New paper published in Global Change Biology
New paper titled “Two sub-annual timescales and coupling modes for terrestrial water and carbon cycles” is now published online in Global Change Biology. Dr. Dan Gianotti from MIT CEE is the lead author while Xiangtao Xu of the BioM2 Lab is a co-author. Using remote sensing data, the study identifies two dominant modes of terrestrial water and carbon cycles across the contiguous United States: (1) a negative-correlation timescale on the order of a few days, during which landscapes dry after precipitation and plants increase their carbon uptake through photosynthetic upregulation, and (2) a slow, seasonal-scale positive covariation through which landscape drying leads to decreased growth and carbon uptake. The spatial pattern of local temporal dynamics — positively sloped tangent lines to a convex long-term mean-state curve — is surprisingly strong and can serve as a benchmark for coupled Earth System Models. The study shows that many such models do not represent this emergent mean-state pattern, and hypothesizes that this may be due to a lack of water-carbon feedbacks at daily scales.