Original scientific paper

SENSITIVITY OF PERTURBATION GROWTH TO FLOW CHARACTERISTICS AND SAMPLING STRATEGY

C. Hohenegger ; Institute for Atmospheric and Climate Science, ETH, Winterthurerstr. 190, 8057 Zürich, Switzerland
C. Schär ; Institute for Atmospheric and Climate Science, ETH, Winterthurerstr. 190, 8057 Zürich, Switzerland

Abstract

The chaotic nature of the weather/climate attractor intrinsically limits the deterministic skill of weather forecasts by promoting rapid growth of errors. In this study, such error growth is simulated by artificially perturbing the atmosphere at initial time, and its sensitivity to the chosen perturbation methodology and to the flow
characteristics is investigated. The different simulations are integrated with the limited-area model LM run on a convection-resolving grid. Results demonstrate that the locations of growing disturbances are insensitive to the definition of the initial temperature perturbation. This can be explained through an analysis of the perturbation growth and propagation mechanisms. In particular, rapid radiation of the imposed initial disturbance through a sound
wave and presence of specific flow characteristics (e.g. convective instability) appear to force localized error growth far remote from the initial perturbation.

Keywords

Predictability; error growth and propagation; Ensemble Prediction System (EPS)

Hrčak ID:

64511

URI

https://hrcak.srce.hr/64511

Publication date:

15.12.2005.

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