An Empirical Mid-Latitude Model of the CkL Irregularity Index from 35 MHz Scintillation Data

This paper summarizes work focused on improving the ability to assess and predict the level of km-scale ionospheric irregularities at mid-latitudes based on a recently developed capability to measure 35 MHz scintillations using cosmic radio sources. The Deployable Low-band Ionosphere and Transient Experiment (DLITE) is a low-cost, interferometric radio telescope optimized for ionospheric remote sensing rather than sensitive astronomical imaging.  DLITE uses intensity scintillations of a handful of exceptionally bright cosmic radio sources to characterize the level of km-scale irregularities via the C_kL irregularity index, which is proportional to the vertically integrated electron density variance.  DLITE arrays are currently operational in Maryland, New Mexico, and Florida.  Here, we describe a spherical harmonic-based model fit to log₁₀C_kL measurements from these arrays that includes a term for short-term forecasting (~1-3 days).  We will show that meter-scale irregularity activity detected with the Blackstone, Virginia SuperDARN radar correlates with C_kL nowcasts/forecasts, indicating that model performs reasonably well.