Wavelet Approximation in Data Assimilation - Softcover

Tangborn, Andrew

Softcover

ISBN 10: 1289289735 ISBN 13: 9781289289737

Publisher: Bibliogov, 2013

Synopsis

Estimation of the state of the atmosphere with the Kalman filter remains a distant goal because of high computational cost of evolving the error covariance for both linear and nonlinear systems. Wavelet approximation is presented here as a possible solution that efficiently compresses both global and local covariance information. We demonstrate the compression characteristics on the the error correlation field from a global two-dimensional chemical constituent assimilation, and implement an adaptive wavelet approximation scheme on the assimilation of the one-dimensional Burger's equation. In the former problem, we show that 99%, of the error correlation can be represented by just 3% of the wavelet coefficients, with good representation of localized features. In the Burger's equation assimilation, the discrete linearized equations (tangent linear model) and analysis covariance are projected onto a wavelet basis and truncated to just 6%, of the coefficients. A nearly optimal forecast is achieved and we show that errors due to truncation of the dynamics are no greater than the errors due to covariance truncation.

Edition details

• Publisher: Bibliogov
• Publication date: 2013
• Language: English
• ISBN 10: 1289289735
• ISBN 13: 9781289289737
• Binding: Paperback
• Number of pages: 38