High-resolution temperature mapping by geostatistical kriging with external drift from large-eddy simulations

TitleHigh-resolution temperature mapping by geostatistical kriging with external drift from large-eddy simulations
Publication TypeJournal Article
Year of Publication2019
AuthorsVarentsov, M, Ezau, I, Wolf, T
JournalMonthly Weather Review
ISSN0027-0644
Abstract

Detailed temperature maps are required in various applications. Any temperature interpolation over complex terrain must account for differences in land cover and elevation. Local circulations and other small-scale factors can also perturb the temperature. This study considers the surface air temperature, T, mapping with geo-statistical kriging. The kriging methods are implemented for both T, and temperature anomalies, Δ T, defined as difference between T at a given location and T at the same elevation in the free atmosphere. The study explores the large-eddy simulation (LES) model PALM as a source for variogram and external drift in the kriging methods. Ten kriging methods for the temperature mapping have been considered: ordinary kriging (OK) of T and Δ T with variogram derived from the observations (methods 1 and 2, correspondingly); OK of T and Δ T with variogram derived from LES data (3 and 4); universal kriging with external drift (KED) that utilizes the LES data (5 and 6); a weighted combination of KED of T and Δ T (method 7); and the methods (5), (6) and (7) enhanced with additional “virtual” points in remote areas (methods 8, 9 and 10). These ten methods are evaluated for eight typical weather situations observed in Bergen, Norway. Our results demonstrate considerable added value of the LES information for the detailed meteorological temperature mapping. The LES data improves both the variogram and the resulting temperature maps, especially in the remote mountain parts of the domain and along the coast.

DOI10.1175/MWR-D-19-0196.1
Refereed DesignationRefereed
Author Address

NERSC