Kangchuan Su ◽  
Haozhe Zhang ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Relative Error ◽  
Urban Areas ◽  
Large Scale ◽  
Population Distribution ◽  
Spatial Optimization ◽  
Distribution Data ◽  
Mountainous Areas ◽  
Mean Relative Error ◽  
Nighttime Light

The sustained growth of non-farm wages has led to large-scale migration of rural population to cities in China, especially in mountainous areas. It is of great significance to study the spatial and temporal pattern of population migration mentioned above for guiding population spatial optimization and the effective supply of public services in the mountainous areas. Here, we determined the spatiotemporal evolution of population in the Chongqing municipality of China from 2000–2018 by employing multi-period spatial distribution data, including nighttime light (NTL) data from the Defense Meteorological Satellite Program’s Operational Linescan System (DMSP-OLS) and the Suomi National Polar-orbiting Partnership Visible Infrared Imaging Radiometer Suite (NPP-VIIRS). There was a power function relationship between the two datasets at the pixel scale, with a mean relative error of NTL integration of 8.19%, 4.78% less than achieved by a previous study at the provincial scale. The spatial simulations of population distribution achieved a mean relative error of 26.98%, improved the simulation accuracy for mountainous population by nearly 20% and confirmed the feasibility of this method in Chongqing. During the study period, the spatial distribution of Chongqing’s population has increased in the west and decreased in the east, while also increased in low-altitude areas and decreased in medium-high altitude areas. Population agglomeration was common in all of districts and counties and the population density of central urban areas and its surrounding areas significantly increased, while that of non-urban areas such as northeast Chongqing significantly decreased.

scholarly journals Analytical Validation and Clinical Application of Rapid Serological Tests for SARS-CoV-2 Suitable for Large-Scale Screening

Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 869
Author(s):  
Amedeo De Nicolò ◽  
Valeria Avataneo ◽  
Jessica Cusato ◽  
Alice Palermiti ◽  
Jacopo Mula ◽  
...  
Keyword(s):  
Early Diagnosis ◽  
Real Time Pcr ◽  
Large Scale ◽  
High Sensitivity ◽  
Analytical Validation ◽  
Pcr Assay ◽  
Serological Tests ◽  
Flow Test ◽  
Lateral Flow Test ◽  
Large Scale Screening

Recently, large-scale screening for COVID-19 has presented a major challenge, limiting timely countermeasures. Therefore, the application of suitable rapid serological tests could provide useful information, however, little evidence regarding their robustness is currently available. In this work, we evaluated and compared the analytical performance of a rapid lateral-flow test (LFA) and a fast semiquantitative fluorescent immunoassay (FIA) for anti-nucleocapsid (anti-NC) antibodies, with the reverse transcriptase real-time PCR assay as the reference. In 222 patients, LFA showed poor sensitivity (55.9%) within two weeks from PCR, while later testing was more reliable (sensitivity of 85.7% and specificity of 93.1%). Moreover, in a subset of 100 patients, FIA showed high sensitivity (89.1%) and specificity (94.1%) after two weeks from PCR. The coupled application for the screening of 183 patients showed satisfactory concordance (K = 0.858). In conclusion, rapid serological tests were largely not useful for early diagnosis, but they showed good performance in later stages of infection. These could be useful for back-tracing and/or to identify potentially immune subjects.

scholarly journals GASTON: Galactic Star Formation with NIKA2. Evidence for the mass growth of star-forming clumps

2021 ◽  
Author(s):  
A J Rigby ◽  
N Peretto ◽  
R Adam ◽  
P Ade ◽  
M Anderson ◽  
...  
Keyword(s):  
Star Formation ◽  
Large Scale ◽  
Galactic Plane ◽  
High Sensitivity ◽  
High Mass ◽  
Evolutionary Stage ◽  
Mass Star ◽  
Mass Growth ◽  
Star Forming ◽  
Compact Source

Abstract Determining the mechanism by which high-mass stars are formed is essential for our understanding of the energy budget and chemical evolution of galaxies. By using the New IRAM KIDs Array 2 (NIKA2) camera on the Institut de Radio Astronomie Millimétrique (IRAM) 30-m telescope, we have conducted high-sensitivity and large-scale mapping of a fraction of the Galactic plane in order to search for signatures of the transition between the high- and low-mass star-forming modes. Here, we present the first results from the Galactic Star Formation with NIKA2 (GASTON) project, a Large Programme at the IRAM 30-m telescope which is mapping ≈2 deg2 of the inner Galactic plane (GP), centred on ℓ = 23${_{.}^{\circ}}$9, b = 0${_{.}^{\circ}}$05, as well as targets in Taurus and Ophiuchus in 1.15 and 2.00 mm continuum wavebands. In this paper we present the first of the GASTON GP data taken, and present initial science results. We conduct an extraction of structures from the 1.15 mm maps using a dendrogram analysis and, by comparison to the compact source catalogues from Herschel survey data, we identify a population of 321 previously-undetected clumps. Approximately 80 per cent of these new clumps are 70 μm-quiet, and may be considered as starless candidates. We find that this new population of clumps are less massive and cooler, on average, than clumps that have already been identified. Further, by classifying the full sample of clumps based upon their infrared-bright fraction – an indicator of evolutionary stage – we find evidence for clump mass growth, supporting models of clump-fed high-mass star formation.

scholarly journals Spatial Agglomeration of China’s Forest Products Manufacturing Industry: Measurement, Characteristics and Determinants

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1006
Author(s):  
Zhenhuan Chen ◽  
Hongge Zhu ◽  
Wencheng Zhao ◽  
Menghan Zhao ◽  
Yutong Zhang
Keyword(s):  
Spatial Distribution ◽  
Spatial Data ◽  
Large Scale ◽  
Manufacturing Industry ◽  
Economies Of Scale ◽  
Forest Products ◽  
Spatial Data Analysis ◽  
Forest Protection ◽  
Spatial Agglomeration ◽  
Continuous Space

China’s forest products manufacturing industry is experiencing the dual pressure of forest protection policies and wood scarcity and, therefore, it is of great significance to reveal the spatial agglomeration characteristics and evolution drivers of this industry to enhance its sustainable development. Based on the perspective of large-scale agglomeration in a continuous space, in this study, we used the spatial Gini coefficient and standard deviation ellipse method to investigate the spatial agglomeration degree and location distribution characteristics of China’s forest products manufacturing industry, and we used exploratory spatial data analysis to investigate its spatial agglomeration pattern. The results show that: (1) From 1988 to 2018, the degree of spatial agglomeration of China’s forest products manufacturing industry was relatively low, and the industry was characterized by a very pronounced imbalance in its spatial distribution. (2) The industry has a very clear core–periphery structure, the spatial distribution exhibits a “northeast-southwest” pattern, and the barycenter of the industrial distribution has tended to move south. (3) The industry mainly has a high–high and low–low spatial agglomeration pattern. The provinces with high–high agglomeration are few and concentrated in the southeast coastal area. (4) The spatial agglomeration and evolution characteristics of China’s forest products manufacturing industry may be simultaneously affected by forest protection policies, sources of raw materials, international trade and the degree of marketization. In the future, China’s forest products manufacturing industry should further increase the level of spatial agglomeration to fully realize the economies of scale.

scholarly journals A New Hybrid Inversion Method for 2D Nuclear Magnetic Resonance Combining TSVD and Tikhonov Regularization

2021 ◽  
Vol 7 (2) ◽  
pp. 18
Author(s):  
Germana Landi ◽  
Fabiana Zama ◽  
Villiam Bortolotti
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Tikhonov Regularization ◽  
Large Scale ◽  
Regularization Parameter ◽  
High Sensitivity ◽  
Inversion Method ◽  
Nmr Relaxometry ◽  
Value Decomposition ◽  
Nuclear Magnetic

This paper is concerned with the reconstruction of relaxation time distributions in Nuclear Magnetic Resonance (NMR) relaxometry. This is a large-scale and ill-posed inverse problem with many potential applications in biology, medicine, chemistry, and other disciplines. However, the large amount of data and the consequently long inversion times, together with the high sensitivity of the solution to the value of the regularization parameter, still represent a major issue in the applicability of the NMR relaxometry. We present a method for two-dimensional data inversion (2DNMR) which combines Truncated Singular Value Decomposition and Tikhonov regularization in order to accelerate the inversion time and to reduce the sensitivity to the value of the regularization parameter. The Discrete Picard condition is used to jointly select the SVD truncation and Tikhonov regularization parameters. We evaluate the performance of the proposed method on both simulated and real NMR measurements.

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