Black carbon concentration and deposition estimations in Finland by the regional aerosol–climate model REMO-HAM A. I. Hienola1, J.-P. Pietikäinen1, D. Jacob2,3, R. Pozdun2,3,†, T. Petäjä4, A.-P. Hyvärinen1, L. Sogacheva1, V.-M. Kerminen4, M. Kulmala4, and A. Laaksonen1 1Finnish Meteorological Institute, Erik Palmenin aukio 1, 00101 Helsinki, Finland 2Max Planck Institute for Meteorology, Bundersstrasse 53, 20146 Hamburg, Germany 3Climate Service Center, Chilehaus - Eingang B, Fischertwiette 1, 20095 Hamburg, Germany 4Department of Physics, Division of Atmospheric Sciences and Geophysics, University of Helsinki, P.O. Box 64, 00014 Helsinki, Finland †Deceased September 2011. RIP
Abstract. The prediction skill of the regional aerosol–climate model REMO-HAM was
assessed against the black carbon (BC) concentration measurements from five
locations in Finland, with focus on Hyytiälä station for the year 2005.
We examined to what extent the model is able to reproduce the measurements
using several statistical tools: median comparison, overlap coefficient (OVL;
the common area under two probability distributions curves) and Z score (a
measure of standard deviation, shape and spread of the distributions). The
results of the statistics showed that the model is biased low. The local and
regional emissions of BC have a significant contribution, and the model
tendency to flatten the observed BC is most likely dominated by the lack of
domestic burning of biofuel in the emission inventories. A further
examination of the precipitation data from both measurements and model showed
that there is no correlation between REMO's excessive precipitation and BC
underestimation. This suggests that the excessive wet removal is not the main
cause of the low black carbon concentration output. In addition, a
comparison of wind directions in relation with high black carbon
concentrations shows that REMO-HAM is able to predict the BC source
directions relatively well. Cumulative black carbon deposition fluxes over
Finland were estimated, including the deposition on snow.
Citation: Hienola, A. I., Pietikäinen, J.-P., Jacob, D., Pozdun, R., Petäjä, T., Hyvärinen, A.-P., Sogacheva, L., Kerminen, V.-M., Kulmala, M., and Laaksonen, A.: Black carbon concentration and deposition estimations in Finland by the regional aerosol–climate model REMO-HAM, Atmos. Chem. Phys., 13, 4033-4055, doi:10.5194/acp-13-4033-2013, 2013.