Figure 7. Evaluation of the inverse model results against independent measurements of surface concentration and deposition flux in the Northern Hemisphere.

Shown are comparisons of inverse model results against (a) seasonally averaged (Winter, Spring, Summer, and Fall are respectively denoted by magenta, green, orange, and blue) and (b) annually averaged dust surface concentration measurements at 15 NH stations, and against (c) a compilation of 77 measurements of the dust deposition flux. Results are grouped by regions as shown in Fig. 2. Statistics of the comparisons are noted in the figures and are calculated in log-space because the measurements span several orders of magnitude. Uncertainties on inverse model results and measurements represent one standard error and are calculated as described in Sects. 2.5 and 3.1, respectively. Also shown are Taylor diagrams summarizing the statistics of the ability of the different models to reproduce the spatial variability in the measured fields of (d) seasonal and (e) annual surface concentration, and (f) dust deposition flux (Taylor diagrams do not capture biases between model predictions and observations). The different symbols represent the measurements (purple triangle), the 13 AeroCom models (black letters), MERRA-2 (red “R”), the six models in the model ensemble (brown numbers), the six improved models (green numbers with prime), and the inverse model results (large blue star). An exact legend for the different models is provided in Fig. 3.