Incremental Nonlinear Normal-Mode Initialization

Ballish, Bradley Alan; Cao, Xianhe; Kalnay, Eugenia; Kanamitsu, Masao

doi:10.1175/1520-0493(1992)120<1723:innmi>2.0.co;2

Cited by 39 publications

(20 citation statements)

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“…This problem may be further exacerbated here by the use of stratospheric and mesospheric limb measurements which have sparser spatial sampling than most nadir sounders. We plan to investigate the use of both nonlinear normal-mode initialization of analysis increments (Errico et al, 1988;Ballish et al, 1992) and other incremental analysis update methods (Bloom et al, 1996) which produce analysis fields that generate less spurious gravity wave energy in the forecasts. We are also exploring the use of NAVDAS-AR (accelerated representer), a 4DVAR assimilation algorithm that is currently being tested for operational use (Rosmond and Xu, 2006 …”

Section: Medium Range Forecast Skillmentioning

confidence: 99%

Assimilation of stratospheric and mesospheric temperatures from MLS and SABER into a global NWP model

Hoppel

Baker²,

Coy

et al. 2008

Atmos. Chem. Phys.

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Abstract. The forecast model and three-dimensional variational data assimilation components of the Navy Operational Global Atmospheric Prediction System (NOGAPS) have each been extended into the upper stratosphere and mesosphere to form an Advanced Level Physics High Altitude (ALPHA) version of NOGAPS extending to ∼100 km. This NOGAPS-ALPHA NWP prototype is used to assimilate stratospheric and mesospheric temperature data from the Microwave Limb Sounder (MLS) and the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instruments. A 60-day analysis period in January and February 2006, was chosen that includes a well documented stratospheric sudden warming. SABER and MLS temperatures indicate that the SSW caused the polar winter stratopause at ∼40 km to disappear, then reform at ∼80 km altitude and slowly descend during February. The NOGAPS-ALPHA analysis reproduces this observed stratospheric and mesospheric temperature structure, as well as realistic evolution of zonal winds, residual velocities, and Eliassen-Palm fluxes that aid interpretation of the vertically deep circulation and eddy flux anomalies that developed in response to this wavebreaking event. The observation minus forecast (O-F) standard deviations for MLS and SABER are ∼2 K in the midstratosphere and increase monotonically to about 6 K in the upper mesosphere. Increasing O-F standard deviations in the mesosphere are expected due to increasing instrument error and increasing geophysical variance at small spatial scales in the forecast model. In the mid/high latitude winter regions, 10-day forecast skill is improved throughout the upper stratosphere and mesosphere when the model is initialized using the high-altitude analysis based on assimilation of both SABER and MLS data.

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Section: Medium Range Forecast Skillmentioning

confidence: 99%

Assimilation of stratospheric and mesospheric temperatures from MLS and SABER into a global NWP model

Hoppel

Baker²,

Coy

et al. 2008

Atmos. Chem. Phys.

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“…The time integration for each forecast is carried out for 96 hours. A deterministic 6-hour forecast during the 96-hour forecast was used for the incremental normal-mode initialization (Ballish et al 1992;Murakami and Matsumura 2007) at the next initial time (see box marked as "Guess" in Fig. 2).…”

Section: B Initial Conditionmentioning

confidence: 99%

Verification of Typhoon Forecasts for a 20 km-mesh High-Resolution Global Model

Murakami

Matsumura

Sakai

et al. 2008

Journal of the Meteorological Society of Japan

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In this study, twelve tropical storms between 2002 and 2005 over the western North Pacific Ocean, namely, typhoons, were simulated through medium-range forecast experiments with the 20 km-mesh Japan Meteorological Agency (JMA) and Meteorological Research Institute (MRI) Atmospheric General Circulation Model (JM-AGCM). These simulations were compared with the 60 km-mesh JMA Global Spectral Model (GSM) to evaluate differences in resolution. They are verified with the best-track data as an observation. The verification was conducted in terms of estimating error of position, intensifying tendency, radius of 50 knot, 30 knot, and composite wind profile. This paper addresses the importance of such high resolution to predict typhoon's intensity and inner-core structure.As a result, the JM-AGCM shows slightly smaller position error than the GSM. Moreover, much improvement was seen in the intensity prediction. The JM-AGCM outstandingly can both decrease the central sea level pressure and increase maximum wind velocity, while the GSM can not simulate them because of low resolution. The JM-AGCM also shows better intensifying and decaying tendency than the GSM.The verifications of 50 knot and 30 knot radii, and the composite wind profile indicate that the typhoon structure by the JM-AGCM is quite realistic. Moreover, the JM-AGCM expresses the drastic transformation of inner-core wind profile within 100km from the typhoon center more realistically than the GSM. These results indicate that a high resolution global model, such as 20 km-mesh, is vital when discussing the intensity and wind profile of tropical storms.Corresponding author and present affiliation: Hiroyuki Murakami,

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“…A three-dimensional optimal interpolation (3DOI) scheme is used in the data assimilation cycle. An incremental nonlinear normal mode initialization (NLNMI), is applied to suppress the gravity wave growth (Ballish et al 1992). Ten day predictions are performed at every 1200 UTC, and six-hour predictions are conducted at another specified starting time, to provide the first guess field to the 3DOI assimilation system.…”

Section: Experimental Designmentioning

confidence: 99%

An Evaluation of a Mass-Flux Cumulus Parameterization Scheme in the KMA Global Forecast System

Park

Hong

2007

Journal of the Meteorological Society of Japan

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A mass-flux type cumulus parameterization scheme is evaluated in the Korea Meteorological Administration (KMA)'s Global Data Assimilation and Prediction System (GDAPS). Two sets of parallel assimilation runs, with a horizontal resolution corresponding to the spectral truncation of T213, approximately 50 km, are designed, one with the operational Kuo convection scheme, and another with a simplified Arakawa-Schubert (SAS) convection scheme, for the month of July 2001, which was a typical summer monsoon period in Korea. An additional sensitivity experiment, that excludes the moist downdrafts in the SAS scheme, is conducted. A 10-day forecast cycle is run, within a data assimilation window, beginning at every 1200 UTC in July 2001. A heavy rainfall event, that occurred in the Korean peninsula on 14-15 July 2001, is investigated in detail.For the heavy rainfall case, the SAS scheme tends to reduce the precipitation amount, as compared to the Kuo scheme. It is found that the exclusion of moist downdrafts in the SAS scheme, increases drying and heating rates, resulting in enhanced rainfall, as shown in the Kuo scheme. The monthly verification demonstrates that the systematic warm bias in the lower troposphere in the operational model is nearly absent when the SAS scheme is employed. In terms of statistical measure of the skill for the predicted sea-level pressure, and that for the upper level patterns, the experiment with the SAS (Kuo) scheme outperforms in the northern (southern) hemisphere. In the case of precipitation forecasts, the SAS scheme effectively corrects the spurious excessive precipitation over the tropical land area, due to the inclusion of moist downdrafts. However, the reduction in precipitation in the SAS scheme, deteriorates the forecast skill for high precipitation categories.

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Incremental Nonlinear Normal-Mode Initialization

Cited by 39 publications

References 0 publications

Assimilation of stratospheric and mesospheric temperatures from MLS and SABER into a global NWP model

Assimilation of stratospheric and mesospheric temperatures from MLS and SABER into a global NWP model

Verification of Typhoon Forecasts for a 20 km-mesh High-Resolution Global Model

An Evaluation of a Mass-Flux Cumulus Parameterization Scheme in the KMA Global Forecast System

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