<div class="eI0">
  <div class="eI1">Modell:</div>
  <div class="eI2"><h2><a href="http://polar.ncep.noaa.gov/" target="_blank">WAVEWATCH III</a> Environmental Modeling Center</h2></div>
 </div>
 <div class="eI0">
  <div class="eI1">Aktualisierung:</div>
  <div class="eI2">4 times per day, from 0:00, 05:00, 11:00 and 17:00 UTC</div>
 </div>
 <div class="eI0">
  <div class="eI1">Greenwich Mean Time:</div>
  <div class="eI2">12:00 UTC = 13:00 MEZ</div>
 </div>
 <div class="eI0">
  <div class="eI1">Aufl&ouml;sung:</div>
  <div class="eI2">0.0833&deg; x 0.0833&deg;</div>
 </div>
 <div class="eI0">
  <div class="eI1">Parameter:</div>
  <div class="eI2">Sea surface temperature</div>
 </div>
 <div class="eI0">
  <div class="eI1">Beschreibung:</div>
  <div class="eI2">

    
  </div>
 </div>
  <div class="eI0">
   <div class="eI1">SST:</div>
   <div class="eI2">
A daily, high-resolution, real-time, global, sea surface temperature (RTG_SST) analysis has been developed at the National Centers for Environmental Prediction/Marine Modeling and Analysis Branch (NCEP / MMAB). The analysis was implemented in the NCEP parallel production suite 16 August 2005. It became fully operational on September 27, 2005.
<br>
The daily sea surface temperature product is produced on a twelfth-degree (latitude, longitude) grid, with a two-dimensional variational interpolation analysis of the most recent 24-hours buoy and ship data, satellite-retrieved SST data, and SST's derived from satellite-observed sea-ice coverage. The algorithm employs the following data-handling and analysis techniques:
<br>
Satellite retrieved SST values are averaged within 1/12 o grid boxes with day and night 'superobs' created separately for each satellite;
<br>
Bias calculation and removal, for satellite retrieved SST, is the technique employed in the 7-day Reynolds-Smith climatological analysis;
<br>
Currently, the satellite SST retrievals are generated by a physically-based algorithm from the Joint Center for Satellite Data Assimilation. Retrievals are from NOAA-17 and NOAA-18 AVHRR data;
<br>
SST reports from individual ships and buoys are separately averaged within grid boxes;
<br>
The first-guess is the prior (un-smoothed) analysis with one-day's climate adjustment added;
<br>
Late-arriving data which did not make it into the previous SST analysis are accepted if they are less than 36 hours old;
<br>
Surface temperature is calculated for water where the ice cover exceeds 50%, using salinity climatology in Millero's formula for the freezing point of salt water:
<br>
t(S) = -0.0575 S + 0.0017 S3/2 - 0.0002 S2, 
<br>
with S in psu.
<br>
An inhomogeneous correlation-scale-parameter l, for the correlation function: exp(-d2/l2) , is calculated from a climatological temperature gradient, as
<br>
l = min ( 450 , max( 2.25 / |grad T| , 100 )), 
<br>
with d and l in kilometers. "grad T" is in oC / km
<br>
Evaluations of the analysis products have shown it to produce realistically tight gradients in the Gulf Stream regions of the Atlantic and the Kuroshio region of the Pacific, and to be in close agreement with SST reports from moored buoys in both oceans. Also, it has been shown to properly depict the wintertime colder shelf water -- a feature critical in getting an accurate model prediction for coastal winter storms.
 </div></div>
 <div class="eI0">
  <div class="eI1">NWP:</div>
  <div class="eI2">Numerische Wettervorhersagen sind rechnergest&uuml;tzte Wettervorhersagen. Aus dem Zustand der Atmosph&auml;re zu einem gegebenen Anfangszeitpunkt wird durch numerische L&ouml;sung der relevanten Gleichungen der Zustand zu sp&auml;teren Zeiten berechnet. Diese Berechnungen umfassen teilweise mehr als 14 Tage und sind die Basis aller heutigen Wettervorhersagen.<br><br>
In einem solchen numerischen Vorhersagemodell wird das Rechengebiet mit Gitterzellen und/oder durch eine spektrale Darstellung diskretisiert, so dass die relevanten physikalischen Gr&ouml;&szlig;en, wie vor allem Temperatur, Luftdruck, Windrichtung und Windst&auml;rke, im dreidimensionalen Raum und als Funktion der Zeit dargestellt werden k&ouml;nnen. Die physikalischen Beziehungen, die den Zustand der Atmosph&auml;re und seine Ver&auml;nderung beschreiben, werden als System partieller Differentialgleichungen modelliert. Dieses dynamische System wird mit Verfahren der Numerik, welche als Computerprogramme meist in Fortran implementiert sind, n&auml;herungsweise gel&ouml;st. Aufgrund des gro&szlig;en Aufwands werden hierf&uuml;r h&auml;ufig Supercomputer eingesetzt.<br><br>
<br>Seite „Numerische Wettervorhersage“. In: Wikipedia, Die freie Enzyklop&auml;die. Bearbeitungsstand: 21. Oktober 2009, 21:11 UTC. URL: <a href="http://de.wikipedia.org/w/index.php?title=Numerische_Wettervorhersage&amp;oldid=65856709" target="_blank">http://de.wikipedia.org/w/index.php?title=Numerische_Wettervorhersage&oldid=65856709</a> (Abgerufen: 9. Februar 2010, 20:46 UTC) <br>
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