Impact of enriched analyses on regional numerical forecasts over Southeastern South America during salljex

During the warm season 2002-2003, the South American Low-Level Jet Experiment (SALLJEX) was carried out in southeastern South America. Taking advantage of the unique database collected in the region, a set of analyses is generated for the SALLJEX period assimilating all available data. The spatial a...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: García Skabar, Y., Nicolini, M.
Formato: JOUR
Materias:
Data assimilation
Numerical forecasts
SALLJEX
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_01027786_v29_n3_p315_GarciaSkabar
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id todo:paper_01027786_v29_n3_p315_GarciaSkabar
record_format dspace
spelling todo:paper_01027786_v29_n3_p315_GarciaSkabar2023-10-03T14:57:28Z Impact of enriched analyses on regional numerical forecasts over Southeastern South America during salljex García Skabar, Y. Nicolini, M. Data assimilation Numerical forecasts SALLJEX During the warm season 2002-2003, the South American Low-Level Jet Experiment (SALLJEX) was carried out in southeastern South America. Taking advantage of the unique database collected in the region, a set of analyses is generated for the SALLJEX period assimilating all available data. The spatial and temporal resolution of this new set of analyses is higher than that of analyses available up to present for southeastern South America. The aim of this paper is to determine the impact of assimilating data into initial fields on mesoscale forecasts in the region, using the Brazilian Regional Atmospheric Modeling System (BRAMS) with particular emphasis on the South American Low-Level Jet (SALLJ) structure and on rainfall forecasts. For most variables, using analyses with data assimilated as initial fields has positive effects on short term forecast. Such effect is greater in wind variables, but not significant in forecasts longer than 24 hours. In particular, data assimilation does not improve forecasts of 24-hour accumulated rainfall, but it has slight positive effects on accumulated rainfall between 6 and 12 forecast hours. As the main focus is on the representation of the SALLJ, the effect of data assimilation in its forecast was explored. Results show that SALLJ is fairly predictable however assimilating additional observation data has small impact on the forecast of SALLJ timing and intensity. The strength of the SALLJ is underestimated independently of data assimilation. However, Root mean square error (RMSE) and BIAS values reveal the positive effect of data assimilation up to 18-hours forecasts with a greater impact near higher topography. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_01027786_v29_n3_p315_GarciaSkabar
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Data assimilation
Numerical forecasts
SALLJEX
spellingShingle Data assimilation
Numerical forecasts
SALLJEX
García Skabar, Y.
Nicolini, M.
Impact of enriched analyses on regional numerical forecasts over Southeastern South America during salljex
topic_facet Data assimilation
Numerical forecasts
SALLJEX
description During the warm season 2002-2003, the South American Low-Level Jet Experiment (SALLJEX) was carried out in southeastern South America. Taking advantage of the unique database collected in the region, a set of analyses is generated for the SALLJEX period assimilating all available data. The spatial and temporal resolution of this new set of analyses is higher than that of analyses available up to present for southeastern South America. The aim of this paper is to determine the impact of assimilating data into initial fields on mesoscale forecasts in the region, using the Brazilian Regional Atmospheric Modeling System (BRAMS) with particular emphasis on the South American Low-Level Jet (SALLJ) structure and on rainfall forecasts. For most variables, using analyses with data assimilated as initial fields has positive effects on short term forecast. Such effect is greater in wind variables, but not significant in forecasts longer than 24 hours. In particular, data assimilation does not improve forecasts of 24-hour accumulated rainfall, but it has slight positive effects on accumulated rainfall between 6 and 12 forecast hours. As the main focus is on the representation of the SALLJ, the effect of data assimilation in its forecast was explored. Results show that SALLJ is fairly predictable however assimilating additional observation data has small impact on the forecast of SALLJ timing and intensity. The strength of the SALLJ is underestimated independently of data assimilation. However, Root mean square error (RMSE) and BIAS values reveal the positive effect of data assimilation up to 18-hours forecasts with a greater impact near higher topography.
format JOUR
author García Skabar, Y.
Nicolini, M.
author_facet García Skabar, Y.
Nicolini, M.
author_sort García Skabar, Y.
title Impact of enriched analyses on regional numerical forecasts over Southeastern South America during salljex
title_short Impact of enriched analyses on regional numerical forecasts over Southeastern South America during salljex
title_full Impact of enriched analyses on regional numerical forecasts over Southeastern South America during salljex
title_fullStr Impact of enriched analyses on regional numerical forecasts over Southeastern South America during salljex
title_full_unstemmed Impact of enriched analyses on regional numerical forecasts over Southeastern South America during salljex
title_sort impact of enriched analyses on regional numerical forecasts over southeastern south america during salljex
url http://hdl.handle.net/20.500.12110/paper_01027786_v29_n3_p315_GarciaSkabar
work_keys_str_mv AT garciaskabary impactofenrichedanalysesonregionalnumericalforecastsoversoutheasternsouthamericaduringsalljex
AT nicolinim impactofenrichedanalysesonregionalnumericalforecastsoversoutheasternsouthamericaduringsalljex
_version_ 1782026498084962304

Ejemplares similares