Publication details
- HEALPix For Climate Model Analysis: Scaling Behavior of Spectral-Analysis Tasks (Jakob Ludwig Sachs), Bachelor's Thesis, School: Universität Hamburg, 2023-09-21
Publication details
Abstract
The HEALPix grid is a promising new approach to the problem of discretizing the surface of the globe. Its use in climate model analysis is still in its infancy, and so in this work, we investigate its performance for spectral analysis of climate data. We measure the error introduced by remapping from an icosahedral grid (ICON) to the HEALPix grid and compare it to the error introduced by remapping to a Gaussian-Grid. Specifically, we investigate the error for the spectral analysis of input data by generating a set of spherical harmonics up to a degree of 100 (wave-length of 400km) on the ICON grid, remapping them to HEALPix/Gaussian grids, and then comparing the results of spectral analysis on the remapped grids to the expected results. We find that the error for the HEALPix grid is roughly an order of magnitude larger then for a gaussian grid with a similar cell count (on average 5.1 10^-6 Mean-Absolute-Error for a HEALPix grid with nside=1024, and 6.8 10^-7 for the N1024 Gaussian-Grid ). While the error might be higher, the HEALPix method might still be preferable for analysis when using lower-resolution grids (down to nside=128), due to much lower resource requirements of resolutions, if an Mean-Absolute-Error of 10^(-5)is acceptable for the spectrum.
BibTeX
@misc{HFCMASBOST23,
author = {Jakob Ludwig Sachs},
title = {{HEALPix For Climate Model Analysis: Scaling Behavior of Spectral-Analysis Tasks}},
advisors = {Jannek Squar and Anna Fuchs and Florian Ziemen},
year = {2023},
month = {09},
school = {Universität Hamburg},
howpublished = {{Online \url{https://wr.informatik.uni-hamburg.de/_media/research:theses:jakob_ludwig_sachs_healpix_for_climate_model_analysis_scaling_behavior_of_spectral_analysis_tasks.pdf}}},
type = {Bachelor's Thesis},
abstract = {The HEALPix grid is a promising new approach to the problem of discretizing the
surface of the globe. Its use in climate model analysis is still in its infancy, and so in
this work, we investigate its performance for spectral analysis of climate data. We measure
the error introduced by remapping from an icosahedral grid (ICON) to the HEALPix grid and
compare it to the error introduced by remapping to a Gaussian-Grid. Specifically, we
investigate the error for the spectral analysis of input data by generating a set of spherical
harmonics up to a degree of 100 (wave-length of 400km) on the ICON grid, remapping them to
HEALPix/Gaussian grids, and then comparing the results of spectral analysis on the remapped
grids to the expected results. We find that the error for the HEALPix grid is roughly an order
of magnitude larger then for a gaussian grid with a similar cell count (on average 5.1 10^-6
Mean-Absolute-Error for a HEALPix grid with nside=1024, and 6.8 10^-7 for the N1024
Gaussian-Grid ). While the error might be higher, the HEALPix method might still be preferable
for analysis when using lower-resolution grids (down to nside=128), due to much lower resource
requirements of resolutions, if an Mean-Absolute-Error of 10^(-5)is acceptable for the
spectrum.},
}