Details
| Original language | English |
|---|---|
| Title of host publication | Gravity, Positioning and Reference Frames - Proceedings of the IAG Symposia - GGHS2022 |
| Subtitle of host publication | Gravity, Geoid, and Height Systems 2022; IAG Commission 4: Positioning and Applications, 2022; REFAG2022: Reference Frames for Applications in Geosciences, 2022 |
| Editors | Jeffrey T. Freymueller, Laura Sánchez |
| Place of Publication | Berlin, Heidelberg |
| Pages | 129-137 |
| Number of pages | 9 |
| Publication status | Published - 2024 |
| Externally published | Yes |
Publication series
| Name | International Association of Geodesy Symposia |
|---|---|
| Volume | 156 |
| ISSN (Print) | 0939-9585 |
| ISSN (electronic) | 2197-9359 |
Abstract
We assess the impact of varying the mass anomaly sources on the calculation of atmospheric tidal displacement harmonics. Atmospheric mass anomalies are obtained from five state-of-the-art numerical weather models (NWM): DWD’s ICON-Global, ECMWF’s IFS, JMA’s JRA55, ECMWF’s ERA5, and NASA’s MERRA2. To evaluate how the atmospheric tides’ representation in the different models displaces Earth’s crust, we calculate mass harmonics based on a fixed time span (2019.0–2022.0). To evaluate how temporally variable atmospheric tide manifestations are, we also applied a square-root-information filter on displacements spanning seven decades of ERA5. In addition, the variable harmonic atmospheric forcing is used to excite harmonic sea-surface variations employing the barotropic model TiME. The results from the analysis of the five numerical weather models as well as the monthly updated states of ERA5 harmonics are compared. We find that inter-model differences are larger than temporal harmonic modulations for all waves beating at frequencies higher than 1 cpd. We have confirmed that significant modulations are not an artefact in NWM but rather a true effect, and accounting for them might become of relevance for space geodesy at some point as soon as observations increase in spatio-temporal density and accuracy. The global RMS of radial displacements is 0.07 mm (SNR of 16.2 dB) for the “epoch” ensemble and 0.10 mm (SNR of 8.9 dB) for the “NWM” ensemble. We find discrepancies as large as 0.28 mm between harmonics from MERRA2 and early ERA5 batches, which we attribute to data sparsity in the in situ data assimilated into the NWM during the earlier years of the atmospheric reanalysis.
Keywords
- Atmospheric tides, Inter-model variations, Numerical weather model, Temporal modulation, Tidal loading displacements
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Computers in Earth Sciences
- Earth and Planetary Sciences(all)
- Geophysics
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
Gravity, Positioning and Reference Frames - Proceedings of the IAG Symposia - GGHS2022: Gravity, Geoid, and Height Systems 2022; IAG Commission 4: Positioning and Applications, 2022; REFAG2022: Reference Frames for Applications in Geosciences, 2022. ed. / Jeffrey T. Freymueller; Laura Sánchez. Berlin, Heidelberg, 2024. p. 129-137 (International Association of Geodesy Symposia; Vol. 156).
Research output: Chapter in book/report/conference proceeding › Contribution to book/anthology › Research › peer review
}
TY - CHAP
T1 - How Do Atmospheric Tidal Loading Displacements Vary Temporally as Well as across Different Weather Models?
AU - Balidakis, Kyriakos
AU - Sulzbach, Roman
AU - Dobslaw, Henryk
AU - Dill, Robert
N1 - Publisher Copyright: © The Author(s) 2023.
PY - 2024
Y1 - 2024
N2 - We assess the impact of varying the mass anomaly sources on the calculation of atmospheric tidal displacement harmonics. Atmospheric mass anomalies are obtained from five state-of-the-art numerical weather models (NWM): DWD’s ICON-Global, ECMWF’s IFS, JMA’s JRA55, ECMWF’s ERA5, and NASA’s MERRA2. To evaluate how the atmospheric tides’ representation in the different models displaces Earth’s crust, we calculate mass harmonics based on a fixed time span (2019.0–2022.0). To evaluate how temporally variable atmospheric tide manifestations are, we also applied a square-root-information filter on displacements spanning seven decades of ERA5. In addition, the variable harmonic atmospheric forcing is used to excite harmonic sea-surface variations employing the barotropic model TiME. The results from the analysis of the five numerical weather models as well as the monthly updated states of ERA5 harmonics are compared. We find that inter-model differences are larger than temporal harmonic modulations for all waves beating at frequencies higher than 1 cpd. We have confirmed that significant modulations are not an artefact in NWM but rather a true effect, and accounting for them might become of relevance for space geodesy at some point as soon as observations increase in spatio-temporal density and accuracy. The global RMS of radial displacements is 0.07 mm (SNR of 16.2 dB) for the “epoch” ensemble and 0.10 mm (SNR of 8.9 dB) for the “NWM” ensemble. We find discrepancies as large as 0.28 mm between harmonics from MERRA2 and early ERA5 batches, which we attribute to data sparsity in the in situ data assimilated into the NWM during the earlier years of the atmospheric reanalysis.
AB - We assess the impact of varying the mass anomaly sources on the calculation of atmospheric tidal displacement harmonics. Atmospheric mass anomalies are obtained from five state-of-the-art numerical weather models (NWM): DWD’s ICON-Global, ECMWF’s IFS, JMA’s JRA55, ECMWF’s ERA5, and NASA’s MERRA2. To evaluate how the atmospheric tides’ representation in the different models displaces Earth’s crust, we calculate mass harmonics based on a fixed time span (2019.0–2022.0). To evaluate how temporally variable atmospheric tide manifestations are, we also applied a square-root-information filter on displacements spanning seven decades of ERA5. In addition, the variable harmonic atmospheric forcing is used to excite harmonic sea-surface variations employing the barotropic model TiME. The results from the analysis of the five numerical weather models as well as the monthly updated states of ERA5 harmonics are compared. We find that inter-model differences are larger than temporal harmonic modulations for all waves beating at frequencies higher than 1 cpd. We have confirmed that significant modulations are not an artefact in NWM but rather a true effect, and accounting for them might become of relevance for space geodesy at some point as soon as observations increase in spatio-temporal density and accuracy. The global RMS of radial displacements is 0.07 mm (SNR of 16.2 dB) for the “epoch” ensemble and 0.10 mm (SNR of 8.9 dB) for the “NWM” ensemble. We find discrepancies as large as 0.28 mm between harmonics from MERRA2 and early ERA5 batches, which we attribute to data sparsity in the in situ data assimilated into the NWM during the earlier years of the atmospheric reanalysis.
KW - Atmospheric tides
KW - Inter-model variations
KW - Numerical weather model
KW - Temporal modulation
KW - Tidal loading displacements
UR - http://www.scopus.com/inward/record.url?scp=85200657221&partnerID=8YFLogxK
U2 - 10.1007/1345_2023_201
DO - 10.1007/1345_2023_201
M3 - Contribution to book/anthology
SN - 9783031638541
T3 - International Association of Geodesy Symposia
SP - 129
EP - 137
BT - Gravity, Positioning and Reference Frames - Proceedings of the IAG Symposia - GGHS2022
A2 - Freymueller, Jeffrey T.
A2 - Sánchez, Laura
CY - Berlin, Heidelberg
ER -