The Jurassic Prehodavci Formation of the Julian Alps: easternmost outcrops of Rosso Ammonitico in the Southern Alps (NW Slovenia)     

Andrej Šmuc  Boštjan Rožič 《Swiss Journal of Geoscience》2010,103(2):241-255

The Julian Alps are located in NW Slovenia and structurally belong to the Julian Nappe where the Southern Alps intersect with the Dinarides. In the Jurassic, the area was a part of the southern Tethyan continental margin and experienced extensional faulting and differential subsidence during rifting of the future margin. The Mesozoic succession in the Julian Alps is characterized by a thick pile of Upper Triassic to Lower Jurassic platform limestones of the Julian Carbonate Platform, unconformably overlain by Bajocian to Tithonian strongly condensed limestones of the Prehodavci Formation of the Julian High. The Prehodavci Formation is up to 15 m thick, consists of Rosso Ammonitico type limestone and is subdivided into three members. The Lower Member consists of a condensed red, well-bedded bioclastic limestone with Fe–Mn nodules, passing into light-grey, faintly nodular limestone. The Middle Member occurs discontinuously and consists of thin-bedded micritic limestone. The Upper Member unconformably overlies the Lower or Middle Members. It is represented by red nodular limestone, and by red-marly limestone with abundant Saccocoma sp. The Prehodavci Formation unconformably overlies the Upper Triassic to Lower Jurassic platform limestone of the Julian Carbonate Platform; the contact is marked by a very irregular unconformity. It is overlain by the upper Tithonian pelagic Biancone (Maiolica) limestone. The sedimentary evolution of the Julian High is similar to that of Trento Plateau in the west and records: (1) emergence and karstification of part of the Julian Carbonate Platform in the Pliensbachian, or alternatively drowning of the platform and development of the surface by sea-floor dissolution; (2) accelerated subsidence and drowning in the Bajocian, and onset of the condensed pelagic sedimentation (Prehodavci Formation) on the Julian High; (3) beginning of sedimentation of the Biancone limestone in the late Tithonian.  相似文献   

Kinematics of Interacting ICMEs and Related Forbush Decrease: Case Study     

D. Maričić  B. Vršnak  M. Dumbović  T. Žic  D. Roša  D. Hržina  S. Lulić  I. Romštajn  I. Bušić  K. Salamon  M. Temmer  T. Rollett  A. Veronig  N. Bostanjyan  A. Chilingarian  B. Mailyan  K. Arakelyan  A. Hovhannisyan  N. Mujić 《Solar physics》2014,289(1):351-368

We study heliospheric propagation and some space weather aspects of three Earth-directed interplanetary coronal mass ejections (ICMEs), successively launched from the active region AR 11158 in the period 13?–?15 February 2011. From the analysis of the ICME kinematics, morphological evolution, and in situ observations, we infer that the three ICMEs interacted on their way to Earth, arriving together at 1 AU as a single interplanetary disturbance. Detailed analysis of the in situ data reveals complex internal structure of the disturbance, where signatures of the three initially independent ICMEs could be recognized. The analysis also reveals compression and heating of the middle ICME, as well as ongoing magnetic reconnection between the leading and the middle ICME. We present evidence showing that the propagation of these two, initially slower ICMEs, was boosted by the fastest, third ICME. Finally, we employ the ground-based cosmic ray observations, to show that this complex disturbance produced a single cosmic ray event, i.e., a simple Forbush decrease (FD). The results presented provide a better understanding of the ICME interactions and reveal effects that should be taken into account in forecasting of the arrival of such compound structures.  相似文献   

Validity of the Relations Between the Synodic and Sidereal Rotation Velocities of the Sun     

I. Skokić  R. Brajša  D. Roša  D. Hržina  H. Wöhl 《Solar physics》2014,289(5):1471-1476

Existing methods for conversion between synodic and sidereal rotation velocities of the Sun are tested for validity using state-of-the-art ephemeris data. We found that some of them agree well with ephemeris calculations while others show a discrepancy of almost 0.01^° day^?1. This discrepancy is attributed to a missing factor and a new corrected relation is given.  相似文献   

The pyrogeography of sub-Saharan Africa: a study of the spatial non-stationarity of fire–environment relationships using GWR     

Ana?C.?L.?SáEmail author  José?M.?C.?Pereira  Martin?E.?Charlton  Bernardo?Mota  Paulo?M.?Barbosa  A.?Stewart Fotheringham 《Journal of Geographical Systems》2011,13(3):227-248

This study analyses the relationship between fire incidence and some environmental factors, exploring the spatial non-stationarity of the phenomenon in sub-Saharan Africa. Geographically weighted regression (GWR) was used to study the above relationship. Environment covariates comprise land cover, anthropogenic and climatic variables. GWR was compared to ordinary least squares, and the hypothesis that GWR represents no improvement over the global model was tested. Local regression coefficients were mapped, interpreted and related with fire incidence. GWR revealed local patterns in parameter estimates and also reduced the spatial autocorrelation of model residuals. All the covariates were non-stationary and in terms of goodness of fit, the model replicates the data very well (R ² = 87%). Vegetation has the most significant relationship with fire incidence, with climate variables being more important than anthropogenic variables in explaining variability of the response. Some coefficient estimates exhibit locally different signs, which would have gone undetected by a global approach. This study provides an improved understanding of spatial fire–environment relationships and shows that GWR is a valuable complement to global spatial analysis methods. When studying fire regimes, effects of spatial non-stationarity need to be incorporated in vegetation-fire modules to have better estimates of burned areas and to improve continental estimates of biomass burning and atmospheric emissions derived from vegetation fires.  相似文献   

Adapting to climate change impacts on water resources in England—An assessment of draft Water Resources Management Plans     

Matthew B. Charlton  Nigel W. Arnell 《Global Environmental Change》2011,21(1):238-248

Climate change is expected to produce reductions in water availability in England, potentially necessitating adaptive action by the water industry to maintain supplies. As part of Ofwat's fifth Periodic Review (PR09), water companies recently released their draft Water Resources Management Plans, setting out how each company intends to maintain the balance between the supply and demand for water over the next 25 years, following Environment Agency guidelines. This paper reviews these plans to determine company estimates of the impact of climate change on water supply relative to other resource pressures. The approaches adopted for incorporating the impact in the plans and the proposed management solutions are also identified.Climate change impacts for individual resource zones range from no reductions in deployable output to greater than 50% over the planning period. The estimated national aggregated loss of deployable output under a “core” climate scenario is ∼520 Ml/d (3% of deployable output) by 2034/2035, the equivalent of the supply of one entire water company (South West Water). Climate change is the largest single driver of change in water supplies over the planning period. Over half of the climate change impact is concentrated in southern England. In extreme cases, climate change uncertainty is of the same magnitude as the change under the core scenario (up to a loss of ∼475 Ml/d). 44 of the 68 resource zones with available data are estimated to have a climate change impact. In 35 of these climate change has the greatest impact although in 10 zones sustainability reductions have a greater impact. Of the overall change in downward pressure on the supply-demand balance over the planning period, ∼56% is accounted for by increased demand (620 Ml/d) and supply side climate change accounts for ∼37% (407 Ml/d). Climate change impacts have a cumulative impact in concert with other changing supply side reducing components increasing the national pressure on the supply-demand balance. Whilst the magnitude of climate change appears to justify its explicit consideration, it is rare that adaptation options are planned solely in response to climate change but as a suite of options to provide a resilient supply to a range of pressures (including significant demand side pressures). Supply-side measures still tend to be considered by water companies to be more reliable than demand-side measures.  相似文献   

The comap as a diagnostic tool for non-stationary kriging models     

Paul Harris  Chris Brunsdon  Martin Charlton 《International journal of geographical information science》2013,27(3):511-541

In this study, we demonstrate a novel use of comaps to explore spatially the performance, specification and parameterisation of a non-stationary geostatistical predictor. The comap allows the spatial investigation of the relationship between two geographically referenced variables via conditional distributions. Rather than investigating bivariate relationships in the study data, we use comaps to investigate bivariate relationships in the key outputs of a spatial predictor. In particular, we calibrate moving window kriging (MWK) models, where a local variogram is found at every target location. This predictor has often proved worthy for processes that are heterogeneous, and most standard (global variogram) kriging algorithms can be adapted in this manner. We show that the use of comaps enables a better understanding of our chosen MWK models, which in turn allows a more informed choice when selecting one MWK specification over another. As case studies, we apply four variants of MWK to two heterogeneous example data sets: (i) freshwater acidification critical load data for Great Britain and (ii) London house price data. As both of these data sets are strewn with local anomalies, three of our chosen models are robust (and novel) extensions of MWK, where at least one of which is shown to perform better than a non-robust counterpart.  相似文献   

Differential Rotation of Stable Recurrent Sunspot Groups     

Brajša  R.  Wöhl  H.  Vršnak  B.  Ruždjak  D.  Sudar  D.  Roša  D.  Hržina  D. 《Solar physics》2002,206(2):229-241

Stable recurrent sunspot groups from the Greenwich data set which were identified in at least two subsequent solar rotations were traced. The solar rotation was determined by the period method from the time difference of the two central meridian passages of each of the 327 identified groups. Sidereal rotation periods were calculated from the synodic ones by a seasonal-dependent procedure taking into account the details of the Earth's motion around the Sun. Growing recurrent sunspot groups rotate on the average faster than decaying recurrent sunspot groups, while sunspot groups of all types taken together rotate faster than both growing and decaying recurrent sunspot groups. A north–south rotational asymmetry and a cycle-dependence of rotational velocity of recurrent sunspot groups were analyzed. Positive rotation velocity deviations are larger, but less numerous than the negative ones. Signatures of torsional oscillations were not found analyzing the rotation velocity residual of recurrent sunspot groups as a function of the distance from the average latitude of activity.  相似文献   

Smoothing/filtering LiDAR digital surface models. Experiments with loess regression and discrete wavelets     

Nicholas J. Tate  Chris Brunsdon  Martin Charlton  A. Stewart Fotheringham  Claire H. Jarvis 《Journal of Geographical Systems》2005,7(3-4):273-290

This paper reports on the smoothing/filtering analysis of a digital surface model (DSM) derived from LiDAR altimetry for part of the River Coquet, Northumberland, UK using loess regression and the 2D discrete wavelet transform (DWT) implemented in the S-PLUS and R statistical packages. The chosen method of analysis employs a simple method to generate ‘noise’ which is then added to a smooth sample of LiDAR data; loess regression and wavelet methods are then used to smooth/filter this data and compare with the original ‘smooth’ sample in terms of RMSE. Various combinations of functions and parameters were chosen for both methods. Although wavelet analysis was effective in filtering the noise from the data, loess regression employing a quadratic parametric function produced the lowest RMSE and was the most effective.  相似文献   

Regional Air Quality Modelling in Canada – Applications for Policy and Real-Time Prediction     

Venkatesh  S.  Gong  W.  Kallaur  A.  Makar  P. A.  Moran  M. D.  Pabla  B.  Ro  C.  Vet  R.  Burrows  W. R.  Montpetit  R. 《Natural Hazards》2000,21(2-3):101-129

Acid rain and photochemical smog are two regionalair-quality issues that have received considerableattention in the last two decades due to their harmfuleffects. Health impacts of particulate matter (PM) inthe atmosphere is another issue of concern.Sulphur dioxide emission controls were introducedin both Canada and the U.S.A. to reduceacid-deposition-related damage. While these emissionreductions have already resulted in reduced sulphatedeposition, based on results from modelling studiesmuch of southeastern Canada is still expected toexperience damaging levels of acid deposition evenafter all currently legislated emission controls arefully implemented. Moreover, there has not been acorresponding reduction in the acidity ofprecipitation. This may be attributable to aconcurrent reduction in base-cation concentration inprecipitation.Models were also developed to understand theformation, transport and diffusion of troposphericozone. The models have been used to provide policyguidance for emission control options to reduceground-level ozone to acceptable limits. In thesummer of 1997 a Canadian pilot project was initiatedto provide real-time forecasts of ground-level ozonein the southeastern part of the province of NewBrunswick in eastern Canada.With the emergence of fine Particulate Matter(PM_2.5) as a health concern, efforts are underwayin Canada to develop a unified' regional air-qualitymodel that will address the combined impacts ofvarious pollutants in the atmosphere. In this effortthe atmosphere is viewed as a single entity where theimpacts of multiple pollutants are considered at thesame time.  相似文献   

A response to ‘A comment on geographically weighted regression with parameter-specific distance metrics’     

Binbin Lu  Chris Brunsdon  Martin Charlton  Paul Harris 《International journal of geographical information science》2019,33(7):1300-1312

In this article, we respond to ‘A comment on geographically weighted regression with parameter-specific distance metrics’ by Oshan et al. (2019), published in this journal, where several concerns on the parameter-specific distance metric geographically weighted regression (PSDM GWR) technique are raised. In doing so, we review the developmental timeline of the multiscale geographically weighed regression modelling framework with related and equivalent models, including flexible bandwidth GWR, conditional GWR and PSDM GWR. In our response, we have tried to answer all the concerns raised in terms of applicability, veracity, interpretability and computational efficiency of the PSDM GWR model.  相似文献