Sea Level Pressure Reconstructions, Eastern North Atlantic and Europe: Readme file
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                   NOAA Paleoclimatology Program
                               and
              World Data Center for Paleoclimatology, Boulder
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NOTE: PLEASE CITE ORIGINAL REFERENCE WHEN USING THIS DATA!!!!!

NAME OF DATA SET: Sea Level Pressure Reconstructions, Eastern North Atlantic and Europe
LAST UPDATE: 12/2001 (Original Receipt by WDCA Paleo)  
CONTRIBUTOR: Juerg Luterbacher, University of Bern, juerg@giub.unibe.ch

IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2001-086

SUGGESTED DATA CITATION: Luterbacher, J., et al., 2001,
Sea Level Pressure Reconstructions, Eastern North Atlantic and Europe. 
IGBP PAGES/World Data Center A for Paleoclimatology 
Data Contribution Series #2001-086. 
NOAA/NGDC Paleoclimatology Program, Boulder CO, USA. 

ORIGINAL REFERENCE: 
Luterbacher, J., E. Xoplaki, D. Dietrich, R. Rickli, J. Jacobeit, C. Beck, 
D. Gyalistras, C. Schmutz and H. Wanner (2002) Reconstruction of 
Sea Level Pressure fields over the Eastern North Atlantic and Europe
back to 1500. Clim. Dyn., 18, 545-561, DOI 10.1007/s00382-001-0196-6..

ADDITIONAL REFERENCES: 
Kistler R. et al., (2001) The NCEP-NCAR 50-year Reanalysis: Monthly Means
CD-ROM and Documentation. Bull Americ Met Soc 82: 247-267 

Trenberth, K., and Paolino, D. A. (1980) The Northern Hemisphere sea-level
pressure data set: trends, errors and discontinuities. Mon. Wea. Rev.,
108, 855-872.

Kalnay E. et al. (1996) The NCEP/NCAR 40-Year Reanalysis Project. 
Bull. American Met. Soc. 77: 437-471.


GEOGRAPHIC REGION: Eastern North Atlantic and Europe
PERIOD OF RECORD: 1500-1999 AD 

LIST OF FILES: Readme_Luterbacher2002.txt (this file),
500hpa_1500-1658.txt (Seasonal 500 hPa fields from 1500-1658),
500hpa_1659-1999.txt (Monthly 500 hPa fields from December 1658-December 1999)
slp_1500-1658.txt    (Seasonal SLP fields from 1500-1658)
slp_1659-1999.txt    (Monthly SLP fields from December 1658-December 1999) 
(tab-delimited ASCII format).


DESCRIPTION:
Description and file formats of gridded sea level pressure (SLP) and 500 hPa files,
AD 1500-1999 (Luterbacher et al. 2002, Clim.Dyn., in press)

500hpa_1500-1658.txt (Seasonal 500 hPa fields from 1500-1658)
500hpa_1659-1999.txt (Monthly 500 hPa fields from December 1658-December 1999)
slp_1500-1658.txt    (Seasonal SLP fields from 1500-1658)
slp_1659-1999.txt    (Monthly SLP fields from December 1658-December 1999)

Grid: 5° x 5° for SLP 
Grid: 2.5° x 2.5° for 500 hPa


Spatial area: 30W - 40E und 70 - 30 N, no missing values

Time period: Winter 1500 until Autumn 1658 
(for files 500hpa_1500-1658.txt and slp_1500-1658.txt) 
December 1658 until December 1999
(for files slp_1659-1999.txt, 500hpa_1659-1999.txt) 


Months are given as  '1', '2', '3', '4', '5', '6', '7', '8', '9', '10', '11', '12'.
Seasons are denoted as 'wi' (Winter); 'sp' (Spring); 'su' (Summer); 'au' (Autumn) 


Datafile:

Year, Month (Season, wi, sp, su, au), 135 (for SLP), 493 for 500 hPa Gridpoints

Year1 Month1 (Season1) Gridpoint1 Gridpoint2 Gridpoint3 Gridpoint4 .....Gridpointy
Year1 Month2 (Season2) Gridpoint1 Gridpoint2 Gridpoint3 Gridpoint4 .....Gridpointy
.....
.
Year1 Month12 (Season4) Gridpoint1 Gridpoint2 Gridpoint3 Gridpoint4 .....Gridpointy
Year2 Month1  (Season1) Gridpoint1 Gridpoint2 Gridpoint3 Gridpoint4 .....Gridpointy
....
.
Year2  Month12 (Season4) Gridpoint1 Gridpoint2 Gridpoint3 Gridpoint4 .....Gridpointy
.
.
.
Year end Month12 (Season4) Gridpoint1 Gridpoint2 Gridpoint3 Gridpoint4 .....Gridpointy

Therefore, each row consist of year, month (Season) and a long string 
with 135 (SLP) or 493 (500 hPa) gridpoints 

Meaning, for each month (season) all gridpoints on the same latutide,
 one after the other, starting in the NW, ending in the SE.

1st gridpoint: 70N/30W 
2nd gridpoint: 70N/25W 
... 
... 
15th gridpoint: 70N/40E 
16th gridpoint: 65N/30W 
17th gridpoint: 65N/25W 
... 
... 
30th gridpoint: 65N/40E 
... 
.. 
135th gridpoint (last one): 30N/40E
For the 500 hPa fields it is the same structure, but the grid spacing is 2.5deg.
  

The SLP data from Winter 1500 to December 1900 (SLP) and
the 500 hPa data from Winter 1500 to December 1947 are our
reconstructions (Luterbacher et al. 2002, Clim. Dyn.in press),
 
The SLP data from January 1901 to December 1999 are taken from 
Trenberth and Paolino (1980, updated; available through 
http://dss.ucar.edu/datasets/ds010.1/data/)

The 500 hPa data from January 1948 to December 1999 stem from 
the NCEP/NCAR reanalysis data (Kalnay et al. 1996, Kistler et al. 2001).