Technical Note: Propagating correlations in atmospheric inversions using different Kalman update smoothers 1Department of Earth and Atmospheric Sciences, Purdue University, West Lafayette, IN, USA
02 Feb 2011
2Purdue Climate Change Research Center, West Lafayette, IN, USA
3Department of Agronomy, Purdue University, West Lafayette, IN, USA
Received: 27 July 2010 – Published in Atmos. Chem. Phys. Discuss.: 16 August 2010 Abstract. The scheme to propagate correlations between on-line and off-line state variables
in atmospheric inversions using the fixed-lag Kalman smoother proposed in Bruhwiler
et al. (2005) is explained as a process to impose a balanced constraint on the on-line state variables.
It is then extended to the fixed-lag ensemble square root Kalman smoother
and fixed-lag square root sigma-point Kalman smoother, allowing us to treat nonlinear
observation operators easily. Further, to constrain the posterior fluxes within their feasible
ranges, the constrained fixed-lag Kalman smoother is presented and the variable
transform technique is proposed for the other two smoothers. Comparisons between
various methods and observational data are conducted using a synthetic inversion of
atmospheric CH4 fluxes. The results indicate that our developed methods are
good alternatives to existing methods for conducting sequential inversion
of atmospheric trace gases. It is also shown that the benefit to include the correlations
between on-line and off-line state variables is case dependent.
Revised: 20 December 2010 – Accepted: 24 January 2011 – Published: 02 February 2011
Citation: Tang, J. and Zhuang, Q.: Technical Note: Propagating correlations in atmospheric inversions using different Kalman update smoothers, Atmos. Chem. Phys., 11, 921-929, doi:10.5194/acp-11-921-2011, 2011.