Otte, Tanya L., U.S. Environmental Protection Agency,
Martin J. Otte, U.S. EPA, Jared H. Bowden, University of North Carolina, and
Christopher G. Nolte, U.S. EPA
Several studies with WRF
and other models have shown that spectral nudging can improve predictions of
2-m temperature and large-scale fields for regional climate modeling. However, compared to analysis nudging,
precipitation predictions with spectral nudging are inferior for both means and
extremes (Bowden et al. 2012; Otte et al. 2012). In this work, we implemented spectral nudging toward
moisture and performed several multi-decadal sensitivity runs with WRF. We show that careful and conservative
use of spectral nudging toward moisture (specific humidity) improves the
prediction of precipitation without compromising other thermodynamic fields.