Amir Hakami

TL;DR: In this paper, the authors present the adjoint of the global chemical transport model GEOS-Chem, focusing on the chemical and thermodynamic relationships between sulfate and ammonium-nitrate aerosols and their gas-phase precursors.

TL;DR: This work explores the nonlinear responses of ozone to emissions of its precursors, nitrogen oxides (NOx) and volatile organic compounds, and introduces a method for applying second-order direct sensitivity method to assess the uncertainty of sensitivity and source apportionment estimates arising from uncertainty in an emissions inventory.

TL;DR: Higher-order sensitivity analysis shows a noticeable improvement in terms of accuracy over the conventional first-order analysis, and is better equipped to address the nonlinear behavior around the peak ozone in NO(x)-rich plumes.

TL;DR: An adjoint model for the internationally used Community Multiscale Air Quality (CMAQ) modeling platform of the U.S. EPA is developed and results show good agreement with brute-force and DDM sensitivities, but the agreement is not perfect for horizontal transport.

TL;DR: In this paper, an adjoint model is used for inverse modeling of black carbon during the Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia), using the four-dimensional variational data assimilation (4D-Var) approach to optimally recover spatially resolved anthropogenic and biomass-burning emissions and initial and boundary conditions.