Radiative impact of ozone on temperature predictability in a coupled chemistry-dynamics data assimilation system

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Authors
De Grandpré, J.
Ménard, R.
Rochon, Y.J.
Charette, C.
Chabrillat, S.
Robichaud, A.
Discipline
Earth and related Environmental sciences
Subject
Assimilation system
Coupled chemistry
Coupled models
Data assimilation
Data assimilation systems
FORECAST model
Linearized methods
Lower stratosphere
Michelson interferometer for passive atmospheric soundings
Non-interactive
Northern Hemispheres
Ozone analysis
Ozone assimilation
Ozone distribution
Ozone forecast
Ozone forecasting
Ozone measurements
Photochemical interactions
Radiative impacts
Root-mean square errors
Southern Hemisphere
Stratospheric chemistry
Temperature forecasts
Time-scales
Variational data assimilation
Atmospheric spectra
Atmospherics
Climatology
Data processing
Heating
Heating rate
Michelson interferometers
Ozone
Radiosondes
Sulfur compounds
Systematic errors
Three dimensional
Upper atmosphere
Value engineering
Weather forecasting
Atmospheric temperature
air temperature
climate prediction
data assimilation
Northern Hemisphere
ozone
radiative forcing
radiosonde
Southern Hemisphere
stratosphere-troposphere interaction
weather forecasting
Audience
Scientific
Date
2009Metadata
Show full item recordDescription
The objective of this study is to investigate the impact on temperature forecast of using ozone analyses for the computation of heating rates in a three-dimensional variational data assimilation (3D-Var) system with a coupled model. The system is based on a tropospheric-stratospheric forecast model that includes a comprehensive stratospheric chemistry module for online resolution of the dynamical, radiative, and photochemical interactions. The system assimilates conventional observations as well as temperature and ozone measurements from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instrument. Several data assimilation cycles have been performed over the period August-October 2003 to produce a set of analyses that have been used for launching an ensemble of 10-day forecasts. Temperature and ozone forecasts have been compared with MIPAS and radiosonde observations in different regions. Results show that, in the absence of ozone assimilation, the impact of using a prognostic ozone distribution for the computation of heating rates as opposed to monthly mean climatologies is generally neutral. With the addition of ozone assimilation, the improvement against a noninteractive assimilation system is systematic and occurs over a wide range of time scales throughout the lower stratosphere. The improvement on 6-h temperature forecasts is mainly seen in the Southern Hemisphere, where ozone analyses are in good agreement with observations. For 10-day forecasts, the impact of using ozone analyses is more important in the Northern Hemisphere, where it improves the temperature predictability by more than 1 day at 50 hPa. Comparisons with analyses also show a systematic reduction of the temperature root-mean-square errors and biases throughout the assimilation period. The overall results demonstrate that a comprehensive coupled 3D-Var system that incorporates the radiative feedback from ozone analyses can be used for improving temperature predictability throughout the stratosphere. Comprehensive approaches can be used as a benchmark for the development of linearized methods for improving temperature and ozone forecasting in the region. © 2009 American Meteorological Society.
Citation
De Grandpré, J.; Ménard, R.; Rochon, Y.J.; Charette, C.; Chabrillat, S.; Robichaud, A. (2009). Radiative impact of ozone on temperature predictability in a coupled chemistry-dynamics data assimilation system. , Monthly Weather Review, Vol. 137, Issue 2, 679-692, DOI: 10.1175/2008MWR2572.1.Identifiers
scopus: 2-s2.0-68249144478
Type
Article
Peer-Review
Yes
Language
eng