What are some examples of experimentally confirmed quantum effects at macroscopic level? Please only answer with detailed description and explanations It would be very helpful if you can give a few examples that are at micrometer level or above, and include some explanations or insight on the causes of these behaviors.
 A: Black body radiation. . It cannot be fitted classically. It needs quantum mechanics.
The atomic spectra can only be explained by quantum mechanics.
A: Just two simple examples: 
(1) The decrease of specific heat with temperature. 
(2) Superconductivity.
A: The periodic table of elements. Explainable using Schrödinger's equation, electron spin and the exclusion principle.
A: This is an interesting question. Macroscopic instances of quantum phenomena are usually very dependent on how people interpret quantum mechanics. For some, quantum phenomena are exclusively microscopic so that the macroscopic effects that we see are mere consequence of microscopic quantum phenomena, but not quantum phenomena in and of themselves.
One clear example is that of semiconductors and transistors. In both cases, the underlying theory is manifestly quantum mechanical. Both systems are essential components of modern electronic devices. But would you say that a computer or a smartphone are quantum systems? Conventionally speaking, the answer would be no.
I do have a goodie for you, however. It consists of an experiment in fluid dynamics that exhibits such strong analogies to exclusively quantum phenomena that it has been cited as evidence for the Pilot Wave interpretation of QM. I'll let this Veritasium video paint the rest of the picture for you:
A: According to Seth Lloyd (MIT), the phenomenon of birds migrating, photosynthesis, and even smelling and sneezing might be explained by quantum physics in addition to chemistry. 
A: line emission spectra of elements. lasers and masers. 
