Artist’s representation of how 14C produced by cosmic rays is recorded in tree ring cellulose (IMAGE)
Caption
The path of 14C from cosmic rays to cellulose. Green arrows denote newer pools of 14C and brown arrows denote older pools. The size of the arrow reflects best estimates of size of the carbon pool. During a Miyake event, (1) solar energetic particles (SEPs), likely propelled by coronal mass ejections (CME), bombard the Earth’s atmosphere, forming 14C through a cascade of nuclear interactions. Production during SEPs is strongly dependent on latitude (2), but atmospheric transport of 14C to the surface is poorly understood. Trees take up 14C through photosynthesis (3) and store it in their tissues as nonstructural carbohydrate (NSC) (4). The physiology of trees, as well as tree stress, may influence the proportion of new leaf carbon vs stored NSC, or the timing and duration of xylogenesis (5) that is allocated to new wood growth (6).
Credit
Victor Leshyk, Northern Arizona University.
Usage Restrictions
Use with appropriate credit and no modifications
License
Original content