Gerhard Smiatek

SOAP-based web services in GIS/RDBMS environment

Implementation of Simple Object Access Protocol (SOAP)-based Web services within a collection of classes GSfM (GIS Support for MCCM) is presented. GSfM facilitates the provision of various geographical and tabular input data into the MCCM (Multiscale Chemistry Climate Model). The classes have been written in object-oriented Perl. They allow to write simple Perl scripts and to perform data provision while making intensive use of the GIS and RDBMS running on remote hosts. Appropriate GIS/RDBMS functions are used to create coverages representing the modeling area, to adjust the map projection and to intersect the available land use data as well as to retrieve all required tabular data from the relational database. Due to the ability of GSfM to use two SOAP-based Web services providing access to GIS and RDBMS on foreign hosts, the Perl scripts can run on almost any platform connected to the corporate network. The article describes the setup of SOAP server and client applications based on the SOAP::Lite library. Also an application example in provision data for modeling volatile organic compounds from biogenic sources (BVOC) is presented.

Time invariant data preprocessor for the climate version of the COSMO model (COSMO-CLM)

The PrEProcessor of time invariant parameters required for the boundary data definition in the COSMO-CLM is described. PEP incorporates the present preprocessor from DWD and gives additional access to the geospatial information provided by the ECOCLIMAP data. It processes various global geospatial data into spatial resolution and into rotated coordinates system specified by the user. Available global topography, land cover as well as soil characteristics datasets are reviewed and their use in various processing options of PEP is presented.

High-Resolution Climate Change Impact Analysis on Expected Future Water Availability in the Upper Jordan Catchment and the Middle East

AbstractThe impact of climate change on the future water availability of the upper Jordan River (UJR) and its tributaries Dan, Snir, and Hermon located in the eastern Mediterranean is evaluated by a highly resolved distributed approach with the fifth-generation Pennsylvania State University–NCAR Mesoscale Model (MM5) run at 18.6- and 6.2-km resolution offline coupled with the Water Flow and Balance Simulation Model (WaSiM). The MM5 was driven with NCEP reanalysis for 1971–2000 and with Hadley Centre Coupled Model, version 3 (HadCM3), GCM forcings for 1971–2099. Because only one regional–global climate model combination was applied, the results may not give the full range of possible future projections. To describe the Dan spring behavior, the hydrological model was extended by a bypass approach to allow the fast discharge components of the Snir to enter the Dan catchment. Simulation results for the period 1976–2000 reveal that the coupled system was able to reproduce the observed discharge rates in the pa...

Implementation and performance analysis of a high resolution coupled numerical weather and river runoff prediction model system for an Alpine catchment

This study describes the implementation of a one way coupled high resolution numerical weather and river runoff forecasting system within the Perl Object Environment (POE) framework and presents its application and performance analysis for the Alpine catchment of the Ammer River located in southern Germany. The simulation system employs the hydrological water balance model WaSiM-ETH run at 100 m x 100 m grid resolution one way coupled with the numerical weather prediction model (NWP) MM5 driven at 3.5 km grid cell resolution. The state and event driven forecasting system implements the input data download, input data provision via SOAP based WEB service and the run of the hydrology model with observed and with predicted NWP meteorology fields. It applies a lagged ensemble prediction system (EPS) taking into account combination of recent and previous NWP forecasts. The simulation system has been setup and designed for flood forecasting in the alpine environment. It is run operationally as well as in extended time slice experiments for all episodes with highest observed runoff in the period 01.10.2005-30.09.2010. The system application demonstrates the great potential of the POE based system in networking, distributed computing as well in the setup of various experiments. The river runoff simulation results show high correlation with observed runoff when driven with precipitation interpolated from station observations. The performance of the forecast shows limitations resulting from deficient timing and amount of the predicted rainfall in the complex mountainous area. Forecast skills were improved after application of a lagged ensemble prediction system.

Hydrological Climate Change Impact Analysis for the Figeh Spring near Damascus, Syria

AbstractA set of downscaled climate change data from transient experiments with regional climate models has been used to access the future climate change signal in the area of the Figeh spring system in Syria and its potential effects on future water availability. The data ensemble at a spatial resolution of 0.25° has been investigated for the period 1961–90 for present-day climate and the periods 2021–50 and 2070–99 for future climate. The focus is on changes to annual, seasonal, and monthly surface air temperature and precipitation. For the first time, the Figeh spring discharge has been assessed with a hydrological runoff model based on an artificial neural network (ANN) approach. The ANN model was formulated and validated for the years 1987–2007, applying daily meteorological driving data. The investigations show that water supply from the spring might face serious problems under changed climate conditions. An expected, a precipitation decrease of about −11% in winter and −8% in spring, together with ...

Expected Future Runoff of the Upper Jordan River Simulated with a CORDEX Climate Data Ensemble

AbstractData from five different RCMs run in two experiments from the Coordinated Regional Climate Downscaling Experiment (CORDEX) are applied together with the Water Flow and Balance Simulation Model (WaSiM) to assess the future availability of water in the upper Jordan River. Simulation results for 1976–2000 show that the modeling system was able to reasonably reproduce the observed discharge rates in the partially karstic complex terrain without bias correction of the precipitation input. For the future climate in the area, the applied CORDEX models indicate an increasing annual mean temperature for 2031–60 by 1.8 K above the 1971–2000 mean and by 2.6 K for 2071–2100. The simulated ensemble mean precipitation is predicted to decrease by 16.3% in the first period and 22.1% at the end of the century. In relation to the mean for 1976–2000, the discharge of the upper Jordan River is simulated to decrease by 7.4% until 2060 and by 17.5% until 2100, together with a reduction of high river flow years.

Time invariant boundary data of regional climate models COSMO-CLM and WRF and their application in COSMO-CLM

Basic time invariant boundary parameters, such as topography, land use, soil texture, and derived vegetation and soil properties as defined in the regional climate models Consortium for Small-scale Modeling in Climate Mode (CCLM), and the Weather Research and Forecasting Model (WRF), are investigated in terms of their applicability. The focus is on the comparison of the four available data sets and the investigation of their influences on actual CCLM simulations. Several runs of the CCLM model with National Centers for Environmental Prediction (NCEP) and ERA40 boundary forcings in the Mediterranean Coordinated Regional Climate Downscaling Experiment indicate that the investigated data sets are suitable for the considered region. The variations introduced by the different time invariant boundary data are within the range of the variations resulting from different driving reanalysis data, but lower than the differences obtained in intermodel evaluations, e.g., in Prediction of Regional scenarios and Uncertainties for Defining European Climate Change Risks and Effects (PRUDENCE) and Ensembles-based predictions of climate changes and their impacts (ENSEMBLES). The variation in the monthly mean values resulting from differences in the land use, topography, and soil data are up to 1.1 K in the area average monthly mean temperature and up to 17% of the observed value of the area average monthly precipitation. The study indicates that CCLM would benefit from further improvements of the time invariant boundary data, especially the soil texture data.

Parallelization of a grid-oriented model on the example of a biogenic volatile organic compounds emission model

A general fast parallelization approach of a grid-oriented model is described on the example of the semi-empirical biogenic volatile compound (BVOC) emission model (seBVOC). It uses distributed memory parallel (DMP) model relying on the MPI (message passing interface) library. The parallel version achieves nearly linear decrease in execution time as the number of processors is increased. However, with some numbers of processors the efficiency suffers from unequal load balance caused by different number of calculations within the grid cells. Application of variable domain decomposition improves the load balance adding up to 35% additional decrease of processing time.

Simulation of the Rain Belt of the West African Monsoon (WAM) in High Resolution CCLM Simulation

We present the results of our regional climate modeling experiments conducted on ForHLR1, using the consortium for small-scale modeling (COSMO) regional climate model CCLM over West Africa. This work is embedded in the context of the West African Science Service Center on Climate Change and Adapted Land Use (WASCAL) research project. We conduct nested runs at 50 and 12 km resolution driven by ERA-Interim data to assess the modeled location and intensity of the tropical rainbelt over West Africa for the period 1979–2013. The simulation period includes the years 1983 and 1999 with observed extreme anomalies (dry as well as wet). These anomalies are captured by our experiment: The model reproduces the observed zonal-mean variations in precipitation within the range of comparable regional climate model (RCM) studies, but reduces the dry bias in the Golf of Guinea and shows an increased accuracy for the driest years in general. Based on these encouraging results, we are currently extending our work towards historical climate runs and climate projections for an improved understanding of the different processes involved in the West Africa climate system and their role in generating extreme climatic conditions.