Solar Records: The Wolf Sunspot Index and Umbral/Penumbral Ratio, CDIAC NDP-014Entry ID: CDIAC_NDP14
Abstract: Observational records of sunspot activity are available from about 1875, with
reconstructions going back, possibly, to 1832. Available sunspot models and
the theory of mixing length indicate that the observed changes in the
umbral/penumbral (U/P) ratio may be equivalent to changes in the solar
constant. The U/P ratio is calculated from measurements of sunspot activity
and has been shown to be in ... agreement with the Northern Hemisphere temperature
Sunspot studies have a long history, and indices of solar activity have led to
many studies of the relationship of climatic variability and fluctuations with
solar variations. Another index that has recently been derived is this
'umbral/penumbral ratio', a measure of the convective energy transport in the
photosphere of the sun.
The data can be used to study solar-induced climate change. Reconstructions of
short-term solar fluctuations over the last century can also be made.
Application of these data to climate models and study of the first detection
signal due to increasing atmospheric carbon dioxide can lead to a better
understanding of the relationships of external forcing functions on climate.
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 18.104.22.168 and input your
email address as the password.
The NDP-014 data set is located in CDIAC's anonymous FTP in pub/ndp014.
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: 1875-01-01Stop Date: 1981-12-31
Distribution Media: CD-ROM
Distribution Media: on-line (FTP)
Hoyt, D.V., 1979: 'Variations in sunspot structure and climate.' Climatic
Hoyt, D.V., 1979: 'An empirical determination of the heating of the earth
by the carbon dioxide greenhouse effect.' Nature, 282:388-390.
Creation and Review Dates
Last DIF Revision Date: 1997-08-26