Search Results - "Waller, Joanne A"

A pragmatic strategy for implementing spatially correlated observation errors in an operational system: An application to Doppler radial winds by Simonin, David, Waller, Joanne A., Ballard, Susan P., Dance, Sarah L., Nichols, Nancy K.

“…Recent research has shown that high‐resolution observations, such as Doppler radar radial winds, exhibit spatial correlations. High‐resolution observations are…”
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Exploring the characteristics of a vehicle‐based temperature dataset for kilometre‐scale data assimilation by Bell, Zackary, Dance, Sarah L., Waller, Joanne A.

“…Crowdsourced vehicle‐based observations have the potential to improve forecast skill in convection‐permitting numerical weather prediction (NWP). The aim of…”
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Accounting for observation uncertainty and bias due to unresolved scales with the Schmidt-Kalman filter by Bell, Zackary, Dance, Sarah L., Waller, Joanne A.

“…Data assimilation combines observations with numerical model data, to provide a best estimate of a real system. Errors due to unresolved scales arise when…”
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Improving the condition number of estimated covariance matrices by Tabeart, Jemima M., Dance, Sarah L., Lawless, Amos S., Nichols, Nancy K., Waller, Joanne A.

“…High dimensional error covariance matrices and their inverses are used to weight the contribution of observation and background information in data…”
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Diagnosing Horizontal and Inter-Channel Observation Error Correlations for SEVIRI Observations Using Observation-Minus-Background and Observation-Minus-Analysis Statistics by Waller, Joanne A, Ballard, Susan P, Dance, Sarah L, Kelly, Graeme, Nichols, Nancy K, Simonin, David

“…It has been common practice in data assimilation to treat observation errors as uncorrelated; however, meteorological centres are beginning to use correlated…”
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Comparing diagnosed observation uncertainties with independent estimates: A case study using aircraft‐based observations and a convection‐permitting data assimilation system by Mirza, Andrew K., Dance, Sarah L., Rooney, Gabriel G., Simonin, David, Stone, Edmund K., Waller, Joanne A.

“…Aircraft can report in situ observations of the ambient temperature by using aircraft meteorological data relay (AMDAR) or these can be derived using…”
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Estimating correlated observation error statistics using an ensemble transform Kalman filter by Waller, Joanne A., Dance, Sarah L., Lawless, Amos S., Nichols, Nancy K.

“…For certain observing types, such as those that are remotely sensed, the observation errors are correlated and these correlations are state- and…”
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Collecting and utilising crowdsourced data for numerical weather prediction: Propositions from the meeting held in Copenhagen, 4–5 December 2018 by Hintz, Kasper S., O'Boyle, Katharine, Dance, Sarah L., Al‐Ali, Saja, Ansper, Ivar, Blaauboer, Dick, Clark, Matthew, Cress, Alexander, Dahoui, Mohamed, Darcy, Rónán, Hyrkkanen, Juhana, Isaksen, Lars, Kaas, Eigil, Korsholm, Ulrik S., Lavanant, Marion, Le Bloa, Gwenaelle, Mallet, Emilie, McNicholas, Conor, Onvlee‐Hooimeijer, Jeanette, Sass, Bent, Siirand, Valeria, Vedel, Henrik, Waller, Joanne A., Yang, Xiaohua

“…In December 2018, the Danish Meteorological Institute organised an international meeting on the subject of crowdsourced data in numerical weather prediction…”
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Recommendations for Improving Integration in National End-to-End Flood Forecasting Systems: An Overview of the FFIR (Flooding From Intense Rainfall) Programme by Flack, David, Skinner, Christopher, Hawkness-Smith, Lee, O’Donnell, Greg, Thompson, Robert, Waller, Joanne, Chen, Albert, Moloney, Jessica, Largeron, Chloé, Xia, Xilin, Blenkinsop, Stephen, Champion, Adrian, Perks, Matthew, Quinn, Niall, Speight, Linda

“…Recent surface-water and flash floods have caused millions of pounds worth of damage in the UK. These events form rapidly and are difficult to predict due to…”
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Collection and extraction of water level information from a digital river camera image dataset by Vetra-Carvalho, Sanita, Dance, Sarah L., Mason, David C., Waller, Joanne A., Cooper, Elizabeth S., Smith, Polly J., Tabeart, Jemima M.

“…We present a new water level dataset extracted from images taken by four Farson Digital Ltd river cameras for a Tewkesbury, UK flood event (21st November – 5th…”
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Editorial: The use of unconventional observations in numerical weather prediction by Waller, Joanne A.

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Evaluating errors due to unresolved scales in convection‐permitting numerical weather prediction by Waller, Joanne A., Dance, Sarah L., Lean, Humphrey W.

“…In numerical weather prediction (NWP), observations and models are quantitatively compared for the purposes of data assimilation and forecast verification. The…”
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The impact of using reconditioned correlated observation‐error covariance matrices in the Met Office 1D‐Var system by Tabeart, Jemima M., Dance, Sarah L., Lawless, Amos S., Migliorini, Stefano, Nichols, Nancy K., Smith, Fiona, Waller, Joanne A.

“…Recent developments in numerical weather prediction have led to the use of correlated observation‐error covariance (OEC) information in data assimilation and…”
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New bounds on the condition number of the Hessian of the preconditioned variational data assimilation problem by Tabeart, Jemima M., Dance, Sarah L., Lawless, Amos S., Nichols, Nancy K., Waller, Joanne A.

“…Data assimilation algorithms combine prior and observational information, weighted by their respective uncertainties, to obtain the most likely posterior of a…”
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The conditioning of least‐squares problems in variational data assimilation by Tabeart, Jemima M., Dance, Sarah L., Haben, Stephen A., Lawless, Amos S., Nichols, Nancy K., Waller, Joanne A.

“…Summary In variational data assimilation a least‐squares objective function is minimised to obtain the most likely state of a dynamical system. This objective…”
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Technical note: Assessment of observation quality for data assimilation in flood models by Waller, Joanne A, Garcia-Pintado, Javier, Mason, David C, Dance, Sarah L, Nichols, Nancy K

“…The assimilation of satellite-based water level observations (WLOs) into 2-D hydrodynamic models can keep flood forecasts on track or be used for reanalysis to…”
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Improvements in Forecasting Intense Rainfall: Results from the FRANC (Forecasting Rainfall Exploiting New Data Assimilation Techniques and Novel Observations of Convection) Project by Dance, Sarah, Ballard, Susan, Bannister, Ross, Clark, Peter, Cloke, Hannah, Darlington, Timothy, Flack, David, Gray, Suzanne, Hawkness-Smith, Lee, Husnoo, Nawal, Illingworth, Anthony, Kelly, Graeme, Lean, Humphrey, Li, Dingmin, Nichols, Nancy, Nicol, John, Oxley, Andrew, Plant, Robert, Roberts, Nigel, Roulstone, Ian, Simonin, David, Thompson, Robert, Waller, Joanne

“…The FRANC project (Forecasting Rainfall exploiting new data Assimilation techniques and Novel observations of Convection) has researched improvements in…”
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Exploring the characteristics of a vehicle-based temperature dataset for convection-permitting numerical weather prediction by Bell, Zackary, Dance, Sarah L, Waller, Joanne A

“…Crowdsourced vehicle-based observations have the potential to improve forecast skill in convection-permitting numerical weather prediction (NWP). The aim of…”
Get full text

New bounds on the condition number of the Hessian of the preconditioned variational data assimilation problem by Tabeart, Jemima M, Dance, Sarah L, Lawless, Amos S, Nichols, Nancy K, Waller, Joanne A

“…Data assimilation algorithms combine prior and observational information, weighted by their respective uncertainties, to obtain the most likely posterior of a…”
Get full text

Improving the condition number of estimated covariance matrices by Tabeart, Jemima M, Dance, Sarah L, Lawless, Amos S, Nichols, Nancy K, Waller, Joanne A

“…High dimensional error covariance matrices and their inverses are used to weight the contribution of observation and background information in data…”
Get full text