The Chan Hol cave near Tulum (Quintana Roo,Mexico): evidence for long‐lasting human presence during the early to middle Holocene          下载免费PDF全文

Fabio Hering  Wolfgang Stinnesbeck  Jens Folmeister  Eberhard Frey  Sarah Stinnesbeck  Jerónimo Avilés  Eugenio Aceves Núñez  Arturo González  Alejandro Terrazas Mata  Martha Elena Benavente  Carmen Rojas  Adriana Velázquez Morlet  Norbert Frank  Patrick Zell  Julia Becker 《第四纪科学杂志》2018,33(4):444-454

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River management response to multi-decade changes in timing of reservoir inflows,Columbia River Basin,USA     

Julia A. Jones  John C. Hammond 《水文研究》2020,34(25):4814-4830

Around the world, long-term changes in the timing and magnitude of streamflow are testing the ability of large managed water resource systems constructed in the 20th century to continue to meet objectives in the 21st century. Streamflow records for unregulated rivers upstream of reservoirs can be combined with records downstream of reservoirs using a paired-watershed framework and concepts of water resource system performance to assess how reservoir management has responded to long-term change. Using publicly available data, this study quantified how the intra-annual timing of inflows and outflows of 25 major reservoirs has shifted, how management has responded, and how this has influenced reliability and vulnerability of the water resource system in the 668,000 km² Columbia River basin from 1950 to 2012. Reservoir inflows increased slightly in early spring and declined in late spring to early fall, but reservoir outflows increased in late summer from 1950 to 2012. Average inflows to reservoirs in the low flow period exceeded outflows in the1950s, but inflows are now less than outflows. Reservoirs have increased hedging, that is, they have stored more water during the spring, in order to meet the widening gap between inflows and outflows during the summer low flow period. For a given level of reliability (the fraction of time flow targets were met), vulnerability (the maximum departure from the flow target) was greater during periods with lower than average inflows. Thus, the water management system in this large river basin has adjusted to multi-decade trends of declining inflows, but vulnerability, that is, the potential for excess releases in spring and shortfalls in summer, has increased. This study demonstrates the value of combining publicly available historical data on streamflow with concepts from paired-watershed analyses and metrics of water resource performance to detect, evaluate, and manage water resource systems in large river basins.  相似文献   

Sensitivity of WRF to driving data and physics options on a seasonal time-scale for the southwest of Western Australia     

Jatin Kala  Julia Andrys  Tom J. Lyons  Ian J. Foster  Bradley J. Evans 《Climate Dynamics》2015,44(3-4):633-659

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An early warning system for wave-driven coastal flooding at Imperial Beach,CA     

Merrifield  Mark A.  Johnson  Mele  Guza  R. T.  Fiedler  Julia W.  Young  Adam P.  Henderson  Cassandra S.  Lange  Athina M. Z.  O’Reilly  William C.  Ludka  Bonnie C.  Okihiro  Michele  Gallien  Timu  Pappas  Kyle  Engeman  Laura  Behrens  James  Terrill  Eric 《Natural Hazards》2021,108(3):2591-2612

Natural Hazards - Waves overtop berms and seawalls along the shoreline of Imperial Beach (IB), CA when energetic winter swell and high tide coincide. These intermittent, few-hour long events flood...  相似文献   

Influence of redox conditions on the intensity of Mars crustal magnetic anomalies          下载免费PDF全文

Stefanie Brachfeld  Deepa Shah  Emily First  Julia Hammer  Julie Bowles 《Meteoritics & planetary science》2015,50(10):1703-1717

We evaluate the relationship between the intensity of remanent magnetization and fO₂ in natural and synthetic Mars meteorites. The olivine‐phyric shergottite meteorite Yamato 980459 (Y‐980459) and a sulfur‐free synthetic analog (Y‐98*) of identical major element composition were analyzed to explore the rock magnetic and remanence properties of a basalt crystallized from a primitive melt, and to explore the role of magmatic and alteration environment fO₂ on Mars crustal anomalies. The reducing conditions under which Y‐980459 is estimated to have formed (QFM‐2.5; Shearer et al. 2006) were replicated during the synthesis of Y‐98*. Y‐980459 contains pyrrhotite and chromite. Chromite is the only magnetic phase in Y‐98*. The remanence‐carrying capacity of Y‐980459 is comparable to other shergottites that formed in the fO₂ range of QFM‐3 to QFM‐1. The remanence‐carrying capacity of these low fO₂ basalts is 1–2 orders of magnitude too weak to account for the intense crustal anomalies observed in Mars's southern cratered highlands. Moderately oxidizing conditions of >QFM‐1, which are more commonly observed in nakhlites and Noachian breccias, are key to generating either a primary igneous assemblage or secondary alteration assemblage capable of acquiring an intense remanent magnetization, regardless of the basalt character or thermal history. This suggests that if igneous rocks are responsible for the intensely magnetized crust, these oxidizing conditions must have existed in the magmatic plumbing systems of early Mars or must have existed in the crust during secondary processes that led to acquisition of a chemical remanent magnetization.  相似文献   

Field accumulative behavior of organochlorine pesticides. The role of crabs and sediment characteristics in coastal environments     

Menone ML  Miglioranza KS  Botto F  Iribarne O  Aizpún de Moreno JE  Moreno VJ 《Marine pollution bulletin》2006,52(12):1717-1724

The influence of intertidal crab beds on the concentrations of organochlorine (OC) pesticides in sediment was studied in two different coastal environments in Argentina. Samples of male burrowing crabs (Chasmagnathus granulatus) were collected for this study. Our field data showed lower bioaccumulation of OC pesticides in crabs from sediments with a higher total organic carbon (TOC) and higher clay content. Thus, concentrations in crabs depend on the physico-chemical characteristics of the sediment where they live more than on the OC pesticide concentrations in the environment. The distribution patterns in sediment from inside and outside crab burrows were similar for both coastal areas being HCHs  γ-chlordane > p,p′-DDE for San Antonio Bay (SAO), and HCHs > p,p′-DDE  γ-chlordane for Mar Chiquita (MCh) coastal lagoon. OC pesticide concentrations in sediment were significantly lower inside than outside crab burrows, irrespective of the sediment physico-chemical characteristics due to the bioturbation activity of C. granulatus.  相似文献   

The GMRT EoR experiment: limits on polarized sky brightness at 150 MHz     

Ue-Li Pen  Tzu-Ching Chang  Christopher M. Hirata  Jeffrey B. Peterson  Jayanta Roy  Yashwant Gupta  Julia Odegova  Kris Sigurdson 《Monthly notices of the Royal Astronomical Society》2009,399(1):181-194

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Starburst99 for Windows     

Claus Leitherer  Julia Chen 《New Astronomy》2009,14(4):356-362

We present a Windows compatible version of the evolutionary synthesis code Starburst99. Starburst99 for Windows was developed from the public UNIX-based version at STScI. We converted the original Fortran77 source code into a version for a Win32 environment with an Absoft² Fortran Pro x86 compiler. Extensive testing showed no significant numerical differences in comparison with the previous UNIX version. The software application consists of the source code, executable, and a number of auxiliary files. The package installs on any PC running Windows 2000, XP, or Vista and can be obtained as freeware at http://www.stsci.edu/science/starburst/PCStarburst99.html. We give an overview of the different running modes and provide instructions for getting started with the initial set-up.  相似文献   

Upper-ocean heat budget and ocean eddy transport in the south-east Pacific in a high-resolution coupled model   总被引：1，自引：1，他引：0  

Thomas Toniazzo  Carlos R. Mechoso  Leonard C. Shaffrey  Julia M. Slingo 《Climate Dynamics》2010,35(7-8):1309-1329

We present an analysis of the oceanic heat advection and its variability in the upper 500 m in the southeastern tropical Pacific (100W–75W, 25S–10S) as simulated by the global coupled model HiGEM, which has one of the highest resolutions currently used in long-term integrations. The simulated climatology represents a temperature advection field arising from transient small-scale (<450 km) features, with structures and transport that appear consistent with estimates based on available observational data for the mooring at 20S, 85W. The transient structures are very persistent (>4 months), and in specific locations they generate an important contribution to the local upper-ocean heat budget, characterised by scales of a few hundred kilometres, and periods of over a year. The contribution from such structures to the local, long-term oceanic heat budget however can be of either sign, or vanishing, depending on the location; and, although there appears some organisation in preferential areas of activity, the average over the entire region is small. While several different mechanisms may be responsible for the temperature advection by transients, we find that a significant, and possibly dominant, component is associated with vortices embedded in the large-scale, climatological salinity gradient associated with the fresh intrusion of mid-latitude intermediate water which penetrates north-westward beneath the tropical thermocline.  相似文献   

The marine record of deglaciation of the South Shetland Islands,Antarctica since the Last Glacial Maximum     

Alexander R. Simms  Kristy T. Milliken  John B. Anderson  Julia S. Wellner 《Quaternary Science Reviews》2011,30(13-14):1583-1601

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