Science2 publishers2 min readPublished
Radiative cooling and a falling Bowen ratio nearly cancel in a new global wind theory
Malte Jansen and colleagues derive the work that drives Earth's winds from two atmospheric quantities and find that warming's effects on them almost cancel, while the same simulations push storm tracks poleward.
The Scientist · Science desk
What happened
- Malte Jansen and colleagues, writing in AGU Advances, estimate the work that drives global winds from two quantities: the height-weighted radiative energy loss of the atmosphere and a bulk Bowen ratio.
- Under current climate conditions the two warming effects the theory tracks largely cancel each other out, leaving the work output that sustains the winds close to constant.
- That near-cancellation could explain why comprehensive climate models and atmospheric reanalysis show only weak and inconsistent 21st-century changes in global wind energy dissipation.
- The authors note that a near-constant global total still allows significant shifts in circulation, and their own simulations show storm tracks moving poleward with substantial regional wind changes.
Compiled by The ScientistSomething wrong?How this is made
Why it matters
- constraint Established treatments of the heat engine run through cloud microphysics that remains poorly constrained, so diagnosing wind work from two bulk quantities moves the estimate off the part of a model least trusted.
- decision A stable global total does not underwrite any particular site, so a developer's resource case has to be argued from regional projections of where the wind goes.
- capability Two bulk quantities can be estimated for atmospheres nobody can instrument, and the authors propose using the theory to estimate circulation on exoplanets.
The Bowen ratio is where the moisture question enters. Jansen and colleagues use a bulk version: the column-integrated upward sensible heat flux divided by the latent heat flux, a measure of how much energy leaves the surface as warm air and how much as water vapor [4]. When that ratio falls with warming, the vapor share is the one growing [17]. Whether a wetter atmosphere makes the heat engine less efficient, and so weakens global wind energy dissipation, has been an open argument [13]. In this theory the moistening does cut the work output, and stronger radiative cooling in the upper troposphere pushes it back up, so the two run against each other [5].
The two-term result comes from first principles, and the authors then applied it across climate scenarios including the present one [11]. Pushed well outside today's range, the near-cancellation stops holding: in very cold climates the energy driving the winds drops sharply, matching the far less energetic circulation seen for Neoproterozoic snowball Earth [9]. The comparison there is to simulations of that climate [9].
Assessing global wind power capacity is one of the reasons the authors give for wanting wind's response to warming pinned down [12]. The quantity their theory predicts is a global total, atmospheric kinetic energy dissipation summed over the whole atmosphere, and not a wind speed at a place [20]. A turbine sees near-surface flow in one location [20].
The paper is in AGU Advances, with the DOI 10.1029/2026av002593 [2]. The account of it that has circulated is a single Eos research spotlight written by Rebecca Dzombak [15] and republished by phys.org [16], so there is one secondary write-up behind both versions [18]. I'd take the cancellation as a credible explanation for a puzzle in the model literature, and the two figures that would extend it toward a specific region, the size of the residual global change and the size of the regional changes, are not in either write-up [19].
What to watch
- A test of the two-term balance against observationally constrained reanalysis over recent decades.
- Whether other modeling groups reproduce the near-cancellation with different convection and cloud schemes.
- Whether regional wind resource assessments pick up the two-quantity diagnostic for downscaled projections.