Dataset Identification:
Resource Abstract:
- description: Atmospheric blocking is commonly referred to as the situation when the normal zonal flow is interrupted by strong
and persistent meridional flow. The normal eastward progression of synoptic disturbances is obstructed leading to episodes
of prolonged extreme weather conditions. On intraseasonal time scales the persistent weather extremes can last from several
days up to a few weeks, often accompanied by significant temperature and precipitation anomalies. Numerous definitions of
blocking exist in the literature and all involve a level if subjectivity. We use the blocking index of Tibaldi and Molteni
(1990) modified from that of Lejenas and Okland (1983). This product displays the daily observed blocking index for the past
3 months up to and including the present day. Additionally, outlookss of the blocking index and the 500 hPa geopotential height
field anomalies are generated form the NCEP Global Forecast System (GFS) model. The outlooks mare displayed for days 1-9 for
both the northern and southern Hemispheres. The product is not archived so a historical time series is not available. To produce
a time series it is recommended that the methodology of Tibaldi and Molteni (1990) be applied using the reanalysis dataset
of choice. Blocking frequency over the 1950-2000 time period and composites as a function of ENSO phase are also provided.;
abstract: Atmospheric blocking is commonly referred to as the situation when the normal zonal flow is interrupted by strong
and persistent meridional flow. The normal eastward progression of synoptic disturbances is obstructed leading to episodes
of prolonged extreme weather conditions. On intraseasonal time scales the persistent weather extremes can last from several
days up to a few weeks, often accompanied by significant temperature and precipitation anomalies. Numerous definitions of
blocking exist in the literature and all involve a level if subjectivity. We use the blocking index of Tibaldi and Molteni
(1990) modified from that of Lejenas and Okland (1983). This product displays the daily observed blocking index for the past
3 months up to and including the present day. Additionally, outlookss of the blocking index and the 500 hPa geopotential height
field anomalies are generated form the NCEP Global Forecast System (GFS) model. The outlooks mare displayed for days 1-9 for
both the northern and southern Hemispheres. The product is not archived so a historical time series is not available. To produce
a time series it is recommended that the methodology of Tibaldi and Molteni (1990) be applied using the reanalysis dataset
of choice. Blocking frequency over the 1950-2000 time period and composites as a function of ENSO phase are also provided.
Citation
- Title Climate Prediction Center (CPC) Northern and Southern Hemisphere Blocking Index.
-
- creation Date
2016-02-26T22:16:23.224269
Resource language:
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Metadata data stamp:
2018-08-06T22:19:04Z
Resource Maintenance Information
- maintenance or update frequency:
- notes: This metadata record was generated by an xslt transformation from a dc metadata record; Transform by Stephen M. Richard, based
on a transform by Damian Ulbricht. Run on 2018-08-06T22:19:04Z
Metadata contact
-
pointOfContact
- organisation Name
CINERGI Metadata catalog
-
- Contact information
-
-
- Address
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- electronic Mail Address cinergi@sdsc.edu
Metadata language
eng
Metadata character set encoding:
utf8
Metadata standard for this record:
ISO 19139 Geographic Information - Metadata - Implementation Specification
standard version:
2007
Metadata record identifier:
urn:dciso:metadataabout:bbdd9009-5444-40bb-9626-b78acd583da4
Metadata record format is ISO19139 XML (MD_Metadata)