Impact of the mesoscale range on error growth and the limits to atmospheric predictability
- Global numerical weather prediction (NWP) models have begun to resolve the mesoscale k(-5/3) range of the energy spectrum, which is known to impose an inherently finite range of deterministic predictability per se as errors develop more rapidly on these scales than on the larger scales. However, the dynamics of these errors under the influence of the synoptic-scale k(-3) range is little studied. Within a perfect-model context, the present work examines the error growth behavior under such a hybrid spectrum in Lorenz's original model of 1969, and in a series of identical-twin perturbation experiments using an idealized two-dimensional barotropic turbulence model at a range of resolutions. With the typical resolution of today's global NWP ensembles, error growth remains largely uniform across scales. The theoretically expected fast error growth characteristic of a k(-5/3) spectrum is seen to be largely suppressed in the first decade of the mesoscale range by the synoptic-scale k(-3) range. However, it emerges once models become fullyGlobal numerical weather prediction (NWP) models have begun to resolve the mesoscale k(-5/3) range of the energy spectrum, which is known to impose an inherently finite range of deterministic predictability per se as errors develop more rapidly on these scales than on the larger scales. However, the dynamics of these errors under the influence of the synoptic-scale k(-3) range is little studied. Within a perfect-model context, the present work examines the error growth behavior under such a hybrid spectrum in Lorenz's original model of 1969, and in a series of identical-twin perturbation experiments using an idealized two-dimensional barotropic turbulence model at a range of resolutions. With the typical resolution of today's global NWP ensembles, error growth remains largely uniform across scales. The theoretically expected fast error growth characteristic of a k(-5/3) spectrum is seen to be largely suppressed in the first decade of the mesoscale range by the synoptic-scale k(-3) range. However, it emerges once models become fully able to resolve features on something like a 20-km scale, which corresponds to a grid resolution on the order of a few kilometers.…
| Author details: | Tsz Yan LeungORCiD, Martin LeutbecherORCiDGND, Sebastian ReichORCiDGND, Theodore G. ShepherdORCiDGND |
|---|---|
| DOI: | https://doi.org/10.1175/JAS-D-19-0346.1 |
| ISSN: | 0022-4928 |
| ISSN: | 1520-0469 |
| Title of parent work (English): | Journal of the atmospheric sciences |
| Publisher: | American Meteorological Soc. |
| Place of publishing: | Boston |
| Publication type: | Article |
| Language: | English |
| Date of first publication: | 2020/10/20 |
| Publication year: | 2020 |
| Release date: | 2023/07/14 |
| Tag: | mesoscale forecasting; numerical analysis/modeling; numerical weather prediction/forecasting; short-range prediction |
| Volume: | 77 |
| Issue: | 11 |
| Number of pages: | 11 |
| First page: | 3769 |
| Last Page: | 3779 |
| Funding institution: | Engineering and Physical Sciences Research CouncilUK Research &; Innovation (UKRI)Engineering & Physical Sciences Research Council; (EPSRC) [EP/L016613/1]; European Research Council Advanced Grant; "Understanding the Atmospheric Circulation Response to Climate Change''; (ACRCC) [339390]; Deutsche Forschungsgemeinschaft (DFG; German Science; Foundation)German Research Foundation (DFG) [SFB 1114/2 235221301] |
| Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Mathematik |
| DDC classification: | 5 Naturwissenschaften und Mathematik / 51 Mathematik / 510 Mathematik |
| Peer review: | Referiert |
| Publishing method: | Open Access / Hybrid Open-Access |
