||Rapid variability at the footpoints of active region coronal loops has been observed (Testa et al. 2013, 2014), and provides powerful diagnostics of the properties of coronal heating and energy transport (e.g., Testa et al. 2014, Polito et al. 2018).
We will present results of our detailed analysis of a dozen of IRIS/AIA observations of footpoints brightenings associated with coronal heating, and will present the distribution of the observed properties (e.g., duration of brightenings, intensity ratios, Doppler shifts, non-thermal broadening,..). We will discuss the properties of coronal heating as inferred from the coupling of these high spatial, spectral, and temporal resolution chromospheric/transition region/coronal observations, with modeling.
We will also present results of a new algorithm we have developed for an automatic detection of these footpoint brightenings in AIA observations (Graham et al. 2019), which will allow us, in our next step, to significantly expand the number of events detected, and build more robust statistics of the properties of nanoflares in active region loops.