Tomas Tranströmer, the 80-year-old Swedish poet deservedly honoured last October with the Nobel prize for literature, is the author of this week's poem-sequence, Six Winters, translated by Robin Fulton. It comes from his 1989 collection, För Levande och Döda (For Living and Dead) and is included in a highly recommended New Collected Poems, published recently in an expanded edition by Bloodaxe Books.

These six short imagist poems are rather like extended haiku, a form in which the poet has always excelled. They may centre on a single image, or use surreal combinations of imagery, as does the first, with its haunting triad of black hotel, sleeping child and dice. In this poem, even the proportions of the objects seem altered. The dice, having eyes, are larger and more menacing than real dice, for all that "wide-eyed", in English, has connotations of innocence. Perhaps these dice are being rolled by a vast, unseen, malevolent hand? The atmosphere is that of the child's nightmare, transposed into the winter night beyond the hotel's walls. Terse syntax heightens the strangeness, with the colon in the middle line acting as a kind of portal, similar in dramatic effect to the haiku's traditional "cutting word".

In the second poem, we're deep in the Kingdom of Winter. The concept of an "elite of the dead" is ironical and appalling. It prefigures the subsequent reference to wartime. That this is an elite of conquerors is reinforced by the entrance of the armoured wind. The dead may be reduced to emblems of grim and silent stone, but the wind from icy Svalbard "shakes" in its armour, suggesting not fear or even cold, but vigorous movement, the brandishing of noisy weapons, fresh savagery.

There's a more anecdotal tone to the next poem. "Neighbour and harpoon" are kept separate, but the imagination adds them up to the cartoonish figure of a harpoon-wielding neighbour. Perhaps the child had a half-delirious notion of the icicle as a whale, and the neighbour as a local Ahab. The poet sets these images squarely before us, not trying to make sense of them. They are simple there, elements of "unexplained memory".

The image of icicle as animal is pursued further in the next tercet. Here again we get a haunting juxtaposition – the architectural "upside-down Gothic" and the weird cow whose udders are made of icicles and resemble glass.

The fifth takes us farther beyond the window-frame. Trains are usually comforting sights, belonging to the pleasures of childhood. This one has become a wild beast, though a heraldic one, holding "the journey in its claws". As in the first terect, we sense that events have been set uncontrollably in motion. The shape of the child's unlived life is already decided by forces that cannot be checked or altered.

Of course, there is no obligation to imagine we are still in the child's world at this point. The six winters are not necessarily consecutive. They may have been picked at random from the poet's memory: some may have simply been assembled with no autobiographical intent. They could also be read as the entire life-story, moving swiftly on at the rate of one winter per decade. They might be the omniscient narrator's different views of a single winter. It's up to the reader to decide the chronology, if it exists.

An obvious reading of the sixth poem, nevertheless, would suggest a post-childhood, post-war setting, that of adolescence and first love, or even maturity and marriage. The "snow-haze" and "moonlight" are romantic images, contrasting with the earlier surreal nightmare and Gothic humour. But a characteristic flick of the wrist produces the unexpected jellyfish. "Jellyfish moonlight" packs two nouns together: although "moonlight" is a noun that may do duty as a modifier, the substantive adds more force to the image. Having seen large white jellyfish stranded on the sands at Portmeirion last summer, I find the metaphor of hazy, mis-shapen moonlight a brilliantly accurate one.

The menace of future journeys has now been left behind, and, for the first time, there is the collective pronoun, "our", providing reassurance. The isolating dread has diminished in the pleasure of a new and shared perspective. What lies ahead is only an avenue, a slender element in the journey, but a promising one. The word "bewitched" might have been ominous, but instead it seems to imply a benign and beautiful enchantment effected by snow, moonlight and companionship.

Dreams and the transitions between different levels of consciousness are suggested by the poet's very name. They are Tranströmer's territory. He worked as a psychologist for many years, and his poems seem to me to be extraordinarily honest elucidations of the "secret ministry" of the mind. From the fascinating childhood memoirs included in the Bloodaxe collection, one might guess that Tranströmer, like a number of poets, could suffer from Asperger's (see, particularly, "Museums"). How impressive it is that he has never compromised on his singular perceptions, and that the resulting poetry is so luminous, and has yielded so much meaning to his readers.

Six Winters

1

In the black hotel a child is asleep.

And outside: the winter night

where the wide-eyed dice roll.

2

An élite of the dead became stone

in Katarina Churchyard

where the wind shakes in its armour from Svalbard.

3

One wartime winter when I lay sick

a huge icicle grew outside the window.

Neighbour and harpoon, unexplained memory.

4

Ice hangs down from the roof edge.

Icicles: the upside-down Gothic.

Abstract cattle, udders of glass.

5

On a side-track, an empty railway-carriage.

Still. Heraldic.

With the journeys in its claws.

6

Tonight snow-haze, moonlight. The moonlight jellyfish itself

is floating before us. Our smiles

on the way home. Bewitched avenue.