Integrated Summer Insolation Calculations
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               World Data Center for Paleoclimatology, Boulder
                                  and
                     NOAA Paleoclimatology Program
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NOTE: PLEASE CITE CONTRIBUTORS WHEN USING THIS DATA!!!!!


NAME OF DATA SET: Integrated Summer Insolation Calculations
LAST UPDATE: 8/2006 (Original receipt by WDC Paleo)
CONTRIBUTOR: Peter Huybers, Harvard University
IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2006-079

SUGGESTED DATA CITATION: Huybers, P. and Eisenman, I. 2006. 
Integrated Summer Insolation Calculations.
IGBP PAGES/World Data Center for Paleoclimatology 
Data Contribution Series # 2006-079.
NOAA/NCDC Paleoclimatology Program, Boulder CO, USA.


ORIGINAL REFERENCE: 
Huybers, P. 2006. 
Early Pleistocene Glacial Cycles and the Integrated Summer Insolation Forcing. 
Science, v313, p508-511, 10.1126/science.1125249, 28 July 2006.

ABSTRACT:
Long-term variations in Northern Hemisphere summer insolation are generally 
thought to control glaciation. But the intensity of summer insolation is 
primarily controlled by 20,000-year cycles in the precession of the equinoxes, 
whereas early Pleistocene glacial cycles occur at 40,000-year intervals,
matching the period of changes in Earth's obliquity. The resolution of this 
40,000-year problem is that glaciers are sensitive to insolation integrated 
over the duration of the summer. The integrated summer insolation is primarily 
controlled by obliquity and not precession because, by Kepler's second law, 
the duration of the summer is inversely proportional to Earth's distance 
from the Sun.

GEOGRAPHIC REGION: Global
PERIOD OF RECORD: 5 million years BP - present
FUNDING SOURCE: 
National Science Foundation (USA) Paleoclimate Program grant no. ATM-0455470.


DESCRIPTION:  
Integrated Summer Insolation Calculations.  
Values are stored in individual data files for each 5-degree latitude band from 
90 North to 90 South.  Matlab program code files used to generate these values 
are also provided.  List of files is as follows:

Matlab program code files:
daily_insolation.m
make_integrated_insolation_tables.m
orbital_parameter_data.mat

Integrated Summer Insolation 5-degree latitude band data files:
j_0north.txt
j_10north.txt
j_10south.txt
j_15north.txt
j_15south.txt
j_20north.txt
j_20south.txt
j_25north.txt
j_25south.txt
j_30north.txt
j_30south.txt
j_35north.txt
j_35south.txt
j_40north.txt
j_40south.txt
j_45north.txt
j_45south.txt
j_50north.txt
j_50south.txt
j_55north.txt
j_55south.txt
j_5north.txt
j_5south.txt
j_60north.txt
j_60south.txt
j_65north.txt
j_65south.txt
j_70north.txt
j_70south.txt
j_75north.txt
j_75south.txt
j_80north.txt
j_80south.txt
j_85north.txt
j_85south.txt
j_90north.txt
j_90south.txt