[Parameters: Topic='PALEOCLIMATE', Term='LAND RECORDS', Variable_Level_1='VOLCANIC DEPOSITS']
Volcanic Loading: The Dust Veil Index, CDIAC NDP-013Entry ID: CDIAC_NDP13
Abstract: Lamb (1970) formulated the Dust Veil Index (DVI) in an attempt to quantify the
impact on the Earth's energy balance of changes in atmospheric composition due
to explosive volcanic eruptions. The DVI is a numerical index that quantifies
the impact of a particular volcanic eruption's release of dust and aerosols
over the years following the event. This package provides DVI's for the period
1500 - ... 1983 (DVI = 1,000 for Krakatoa in 1883), along with DVI estimates for
the eruptions of Santorin in 1470 B.C., Vesuvius in 79 A.D., and Oraefajokull
in 1362 A.D.
Dust ejected into the high atmosphere during explosive volcanic eruptions has
been considered a possible cause for climatic change. Dust veils created by
volcanic eruptions can reduce the amount of light reaching the Earth's surface
and can cause reductions in surface temperatures. These climatic effects can be
seen for several years following some eruptions and the magnitude and duration
of the effects depend largely on the density of tephra (i.e. dust) ejected, the
latitude of injection, and atmospheric circulation patterns.
Lamb has used five different methods to determine the DVI for any particular
eruption. Final DVI values are averages, sometimes corrected subjectively, of
the estimates produced by as many of the five methods as data availability
permits. One method used was to make subjective estimates based on previous
compilations of secondary historical sources. Three methods that were
developed incorporate formulas devised to systematize the estimation of the DVI
after the initial subjective or 'free' estimates had been made. These three
formulas estimate the DVI based on (1) the depletion of radiation following the
eruption, (2) temperature variations following the eruption, and (3) the amount
of solid material dispersed as dust after an eruption.
All CDIAC numerical data packages include copies of pertinent literature
discussing the data, summaries discussing the background, source and scope of
the data, as well as applications limitations and restrictions of the data.
This data set also resides on the CDIAC CD-ROM which contains many other CDIAC
CDIAC has provided an anonymous FTP area to all data files, retrieval codes,
and descriptive files for the NDP's that are presently available. The FTP
address is ftp://cdiac.esd.ornl.gov or 220.127.116.11 and input your
email address as the password.
The NDP-013 data set is located in CDIAC's anonymous FTP in pub/ndp013.
All files are compressed (UNIX) ASCII text files. All the data bases provided
in this area are fully documented and are also available on 9-track magnetic
tape, CD-ROM, or IBM-formatted, high or low-density floppy diskettes.
Start Date: 1500-01-01Stop Date: 1983-12-31
ATMOSPHERE > AEROSOLS > DUST/ASH/SMOKE > DUST VEIL INDEX
PALEOCLIMATE > LAND RECORDS > VOLCANIC DEPOSITS
SOLID EARTH > TECTONICS > VOLCANIC ACTIVITY > ERUPTION DYNAMICS
SOLID EARTH > TECTONICS > VOLCANIC ACTIVITY > ERUPTION DYNAMICS > ASH/DUST COMPOSITION > DUST VEIL INDEX
SOLID EARTH > TECTONICS > VOLCANIC ACTIVITY > ERUPTION DYNAMICS > VOLCANIC GASES
Distribution Media: CD-ROM
Distribution Media: on-line (FTP)
Climatic Research Unit University of East Anglia
Province or State: NORWICH
Country: UNITED KINGDOM
Lamb, H. H., 1970: 'Volcanic Dust in the Atmosphere; With a Chronology and
Assessment of its Meteorological Significance.' Philosophical Transactions
of the Royal Society of London, Series A, 266:425-533.
Lamb, H. H., 1977: 'Supplementary Volcanic Dust Veil Assessments.' Climate
Lamb, H. H., 1983: 'Update of the Chronology of Assessment of the Volcanic
Dust Veil Index.' Climate Monitor, 12:79-90.
Extended Metadata Properties
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Creation and Review Dates
Last DIF Revision Date: 2006-08-07