A Full-Spectrum Bedrock Thermal Expansion Model and Its Impact on the Global Positioning System Height Time Series

Jintao Lei, Wu Chen, Zhao Li, Fei Li, Shengkai Zhang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

Abstract

Bedrock thermal expansion includes prominent seasonal (annual and semiannual) terms and intricate nonseasonal variations (high-frequency change and transient signals). However, the nonseasonal variations are usually ignored in geodetic studies due to defects in analytical solutions. In this study, we calculate the full-spectrum bedrock thermal expansion displacement using the skin temperature from the ERA5 reanalysis data set. The results show that the nonseasonal variations of bedrock thermal expansion, with a range (maximum minus minimum) reaching 3 mm in some regions, can be observed by geodetic instruments and thus cannot be ignored. Moreover, the mean power of the nonseasonal variations accounts for 20% of the entire thermal expansion. Without considering the influence of the nonseasonal variations, this “noise” would remain in the original observations and contaminate related geophysical inversions.

Original languageEnglish
Article numbere2019GL086022
JournalGeophysical Research Letters
Volume47
Issue number1
DOIs
Publication statusPublished - 16 Jan 2020

ASJC Scopus subject areas

  • Geophysics
  • Earth and Planetary Sciences(all)

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