What are the best months to see northern lights in Alas and under what atmospheric conditions it is seen?

An aurora does not depend on the time of year, so no month is better or worse than any other. The same applies to atmospheric conditions. The reason is that an aurora is caused by high speed charged particles from the Sun being redirected down into the atmosphere over the poles by the magnetic field of the Earth. Therefore, it is the Sun which determines when or if we have an aurora. Of course, during the winter in the North the nights are longer and you are more likely to see one if there IS one happening. The Sun runs through sunspot cycles, which are much like seasons as far as the Sun is concerned, so in that respect, the Sun does have periods when more or less particles are given off per unit time which makes an aurora more or less likely. There is ONE way to tell if an aurora is likely to happen, by use of a magnetometer. The amount of charged particles impinging on the atmosphere affects the magnetic field of the Earth. So, if you see the field change a little from the average, then that MIGHT point to more particles, which might mean an aurora. This is where the magnetometer comes in. You can build one easily. Find a clear gl or plastic container. Suspend a mirror inside using something like the thinnest fishline you can find. The thinner the better. I've used a strand peeled out from a piece of dental floss. You could even use a single strand of your hair if it is long enough. It only has to be strong enough to hold the weight of the mirror and a magnet.. Attach a magnet to the mirror. The suspended mirror inside the clear container will be protected from air currents and start acting just like a comp, which is exactly what you want. Let it sit until is stops acting like a pendulum and settles to a stop and shine a light at the mirror and let the spot fall on a wall across the room. Fasten the light source so it can NOT move and use an external switch to turn the light on and off. I've used a laser pointer with great success. Mark this spot on the wall. Repeat every day at about the same time. There is a daily cycle to the magnetic field from the rotation of the Earth and the effect of the moon in orbit about the Earth. Then there is a yearly cycle from our orbit about the Sun. What you are doing is tracking the field so you know what is the average so you can then determine if there is an unusual change. It is the unusual change that you are really interested IN, as that might mean more particles, and more particles might mean an aurora is in the making. The reason for the mirror is a mechanical amplifier. You are looking for changes so small the mirror will not apparently move at all. The further away the wall is from the mirror, the smaller changes you will see in the movement of the spot as a result of the field. With the one I have, I can literally see the effect of a large metal m, a truck for example, going by my house, from the change in the field and the vibration coming through the ground. I can see the spot shake and swing in real time.