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91.
Randy Johnson Steven Businger Annette Baerman 《Tellus. Series B, Chemical and physical meteorology》2000,52(2):321-334
A 3rd‐generation smart balloon designed at National Oceanic and Atmospheric Administration, Air Resources Laboratory Field Research Division, in collaboration with the University of Hawaii, was released from ship‐board during the recent Second Aerosol Characterization Experiment (ACE‐2) to provide Lagrangian air‐mass tracking data. ACE‐2 is the 3rd in a series of field experiments designed to study the chemical, physical, and radiative properties and processes of atmospheric aerosols and their role in climate and is organized by the international global atmospheric chemistry (IGAC) program. The adjective smart in the title of this paper refers to the fact that the buoyancy of the balloon automatically adjusts through the act of pumping air into or releasing air from the ballast portion of the balloon when it travels vertically outside a barometric pressure range set prior to release. The smart balloon design provides GPS location, barometric pressure, temperature, relative humidity, and other data via a transponder to a C130 research aircraft flying in the vicinity of the balloon. The addition of 2‐way communication allows interactive control of the balloon operating parameters by an observer. A total of 3 cloudy Lagrangian experiments were conducted during the ACE‐2 field program which lasted from 16 June through 26 July 1997. This paper reviews the design and capability of the smart balloons and their performance during the ACE‐2 Lagrangian experiments. Future development and applications of the technology are discussed. 相似文献
92.
Urban Water Management vs. Climate Change: Impacts on Cold Region Waste Water Inflows 总被引:1,自引:0,他引:1
Annette Semadeni-Davies 《Climatic change》2004,64(1-2):103-126
Failure to account for non-climatic changes to water systems, such as design and operation, within climate change impact assessments leads to misconceptions because these activities buffer the human built enviroment from bio-physical impacts. Urban drainage in cold regions, which is dominated by snowmelt, is especially vulnerable to climate change and is investigated in this paper within the context of future rehabilitation of the sewer network. The objectives are to illustrate the relative response of urban drainage to changes in both the pipe network and climate and demonstrate the use of response surfaces for climate change studies. An incremental climate scenario approach is used to generate two sensitivity analyses for waste water inflows to the Lycksele waste water treatment plant in north-central Sweden. Air temperature and precipitation data (1984–1993) are altered incrementally between –5 and +15 °C and –10 and +40% respectively. These data are then used to drive a hydrological transformation model to obtain estimates of sewer infiltration from groundwater. The results are presented as winter and spring response surfaces – these are graphical representations of a response matrix where each point relates to a single model run. Climate scenario envelopes which summarise a series of GCM runs (ACACIA; Carter, 2002, pers. comm.) are overlaid to indicate the range of plausible waste water inflows. Estimates of natural multi-decadal variability are also included. The first sensitivity analysis assumes no change to the drainage system while the second simulates sewer renovation in which the system is fully separated and sewer infiltration is reduced. The main conclusions are that innovations in drainage network technology have a greater potential to alter waste water inflows than climate change and that, while the direction of climate change is fairly certain, there is great uncertainty surrounding magnitude of those changes and their impacts. 相似文献
93.
Annette Spies Elaine D. Nutbrown Timothy R. Parsons 《Estuarine, Coastal and Shelf Science》1983,17(1):97-105
An experimental approach was used in determining which factors, natural or man made, had the greatest impact on estuarine microplankton ecology. In microcosms, filled with natural water of <5‰, 10‰, 18‰ and > 26‰ salinity, the impact of high organic load (glucose), shading, Cu and a heavy metal mixture on the microplankton populations was monitored. Naturally occurring perturbations were of much greater impact to estuarine ecology than the addition of heavy metals in concentrations five to ten times that which are known to occur in moderately polluted estuaries. 相似文献
94.
An evaluation of Arctic cloud and radiation processes during the SHEBA year: simulation results from eight Arctic regional climate models 总被引:1,自引:1,他引:0
K. Wyser C. G. Jones P. Du E. Girard U. Willén J. Cassano J. H. Christensen J. A. Curry K. Dethloff J.-E. Haugen D. Jacob M. Køltzow R. Laprise A. Lynch S. Pfeifer A. Rinke M. Serreze M. J. Shaw M. Tjernström M. Zagar 《Climate Dynamics》2008,30(2-3):203-223
Eight atmospheric regional climate models (RCMs) were run for the period September 1997 to October 1998 over the western Arctic
Ocean. This period was coincident with the observational campaign of the Surface Heat Budget of the Arctic Ocean (SHEBA) project.
The RCMs shared common domains, centred on the SHEBA observation camp, along with a common model horizontal resolution, but
differed in their vertical structure and physical parameterizations. All RCMs used the same lateral and surface boundary conditions.
Surface downwelling solar and terrestrial radiation, surface albedo, vertically integrated water vapour, liquid water path
and cloud cover from each model are evaluated against the SHEBA observation data. Downwelling surface radiation, vertically
integrated water vapour and liquid water path are reasonably well simulated at monthly and daily timescales in the model ensemble
mean, but with considerable differences among individual models. Simulated surface albedos are relatively accurate in the
winter season, but become increasingly inaccurate and variable in the melt season, thereby compromising the net surface radiation
budget. Simulated cloud cover is more or less uncorrelated with observed values at the daily timescale. Even for monthly averages,
many models do not reproduce the annual cycle correctly. The inter-model spread of simulated cloud-cover is very large, with
no model appearing systematically superior. Analysis of the co-variability of terms controlling the surface radiation budget
reveal some of the key processes requiring improved treatment in Arctic RCMs. Improvements in the parameterization of cloud
amounts and surface albedo are most urgently needed to improve the overall performance of RCMs in the Arctic. 相似文献
95.
Ralf Srama Thomas Stephan Eberhard Grün Norbert Pailer Anton Kearsley Amara Graps Rene Laufer Pascale Ehrenfreund Nicolas Altobelli Kathrin Altwegg Siegfried Auer Jack Baggaley Mark J. Burchell James Carpenter Luigi Colangeli Francesca Esposito Simon F. Green Hartmut Henkel Mihaly Horanyi Annette Jäckel Sascha Kempf Neil McBride Georg Moragas-Klostermeyer Harald Krüger Pasquale Palumbo Andre Srowig Mario Trieloff Peter Tsou Zoltan Sternovsky Oliver Zeile Hans-Peter Röser 《Experimental Astronomy》2009,23(1):303-328
The scientific community has expressed strong interest to re-fly Stardust-like missions with improved instrumentation. We
propose a new mission concept, SARIM, that collects interstellar and interplanetary dust particles and returns them to Earth.
SARIM is optimised for the collection and discrimination of interstellar dust grains. Improved active dust collectors on-board
allow us to perform in-situ determination of individual dust impacts and their impact location. This will provide important
constraints for subsequent laboratory analysis.
The SARIM spacecraft will be placed at the L2 libration point of the Sun–Earth system, outside the Earth’s debris belts and
inside the solar-wind charging environment. SARIM is three-axes stabilised and collects interstellar grains between July and
October when the relative encounter speeds with interstellar dust grains are lowest (4 to 20 km/s). During a 3-year dust collection
period several hundred interstellar and several thousand interplanetary grains will be collected by a total sensitive area
of 1 m2. At the end of the collection phase seven collector modules are stored and sealed in a MIRKA-type sample return capsule.
SARIM will return the capsule containing the stardust to Earth to allow for an extraction and investigation of interstellar
samples by latest laboratory technologies. 相似文献
96.
Eberhard Grün Ralf Srama Nicolas Altobelli Kathrin Altwegg James Carpenter Luigi Colangeli Karl-Heinz Glassmeier Stefan Helfert Hartmut Henkel Mihaly Horanyi Annette Jäckel Sascha Kempf Markus Landgraf Neil McBride Georg Moragas-Klostermeyer Pasquale Palumbo Han Scholten Andre Srowig Zoltan Sternovsky Xavier Vo 《Experimental Astronomy》2009,23(3):981-999
The DuneXpress observatory will characterize interstellar and interplanetary dust in-situ, in order to provide crucial information
not achievable with remote sensing astronomical methods. Galactic interstellar dust constitutes the solid phase of matter
from which stars and planetary systems form. Interplanetary dust, from comets and asteroids, represents remnant material from
bodies at different stages of early solar system evolution. Thus, studies of interstellar and interplanetary dust with DuneXpress
in Earth orbit will provide a comparison between the composition of the interstellar medium and primitive planetary objects.
Hence DuneXpress will provide insights into the physical conditions during planetary system formation. This comparison of
interstellar and interplanetary dust addresses directly themes of highest priority in astrophysics and solar system science,
which are described in ESA’s Cosmic Vision. The discoveries of interstellar dust in the outer and inner solar system during
the last decade suggest an innovative approach to the characterization of cosmic dust. DuneXpress establishes the next logical
step beyond NASA’s Stardust mission, with four major advancements in cosmic dust research: (1) analysis of the elemental and
isotopic composition of individual interstellar grains passing through the solar system, (2) determination of the size distribution
of interstellar dust at 1 AU from 10 − 14 to 10 − 9 g, (3) characterization of the interstellar dust flow through the planetary system, (4) establish the interrelation of interplanetary
dust with comets and asteroids. Additionally, in supporting the dust science objectives, DuneXpress will characterize dust
charging in the solar wind and in the Earth’s magnetotail. The science payload consists of two dust telescopes of a total
of 0.1 m2 sensitive area, three dust cameras totaling 0.4 m2 sensitive area, and a nano-dust detector. The dust telescopes measure high-resolution mass spectra of both positive and negative
ions released upon impact of dust particles. The dust cameras employ different detection methods and are optimized for (1)
large area impact detection and trajectory analysis of submicron sized and larger dust grains, (2) the determination of physical
properties, such as flux, mass, speed, and electrical charge. A nano-dust detector searches for nanometer-sized dust particles
in interplanetary space. A plasma monitor supports the dust charge measurements, thereby, providing additional information
on the dust particles. About 1,000 grains are expected to be recorded by this payload every year, with 20% of these grains
providing elemental composition. During the mission submicron to micron-sized interstellar grains are expected to be recorded
in statistically significant numbers. DuneXpress will open a new window to dusty universe that will provide unprecedented
information on cosmic dust and on the objects from which it is derived. 相似文献
97.
Achim?KopfEmail author Annette?Deyhle Vasili?Y.?Lavrushin Boris?G.?Polyak Joris?M.?Gieskes Guram?I.?Buachidze Klaus?Wallmann Anton?Eisenhauer 《International Journal of Earth Sciences》2003,92(3):407-425
The Caucasian orogenic wedge formed as a consequence of the closure of the Tethyan Ocean, and numerous fields of active mud volcanoes pepper the area adjacent to the Black and Caspian Seas. Stable isotope ratios of boron, helium, and carbon have been measured for gas, fluid and sediment samples from active mud volcanoes of Taman Peninsula and Georgia to estimate the sources and mobilization depths of the fluid phase and mud. Boron concentrations in mud volcano fluids were found to be 5–35× higher than seawater. Fluid isotope ratios vary between 11B=22 and 39, while isotope ratios of the smectite- and illite-rich extruded mud are considerably depleted in heavy 11B (11B=–8 to +7). B contents of these muds are ~8× higher than modern marine sediments. This suggests that liquefaction prior to mud volcanism was accompanied by both B enrichment and isotope fractionation, most likely at an intermediate depth mud reservoir at 2–4 km.The hydrocarbon-generating source beds to the mud volcanoes are located at 7 to >10 km depth in the folded Maikop Formation and are of proposed Oligocene–Miocene age. The most likely mechanism is re-hydration of these shales by both hydrocarbons and a geochemically mature fluid from greater depth within the orogenic wedge. Such a deep fluid source is supported by our results from gas analyses, which imply an admixture of minor amounts (less than 1%vol) of 3He (Georgia), thermogenic 13C in methane as well as "ultraheavy" 13C in CO2 (both Taman and Georgia). The overall results attest active local flow of geochemically different fluids along deep-seated faults penetrating the two study areas in the Caucasian orogenic wedge, with the waters as well as the gases coming from below the Maikop Formation. 相似文献
98.
Annette E. Götz Joachim Szulc Susanne Feist-Burkhardt 《International Journal of Earth Sciences》2005,94(2):267-274
The stratigraphic distribution of sedimentary organic matter in Anisian carbonate series of southern Poland is studied with respect to relative sea-level fluctuations. Palynofacies patterns clearly reflect transgressive–regressive trends that are interpreted in terms of third-order cyclicity. Major flooding phases are detected by maximum abundance of marine plankton in the upper Bithynian and Pelsonian. Transgressive and highstand deposits are recognized by changes in the terrestrial input of organic particles and the relative percentages and diversity of the plankton group. The palynological data support the sequence stratigraphic interpretation based on sedimentological features and geochemical signatures. The corresponding eustatic signals of sedimentary and organic facies are discussed. The study highlights the potential of palynofacies analysis for sequence stratigraphical interpretation. 相似文献
99.
Michael Schmidt Martin Fengler Torsten Mayer-Gürr Annette Eicker Jürgen Kusche Laura Sánchez Shin-Chan Han 《Journal of Geodesy》2007,81(1):17-38
This article provides a survey on modern methods of regional gravity field modeling on the sphere. Starting with the classical
theory of spherical harmonics, we outline the transition towards space-localizing methods such as spherical splines and wavelets.
Special emphasis is given to the relations among these methods, which all involve radial base functions. Moreover, we provide
extensive applications of these methods and numerical results from real space-borne data of recent satellite gravity missions,
namely the Challenging Minisatellite Payload (CHAMP) and the Gravity Recovery and Climate Experiment (GRACE). We also derive
high-resolution gravity field models by effectively combining space-borne and surface measurements using a new weighted level-combination
concept. In addition, we outline and apply a strategy for constructing spatio-temporal fields from regional data sets spanning
different observation periods. 相似文献
100.
Distinctive, metre‐scale antiformal structures are well developed in a Famennian carbonate platform in the Chedda Cliffs area of the Lennard Shelf reef complexes. The structures are distinguished by chevron‐shaped crests and thickened cores and contain abundant non‐skeletal allochems (ooids/pisoids, peloids and intraclasts) of silt to pebble size and variably developed laminations and fenestrae. The internal morphology and pervasive occurrence of fenestral clotted and wavy laminated fabrics suggest that these structures are microbial mounds composed of agglutinated stromatolites and thrombolites. Microbial fabrics most probably originated through sediment trapping and binding by microbial mats with early lithification involving microbial calcification and cementation of trapped sediment. The facies and stratigraphic context of the mounds support a shallow subtidal, transitional backreef to reef‐flat setting; however, alone these mounds do not provide unequivocal environmental information. Other large antiformal structures in Famennian platforms on the Lennard Shelf, previously described as tepee structures, show morphological similarities to the Chedda Cliffs mounds, which suggests that these other structures may also be microbial mounds. The presence of microbial mounds in platform successions further highlights the importance of microbial communities in the Lennard Shelf reef complexes. 相似文献