Sensitivity of Surface Analyses to Mobile Observations

Weather Telematics and Global Science & Technology Inc. collaborate to provide environmental observations collected on board commercial vehicles to the National and Oceanic Atmospheric Administration. The Mobile Platform Environmental Data (MoPED) system acquires the data from over 600 vehicles that are travelling primarily during weekday daylight hours along major transportation routes in the eastern third of the United States as well as a more limited amount of highway routes in the West. MoPED observations at subminute intervals of temperature, pressure, and relative humidity are accessed and bundled at the University of Utah into 5 minute median values. Utilizing the 12 values available for each hour, over 2500 observations are available typically to use in surface analyses of temperature, relative humidity, and dew point temperature as part of the University of Utah Two-Dimensional Variational Analysis (UU2DVAR) system. The UU2DVAR analyses at 2.5 km horizontal resolution incorporate an additional ~12,000 observations within the continental United States from fixed sites.

The impact on the hourly surface analyses to the MoPED observations is assessed. Statistics on model improvement as a function of network (ASOS, RAWS, CWOP, MoPED, etc.) have been collected since March 2014. Generally, the quality of the MoPED observations are comparable to those from other networks. MoPED observations provide the greatest improvement to the surface analyses during active weather periods in rural highway stretches in the southeastern United States where routine weather observations tend to be sparse.