Possible application of GPS RO refractivity to study wave amplitude enhancements at the tropopause region

A. DE LA TORRE, P. ALEXANDER, P. LLAMEDO, R. HIERRO, T. SCHMIDT, J. WICKERT

Bremen

Congreso; COSPAR; 2010

In the last years, diverse climatologies of the global wave activity derived from GPS radio occultation temperature profiles posed the following question: To what extent are the enhancements systematically observed below and at tropopause levels due to physical processes (critical level interactions, reflection, abrupt changes in lapse rates and stability) or to a simple artifact generated by a digital filter used to isolate the wave component? These processes must be closely related to the balance between up and down-going waves.We discuss here the possibility of deriving the temperature variance at the tropopause region from the relative refractivity, making use of the less abrupt variability of this last parameter. We filter measured refractivity profiles at mid latitudes, verifying the expected equivalence between the relative temperature and refractivity variances, at pressure levels well below and above the tropopause region. In this test, we use previous results obtained to estimate the uncertainty in the calculation of wave potential energy, due exclusively to the filtering process of vertical temperature profiles