What is the role of the word "autumn" in Notes for Friends in the North on a Rainy Night besides explaining the seasons?

The word "autumn" in Notes for Friends in the North on a Rainy Night has the following functions besides explaining the seasons:

1, the sad atmosphere is rendered from the side, creating a lonely atmosphere for the whole poem;

2. Taking advantage of the image characteristics of depression in autumn, the poet's sadness is entrusted, suggesting that the poet misses his wife in the lingering autumn rain.

Original text:

A note to a friend in Bei Tang on a rainy night: Li Shangyin.

When you ask about the return date, it's hard to say, evening rain, Manqiuchi.

When * * * cut the candle at the west window, but talk about the rain at night.

Translation:

You asked me when I would go home, but I'm not sure of the date! The only thing I can tell you at this time is that this endless late rain is full of autumn pools. If one day, we will sit together at home under the west window, cut candles and flowers, and talk to each other about our thoughts in the rainy night tonight.

Extended data

This poem is selected from Volume III of Yuxi Shi Sheng, which was written by Li Shangyin when he was in Bashu (present-day Sichuan). Because Chang 'an is in the north of Bashu, it is entitled "A note to friends in the north on a rainy night".

In Ten Thousand Tang Poems edited by Hong Mai in the Southern Song Dynasty, the title of this poem is Rain at Night, which means this poem is for his wife. In their view, Li Shangyin went to Dongchuan in July of the fifth year of Dazhong (85 1), and Wang died at the turn of summer and autumn this year. It was several months before Li Shangyin learned of his wife's death.

The note to friends in the north on a rainy night is the title of Shi Li's poems. "North" refers to people in the north, either wives or friends. Some people think that it was written after the death of the author's wife Wang, so it is not a poem "Send Inside", but a gift to friends in Chang 'an.

As far as the content of poetry is concerned, if we understand it by "sending it inside", we will feel sad and lingering; Think of it as "north delivery", too delicate, too plain and too delicate.