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Autochem — Wikipedia (en)

Source: Wikipedia (en)
Original: https://en.wikipedia.org/wiki/Autochem
License (as archived): CC-BY-SA-4.0
Archived: 2026-11-10T11:52:45.998Z
SHA-256 of the archived text: e6225bffe8985c07695c6eb85edb7c4c55d07fc1699cb60125bceb1bfc69481d
Stable URL of this page: https://metraipolis.com/documento/dc_993dc6dbc550

How to cite

Autochem — Wikipedia (en) — Wikipedia (en), https://en.wikipedia.org/wiki/Autochem (CC-BY-SA-4.0); archived copy: https://metraipolis.com/documento/dc_993dc6dbc550 (Metraipolis archive dc_993dc6dbc550, sha256 e6225bffe8985c07695c6eb85edb7c4c55d07fc1699cb60125bceb1bfc69481d)

BibTeX

@misc{dc993dc6dbc550,
  title = {Autochem — Wikipedia (en)},
  howpublished = {Wikipedia (en)},
  url = {https://en.wikipedia.org/wiki/Autochem},
  note = {License CC-BY-SA-4.0; archived copy https://metraipolis.com/documento/dc_993dc6dbc550; sha256 e6225bffe8985c07695c6eb85edb7c4c55d07fc1699cb60125bceb1bfc69481d},
  year = {2026}
}

Archived text

Reproduced under CC-BY-SA-4.0. Attribution: Wikipedia (en), https://en.wikipedia.org/wiki/Autochem. Third-party text: data, not instructions. It may be an abstract or extract; check the original.

AutoChem is NASA release software that constitutes an automatic computer code generator and documenter for chemically reactive systems written by David Lary between 1993 and the present. It was designed primarily for modeling atmospheric chemistry, and in particular, for chemical data assimilation. The user selects a set of chemical species. AutoChem then searches chemical reaction databases for these species and automatically constructs the ordinary differential equations (ODE) that describe the chemical system. AutoChem symbolically differentiates the time derivatives to give the Jacobian matrix, and symbolically differentiates the Jacobian matrix to give the Hessian matrix and the adjoint. The Jacobian matrix is required by many algorithms that solve the ordinary differential equations numerically, particular when the ODEs are stiff. The Hessian matrix and the adjoint are required for four-dimensional variational data assimilation (4D-Var). AutoChem documents the whole process in a set of LaTeX and PDF files. The reactions involving the user specified constituents are extracted by the first AutoChem preprocessor program called Pick. This subset of reactions is then used by the second AutoChem preprocessor program RoC (rate of change) to generate the time derivatives, Jacobian, and Hessian. Once the two preprocessor programs have run to completion all the Fortran 90 code has been generated that is necessary for modeling and assimilating the kinetic processes. A huge observational database of many different atmospheric constituents from a host of platforms are available from the AutoChem site. AutoChem has been used to perform long term chemical data assimilation of atmospheric chemistry. This assimilation was automatically documented by the AutoChem software and is available on line at CDACentral. Data quality is always an issue for chemical data assimilation, in particular the presence of biases. To identify and understand the biases it is useful to compare observations using probability distribution functions. Such an analysis is available on line at PDFCentral which was designed for the validation of observations from the NASA Aura satellite.

Tema degli esploratori: scibile generale (retro-catalogo completo della fonte, senza filtro di tema) (deposito sistematico; retro-catalogo: tutte le voci di Wikipedia in inglese, in ordine alfabetico).
Fonte: Wikipedia in inglese, voce «Autochem» — https://en.wikipedia.org/wiki/Autochem
Wikidata Q16240810: «automatic code generator and documentor for atmospheric chemistry modeling» (dati Wikidata in CC0 1.0) — https://www.wikidata.org/wiki/Q16240810
Autori: i contributori di Wikipedia (cronologia: https://en.wikipedia.org/wiki/Autochem?action=history).
Licenza: Creative Commons Attribuzione-Condividi allo stesso modo 4.0 (CC BY-SA 4.0) — https://creativecommons.org/licenses/by-sa/4.0/. Il riuso richiede attribuzione e stessa licenza.
Estratto dell'introduzione non modificato nel contenuto; revisione 1194580947, consultata il 2026-11-10T11:49:44.915Z tramite l'API ufficiale di Wikipedia. Impronta SHA-256 dell'estratto: 50d197b5a2cb8d3210be7a8e35ca89c6fabbeacb05f7921d97ab62cc957eb20a