Confronting the WRF and RAMS mesoscale models with innovative observations in the Netherlands: Evaluating the boundary layer heat budget

Abstract

[1] The Weather Research and Forecasting Model (WRF) and the Regional Atmospheric Mesoscale Model System (RAMS) are frequently used for (regional) weather, climate and air quality studies. This paper covers an evaluation of these models for a windy and calm episode against Cabauw tower observations (Netherlands), with a special focus on the representation of the physical processes in the atmospheric boundary layer (ABL). In addition, area averaged sensible heat flux observations by scintillometry are utilized which enables evaluation of grid scale model fluxes and flux observations at the same horizontal scale. Also, novel ABL height observations by ceilometry and of the near surface longwave radiation divergence are utilized. It appears that WRF in its basic set-up shows satisfactory model results for nearly all atmospheric near surface variables compared to field observations, while RAMS needed refining of its ABL scheme. An important inconsistency was found regarding the ABL daytime heat budget: Both model versions are only able to correctly forecast the ABL thermodynamic structure when the modeled surface sensible heat flux is much larger than both the eddy-covariance and scintillometer observations indicate. In order to clarify this discrepancy, model results for each term of the heat budget equation is evaluated against field observations. Sensitivity studies and evaluation of radiative tendencies and entrainment reveal that possible errors in these variables cannot explain the overestimation of the sensible heat flux within the current model infrastructure.

The Performance of Different Boundary-Layer Parameterisations in Meteorological Modelling in a Southwestern Coastal Area of the Iberian Peninsula

“…The best approximation for the SW-NW flow scenario was in agreement with [31], in which the optimal reproduction of the surface temperature was strongly correlated with a good approximation of the wind speed phase when the diurnal cycle of continental wind speed was approximately in phase with the thermal cycle [32]. These results were in contrast with those obtained by Steeneveld et al [33], who found the largest differences between WRF-YSU and MRF results for nighttime during strong winds.…”

Relative impacts of land use and climate change on summer precipitation in the Netherlands

“…The model is run for 48 h, including 12 h of spin-up from 12:00 to 00:00 UTC the previous day, 24 h of simulation on the chosen day, and 12 additional hours to be able to compare it to both radar data (00:00-00:00 UTC) and station data (08:00-08:00 UTC). Following earlier studies with WRF in the Netherlands (e.g., Steeneveld et al, 2011;Daniels et al, 2015a;Theeuwes et al, 2013), we selected the following schemes to represent subgrid processes: the YSU PBL scheme , the WRF Single-Moment 6-Class Microphysics Scheme (WSM6) (Hong and Lim, 2006), the RRTMG schemes for both longwave and shortwave radiation (Iacono et al, 2008), the Grell 3-D cumulus parameterization scheme (Grell, 1993;Grell and Devenyi, 2002), and the Unified Noah Land Surface Model (Tewari et al, 2004) with the Urban Canopy Model (UCM). The UCM is a single-layer model that has a simplified urban geometry.…”

Can seasonal and interannual variation in landscape CO<sub>2</sub> fluxes be detected by atmospheric observations of CO<sub>2</sub> concentrations made at a tall tower?

“…Forward running models, such as WRF (Weather Research and Forecasting model) or RAMS (Regional Atmospheric Modeling System), have been used to investigate a wide range of topics, including the impact of surface processes on atmospheric transport (e.g. Steeneveld et al, 2011) and how ecosystems contribute to observations made at the regional scale (e.g. Tolk et al, 2009).…”