{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"53a993a13c8eb3dae0124e72af1cf28cf1d94e170384726210b625a447b87e5c","created":"2026-10-03T07:18:02Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["0c7c9ed5e2d8fd1bd3bece5152d8c6e1a644e52fc34fec7edad9f38e0680915e","5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"8aa4c0bd824123bdc38a1e641dcf1397c27587e692b32315c63b80eeb576742f","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"earth.climate-sensitivity.anvil-feedback","kind":"well-posed","literature_status":"open","n":"1","parents":[{"note":"","parent_revision":"0c7c9ed5e2d8fd1bd3bece5152d8c6e1a644e52fc34fec7edad9f38e0680915e","relation":"special_case"}],"plain":"High, thin anvil-shaped clouds spread out from tropical thunderstorms and trap heat. If they shrink with warming, more heat escapes to space, a cooling effect called the 'iris' hypothesis, but its size is debated.","posed_since":"","precise":"The tropical anvil cloud area feedback was assessed at about $-2e2 \\pm 2e2\\,\\mathrm{erg}/(\\mathrm{s}\\,\\mathrm{cm}^2\\,\\mathrm{K})$ (Sherwood and coauthors 2020), while the iris hypothesis (Lindzen and coauthors 2001) argued for a much more negative value. Determine the global anvil-area feedback and its mechanism (stability iris, changes in convective aggregation, anvil lifetime and microphysics) with uncertainty below about $1e2\\,\\mathrm{erg}/(\\mathrm{s}\\,\\mathrm{cm}^2\\,\\mathrm{K})$.","problem_ref":null,"references":"","settled_by":"Cloud-resolving simulations under warming with resolved anvil microphysics, validated against satellite relations between anvil area, cloud radiative effect and surface temperature.","status_note":"McKim, Bony and Dufresne (Nature Geoscience 2024, https://doi.org/10.1038/s41561-024-01414-4) argued that physical and observational constraints imply a weak anvil-area feedback.","title":"How much do tropical anvil clouds shrink as Earth warms?","topic_ref":"9825ae6297d7163c036f24262af4c46a63835d02712ce8b2f6de7b3820ec47e6"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"e3bbdb80b1761eb35e366cc44246dc1765a31295fd901b3efc88ca639aedd406","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"369537b8c4977f2e0ac4a36738d2feda3d303b7f2d0aebea0196862d4232b132","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"2fDxQslKn1f4yZ_kqMGOodjSKonNVoaAqOrR3_0u4714CIHT00y_Ylwc0N3VGULeXzrNHYkYOsn6m4wCmTTQAg"},"schema":"pubphys.envelope/1"},"record_hash":"e3bbdb80b1761eb35e366cc44246dc1765a31295fd901b3efc88ca639aedd406","leaf_index":1298}