WP-P3: Extended interface to mesoscale models: expansion to further variables (precipitation, clouds, chemistry) and models; optimisation and parallelisation

Goals of the project:

Already during period 1 of MOSAIK the DWD developed a first version of the mesoscale interface INIFOR (INItialisation and FORcing) for PALM-4U (Kadasch, 2018). With support of INIFOR users can perform and analyse PALM-4U urban microclimate simulations under real synoptical conditions. INIFOR was developed as a stand-alone pre-processor, which is now part of the PALM-4U model system. It provides realistic, non-stationary forcing data for PALM-4U based on the operational output of the mesoscale model COSMO-DE (and its more recent higher-resolution configuration COSMO-D2). The goal within phase 2 of MOSAIK is the extension and improvement of INIFOR to allow the forcing of PALM-4U by further mesoscale models and the consideration of additional parameters, e.g. cloud physical or air quality parameters.

Tasks of the project

The task for period 2 is the expansion and refinement of INIFOR in the following areas:

1. Support of additional mesoscale models

• Including the support of ICON and WRF model output in order to provide a tool for mesoscale model foricng into PALM-4U to a wider range of national and international users to allow PALM-4U simulations with realistic weather conditions.
• Adding the support of output originating from the chemical add-ons of the named models ICON-ART and WRF-Chem in order to also allow the conducting of simulations with realistic mesoscale meteorologic and air pollution conditions.

2. Precipitation

• Expanding of INIFOR to provide PALM-4U with mesoscale precipitation rates and cloud parameters

3. Performance optimisation and parallelisation

• Parallelisation and optimisation of the code to allow faster processing of larger grid sizes by distributing data on cluster nodes

Structure of the project:

The project consists of one work package (P3) which can be divided into five different steps:

WP-P3.1: Introduction to mesoscale models and PALM-4U’s chemistry module

WP-P3.2: Extension of INIFOR to precipitation and cloud-physical parameters

WP-P3.3: Interface to the mesoscale models ICON and WRF including their chemistry extensions

WP-P3.4: Performance optimisation, parallelisation, and documentation

WP-P3.5: Support for model evaluation and new users of INIFOR

Deliverables:

1) INIFOR release with support for COSMO precipitation and cloud parameters

2) INIFOR release with interface for WRF/WRF-Chem

3) INIFOR release with support for ICON/ICON-ART

4) Parallelised version of INIFOR

5) Documentation for users of the expanded interface

Progress so far:

Since version 2.0.0 (PALM rev r4659, 31. August 2020) INIFOR also delivers cloud and precipitation values. More details can be found in the ​Documentation).

A first version of the WRF-interface has already been developed by colleagues of the Czech Academy of Sciences (K. Eben, J. Resler, P. Krč) and is delivered in combination with PALM (PALM rev. 4766, 2. November 2020). Based on the development experiences of both interfaces a unified tool to be used as a driver for PALM, which will also be the base for the upcoming ICON interface, was developed. Furthermore, INIFOR was enhanced to improve the dynamic driver in complex terrain. INIFOR was also extended by an optimized transformation of the input data in complex terrain (mesoscale-microscale terrain mapping). The development of the plugins (WRF and ICON) is progressing well.

References:

Kadasch, E., Sühring, M., Gronemeier, T., and Raasch, S., (in review): Mesoscale nesting interface of the PALM model system 6.0, Geosci. Model Dev. Discuss., ​doi:​10.5194/gmd-2020-285.

Contacts:

Heike.Noppel[at]dwd.de

Eckhard.Kadasch[at]dwd.de