Radiative sky cooling
A surface emitting strongly in the 8–13 µm atmospheric window and reflecting sunlight cools below ambient air temperature, even at noon, by radiating to space at ~3 K.
Atlas record: 6 claims reference this phenomenon — 3 replicated, 2 established and 1 demonstrated.
Explorerelations · matrix context · routes · sources · cite
Relations
- an emitter with high emissivity in the 8–13 µm window and high solar reflectance
- a clear sky; humidity and cloud close the window
- the cooled surface sits a few kelvin below ambient air
Matrix context
D = disequilibrium row · C = coupling family column. A cell reads the state of the atlas for that pair.
Enumerated routes through this · 60 (showing 24)
- Passive daytime radiative cooler2/2 est · demonstrated
- Night-time radiative-cooling thermoelectric generator5/5 est · demonstrated
- Radiative imbalance with the sky → Radiative sky cooling → Temperature gradient → Thermal emission → Light4/4 est · same energy form
- Radiative imbalance with the sky → Radiative sky cooling → Temperature gradient → Alkali-metal thermal-to-electric conversion → Ionic current → Electrical work3/5 est · extends a recorded pathway
- Radiative imbalance with the sky → Radiative sky cooling → Temperature gradient → Ionic thermoelectric effect → Ionic current → Electrical work5/5 est · candidate
- Radiative imbalance with the sky → Radiative sky cooling → Temperature gradient → Marangoni effect → Mechanical motion → Mechanical work5/5 est · extends a recorded pathway
- Radiative imbalance with the sky → Radiative sky cooling → Temperature gradient → Thermal shape-memory effect → Mechanical motion → Mechanical work5/5 est · extends a recorded pathway
- Radiative imbalance with the sky → Radiative sky cooling → Temperature gradient → Thermochemical redox cycle → Chemical fuel (H₂, CO, syngas) → Chemical fuel5/5 est · candidate
- Radiative imbalance with the sky → Radiative sky cooling → Temperature gradient → Thermopolarization effect → Separated surface charge → Electrical work3/5 est · weakly supported
- Radiative imbalance with the sky → Radiative sky cooling → Temperature gradient → Thermopolarization effect → Separated surface charge → Electrical work3/5 est · weakly supported
- Radiative imbalance with the sky → Radiative sky cooling → Temperature gradient → Heat conduction → Heat flow → Useful heat5/5 est · extends a recorded pathway
- Radiative imbalance with the sky → Radiative sky cooling → Temperature gradient → Thermionic emission → Charge carriers → Electrical work5/5 est · extends a recorded pathway
- Radiative imbalance with the sky → Radiative sky cooling → Temperature gradient → Thermogalvanic effect → Ionic current → Electrical work5/5 est · extends a recorded pathway
- Radiative imbalance with the sky → Radiative sky cooling → Temperature gradient → Thermally regenerative electrochemical cycle → Ionic current → Electrical work3/5 est · extends a recorded pathway
- Radiative imbalance with the sky → Radiative sky cooling → Temperature gradient → Nernst effect → Charge carriers → Electrical work5/5 est · extends a recorded pathway
- Radiative imbalance with the sky → Radiative sky cooling → Temperature gradient → Anomalous Nernst effect → Charge carriers → Electrical work5/5 est · extends a recorded pathway
- Radiative imbalance with the sky → Radiative sky cooling → Temperature gradient → Working-fluid expansion (heat-engine cycle) → Mechanical motion → Mechanical work5/5 est · extends a recorded pathway
- Radiative imbalance with the sky → Radiative sky cooling → Temperature gradient → Ocean thermal energy conversion → Mechanical motion → Mechanical work3/5 est · candidate
- Radiative imbalance with the sky → Radiative sky cooling → Temperature gradient → Advective heat transport → Heat flow → Useful heat5/5 est · extends a recorded pathway
- Radiative imbalance with the sky → Radiative sky cooling → Temperature gradient → Thermo-osmosis → Streaming potential → Ionic current → Electrical work5/6 est · extends a recorded pathway
- Radiative imbalance with the sky → Radiative sky cooling → Temperature gradient → Thermomagnetic convection → Electromagnetic induction → Charge carriers → Electrical work5/6 est · extends a recorded pathway
- Radiative imbalance with the sky → Radiative sky cooling → Temperature gradient → Soret effect → Concentration gradient → Chemiosmosis → Chemical fuel6/6 est · extends a recorded pathway
- Radiative imbalance with the sky → Radiative sky cooling → Temperature gradient → Thermal expansion → Mechanical stress or strain → Elastocaloric effect → Cooling5/6 est · candidate
- Radiative imbalance with the sky → Radiative sky cooling → Temperature gradient → Thermal expansion → Mechanical stress or strain → Elastocaloric effect → Useful heat5/6 est · candidate
Cited sources · 4
- [1]A. P. Raman et al.. Passive radiative cooling below ambient air temperature under direct sunlight (2014)
- [2]A. P. Raman, W. Li, S. Fan. Generating light from darkness (2019)
- [3]J.-l. Kou et al.. Daytime radiative cooling using near-black infrared emitters (2017)
- [4]Y. Zhai et al.. Scalable-manufactured randomized glass-polymer hybrid metamaterial for daytime radiative cooling (2017)
Cite this entity
Physical Transformation Atlas (2026). entity phenomenon:radiative-cooling: Radiative sky cooling. Dataset revision rbfbfcbb70e57 (hash of the canonical data). https://physical-transformation-atlas.wldud5192.workers.dev/phenomenon/radiative-cooling
Ids and matrix addresses are stable across revisions; the revision hash identifies the exact canonical files the record was compiled from and is meta.data_hash in every /api export. Reuse terms: see the license field in any export.