Pregled bibliografske jedinice broj: 47703
Stabilization of nonlinear vertical diffusion schemes in the context of NWP models
Stabilization of nonlinear vertical diffusion schemes in the context of NWP models // Monthly Weather Review, 128 (2000), 6; 1937-1948 (međunarodna recenzija, članak, znanstveni)
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Naslov
Stabilization of nonlinear vertical diffusion schemes in the context of NWP models
Autori
Bénard, Pierre ; Marki, Antun ; Neytchev, Plamen N. ; Telišman Prtenjak, Maja
Izvornik
Monthly Weather Review (0027-0644) 128
(2000), 6;
1937-1948
Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni
Ključne riječi
NWP model; ARPEGE/ALADIN model; fibrillation; anti-fibrillation scheme
Sažetak
The stability of the nonlinear vertical diffusion equation such as commonly used for parameterizing the turbulence in NWP models is examined. As a starting point, this paper adopts the idea of Girard and Delage and shows how their results can be modified when the problem is examined in a less restrictive framework, typical of practical NWP applications. In Girard and Delages work, an optimal compromise between stability and accuracy was proposed to eliminate the fibrillations resulting from the instability, by applying a time decentering in the diffusion operator for the points likely to be unstable according to a local linear analysis of the stability. This key idea is pursued here, but two important changes are examined: (i) an exact method for the relaxation of the identity between thermal and dynamical exchange coefficients, and (ii) the introduction of a modification to the Richardson number for simulating the destabilization of the top of the PBL in shallow convection conditions. Compared to an approximate solution proposed by Girard and Delage for the first change, the one proposed here is more accurate and possesses a formal justification. For the second one, it is shown that the only consequence is that the stability now depends on the largest value of the modified/not modified Richardson number. A formulation of the temporal decentering consistent with these changes is then proposed and evaluated.
Izvorni jezik
Engleski
Znanstvena područja
Geologija
Citiraj ovu publikaciju:
Časopis indeksira:
- Current Contents Connect (CCC)
- Web of Science Core Collection (WoSCC)
- Science Citation Index Expanded (SCI-EXP)
- SCI-EXP, SSCI i/ili A&HCI
- Scopus