Climate Dynamics Group
 at the University of California, Santa Cruz

The poleward transport of energy by atmospheric and oceanic circulations plays a fundamental role in many characteristics of Earth’s climate including climatological patterns of temperature and precipitation, their variability, and their changes in the future. We analyze the ways in which models are potentially biased relative to observations in their energy transport–specifically in the partitioning between atmosphere and ocean and in trends over the historical period–and the role of sub-seasonal variability in driving extreme heating events such as heat waves. Through this work, we develop a process-level understanding of the model physics at the global scale in order to assess the robustness of projected changes in energy transport and their climate impacts. This research is supported by the National Science Foundation under Award 2311541.

CMIP7 data request: Ocean and sea ice priorities and opportunities
research paper
  • Baylor Fox-Kemper
  • Patricia DeRepentigny
  • Anne Marie Treguier
  • Christian Stepanek
  • Eleanor O’Rourke
  • Chloe Mackallah
  • Alberto Meucci
  • Yevgeny Aksenov
  • Paul J. Durack
  • Nicole Feldl
  • Vanessa Hernaman
  • Céline Heuzé
  • Doroteaciro Iovino
  • Gaurav Madan
  • André L. Marquez
  • François Massonnet
  • Jenny Mecking
  • Dhrubajyoti Samanta
  • Patrick C. Taylor
  • Wan-Ling Tseng
  • Martin Vancoppenolle

Previous work identified an anthropogenic fingerprint pattern in TAC(x, t), the amplitude of the seasonal cycle of mid- to upper-tropospheric temperature (TMT), but did not explicitly consider whether fingerprint identification in satellite TAC(x, t) data could have been influenced by real-world multidecadal internal variability (MIV). We address this question here using large ensembles (LEs) performed with five climate models. LEs provide many different sequences of internal variability noise superimposed on an underlying forced signal. Despite differences in historical external forcings, climate sensitivity, and MIV properties of the five models, their TAC(x, t) fingerprints are similar and statistically identifiable in 239 of the 240 LE realizations of historical climate change. Comparing simulated and observed variability spectra reveals that consistent fingerprint identification is unlikely to be biased... read more →

An energetic perspective on heatwaves using a fixed atmospheric mass calculation of instantaneous atmospheric heat flux convergence
research paper
  • Aaron Donohoe
  • Edward Blanchard-Wrigglesworth
  • Nicole Feldl

The atmospheric energy budget associated with the heating and cooling of the atmosphere on daily time scales across the globe is analyzed using a fixed atmospheric mass calculation of the instantaneous atmospheric heat flux convergence. The heating and moistening of the atmospheric column during a typical heating event requires of order 1000 W m−2 of energy input to the atmosphere. The required energy input is predominantly provided by the atmospheric heat transport convergence. In contrast, the temporal variability of energy inputs by surface turbulent fluxes and radiation are an order of magnitude smaller. This result suggests that the atmospheric temperature variability is set by the magnitude of variability in lateral energy fluxes in the atmosphere, limited by the heat capacity of the atmosphere, and provides... read more →