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A 44-year (1958–2001) homogeneous, Mediterranean, high-resolution atmospheric database was generated through dynamical downscaling within the HIPOCAS (Hindcast of Dynamic Processes of the Ocean and Coastal Areas of Europe) Project framework. This work attempts to provide a validation of the monthly winter HIPOCAS precipitation over the Iberian Peninsula and the Balearic Islands and to evaluate the potential improvement of these new hindcasted data versus global reanalysis datasets. The validation was performed through the comparative analysis with a precipitation database derived from 4,617 in situ stations located over Iberia and the Balearics. The statistical comparative analysis between the observed and the HIPOCAS fields highlights their very good agreement not only in terms of spatial and time distribution, but also in terms of total amount of precipitation. A principal component analysis is carried out, showing that the patterns derived from the HIPOCAS data largely capture the main characteristics of the observed field. Moreover, it is worth to note that the HIPOCAS patterns reproduce accurately the observed regional characteristics linked to the main orographic features of the study domain. The existence of high correlations between the hindcasted and observed principal component time series gives a measure of the model performance ability. An additional comparative study of the HIPOCAS winter precipitation with global reanalysis data (NCEP and ERA) is performed. This study reveals the important regional improvement in the characterization of the observed precipitation introduced by the HIPOCAS hindcast relative to the above global reanalyses. Such improvement is effective not only in terms of total amount values, but also in the spatial distribution, the observed field being much more realistically reproduced by HIPOCAS than by the global reanalysis data. 相似文献
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A.W. Ratsimandresy M.G. Sotillo J.C. Carretero Albiach E. Álvarez Fanjul H. Hajji 《Coastal Engineering》2008
A set of 44-year (1958–2001) homogeneous and high-resolution hindcasts of atmospheric, sea level residuals, and wave states was performed for the Mediterranean Basin within the framework of the HIPOCAS European Project. To this aim, different numerical models were used. As a first step, a Mediterranean high-resolution atmospheric database, suitable to provide realistic and homogeneous forcing for ocean hindcast runs was generated. The HIPOCAS atmospheric database was created by means of dynamical downscaling from the global reanalysis NCEP, using for that the limited area model SN-REMO along with a spectral nudging technique. In a second stage, different Mediterranean oceanic hindcasts were performed. On one hand a long-term database of sea state over the western Mediterranean was generated by means of the wave model WAM and on the other hand a sea level residual database containing storm surge events was obtained from a long-term integration of the HAMSOM model over the entire basin. The three different hindcast runs have been exhaustively validated. On that score, various simulated parameters have been compared to both satellite and in situ measurements. Such comparisons provide a measure of the skills of the different simulated fields to realistically reproduce the observed features. Once these skills are evaluated, a study of the ocean and atmospheric climate trends as well as the interannual variability for the whole 44-year period was carried out with the hindcasted data. The reliability of the data as shown by its comparison to measurements and a proven temporal homogeneity over the 44 years of simulation make the Mediterranean HIPOCAS ocean–atmosphere hindcasted database a useful tool for studies focused on regional climatic variability, as well as for further applications in coastal and environmental decision processes in the Mediterranean area. 相似文献
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Sotillo MG Fanjul EA Castanedo S Abascal AJ Menendez J Emelianov M Olivella R García-Ladona E Ruiz-Villarreal M Conde J Gómez M Conde P Gutierrez AD Medina R 《Marine pollution bulletin》2008,56(4):686-703
The ESEOO Project, launched after the Prestige crisis, has boosted operational oceanography capacities in Spain, creating new operational oceanographic services and increasing synergies between these new operational tools and already existing systems. In consequence, the present preparedness to face an oil-spill crisis is enhanced, significantly improving the operational response regarding ocean, meteorological and oil-spill monitoring and forecasting. A key aspect of this progress has been the agreement between the scientific community and the Spanish Search and Rescue Institution (SASEMAR), significantly favoured within the ESEOO framework. Important achievements of this collaboration are: (1) the design of protocols that at the crisis time provide operational state-of-the-art information, derived from both forecasting and observing systems; (2) the establishment, in case of oil-spill crisis, of a new specialized unit, named USyP, to monitor and forecast the marine oceanographic situation, providing the required met-ocean and oil-spill information for the crisis managers. The oil-spill crisis scenario simulated during the international search and rescue Exercise "Gijón-2006", organized by SASEMAR, represented an excellent opportunity to test the capabilities and the effectiveness of this USyP unit, as well as the protocols established to analyze and transfer information. The results presented in this work illustrate the effectiveness of the operational approach, and constitute an encouraging and improved base to face oil-spill crisis. 相似文献
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Continuous monitoring of bed shear stress in large river systems may serve to better estimate alluvial sediment transport to the coastal ocean.Here we explore the possibility of using a horizontally deployed acoustic Doppler current profiler(ADCP) to monitor bed shear stress,applying a prescribed boundary layer model,previously used for discharge estimation.The model parameters include the local roughness length and a dip correction factor to account for sidewall effects.Both these parameters depend on river stage and on the position in the cross-section, and were estimated from shipborne ADCP data.We applied the calibrated boundary layer model to obtain bed shear stress estimates over the measuring range of the HADCP.To validate the results,co-located coupled ADCPs were used to infer bed shear stress,both from Reynolds stress profiles and from mean velocity profiles. From HADCP data collected over a period of 1.5 years,a time series of width profiles of bed shear stress was obtained for a tidal reach of the Mahakam River,East Kalimantan,Indonesia.A smaller dataset covering 25 hours was used for comparison with results from the coupled ADCPs.The bed shear stress estimates derived from Reynolds stress profiles appeared to be strongly affected by local effects causing upflow and downflow,which are not included in the boundary layer model used to derive bed shear stress with the horizontal ADCP.Bed shear stresses from the coupled ADCP are representative of a much more localized flow,while those derived with the horizontal ADCP resemble the net effect of the flow over larger scales.Bed shear stresses obtained from mean velocity profiles from the coupled ADCPs show a good agreement between the two methods,and highlight the robustness of the method to uncertainty in the estimates of the roughness length. 相似文献
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华北北部古生代大陆地壳增生过程中的岩浆作用与成矿效应 总被引：13，自引：7，他引：6
包括前寒武纪克拉通与显生宙造山带两大构造单元的华北北部,古生代时期板块构造体制下古亚洲洋的裂解-扩展-消亡与汇聚大陆边缘的俯冲-碰撞-伸展循环构成了其大陆地壳增生与再造演化的基本图景,并形成了一系列记录这些因果演变连续过程的岩浆侵入与喷发事件。这些物质记录无疑是研究汇聚大陆边缘壳-幔作用和物质交换、大陆地壳演化与大规模成矿作用耦合关系的绝佳窗口。本文在系统总结最近几年积累的年代学和岩石地球化学资料的基础上,以一些带有特定过程印记的标志性岩浆事件为纲领,表征这些古生代岩浆作用形成过程中的地球动力学演变,揭示其所记录的华北北部大陆地壳的多阶段增生与再造演化机制,并初步探讨了有利地球动力学过程制约下的岩浆行为引起的成矿物质聚集效应。 相似文献
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M. G. Sotillo A. W. Ratsimandresy J. C. Carretero A. Bentamy F. Valero F. González-Rouco 《Climate Dynamics》2005,25(2-3):219-236
A 44-year (1958–2001) high-resolution atmospheric hindcast for the whole Mediterranean Basin was performed within the EU-funded
Hindcast of Dynamic Processes of the Ocean and Coastal Areas of Europe (HIPOCAS) Project. The long-term hindcasted data set,
which comprises several atmospheric parameters at different levels, was produced by means of dynamical downscaling from the
NCEP/NCAR global reanalysis using the atmospheric limited area model REMO. The REMO hindcast has been exhaustively validated.
On that score, various hindcasted surface parameters, such as 10-m wind field, 2-m temperature and mean sea level pressure,
have been compared to satellite data (ERS-1/2 scatterometer) and in-situ measurements from offshore stations. In addition,
two ocean models (waves and sea level) have been forced with REMO hindcasted fields (mean sea level pressure and 10-m wind
field). The validation of these ocean runs, performed through comparisons of simulated waves and sea level with oceanographic
measurements, allows to evaluate "indirectly" the quality of the REMO hindcasted data used as atmospheric forcing. Once the
quality of the hindcasted data was verified, the efficiency of the regional enhancement performed through dynamical downscaling
on the NCEP global reanalysis was assessed. The regional improvement was evaluated through comparisons of REMO and NCEP performance
in reproducing observations. The important improvement obtained in the characterization of extreme wind events is particularly
remarkable. 相似文献
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T Sancelme J Goetze S Jaquemet MG Meekan A Flam AM Watts 《African Journal of Marine Science》2020,42(1):95-107
Coastal populations of maritime countries in eastern Africa rely on fish as a primary source of protein, but baseline information on the abundance of fish communities on these coastlines is often lacking. We used baited remote underwater video stations to compare the abundance and diversity of reef fishes targeted by fishing at two sites in southern Mozambique, one at Lighthouse Reef within the Bazaruto Archipelago National Park and the other to the south at San Sebastian Reef on the San Sebastian Peninsula. Fish that are known targets of fisheries (mostly small-scale and artisanal) had an abundance that was almost three-times greater at San Sebastian Reef (80.22 ind. h–1 [SE 18.00]) than at Lighthouse Reef (29.70 ind. h–1 [SE 8.91]). Similarly, there was greater mean species richness at San Sebastian Reef (38.74 species h–1 [SE 2.79]) than at Lighthouse Reef (25.37 species h–1 [SE 3.66]). The main drivers of targeted fish abundance were habitat and depth, with shallow (<15 m) and mixed reef areas having the greatest abundance and richness. More sampling was done over sand habitat at Lighthouse Reef, which likely led to the lower abundance and species richness observed at this site; however, that finding could also be attributable to the fact that protection is provided to only a section of available coral reef habitat in a small area. Nevertheless, fish community structure was comparable between the sites, with similar proportions of carnivores (78–81%), herbivores (12–14%) and omnivores (7–8%). Our findings highlight the variation in species abundance and assemblages of coral-reef fish targeted by fishing in Mozambique and emphasise the importance of localised environmental variables as a driver of these patterns. To ensure maximum protection of Lighthouse Reef fish communities, we recommend an extension of the no-take zone to include the entire reef complex. 相似文献
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Nowadays, many efforts are leading to use the high potential offshore wind energy resources. A detailed assessment of the offshore wind resources arises as a first-rate requirement. Most of such assessment is based on extreme offshore wind atlas generated mainly from global reanalysis and satellite data. Both sort of data show certain shortcomings related, among others, to coarse spatial resolution and time inhomogeneity issues, respectively. This snag seems to be crucial over areas such as the Mediterranean Basin, which is characterized by a complex land–sea distribution and a significant orography. The HIPOCAS Mediterranean long-term (1958–2001) wind database comes to overcome the aforementioned reanalysis shortcoming and provides a Mediterranean wind data set useful to perform extreme wind analysis. This contribution also deals with a statistical extreme wind analysis over the whole Mediterranean offshore areas. Extreme return periods and levels are obtained from annual maxima using a number of distributions. Additionally, an alternative regional statistical method based on regional L-moment statistics is also proposed. The regional technique is applied to reduce uncertainty and allows a higher number of measurements to be included in the analysis, using data from a homogeneous region instead of from a single location. The herein performed extreme wind analysis provides a detailed assessment of high wind offshore areas over the Mediterranean and constitutes a subject of great interest for evaluation of wind resources. 相似文献
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