An Observing System Simulation Experiment to Assess the Potential Impact of a Virtual Mobile Communication Tower-based Observation Network on Weather Forecasting Accuracy in China. Part 1: Weather Stations with a Typical Mobile Tower Height of 40 m

Abstract

The importance of a national or regional network of meteorological stations for improving weather predictions has been recognized for many years. Ground-based automatic weather stations typically observe weather at a height of 2–10 m above ground level (AGL); however, these observations may have two major shortcomings. Large portions of data cannot be used if the station height is significantly lower than the model surface level; and such observations may contain large representativity errors as near-surface observations are often affected by the local environment, such as nearby buildings and tall trees. With the recent introduction of a significant number of mobile communication towers that are typically over 40 m AGL in China, a campaign has been proposed to use such towers to build a future observing system with an observing height of 40 m. A series of observing system simulation experiments has been conducted to assess the potential utility of such a future observing system as part of a feasibility study. The experiments were conducted using the Weather Research and Forecasting model and its Rapid Update Cycle data assimilation system. The results revealed the possibility of improving weather forecasting by raising present weather stations to a height of 40 m; this would not only enable more observations to pass the terrain check, but should also reduce interpolation errors. Additionally, improvements for temperature, humidity and wind forecasting could be achieved as the accuracy of the initial conditions increases.