We numerically study magnetic reconnection on different spatial scales and at different heights in the weakly ionized plasma of the low solar atmosphere ( around 300 - 800 km above the solar surface ) within a reactive 2.5 D multi-fluid plasma-neutral model .
We consider a strongly magnetized plasma ( \beta \sim 6 \% ) evolving from a force-free magnetic configuration and perturbed to initialize formation of a reconnection current sheet .
On large scales , the resulting current sheets are observed to undergo a secondary ’ plasmoid ’ instability .
A series of simulations at different scales demonstrate a cascading current sheet formation process that terminates for current sheets with width of 2m and length of \sim 100 m , corresponding to the critical current sheet aspect ratio of \sim 50 .
We also observe that the plasmoid instability is the primary physical mechanism accelerating the magnetic reconnection in this plasma parameter regime .
After plasmoid instabilities appear , the reconnection rate sharply increases to a value of \sim 0.035 , observed to be independent of the Lundquist number .
These characteristics are very similar to magnetic reconnection in fully ionized plasmas .
In this low \beta guide field reconnection regime , both the recombination and collisionless effects are observed to have a small contribution to the reconnection rate .
The simulations show that it is difficult to heat the dense weakly ionized photospheric plasmas to above 2 \times 10 ^ { 4 } K during the magnetic reconnection process .
However , the plasmas in the low solar chromosphere can be heated above 3 \times 10 ^ { 4 } K with reconnection magnetic fields of 500 G or stronger .