Helsinki Urban Modeling Workshop, June 2005

A recent international workshop organized through the U.S. Weather Research Program (summarized in the Bulletin of the American Meteorological Society, 86(7), pp. 961-982) concludes that enhanced three-dimensional mesoscale observing networks are critical to advancing numerical and empirical modeling for a broad spectrum of mesoscale applications, including severe weather warnings and forecasts, hydrology, air quality forecasting, chemical emergency response, transportation safety, and energy management.  Today’s mostly two-dimensional mesoscale measurement networks do not provide observations of the type, frequency, and density required to optimize mesoscale prediction and nowcasts. The mesoscale measurement challenge is best met by an integrated approach that considers all elements of an end-to-end solution: identifying end users and their needs; designing an optimal mix of observations; defining the balance between static and dynamic (targeted or adaptive) sampling strategies; establishing long-term testbeds; and developing effective implementation strategies.  Mesoscale testbeds are widely recommended as the critical bridge needed to transition from research to operations. Taking on the mesoscale challenge, the Finnish Meteorological Institute (FMI) and Vaisala, together with other public, private and academic partners in Finland, have established the Helsinki Mesoscale Testbed - an open program where collaborators are encouraged to participate. Detailed information is available at http://testbed.fmi.fi/.

International working group

Earlier this year, Professor Robert Bornstein of the San Jose State University in California proposed convening a small international working group of scientists interested in observation and simulation of urban boundary layers to explore ways in which urban modelers could make maximum use of the unique urban meteorological data sets compiled from the Helsinki Testbed.  The resulting Urban Modeling Workshop was held June 15 and 16 at the facilities of Vaisala Oyj and FMI.  In particular, the group of experts explored ways to design optimum observing and modeling strategies, and effectively use the data for modeling of physical and chemical processes within the urban boundary layer (and adjacent regions).  More than 40 scientists and engineers from seven countries participated in the workshop. 

Three broad sets of challenges were addressed:
1) network design and data requirements - what supplemental parameters might need to be observed; with what instruments; and where to locate them;
2) meso- and urban-scale modeling - what processes need to be modeled, what supplemental parameters are needed, and what additional observations are needed; also, how should these larger-scale models link to microscale models; and
3) microscale and physical modeling - what processes need to be simulated; what supplemental parameters and observations are needed; and how to link to larger-scale models.

There was consensus among the participants that the Helsinki Testbed is an invaluable resource that offers modelers and observationalists a unique opportunity to tackle the challenges of modeling a wide variety of atmospheric processes and address the needs of a broad range of practical and societally important applications, such as forecasting high-impact weather events, predicting air quality, managing emergency-response incidents, optimizing weather-sensitive transport operations, and increasing the efficiency of  energy production and consumption patterns. Workshop participants made many valuable recommendations for supplemental meteorological observations, land-surface characterization, quality assurance aspects and modeling studies. Detailed recommendations will be posted on the Helsinki Testbed website in due course.