Environmental Science and Climate Research(ESCR)

Walker Water LLC, Colorado, USA

Publications

• Research Article   
  Antarctic Ice Core Harmonic Analysis
  Author(s): Joseph Higginbotham*
  
  A harmonic analysis of Antarctic ice core proxy temperature, CO2 and CH4 data is presented spanning 350,000 years. To ensure consistent phase comparison, CO2 data were converted from AICC2012 to EDC3 chronology using depth as the invariant coordinate. Using a greedy algorithm to select periodic components, the analysis initially obtained 59 periods for temperature but subsequently refined this to 55 periods after removing four components (22,150, 9,000, 8,000, and 4,540 years) that exhibited high correlations in the normalized covariance matrix. This refinement ensures stable, well-conditioned parameter estimates while maintaining excellent fits: R2 = 0.952 for temperature and R2 = 0.964 for CO2 (truncated at 1515 CE), R2 = 0.873 for CH4. The algorithm independently recovers the canonical Milankovitch orbital periods (approximately 100,000, 41,000, and 23,000 years) without prior spec.. Read More»
  

  Abstract HTML PDF