| 1. Identity statement | ||||
| Reference Type | Conference Paper (Conference Proceedings) | |||
| Site | mtc-m16b.sid.inpe.br | |||
| Holder Code | isadg {BR SPINPE} ibi 8JMKD3MGPCW/3DT298S | |||
| Repository | cptec.inpe.br/adm_conf/2005/10.31.12.25 | |||
| Last Update | 2006:04.16.17.09.20 (UTC) administrator | |||
| Metadata Repository | cptec.inpe.br/adm_conf/2005/10.31.12.25.54 | |||
| Metadata Last Update | 2021:02.10.19.01.55 (UTC) administrator | |||
| Secondary Key | INPE-13835-PRE/9017 | |||
| Citation Key | MendonçaBona:2006:ExEOPe | |||
| Title | Experiments with EOF-Based perturbation method to ensemble weather forecasting in middle latitudes  | |||
| Format | CD-ROM; On-line. | |||
| Year | 2006 | |||
| Access Date | 2024, Dec. 26 | |||
| Secondary Type | PRE CI | |||
| Number of Files | 1 | |||
| Size | 223 KiB | |||
| 2. Context | ||||
| Author | 1 Mendonça, Antônio Marcos 2 Bonatti, José Paulo | |||
| Resume Identifier | 1 2 8JMKD3MGP5W/3C9JHJ7 | |||
| Group | 1 DMD-INPE-MCT-BR 2 DMD-INPE-MCT-BR | |||
| Affiliation | 1 Instituto Nacional de Pesquisas Espaciais (INPE) 2 Instituto Nacional de Pesquisas Espaciais (INPE) | |||
| Author e-Mail Address | 1 mendonca@cptec.inpe.br 2 bonatti@cptec.inpe.br | |||
| Editor | Vera, Carolina Nobre, Carlos | |||
| e-Mail Address | mendonca@cptec.inpe.br | |||
| Conference Name | International Conference on Southern Hemisphere Meteorology and Oceanography, 8 (ICSHMO). | |||
| Conference Location | Foz do Iguaçu | |||
| Date | 24-28 Apr. 2006 | |||
| Publisher | American Meteorological Society (AMS) | |||
| Publisher City | 45 Beacon Hill Road, Boston, MA, USA | |||
| Pages | 1829-1832 | |||
| Book Title | Proceedings | |||
| Tertiary Type | Poster | |||
| Organization | American Meteorological Society (AMS) | |||
| History (UTC) | 2005-10-31 12:25:54 :: mendonca@cptec.inpe.br -> administrator :: 2005-11-11 21:53:48 :: administrator -> adm_conf :: 2005-12-15 23:55:00 :: adm_conf -> mendonca@cptec.inpe.br :: 2006-03-29 17:07:29 :: mendonca@cptec.inpe.br -> administrator :: 2006-04-18 21:05:28 :: administrator -> lise@dpi.inpe.br :: 2010-12-28 12:36:33 :: lise@dpi.inpe.br -> administrator :: 2010-12-29 15:57:01 :: administrator -> lise@dpi.inpe.br :: 2006 2010-12-29 16:05:56 :: lise@dpi.inpe.br -> administrator :: 2006 2010-12-29 18:52:49 :: administrator -> banon :: 2006 2011-01-02 17:14:55 :: banon -> administrator :: 2006 2021-02-10 19:01:55 :: administrator -> :: 2006 | |||
| 3. Content and structure | ||||
| Is the master or a copy? | is the master | |||
| Content Stage | completed | |||
| Transferable | 1 | |||
| Keywords | ensemble weather prediction perturbation method chaos | |||
| Abstract | The atmosphere is an example of system that presents sensitivity to the initial conditions. The importance of the initial conditions for the numerical simulation errors is explained by the theory known as chaos. Briefly, the chaos is related to the sensitivity that some non-linear dynamic systems present to the initial conditions as they evolve in the time, i.e. slightly different initial conditions may produce remarkable distinct solutions. Thus, still that model was perfect, as the real initial state of the atmosphere is not completely known, there are inevitably errors in the model analysis that will grow up with the integration time, leading to reduction of forecast quality and maintaining the impossibility of evaluate the future atmospheric conditions indefinitely. The ensemble weather forecasting approach represents a way to consider these aspects in the atmosphere prediction. The ensemble weather forecasting started operationally at the Center for Weather Forecast and Climate Studies (CPTEC) in October 2001. It is used the EOF-based perturbations method (Zhang and Krishnamurti, 1999), as modified by Coutinho (1999), to generate the perturbed initial conditions. Essentially, the method is based on: a) random perturbations are added to control initial condition to generate random perturbed initial condition; b) the full model is integrated for 36 hours starting from the control and from the perturbed initial conditions saving results each 3 hours; c) a time series is constructed for the successive differences between control and perturbed forecasts; d) an empirical orthogonal functions analysis (EOF) is performed for the time series of difference fields in order to obtain the fastest growing perturbation; e) the eigenmode associated to the largest eigenvalue is considered as the fastest growing mode; f) the fastest growing mode is normalized to pre-fixed amplitudes; g) the optimum ensemble of initial conditions is generated by adding (subtracting) this fastest eigenmode to (from) the control analysis. Currently, two runs are performed starting from 00 and 12 GMT analysis. Each run represents a set of fifteen forecasts (one control plus fourteen perturbed). The CPTEC spectral global model in a T126L28 resolution, which means a horizontal grid with about 100 km x 100 km near to Equator and 28 levels in the vertical, is used for the predictions. Coutinho (1999) used the EOF method to evaluate the tropical unstable modes and found that EOF perturbations grow up faster than random perturbations applied to the same area. In this work the EOF method is applied to extratropical latitudes in order to evaluate the extratropical perturbation characteristics and their impact in the ensemble weather forecasting. Preliminary results indicate that ensemble mean performance and ensemble spread are improved when compared to the version with tropical EOF. These results are encouraging and may contribute to improve the method used at the CPTEC. | |||
| Area | MET | |||
| Type | Weather analysis and forecasting | |||
| Arrangement | urlib.net > DIDMD > Experiments with EOF-Based... | |||
| doc Directory Content | access | |||
| source Directory Content |
| |||
| agreement Directory Content | there are no files | |||
| 4. Conditions of access and use | ||||
| data URL | http://urlib.net/ibi/cptec.inpe.br/adm_conf/2005/10.31.12.25 | |||
| zipped data URL | http://urlib.net/zip/cptec.inpe.br/adm_conf/2005/10.31.12.25 | |||
| Language | en | |||
| Target File | 1829-1832.pdf | |||
| User Group | administrator mendonca@cptec.inpe.br administrator banon | |||
| Visibility | shown | |||
| Copy Holder | SID/SCD | |||
| Read Permission | allow from all | |||
| 5. Allied materials | ||||
| Next Higher Units | 8JMKD3MGPCW/43SKC35 | |||
| Citing Item List | sid.inpe.br/bibdigital/2021/01.01.17.20 4 sid.inpe.br/mtc-m21/2012/07.13.14.52.26 3 | |||
| Host Collection | cptec.inpe.br/nobre/2005/06.02.21.14 cptec.inpe.br/walmeida/2003/04.25.17.12 | |||
| 6. Notes | ||||
| Mark | 1 | |||
| Empty Fields | archivingpolicy archivist callnumber contenttype copyright creatorhistory descriptionlevel dissemination documentstage doi edition identifier isbn issn label lineage mirrorrepository nextedition notes numberofvolumes orcid parameterlist parentrepositories previousedition previouslowerunit progress project readergroup rightsholder schedulinginformation secondarydate secondarymark serieseditor session shorttitle sponsor subject tertiarymark url versiontype volume | |||