A calendar conversion method for monthly mean paleoclimate model output with orbital forcing

David Pollard, David Reusch

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

A computationally cheap method is described for estimating monthly means of climatolpgical variables on alternate calendars, given their monthly means on an original calendar. This can be used to convert archived paleoclimatic GCM monthly mean results originally saved on the modern calendar to a more appropriate equi-angular calendar, thus avoiding spurious orbital signals when comparing monthly means for modern and past simulations. The method is tested using GCM simulations for the present and 126 ka BP. The method works well for temperature, which has relatively smooth seasonal cycles, and satisfactorily for other climatological variables in most regions except mid to high southern latitudes. It is also satisfactory for precipitation in most regions, but in the tropical ITCZ, it fails to significantly reduce the spurious calendar errors. However, this is largely due to high-frequency natural interannual variability in the 10-year simulations, and the errors are of the same order as the uncertainty in monthly means on a single calendar.

Original languageEnglish (US)
JournalJournal of Geophysical Research Atmospheres
Volume107
Issue number22
DOIs
StatePublished - Jan 1 2002

Fingerprint

calendars
orbital forcing
paleoclimate
orbitals
general circulation model
output
simulation
Natural frequencies
Equus
intertropical convergence zone
tropics
uncertainty
methodology
Temperature
method
temperature
estimating
cycles
Uncertainty

All Science Journal Classification (ASJC) codes

  • Geochemistry and Petrology
  • Geophysics
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science
  • Atmospheric Science
  • Astronomy and Astrophysics
  • Oceanography

Cite this

@article{c3415fa962cc4e63b2c1d7a2fb884e1a,
title = "A calendar conversion method for monthly mean paleoclimate model output with orbital forcing",
abstract = "A computationally cheap method is described for estimating monthly means of climatolpgical variables on alternate calendars, given their monthly means on an original calendar. This can be used to convert archived paleoclimatic GCM monthly mean results originally saved on the modern calendar to a more appropriate equi-angular calendar, thus avoiding spurious orbital signals when comparing monthly means for modern and past simulations. The method is tested using GCM simulations for the present and 126 ka BP. The method works well for temperature, which has relatively smooth seasonal cycles, and satisfactorily for other climatological variables in most regions except mid to high southern latitudes. It is also satisfactory for precipitation in most regions, but in the tropical ITCZ, it fails to significantly reduce the spurious calendar errors. However, this is largely due to high-frequency natural interannual variability in the 10-year simulations, and the errors are of the same order as the uncertainty in monthly means on a single calendar.",
author = "David Pollard and David Reusch",
year = "2002",
month = "1",
day = "1",
doi = "10.1029/2002JD002126",
language = "English (US)",
volume = "107",
journal = "Journal of Geophysical Research",
issn = "0148-0227",
publisher = "American Geophysical Union",
number = "22",

}

A calendar conversion method for monthly mean paleoclimate model output with orbital forcing. / Pollard, David; Reusch, David.

In: Journal of Geophysical Research Atmospheres, Vol. 107, No. 22, 01.01.2002.

Research output: Contribution to journalArticle

TY - JOUR

T1 - A calendar conversion method for monthly mean paleoclimate model output with orbital forcing

AU - Pollard, David

AU - Reusch, David

PY - 2002/1/1

Y1 - 2002/1/1

N2 - A computationally cheap method is described for estimating monthly means of climatolpgical variables on alternate calendars, given their monthly means on an original calendar. This can be used to convert archived paleoclimatic GCM monthly mean results originally saved on the modern calendar to a more appropriate equi-angular calendar, thus avoiding spurious orbital signals when comparing monthly means for modern and past simulations. The method is tested using GCM simulations for the present and 126 ka BP. The method works well for temperature, which has relatively smooth seasonal cycles, and satisfactorily for other climatological variables in most regions except mid to high southern latitudes. It is also satisfactory for precipitation in most regions, but in the tropical ITCZ, it fails to significantly reduce the spurious calendar errors. However, this is largely due to high-frequency natural interannual variability in the 10-year simulations, and the errors are of the same order as the uncertainty in monthly means on a single calendar.

AB - A computationally cheap method is described for estimating monthly means of climatolpgical variables on alternate calendars, given their monthly means on an original calendar. This can be used to convert archived paleoclimatic GCM monthly mean results originally saved on the modern calendar to a more appropriate equi-angular calendar, thus avoiding spurious orbital signals when comparing monthly means for modern and past simulations. The method is tested using GCM simulations for the present and 126 ka BP. The method works well for temperature, which has relatively smooth seasonal cycles, and satisfactorily for other climatological variables in most regions except mid to high southern latitudes. It is also satisfactory for precipitation in most regions, but in the tropical ITCZ, it fails to significantly reduce the spurious calendar errors. However, this is largely due to high-frequency natural interannual variability in the 10-year simulations, and the errors are of the same order as the uncertainty in monthly means on a single calendar.

UR - http://www.scopus.com/inward/record.url?scp=36448976566&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=36448976566&partnerID=8YFLogxK

U2 - 10.1029/2002JD002126

DO - 10.1029/2002JD002126

M3 - Article

VL - 107

JO - Journal of Geophysical Research

JF - Journal of Geophysical Research

SN - 0148-0227

IS - 22

ER -