JTECH paper Wang et al. 2025 published

Title

Temperature Fluctuations of Different Vertical Scales in Raw and Processed U.S. High Vertical-Resolution Radiosonde Data

Authors

Wang, L., and M. A. Geller

Published

by Journal of Atmospheric and Oceanic Technology (JTECH) at 2025-03-20

Abstract

One-second U.S. high vertical-resolution radiosonde data (HVRRD) contain two different sets of temperature data—the raw data and the processed data. The processed data have been subject to radiation corrections, which have been well documented, and smoothing, the details of which are proprietary to the radiosonde manufacturers. We have tried to characterize this smoothing by computing the root-mean-square (rms) of normalized temperature perturbations derived from removing a second-degree polynomial fit for altitude segments (Δz) from 100 m to 5 km. We find that for Δz = 100 m, rms values are larger at higher altitudes, are larger in the raw data than in the processed data, and are larger during daytime than during nighttime, for both the raw and processed data. The rms values and their daytime to nighttime differences are larger in the raw data than in the processed data. As Δz increases toward 5 km, the geographical patterns of rms over the contiguous United States from both the raw and processed data start resembling previously published gravity wave total energy patterns obtained from the older 6-s U.S. radiosonde data. An example is shown of a discontinuity in the small-scale rms values when radiosonde instrumentation is changed, so it is concluded that small-scale temperature fluctuations will be different for different radiosonde instruments. Examples are shown of enhanced small-scale rms temperature values indicative of turbulence resulting from gravity wave critical levels and from enhanced gravity waves due to seasonal maxima in convection.
 

Citation

Wang, L., and M. A. Geller, 2025: Temperature Fluctuations of Different Vertical Scales in Raw and Processed U.S. High Vertical-Resolution Radiosonde Data. J. Atmos. Oceanic Technol., 42, 309–317, https://doi.org/10.1175/JTECH-D-24-0012.1.
 

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