GLORIA

GEOMAR Library Ocean Research Information Access

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    facet.materialart.
    Unbekannt
    Korrelationsfunktionen des Windes auf See im synoptischen bis kleinräumigen Bereich (1992)
    Deutscher Wetterdienst
    In:  Annalen der Meteorologie, 27 . pp. 15-16.
    Details
    Publikationsdatum: 2018-03-01
    Materialart: Article , PeerReviewed
    Format: text
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OceanRep: Artikel in einer Fachzeitschrift - begutachtet
  • 2
    facet.materialart.
    Unbekannt
    Spatial scales of surface wind observations and analysed wind fields over the North Atlantic Ocean (1995)
    Elsevier
    In:  Journal of Marine Systems, 6 (1-2). pp. 67-75.
    Details
    Publikationsdatum: 2018-08-08
    Beschreibung: It is well known that spatial scales of oceanic eddies are smaller than scales of atmospheric eddies. Since the spectral distribution of kinetic energy of atmospheric eddies may influence the properties of wind driven oceanic eddies, an excellent resolution of small scale variability of wind fields used as input fields of coupled models of atmosphere and ocean is necessary. Analysis of spatial scales of atmospheric fields is done in terms of spectral energy densities. These are determined in two different ways: directly from objectively analysed fields or by using spatial correlation functions of direct observations averaged for 20 km × 20 km boxes. In the spectral range of wavelengths of less than 1000 km spectral energy densities of analysed fields have lost about 15 to 50% of the variance compared to direct observations. A considerable part of this loss of the variance depends on smoothing done by interpolation schemes themselves. Concerning problems of air-sea interaction care should be taken also to avoid that systematic errors of analysed wind fields lead to systematic errors in turbulent exchange. It is shown that high observed wind speeds are considerably underestimated in analysed fields of numerical models of weather prediction.
    Materialart: Article , PeerReviewed
    Format: text
    DOI: 10.1016/0924-7963(95)90267-H
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OceanRep: Artikel in einer Fachzeitschrift - begutachtet
  • 3
    facet.materialart.
    Unbekannt
    Sea surface wind stress and drag coefficients: The hexos results (1992)
    Springer
    In:  Boundary-Layer Meteorology, 60 (1-2). pp. 109-142.
    Details
    Publikationsdatum: 2018-03-09
    Beschreibung: Turbulent fluxes have been measured in the atmospheric surface layer from a boom extending upwind from the Dutch offshore research platform Meetpost Noordwijk (MPN) during HEXMAX (Humidity Exchange over the Sea Main Experiment) in October–November, 1986. We started out to study eddy flux of water vapour, but discrepancies among simultaneous measurements made with three different anemometers led us to develop methods to correct eddy correlation measurements of wind stress for flow distortion by nearby objects. We then found excellent agreement among the corrected wind stress data sets from the three anemometers on the MPN boom and with eddy correlation measurements from a mast on a tripod. Inertial-dissipation techniques gave reliable estimates of wind stress from turbulence spectra, both at MPN and at a nearby ship. The data cover a range of wave ages and the results yield new insights into the variation of sea surface wind stress with sea state; two alternative formulas are given for the nondimensional surface roughness as a function of wave age.
    Materialart: Article , PeerReviewed
    Format: text
    DOI: 10.1007/BF00122064
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OceanRep: Artikel in einer Fachzeitschrift - begutachtet
  • 4
    facet.materialart.
    Unbekannt
    Synoptic-Scale Behavior of the Extratropical Tropopause Inversion Layer (2015)
    AGU (American Geophysical Union) | Wiley
    In:  Geophysical Research Letters, 42 (22). 10,018-10,026.
    Details
    Publikationsdatum: 2020-11-04
    Beschreibung: Key Points: Daily snapshots of TIL strength; synoptic-Scale behavior of the TIL and shear/curl contributions to relative vorticity; TIL within ridges in midlatitude winter is stronger than polar summer TIL High-resolution GPS radio occultation temperature profiles from the COSMIC satellite mission (2007–2013) are used to obtain daily snapshots of the strength of the extratropical tropopause inversion layer (TIL). Its horizontal structure and day-to-day variability are linked to the synoptic situation at near-tropopause level. The strength of the TIL in cyclonic as well as anticyclonic conditions is investigated by separating relative vorticity into curl and shear terms. The analysis shows that the TIL has high zonal variability, and its strength is instantaneously adjusted to the synoptic situation at near-tropopause level. Our key finding is that the TIL within midlatitude ridges in winter is as strong as or stronger than the TIL in polar summer. The strongest TIL in anticyclonic conditions is related to the shear term, while the weaker TIL in cyclonic conditions is enhanced by the curl term.
    Materialart: Article , PeerReviewed
    Format: text
    DOI: 10.1002/2015GL066409
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OceanRep: Artikel in einer Fachzeitschrift - begutachtet
  • 5
    facet.materialart.
    Unbekannt
    Validation of ERA-Interim Precipitation Estimates over the Baltic Sea (2016)
    MDPI
    In:  Atmosphere, 7 (6). p. 82.
    Details
    Publikationsdatum: 2019-06-05
    Beschreibung: European Centre for Medium-Range Weather Forecasts (ECMWF) ERA-Interim reanalysis total precipitation estimates are validated against ten years of in situ precipitation measurements onboard of ships over the Baltic Sea. A statistical analysis for binary forecasts and mean rain rates derived from all data show a good agreement with observations. However, a closer look reveals an underestimation of ERA-Interim total precipitation in spring and an overestimation in autumn, obviously related to stability. Deriving stability and evaporation by a bulk flux scheme it could be shown, in fact, that ERA-Interim underestimates precipitation for conditions with low evaporation and strongly overestimates it for conditions with high evaporation. Since ERA-Interim surface fields become too dry with increasing evaporation compared to independent synoptic ship observations, uncertainties in the ECMWF convection scheme may possibly cause these biases in seasonal precipitation.
    Materialart: Article , PeerReviewed
    Format: text
    DOI: 10.3390/atmos7060082
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OceanRep: Artikel in einer Fachzeitschrift - begutachtet
  • 6
    facet.materialart.
    Unbekannt
    Measured and Parameterized Energy Fluxes estimated for Atlantic Transects of R/V Polarstern (2014)
    AMS (American Meteorological Society)
    In:  Journal of Physical Oceanography, 44 (2). pp. 482-491.
    Details
    Publikationsdatum: 2020-08-04
    Beschreibung: Sensible and latent heat fluxes were estimated from turbulence measurements gathered during several Atlantic transects of the R/V Polarstern. The inertial dissipation method was used to analyze the data. Resulting bulk transfer coefficients were then applied to the data from the ship’s meteorological system to get continuous time series of the heat fluxes. Combined to the measured downward solar and longwave radiation fluxes allows for an estimate of the total energy budget at the air-sea interface. Comparing these parameterized energy fluxes to ones based on the COARE 3.0 bulk flux algorithm show very strong agreement.
    Materialart: Article , PeerReviewed
    Format: text
    DOI: 10.1175/JPO-D-13-0152.1
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OceanRep: Artikel in einer Fachzeitschrift - begutachtet
  • 7
    facet.materialart.
    Unbekannt
    Testing a polarimetric cloud imager aboard research vessel Polarstern: comparison of color-based and polarimetric cloud detection algorithms (2015)
    Optical Society of America
    In:  Applied Optics, 54 (5). pp. 1065-1077.
    Details
    Publikationsdatum: 2018-06-20
    Beschreibung: Cloud cover estimation is an important part of routine meteorological observations. Cloudiness measurements are used in climate model evaluation, nowcasting solar radiation, parameterizing the fluctuations of sea surface insolation, and building energy transfer models of the atmosphere. Currently, the most widespread ground-based method to measure cloudiness is based on analyzing the unpolarized intensity and color distribution of the sky obtained by digital cameras. As a new approach, we propose that cloud detection can be aided by the additional use of skylight polarization measured by 180° field-of-view imaging polarimetry. In the fall of 2010, we tested such a novel polarimetric cloud detector aboard the research vessel Polarstern during expedition ANT-XXVII/1. One of our goals was to test the durability of the measurement hardware under the extreme conditions of a trans-Atlantic cruise. Here, we describe the instrument and compare the results of several different cloud detection algorithms, some conventional and some newly developed. We also discuss the weaknesses of our design and its possible improvements. The comparison with cloud detection algorithms developed for traditional nonpolarimetric full-sky imagers allowed us to evaluate the added value of polarimetric quantities. We found that (1) neural-network-based algorithms perform the best among the investigated schemes and (2) global information (the mean and variance of intensity), nonoptical information (e.g., sun-view geometry), and polarimetric information (e.g., the degree of polarization) improve the accuracy of cloud detection, albeit slightly.
    Materialart: Article , PeerReviewed
    Format: text
    DOI: 10.1364/AO.54.001065
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OceanRep: Artikel in einer Fachzeitschrift - begutachtet
  • 8
    facet.materialart.
    Unbekannt
    Summer upwelling at the Boknis Eck time series station (1982 to 2012) - a combined glider and wind data analysis (2014)
    Copernicus Publications (EGU)
    In:  Biogeosciences (BG), 11 . pp. 3603-3617.
    Details
    Publikationsdatum: 2019-05-23
    Beschreibung: Two consecutive summer upwelling events, each lasting for less than 24 h, were surveyed in high temporal and vertical resolution close to the Boknis Eck time-series station (BE) in the western Belt Sea (Baltic Sea) in summer 2010 with an autonomous glider. Driven only by moderate offshore winds both events resulted in more than 5 K cooling of surface waters, while only for the second event were significant irreversible changes in the vertical stratification observed. Generalizing the glider survey observations with hourly wind data from nearby meteorological stations, it is found that upwelling in the BE area occurs for wind directions between 190 to 260° and wind speed exceeding 4 m s−1. Based on these thresholds the wind-induced summer (June to September) upwelling conditions in the BE area for the period 1982 to 2012 are reconstructed. On average about 18 days of upwelling favourable wind conditions are found for the four summer months, with significant interannual variability ranging from 7.7 days (2006) to more than 28 days (1985). By aligning upwelling favourable wind conditions with the monthly BE surveys it is found that extreme anomalies in BE surveys follow extended periods of upwelling favourable winds.
    Materialart: Article , PeerReviewed , info:eu-repo/semantics/article
    Format: text
    DOI: 10.5194/bg-11-3603-2014
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OceanRep: Artikel in einer Fachzeitschrift - begutachtet
  • 9
    facet.materialart.
    Unbekannt
    Ground validation of oceanic snowfall detection in satellite climatologies during LOFZY (2010)
    Taylor & Francis
    In:  Tellus A: Dynamic meteorology and oceanography, 62 (4). pp. 469-480.
    Details
    Publikationsdatum: 2016-06-15
    Beschreibung: A thorough knowledge of global ocean precipitation is an indispensable prerequisite for the understanding of the water cycle in the global climate system. However, reliable detection of precipitation over the global oceans, especially of solid precipitation, remains a challenging task. This is true for both, passive microwave remote sensing and reanalysis based model estimates. The optical disdrometer ODM 470 is a ground validation instrument capable of measuring rain and snowfall on ships even under high wind speeds. It was used for the first time over the Nordic Seas during the LOFZY 2005 campaign. A dichotomous verification of precipitation occurrence resulted in a perfect correspondence between the disdrometer, a precipitation detector and a shipboard observer's log. The disdrometer data is further point-to-area collocated against precipitation from the satellite based Hamburg Ocean Atmosphere Parameters and fluxes from Satellite data (HOAPS) climatology. HOAPS precipitation turns out to be overall consistent with the disdrometer data resulting in a detection accuracy of 0.96. The collocated data comprises light precipitation events below 1 mm h–1. Therefore two LOFZY case studies with high precipitation rates are presented that indicate plausible HOAPS satellite precipitation rates. Overall, this encourages longer term measurements of ship-to-satellite collocated precipitation in the near future.
    Materialart: Article , PeerReviewed
    Format: text
    DOI: 10.1111/j.1600-0870.2010.00459.x
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OceanRep: Artikel in einer Fachzeitschrift - begutachtet
  • 10
    facet.materialart.
    Unbekannt
    HOAPS precipitation validation with ship-borne rain gauge measurements over the Baltic Sea (2012)
    Taylor & Francis
    In:  Tellus A: Dynamic meteorology and oceanography, 64 (18486).
    Details
    Publikationsdatum: 2016-06-14
    Beschreibung: Global ocean precipitation is an important part of the water cycle in the climate system. A number of efforts have been undertaken to acquire reliable estimates of precipitation over the oceans based on remote sensing and reanalysis modelling. However, validation of these data is still a challenging task, mainly due to a lack of suitable in situ measurements of precipitation over the oceans. In this study, validation of the satellite-based Hamburg Ocean Atmosphere Parameters and fluxes from Satellite data (HOAPS) climatology was conducted with in situ measurements by ship rain gauges over the Baltic Sea from 1995 to 1997. The ship rain gauge data are point-to-area collocated against the HOAPS data. By choosing suitable collocation parameters, a detection rate of up to about 70% is achieved. Investigation of the influence of the synoptic situation on the detectability shows that HOAPS performs better for stratiform than for convective precipitation. The number of collocated data is not sufficient to validate precipitation rates. Thus, precipitation rates were analysed by applying an interpolation scheme based on the Kriging method to both data sets. It was found that HOAPS underestimates precipitation by about 10%, taking into account that precipitation rates below 0.3 mm h−1 cannot be detected from satellite information.
    Materialart: Article , PeerReviewed
    Format: text
    DOI: 10.3402/tellusa.v64i0.18486
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OceanRep: Artikel in einer Fachzeitschrift - begutachtet
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...