  The dynamics of long-wavelength ($k_\theta<1.4 \mathrm{\ cm^{-1}}$),
broadband (20-200 kHz) electron temperature fluctuations ($\tilde T_e/T_e$) of
plasmas in gas-puff experiments were observed for the first time in HL-2A
tokamak. In a relative low density ($n_e(0) \simeq 0.91 \sim 1.20
\times10^{19}/m^3$) scenario, after gas-puffing the core temperature increases
and the edge temperature drops. On the contrary, temperature fluctuation drops
at the core and increases at the edge. Analyses show the non-local emergence is
accompanied with a long radial coherent length of turbulent fluctuations. While
in a higher density ($n_e(0) \simeq 1.83 \sim 2.02 \times10^{19}/m^3$)
scenario, the phenomena were not observed. Furthermore, compelling evidence
indicates that $\textbf{E} \times \textbf{B}$ shear serves as a substantial
contributor to this extensive radial interaction. This finding offers a direct
explanatory link to the intriguing core-heating phenomenon witnessed within the
realm of non-local transport.
