Assessment of the Impact of Simulated Satellite Lidar Wind and Retrieved 183 GHz Water Vapor Observations on a Global Data Assimilation System

Hoffman, Ross N.; Grassotti, Christopher; Isaacs, Ronald G.; Louis, Jean-François; Nehrkorn, T.; Norquist, Donald C.

doi:10.1175/1520-0493(1990)118<2513:aotios>2.0.co;2

Cited by 24 publications

(28 citation statements)

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“…Over time, design criteria and rigorous evaluation procedures, which include calibration when necessary, were developed to ensure that realistic impact assessments are produced (e.g., Atlas et al 1985a,b;Atlas 1997). Over the prior three decades, realistic atmospheric OSSEs have been conducted for many purposes-for example, to evaluate the potential for future observing systems, to improve numerical weather prediction, to plan for the Global Weather Experiment, and to plan for the Earth Observing System (e.g., Atlas et al 1985aAtlas et al , 1999Atlas et al , 2001Arnold and Dey 1986;Hoffman et al 1990). The use of OSEs and OSSEs to test the impact of scatterometer winds on numerical weather prediction was reviewed by Atlas et al (2001).…”

Section: Introductionmentioning

confidence: 99%

Rigorous Evaluation of a Fraternal Twin Ocean OSSE System for the Open Gulf of Mexico

Halliwell

Srinivasan

Kourafalou

et al. 2014

Journal of Atmospheric and Oceanic Technology

102

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A new fraternal twin ocean observing system simulation experiment (OSSE) system is validated in a Gulf of Mexico domain. It is the first ocean system that takes full advantage of design criteria and rigorous evaluation procedures developed to validate atmosphere OSSE systems that have not been fully implemented for the ocean. These procedures are necessary to determine a priori that the OSSE system does not overestimate or underestimate observing system impacts. The new system consists of 1) a nature run (NR) stipulated to represent the true ocean, 2) a data assimilation system consisting of a second ocean model (the ''forecast model'') coupled to a new ocean data assimilation system, and 3) software to simulate observations from the NR and to add realistic errors. The system design is described to illustrate the requirements of a validated OSSE system. The chosen NR reproduces the climatology and variability of ocean phenomena with sufficient realism. Although the same ocean model type is used (the ''fraternal twin'' approach), the forecast model is configured differently so that it approximately satisfies the requirement that differences (errors) with respect to the NR grow at the same rate as errors that develop between state-of-the-art ocean models and the true ocean. Rigorous evaluation procedures developed for atmospheric OSSEs are then applied by first performing observing system experiments (OSEs) to evaluate one or more existing observing systems. OSSEs are then performed that are identical except for the assimilation of synthetic observations simulated from the NR. Very similar impact assessments were realized between each OSE-OSSE pair, thus validating the system without the need for calibration.

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Section: Introductionmentioning

confidence: 99%

Rigorous Evaluation of a Fraternal Twin Ocean OSSE System for the Open Gulf of Mexico

Halliwell

Srinivasan

Kourafalou

et al. 2014

Journal of Atmospheric and Oceanic Technology

102

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“…Ideally, the NR should be as far from the forecast model as the true atmosphere (Hoffman et al, 1990) is. Aside from the difficulty of attaining this goal, the creation of a NR for widespread use is a nontrivial matter.…”

Section: Tropical Cyclone Activity and Structure In Previous Nature Runsmentioning

confidence: 99%

Tropical Cyclones in the 7-km NASA Global Nature Run for Use in Observing System Simulation Experiments

Reale

Achuthavarier

Fuentes

et al. 2017

Journal of Atmospheric and Oceanic Technology

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The National Aeronautics and Space Administration (NASA) Nature Run (NR), released for use in Observing System Simulation Experiments (OSSEs), is a 2-year long global non-hydrostatic freerunning simulation at a horizontal resolution of 7 km, forced by observed sea-surface temperatures (SSTs) and sea ice, and inclusive of interactive aerosols and trace gases. This article evaluates the NR with respect to tropical cyclone (TC) activity. It is emphasized that to serve as a NR, a longterm simulation must be able to produce realistic TCs, which arise out of realistic large-scale forcings. The presence in the NR of the realistic, relevant dynamical features over the African Monsoon region and the tropical Atlantic is confirmed, along with realistic African Easterly Wave activity. The NR Atlantic TC seasons, produced with 2005 and 2006 SSTs, show interannual variability consistent with observations, with much stronger activity in 2005. An investigation of TC activity over all the other basins (eastern and western North Pacific, North and South Indian Ocean, and Australian region), together with relevant elements of the atmospheric circulation, such as, for example, the Somali Jet and westerly bursts, reveals that the model captures the fundamental aspects of TC seasons in every basin, producing realistic number of TCs with realistic tracks, life spans and structures. This confirms that the NASA NR is a very suitable tool for OSSEs targeting TCs and represents an improvement with respect to previous long simulations that have served the global atmospheric OSSE community.

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“…Generally, three basic components should be included in OSSEs (Hoffman et al, 1990): a fourdimensional reference atmosphere, often called the nature run, the purpose of which is considered to be the 'truth'; a procedure to obtain simulated observations by sampling the nature run and adding errors; and a data assimilation system, which comprises a forecast model and the analysis procedure.…”

Section: Experiments Setsmentioning

confidence: 99%

Influence of conditional nonlinear optimal perturbations sensitivity on typhoon track forecasts

Qin

2011

Quart J Royal Meteoro Soc

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This study investigates the influence on typhoon track forecasts by the Mesoscale Model5 and 3D-Var system of assimilating additional simulated dropsonde data in sensitive regions identified by Conditional Nonlinear Optimal Perturbations (CNOPs) for seven typhoons in the western North Pacific. As a reference, a similar analysis was performed for the sensitive regions identified by Singular Vectors (SVs), using the same model and assimilation system as that in the case of CNOPs.Six of the seven cases show an improvement in typhoon track forecasts, with the degree of improvement being 13%-46% in the CNOPs sensitive regions and 14%-25% in SVs sensitive regions. Furthermore, track forecasts that consider dropsonde data show improved performance not only during the optimization period for these six cases (24-48 h), when CNOPs and SVs sensitivities were calculated, but for longer forecast times of 48-72 h. However, relatively large observation errors result in reduced forecast performance for the remaining typhoon case. These results show that the deployment of dropsondes in sensitive regions identified by CNOPs has an overall positive influence on typhoon track forecasts, suggesting in turn that CNOPs can be utilized as an adaptive method in determining sensitive regions in adaptive observations.

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Assessment of the Impact of Simulated Satellite Lidar Wind and Retrieved 183 GHz Water Vapor Observations on a Global Data Assimilation System

Cited by 24 publications

References 0 publications

Rigorous Evaluation of a Fraternal Twin Ocean OSSE System for the Open Gulf of Mexico

Rigorous Evaluation of a Fraternal Twin Ocean OSSE System for the Open Gulf of Mexico

Tropical Cyclones in the 7-km NASA Global Nature Run for Use in Observing System Simulation Experiments

Influence of conditional nonlinear optimal perturbations sensitivity on typhoon track forecasts

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