Sensitivity analysis of numerically-simulated convective storms using direct and adjoint methods
- Univ. of Oklahoma, Norman, OK (United States)
- Argonne National Lab., IL (United States). Mathematics and Computer Science Div.
The goal of this project is to evaluate the sensitivity of numerically modeled convective storms to control parameters such as the initial conditions, boundary conditions, environment, and various physical and computational parameters. In other words, the authors seek the gradient of the solution vector with respect to specified parameters. One can use two approaches to accomplish this task. In the first or so-called brute force method, one uses a fully nonlinear model to generate a control forecast starting from a specified initial state. Then, a number of other forecasts are made in which chosen parameters (e.g., initial conditions) are systematically varied. The obvious drawback is that a large number of full model predictions are needed to examine the effects of only a single parameter. The authors describe herein an alternative, essentially automated method (ADIFOR, or Automatic DIfferentiation of FORtran) for obtaining the solution gradient that bypasses the adjoint altogether yet provides even more information about the gradient. (ADIFOR, like the adjoint technique, is constrained by the linearity assumption.) Applied to a 1-D moist cloud model, the authors assess the utility of ADIFOR relative to the brute force approach and evaluate the validity of the tangent linear approximation in the context of deep convection.
- Research Organization:
- Argonne National Lab., IL (United States). Mathematics and Computer Science Div.
- Sponsoring Organization:
- USDOE, Washington, DC (United States); National Science Foundation, Washington, DC (United States)
- DOE Contract Number:
- W-31109-ENG-38
- OSTI ID:
- 10159235
- Report Number(s):
- ANL/MCS/CP-82981; CONF-940769-4; ON: DE94013399; CNN: Grant ATM92-22576; Grant ATM88-09862; TRN: AHC29415%%12
- Resource Relation:
- Conference: 6. conference on mesoscale processes,Portland, OR (United States),18-22 Jul 1994; Other Information: PBD: [1994]
- Country of Publication:
- United States
- Language:
- English
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