The "U-Tube": An improved aspirated temperature system for mobile meteorological observations, especially in severe weather

Abstract

The ability to obtain quality air temperature measurements in and around thunderstorms is often problematic, and even more challenging from a moving platform such as a ground-based vehicle. Since the original Verification of the Origin of Rotation in Tornadoes Experiment (VORTEX) project in 1994-1995, mobile weather platforms known as Mobile Mesonets (MMs) from the National Severe Storms Laboratory (NSSL) and the Center for Analysis and Prediction of Stotms (CAPS) have used an aspirated temperature shield design called a "J-Tube" that address some, but not all of the issues commonly encountered. Due to these concerns, for VORTEX 2: 2009 an R.M. Young model 43408 temperature shield was added to complement the J-tube. However, it too was found to have certain shortcomings in severe weather environments. Between the end of VORTEX 2: 2009 and the start of VORTEX 2: 2010, a third new and new shield was designed, tested and installed called the "U-Tube."

The results of efforts to better characterize the J-Tube, the RM Young shield, and the design and performance characteristics of the U-Tube, in and around thunderstorms, are reported. Additionally the entire 2010 season of the VORTEX 2 project was used for an intercomparison of these shield designs. Results indicate that compared to the J-tube and the RM Young shield, the U-tube improves the response time, and reduces errors due to solar radiation, rain, varying wind directions, and speed.