Toward Optimal Choices of Control Space Representation for Geophysical Data Assimilation

Bocquet, Marc
July 2009
Monthly Weather Review;Jul2009, Vol. 137 Issue 7, p2331
Academic Journal
In geophysical data assimilation, observations shed light on a control parameter space through a model, a statistical prior, and an optimal combination of these sources of information. This control space can be a set of discrete parameters, or, more often in geophysics, part of the state space, which is distributed in space and time. When the control space is continuous, it must be discretized for numerical modeling. This discretization, in this paper called a representation of this distributed parameter space, is always fixed a priori. In this paper, the representation of the control space is considered a degree of freedom on its own. The goal of the paper is to demonstrate that one could optimize it to perform data assimilation in optimal conditions. The optimal representation is then chosen over a large dictionary of adaptive grid representations involving several space and time scales. First, to motivate the importance of the representation choice, this paper discusses the impact of a change of representation on the posterior analysis of data assimilation and its connection to the reduction of uncertainty. It is stressed that in some circumstances (atmospheric chemistry, in particular) the choice of a proper representation of the control space is essential to set the data assimilation statistical framework properly. A possible mathematical framework is then proposed for multiscale data assimilation. To keep the developments simple, a measure of the reduction of uncertainty is chosen as a very simple optimality criterion. Using this criterion, a cost function is built to select the optimal representation. It is a function of the control space representation itself. A regularization of this cost function, based on a statistical mechanical analogy, guarantees the existence of a solution. This allows numerical optimization to be performed on the representation of control space. The formalism is then applied to the inverse modeling of an accidental release of an atmospheric contaminant at European scale, using real data.


Related Articles

  • Ozone measurements at the mountain station Zavižan (Croatia) for 1997-2000. Cvitaš, Tomislav; Kezele, Nenad; Klasinc, Leo; Šorgo, Glenda // Geofizika;2007, Vol. 24 Issue 2, p109 

    Analysis of ozone concentrations measured at Zaviźan, Croatia's highest altitude meteorological station (1594 m a.s.l.), during the spring and summer months of 1997–2000 shows that the actual new Croatian Air Quality standards are severely exceeded. Implication of this and similar...

  • Improved retrieval of global tropospheric formaldehyde columns from GOME-2/MetOp-A addressing noise reduction and instrumental degradation issues. De Smedt, I.; Van Roozendael, M.; Stavrakou, T.; Müller, J.-F.; Lerot, C.; Theys, N.; Valks, P.; Hao, N.; van der A, R. // Atmospheric Measurement Techniques;2012, Vol. 5 Issue 11, p2933 

    The article discusses a study that presents a dataset of formaldehyde vertical columns retrieved from observations of GOME-2 on board the EUMETSAT MetOp-A platform between 2007 and 2011. It shows that the is ideally suited to support global air quality and chemistry-climate related studies. It...

  • Daily CO2 flux estimates over Europe from continuous atmospheric measurements: 1, inverse methodology. Peylin, P.; Rayner, P. J.; Bousquet, P.; Carouge, C.; Hourdin, F.; Heinrich, P.; Ciais, P. // Atmospheric Chemistry & Physics Discussions;2005, Vol. 5 Issue 2, p1647 

    This paper presents a method for inferring trace gas fluxes at high temporal and spatial resolution from atmospheric concentration measurements. The method is designed for regional applications and for use in intensive campaigns. We apply the method to a one month inversion of fluxes over...

  • Analysis of Air Quality in Eastern China and its Interaction with Other Regions of the World. Zhao, Chunsheng; Tie, Xuexi; Wang, Geli; Qin, Yu; Wang, Peicai // Journal of Atmospheric Chemistry;Nov2006, Vol. 55 Issue 3, p189 

    In this study, we used satellite data (GOME and MOPITT) together with a global chemical-transport-model of atmosphere (MOZART-2) to characterize the chemical/aerosol composition over eastern China. We then estimated the effects of local emissions in China on the chemical budgets in other regions...

  • Evaluation of the United States National Air Quality Forecast Capability experimental real-time predictions in 2010 using Air Quality System ozone and NO2 measurements. T. Chai; H. C. Kim; P. Lee; D. Tong; L. Pan; Y. Tang; J. Huang; McQueen, J.; Tsidulko, M.; Stajner, I. // Geoscientific Model Development;2013, Vol. 6 Issue 5, p1831 

    The National Air Quality Forecast Capability (NAQFC) project provides the US with operational and experimental real-time ozone predictions using two different versions of the three-dimensional Community Multi-scale Air Quality (CMAQ) modeling system. Routine evaluation using near-real-time...

  • Development of a global model of mineral dust aerosol microphysics. Lee, Y. H.; Chen, K.; Adams, P. J. // Atmospheric Chemistry & Physics;2009, Vol. 9 Issue 7, p2441 

    A mineral dust module is developed and implemented into the global aerosol microphysics model, GISSTOMAS. The model is evaluated against long-term measurements of dust surface mass concentrations and deposition fluxes. Predicted mass concentrations and deposition fluxes are in error on average...

  • Tree-ring growth recovers, but δC and δN do not change, after the removal of point-source air pollution: a case study for poplar ( Populus cathayana) in northwestern China. Zeng, Xiaomin; Liu, Xiaohong; Xu, Guobao; Wang, Wenzhi; An, Wenling // Environmental Earth Sciences;Sep2014, Vol. 72 Issue 6, p2173 

    Pollution from urban centers and fossil fuel combustion can decrease forest growth and interfere with physiological processes. To evaluate whether tree growth and the carbon isotope ratio (δC) and nitrogen isotope ratio (δN) in tree rings can serve as proxies for air pollution, this study...

  • Spatial & temporal variations of PM10 and particle number concentrations in urban air. Johansson, Christer; Norman, Michael; Gidhagen, Lars // Environmental Monitoring & Assessment;Apr2007, Vol. 127 Issue 1-3, p477 

    The size of particles in urban air varies over four orders of magnitude (from 0.001 μm to 10 μm in diameter). In many cities only particle mass concentrations (PM10, i.e. particles <10 μm diameter) is measured. In this paper we analyze how differences in emissions, background...

  • Drivers and uncertainties of future global marine primary production in marine ecosystem models. Laufkötter, C.; Vogt, M.; Gruber, N.; Aita-Noguchi, M.; Aumont, O.; Bopp, L.; Buitenhuis, E.; Doney, S. C.; Dunne, J.; Hashioka, T.; Hauck, J.; Hirata, T.; John, J.; Quéré, C. Le; Lima, I. D.; Nakano, H.; Seferian, R.; Totterdell, I.; Vichi, M.; Völker, C. // Biogeosciences;2015, Vol. 12 Issue 23, p6955 

    Past model studies have projected a global decrease in marine net primary production (NPP) over the 21st century, but these studies focused on the multi-model mean rather than on the large inter-model differences. Here, we analyze model-simulated changes in NPP for the 21st century under IPCC's...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics