This paper is presented in the context of sensitivity analysis (SA) of large-scale data assimilation (DA) models. We studied consistency. convergence. stability and roundoff error propagation of the reduced-space optimization technique arising in parallel 4D Variational DA problems. http://www.diegojavierfares.com/flash-pick-Thy-Art-Is-Murder-Thy-Art-Logo-White-Girl-Shorts-hot-buy/