Existence of the frequentistic estimate for power-law regression with a location parameter, with applications for making discharge rating curves     

Trond Reitan  Asgeir Petersen-Øverleir 《Stochastic Environmental Research and Risk Assessment (SERRA)》2006,20(6):445-453

Practical application of the power-law regression model with an unknown location parameter can be plagued by non-finite least squares parameter estimates. This presents a serious problem in hydrology, since stream flow data is mainly obtained using an estimated stage–discharge power-law rating curve. This study provides a set of sufficient requirements for the data to ensure the existence of finite least squares parameter estimates for a power-law regression with an unknown location parameter. It is shown that in practice, these requirements act as necessary for having a finite least squares solution, in most cases. Furthermore, it is proved that there is a finite probability for the model to produce data having non-finite least squares parameter estimates. The implications of this result are discussed in the context of asymptotic predictions, inference and experimental design. A Bayesian approach to the actual regression problem is recommended.  相似文献   

Modeling of prominence threads in magnetic fields: Levitation by incompressible MHD waves     

Pécseli  Hans  Engvold  OddbjØrn 《Solar physics》2000,194(1):73-86

The nature of thin, highly inclined threads observed in quiescent prominences has puzzled solar physicists for a long time. When assuming that the threads represent truly inclined magnetic fields, the supporting mechanism of prominence plasma against gravity has remained an open issue. This paper examines the levitation of prominence plasma exerted by weakly damped MHD waves in nearly vertical magnetic flux tubes. It is shown that the wave damping, and resulting `radiation pressure', caused predominantly by ion-neutral collisions in the `cold' prominence plasma, may balance the acceleration of gravity provided the oscillation frequency is 2 rad s^–1 (f0.5 Hz). Such short wave periods may be the result of small-scale magnetic reconnections in the highly fragmentary magnetic field of quiescent prominences. In the proposed model, the wave induced levitation acts predominantly on plasma – neutral gas mixtures.  相似文献   

The heat goes on—changes in indices of hot extremes in Poland     

Graczyk  Dariusz  Pińskwar  Iwona  Kundzewicz  Zbigniew W.  Hov  Øystein  Førland  Eirik J.  Szwed  Małgorzata  Choryński  Adam 《Theoretical and Applied Climatology》2017,129(1-2):459-471

Theoretical and Applied Climatology - On the basis of temperature observations at 60 meteorological stations in Poland, changes in the indices associated with the presence of extremely high air...  相似文献   

Basin modelling: Advances and applications, Stavanger, Norway, 13–15 March 1991     

Anthony G. Dor  Christian Hermanrud   yvind Sylta  Jan H. Augustson 《Marine and Petroleum Geology》1991,8(4)

  相似文献   

Comparison of geomorphological field mapping and 2D‐InSAR mapping of periglacial landscape activity at Nordnesfjellet,northern Norway          下载免费PDF全文

Markus Eckerstorfer  Harald Øverli Eriksen  Line Rouyet  Hanne H. Christiansen  Tom Rune Lauknes  Lars Harald Blikra 《地球表面变化过程与地形》2018,43(10):2147-2156

The ability to continuously monitor the dynamic response of periglacial landforms in a climate change context is of increasing scientific interest. Satellite radar interferometry provides information on surface displacement that can be related to periglacial processes. Here we present a comparison of two‐dimensional (2D) surface displacement rates and geomorphological mapping at periglacial landform and sediment scale from the mountain Nordnesfjellet in northern Norway. Hence, 2D Interferometric Synthetic Aperture Radar (InSAR) results stem from a 2009–2014 TerraSAR‐X dataset from ascending and descending orbits, decomposed into horizontal displacement vectors along an east–west plane, vertical displacement vectors and combined displacement velocity. Geomorphological mapping was carried out on aerial imagery and validated in the field. This detailed landform and sediment type mapping revealed an altitudinal distribution dominated by, weathered bedrock blockfields, surrounded primarily by slightly, to non‐vegetated solifluction landforms at the mountain tops. Below, an active rockslide and associated rockfall deposits are located on the steep east‐facing side of the study area, whereas glacial sediments dominate on the gentler western side. We show that 2D InSAR correctly depicts displacement rates that can be associated with typical deformation patterns for flat‐lying or inclined landforms, within and below the regional permafrost limit, for both wet and dry areas. A net lowering of the entire landscape caused by general denudation of the periglacial landforms and sediments is here quantified for the first time using radar remote sensing. Copyright © 2018 John Wiley & Sons, Ltd.  相似文献   

The 14th international workshop on wave hindcasting and forecasting and the 5th coastal hazards symposium     

Øyvind Breivik  Jose Henrique Alves  Diana Greenslade  Kevin Horsburgh  Val Swail 《Ocean Dynamics》2017,67(3-4):551-556

Following the 14th International Workshop on Wave Hindcasting and Forecasting and 5th Coastal Hazards Symposium in November 2014 in Key West, Florida, a topical collection has appeared in recent issues of Ocean Dynamics. Here, we give a brief overview of the 16 papers published in this topical collection as well as an overview of the widening scope of the conference in recent years. A general trend in the field has been towards closer integration between the wave and ocean modelling communities. This is also seen in this topical collection, with several papers exploring the interaction between surface waves and mixed layer dynamics and sea ice.  相似文献   

Range and AGC normalization in airborne discrete-return LiDAR intensity data for forest canopies   总被引：1，自引：0，他引：1  

Ilkka Korpela  Hans Ole Ørka  Juha Hyyppä  Ville Heikkinen  Timo Tokola 《ISPRS Journal of Photogrammetry and Remote Sensing》2010,65(4):369-379

  相似文献   

A re-investigation of the bloom-forming unarmored dinoflagellate Karenia longicanalis (syn. Karenia umbella ) from Chinese coastal waters     

Wang  Jianyan  Cen  Jingyi  Li  Si  Lü  Songhui  Moestrup  Øjvind  Chan  Kin-Ka  Jiang  Tao  Lei  Xiangdong 《中国海洋湖沼学报》2018,36(6):2202-2215

The dinoflagellate genus K arenia is known for recurrent harmful blooms worldwide. However, species diversity of the genus is generally overlooked owing to the difficulty of identifying small unarmored dinoflagellates. We have established four clonal cultures of K arenia longicanalis isolated from the type locality, Hong Kong harbor(strain HK01) and other three locations along the Chinese coasts(strains YB01, DT01, and NJ01). The morphology of the strain was studied by light and scanning electron microscopy(LM and SEM) and the pigment composition analyzed by high-performance liquid chromatography. We provide the first molecular data of K. longicanalis based on the large subunit(LSU) rRNA gene sequence and internal transcribed spacer(ITS). The four strains showed identical LSU rDNA sequences with a similarity of 99.4% to the holotype of K arenia umbella(strain KUTN05) from Australia. In the ITS phylogeny, the sequence of K. umbella branched between the Chinese strains of K. longicanalis. A careful comparison of the morphology of K. longicanalis and K. umbella reveals the similarity in the diagnostic characters. Diff erences may appear due to the sample treatment for SEM. We conclude that K. umbella is a junior synonym of K. longicanalis.  相似文献   

Norwegian marine geodetic projects     

Jan Chr. Blankenburgh  Bj⊘rn A. Fossum  Per A. Østerholt  Hans Olav Torsen 《Marine Geodesy》2013,36(2):125-145

The hitherto promising finds of oil and gas on the Norwegian continental shelf have increased the general activity in this area considerably. Consequently, the need for better charts and more precise navigational systems have become more pertinent. During the past few years a number of marine geodetic projects have either been planned or embarked upon by various organizations within both the public and private sectors. This article gives a brief review of the Norwegian projects which have special relevance to marine geodesy; this includes the following areas: recommendations, requirements, precision navigation, satellite positioning, reference systems, boundary problems, bathymetry, geological mapping, marine geoid determination, and data base developments. The reference list will give the reader more detailed sources of information.  相似文献   

Maribo—A new CM fall from Denmark     

Henning HAACK  Thomas GRAU  Addi BISCHOFF  Marian HORSTMANN  John WASSON  Anton SØRENSEN  Matthias LAUBENSTEIN  Ulrich OTT  Herbert PALME  Marko GELLISSEN  Richard C. GREENWOOD  Victoria K. PEARSON  Ian A. FRANCHI  Zelimir GABELICA  Philippe SCHMITT‐KOPPLIN 《Meteoritics & planetary science》2012,47(1):30-50

Abstract– Maribo is a new Danish CM chondrite, which fell on January 17, 2009, at 19:08:28 CET. The fall was observed by many eye witnesses and recorded by a surveillance camera, an all sky camera, a few seismic stations, and by meteor radar observatories in Germany. A single fragment of Maribo with a dry weight of 25.8 g was found on March 4, 2009. The coarse‐grained components in Maribo include chondrules, fine‐grained olivine aggregates, large isolated lithic clasts, metals, and mineral fragments (often olivine), and rare Ca,Al‐rich inclusions. The components are typically rimmed by fine‐grained dust mantles. The matrix includes abundant dust rimmed fragments of tochilinite with a layered, fishbone‐like texture, tochilinite–cronstedtite intergrowths, sulfides, metals, and carbonates often intergrown with tochilinite. The oxygen isotopic composition: (δ¹⁷O = ?1.27‰; δ¹⁸O = 4.96‰; Δ¹⁷O = ?3.85‰) plots at the edge of the CM field, close to the CCAM line. The very low Δ¹⁷O and the presence of unaltered components suggest that Maribo is among the least altered CM chondrites. The bulk chemistry of Maribo is typical of CM chondrites. Trapped noble gases are similar in abundance and isotopic composition to other CM chondrites, stepwise heating data indicating the presence of gas components hosted by presolar diamond and silicon carbide. The organics in Maribo include components also seen in Murchison as well as nitrogen‐rich components unique to Maribo.  相似文献