Development and testing of a coupled ocean–atmosphere mesoscale ensemble prediction system     

Teddy R. Holt  James A. Cummings  Craig H. Bishop  James D. Doyle  Xiaodong Hong  Sue Chen  Yi Jin 《Ocean Dynamics》2011,61(11):1937-1954

A coupled ocean–atmosphere mesoscale ensemble prediction system has been developed by the Naval Research Laboratory. This paper describes the components and implementation of the system and presents baseline results from coupled ensemble simulations for two tropical cyclones. The system is designed to take into account major sources of uncertainty in: (1) non-deterministic dynamics, (2) model error, and (3) initial states. The purpose of the system is to provide mesoscale ensemble forecasts for use in probabilistic products, such as reliability and frequency of occurrence, and in risk management applications. The system components include COAMPS® (Coupled Ocean/Atmosphere Mesoscale Prediction System) and NCOM (Navy Coastal Ocean Model) for atmosphere and ocean forecasting and NAVDAS (NRL Atmospheric Variational Data Assimilation System) and NCODA (Navy Coupled Ocean Data Assimilation) for atmosphere and ocean data assimilation. NAVDAS and NCODA are 3D-variational (3DVAR) analysis schemes. The ensembles are generated using separate applications of the Ensemble Transform (ET) technique in both the atmosphere (for moving or non-moving nests) and the ocean. The atmospheric ET is computed using wind, temperature, and moisture variables, while the oceanographic ET is derived from ocean current, temperature, and salinity variables. Estimates of analysis error covariance, which is used as a constraint in the ET, are provided by the ocean and atmosphere 3DVAR assimilation systems. The newly developed system has been successfully tested for a variety of configurations, including differing model resolution, number of members, forecast length, and moving and fixed nest options. Results from relatively coarse resolution (～27-km) ensemble simulations of Hurricanes Hanna and Ike demonstrate that the ensemble can provide valuable uncertainty information about the storm track and intensity, though the ensemble mean provides only a small amount of improved predictive skill compared to the deterministic control member.  相似文献   

Evaluation of River Water Quality Simulations at a Daily Time Step – Experience with SWAT in the Axe Catchment,UK     

Matjaž Glavan  Sue White  Ian P. Holman 《洁净——土壤、空气、水》2011,39(1):43-54

The Water Framework Directive (WFD) was established for the protection of surface waters (rivers, lakes, transitional and coastal waters) and ground waters in the European Union. The main environmental objective is to achieve and maintain a good status for all waters by the target date of 2015. Models which are able to address the majority of environmental objectives are proposed within the WFD to inform the management changes required to meet current water policy goals. The use of the Soil and Water Assessment Tool (SWAT) catchment model is widespread throughout the world, especially to support river basin management as required by the WFD. This paper provides a critical evaluation of the use of the model by placing model performance in the Axe catchment, UK, in the context of international performance of the model. Within the constraints of the available data, SWAT represents hydrology, sediment and ortho‐phosphorus concentration well for this heterogeneous catchment, but the representation of daily nitrogen concentration dynamics is poor. Temporal aggregation of model outputs from daily to monthly improved the performance metrics for all the river outputs, including nitrate. Wider review of SWAT studies showed widespread reporting of monthly performance metrics within the SWAT studies, despite the model operating at a daily time step. Poor performance for nitrate identified in this current study may be a significant factor in the choice to not report daily results. This demonstrates the importance of ascertaining the reasons for the use of temporal aggregation in modelling studies.  相似文献   

Solute geochemical mass-balances and mineral weathering rates in small watersheds II: Biomass nutrient uptake,more equations in more unknowns,and land use/land cover effects     

Jason R. Price  Christopher R. Hardy  Karen Sue Tefend  David W. Szymanski 《Applied Geochemistry》2012

Paired watersheds are used to develop a deciduous nutrient uptake stoichiometry. The watersheds are those of the House Rock Run and the Brubaker Run located in the Pennsylvania Appalachian Piedmont, USA. These two watersheds are nearly identical with respect to bedrock, regolith, climate, geomorphology, morphometry, baseflow hydrology, and type and successional stage of forest vegetation. They only differ by the percentage of deciduous forest cover, with House Rock Run having 59% and Brubaker Run having 76%. From differences in their stream chemistries the biomass nutrient uptake stoichiometry of K_1.0Mg_1.0Ca_1.4 was determined. This stoichiometry applies to an aggrading deciduous biomass and differs from those previously used which were derived from net primary production (NPP) data. The difference may reflect that macronutrients in plant tissue may also originate from atmospheric inputs and/or decomposing biomass. Although this stoichiometry may not be applied to all deciduous forest-covered watersheds, it is likely an improvement over a stoichiometry determined from NPP data.  相似文献   

The HIPASS catalogue – I. Data presentation     

M. J. Meyer  M. A. Zwaan  R. L. Webster  L. Staveley-Smith  E. Ryan-Weber  M. J. Drinkwater  D. G. Barnes  M. Howlett  V. A. Kilborn  J. Stevens  M. Waugh  M. J. Pierce  R. Bhathal  W. J. G. de Blok  M. J. Disney  R. D. Ekers  K. C. Freeman  D. A. Garcia  B. K. Gibson  J. Harnett  P. A. Henning  H. Jerjen  M. J. Kesteven  P. M. Knezek  B. S. Koribalski  S. Mader  M. Marquarding  R. F. Minchin  J. O'Brien  T. Oosterloo  R. M. Price  M. E. Putman  S. D. Ryder  E. M. Sadler  I. M. Stewart  F. Stootman  A. E. Wright 《Monthly notices of the Royal Astronomical Society》2004,350(4):1195-1209

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The HIPASS catalogue – II. Completeness, reliability and parameter accuracy     

M. A. Zwaan  M. J. Meyer  R. L. Webster  L. Staveley-Smith  M. J. Drinkwater  D. G. Barnes  R. Bhathal  W. J. G. de Blok  M. J. Disney  R. D. Ekers  K. C. Freeman  D. A. Garcia  B. K. Gibson  J. Harnett  P. A. Henning  M. Howlett  H. Jerjen  M. J. Kesteven  V. A. Kilborn  P. M. Knezek  B. S. Koribalski  S. Mader  M. Marquarding  R. F. Minchin  J. O'Brien  T. Oosterloo  M. J. Pierce  R. M. Price  M. E. Putman  E. Ryan-Weber  S. D. Ryder  E. M. Sadler  J. Stevens  I. M. Stewart  F. Stootman  M. Waugh  A. E. Wright 《Monthly notices of the Royal Astronomical Society》2004,350(4):1210-1219

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Evaluation of Urban Local-Scale Aerodynamic Parameters: Implications for the Vertical Profile of Wind Speed and for Source Areas   总被引：1，自引：1，他引：0  

Christoph W. Kent  Sue Grimmond  Janet Barlow  David Gatey  Simone Kotthaus  Fredrik Lindberg  Christos H. Halios 《Boundary-Layer Meteorology》2017,164(2):183-213

Nine methods to determine local-scale aerodynamic roughness length \((z_{0})\) and zero-plane displacement \((z_{d})\) are compared at three sites (within 60 m of each other) in London, UK. Methods include three anemometric (single-level high frequency observations), six morphometric (surface geometry) and one reference-based approach (look-up tables). A footprint model is used with the morphometric methods in an iterative procedure. The results are insensitive to the initial \(z_{d}\) and \(z_{0}\) estimates. Across the three sites, \(z_{d}\) varies between 5 and 45 m depending upon the method used. Morphometric methods that incorporate roughness-element height variability agree better with anemometric methods, indicating \(z_{d}\) is consistently greater than the local mean building height. Depending upon method and wind direction, \(z_{0}\) varies between 0.1 and 5 m with morphometric \(z_{0}\) consistently being 2–3 m larger than the anemometric \(z_{0}\). No morphometric method consistently resembles the anemometric methods. Wind-speed profiles observed with Doppler lidar provide additional data with which to assess the methods. Locally determined roughness parameters are used to extrapolate wind-speed profiles to a height roughly 200 m above the canopy. Wind-speed profiles extrapolated based on morphometric methods that account for roughness-element height variability are most similar to observations. The extent of the modelled source area for measurements varies by up to a factor of three, depending upon the morphometric method used to determine \(z_{d}\) and \(z_{0}\).  相似文献   

Long-range transport of Asian emissions to the West Pacific tropical tropopause layer     

Treadaway  Victoria  Atlas  Elliot  Schauffler  Sue  Navarro  Maria  Ueyama  Rei  Pfister  Leonhard  Thornberry  Troy  Rollins  Andrew  Elkins  James  Moore  Fred  Rosenlof  Karen 《Journal of Atmospheric Chemistry》2022,79(2):81-100

Journal of Atmospheric Chemistry - Rapid transport by deep convection is an important mechanism for delivering surface emissions of reactive halocarbons and other trace species to the tropical...  相似文献   

Lunar Beagle and Lunar Astrobiology     

Everett K. Gibson  Colin T. Pillinger  Lester J. Waugh 《Earth, Moon, and Planets》2010,107(1):25-42

The study of the elements and molecules of astrobiological interest on the Moon can be made with the Gas Analysis Package (GAP) and associated instruments developed for the Beagle 2 Mars Express Payload. The permanently shadowed polar regions of the Moon may offer a unique location for the “cold-trapping” of the light elements (i.e. H, C, N, O, etc.) and their simple compounds. Studies of the returned lunar samples have shown that lunar materials have undergone irradiation with the solar wind and adsorb volatiles from possible cometary and micrometeoroid impacts. The Beagle 2’s analytical instrument package including the sample processing facility and the GAP mass spectrometer can provide vital isotopic information that can distinguish whether the lunar volatiles are indigenous to the moon, solar wind derived, cometary in origin or from meteoroids impacting on the Moon. As future Lunar Landers are being considered, the suite of instruments developed for the Mars Beagle 2 lander can be consider as the baseline for any lunar volatile or resource instrument package.  相似文献   

Further evidence for the existence of sub‐littoral populations of toheroa,Amphidesma ventricosum Gray (eulamelli‐branchiata), off the west coast of New Zealand     

G. Duncan Waugh  J. P. Greenway 《新西兰海洋与淡水研究杂志》2013,47(4):407-411

The finding of shells of toheroa (Amphidesma ventricosum Gray) which had been drilled by gastropods absent from the littoral zone, is presented as evidence for the existence of sub‐littoral populations of toheroa.  相似文献   

Editorial     

Sue Wilkins 《新西兰海洋与淡水研究杂志》2013,47(4)

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