Results 1  10
of
17,475
Sequential data assimilation with a nonlinear quasigeostrophic model using Monte Carlo methods to forecast error statistics
 J. Geophys. Res
, 1994
"... . A new sequential data assimilation method is discussed. It is based on forecasting the error statistics using Monte Carlo methods, a better alternative than solving the traditional and computationally extremely demanding approximate error covariance equation used in the extended Kalman filter. The ..."
Abstract

Cited by 782 (22 self)
 Add to MetaCart
. A new sequential data assimilation method is discussed. It is based on forecasting the error statistics using Monte Carlo methods, a better alternative than solving the traditional and computationally extremely demanding approximate error covariance equation used in the extended Kalman filter. The unbounded error growth found in the extended Kalman filter, which is caused by an overly simplified closure in the error covariance equation, is completely eliminated. Open boundaries can be handled as long as the ocean model is well posed. Wellknown numerical instabilities associated with the error covariance equation are avoided because storage and evolution of the error covariance matrix itself are not needed. The results are also better than what is provided by the extended Kalman filter since there is no closure problem and the quality of the forecast error statistics therefore improves. The method should be feasible also for more sophisticated primitive equation models. The computati...
2003: Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late Nineteenth Century
 J. Geophysical Research
"... data set, HadISST1, and the nighttime marine air temperature (NMAT) data set, HadMAT1. HadISST1 replaces the global sea ice and sea surface temperature (GISST) data sets and is a unique combination of monthly globally complete fields of SST and sea ice concentration on a 1 ° latitudelongitude grid ..."
Abstract

Cited by 517 (3 self)
 Add to MetaCart
data set, HadISST1, and the nighttime marine air temperature (NMAT) data set, HadMAT1. HadISST1 replaces the global sea ice and sea surface temperature (GISST) data sets and is a unique combination of monthly globally complete fields of SST and sea ice concentration on a 1 ° latitudelongitude grid from 1871. The companion HadMAT1 runs monthly from 1856 on a 5 ° latitudelongitude grid and incorporates new corrections for the effect on NMAT of increasing deck (and hence measurement) heights. HadISST1 and HadMAT1 temperatures are reconstructed using a twostage reducedspace optimal interpolation procedure, followed by superposition of qualityimproved gridded observations onto the reconstructions to restore local detail. The sea ice fields are made more homogeneous by compensating satellite microwavebased sea ice concentrations for the impact of surface melt effects on retrievals in the Arctic and for algorithm deficiencies in the Antarctic and by making the historical in situ concentrations consistent with the satellite data. SSTs near sea ice are estimated using statistical relationships between SST and sea ice concentration. HadISST1 compares well with other published analyses, capturing trends in global, hemispheric, and regional SST well,
Tidal meanders
 Water Resources Research
, 2002
"... [1] Observational evidence is presented on the geometry of meandering tidal channels evolved within coastal wetlands characterized by different tidal, hydrodynamic, topographic, vegetational and ecological features. New insight is provided on the geometrical properties of tidal meanders, with possib ..."
Abstract

Cited by 7 (0 self)
 Add to MetaCart
[1] Observational evidence is presented on the geometry of meandering tidal channels evolved within coastal wetlands characterized by different tidal, hydrodynamic, topographic, vegetational and ecological features. New insight is provided on the geometrical properties of tidal meanders
Meander Determinants
, 1996
"... We prove a determinantal formula for quantities related to the problem of enumeration of (semi) meanders, namely the topologically inequivalent planar configurations of nonselfintersecting loops crossing a given (half) line through a given number of points. This is done by the explicit GramSchmi ..."
Abstract

Cited by 3 (1 self)
 Add to MetaCart
We prove a determinantal formula for quantities related to the problem of enumeration of (semi) meanders, namely the topologically inequivalent planar configurations of nonselfintersecting loops crossing a given (half) line through a given number of points. This is done by the explicit Gram
ON THE REPRESENTATION OF MEANDERS
"... ABSTRACT. We will introduce a new approach for studying plane meanders. The set of all meanders of order n possesses a natural order structure and forms a graded poset. We will show how these representations can be used to develop an efficient and very flexible construction algorithm and how to obta ..."
Abstract
 Add to MetaCart
ABSTRACT. We will introduce a new approach for studying plane meanders. The set of all meanders of order n possesses a natural order structure and forms a graded poset. We will show how these representations can be used to develop an efficient and very flexible construction algorithm and how
Meander Graphs
"... We consider a meander M = [A: B] to be formed from two sets A and B of n nonintersecting arcs, lying above and respectively below a horizontal line, which join to form a single closed loop. We prove that the set of meanders is connected under appropriate pairs of balanced local moves, one operating ..."
Abstract
 Add to MetaCart
We consider a meander M = [A: B] to be formed from two sets A and B of n nonintersecting arcs, lying above and respectively below a horizontal line, which join to form a single closed loop. We prove that the set of meanders is connected under appropriate pairs of balanced local moves, one operating
Exact meander . . .
, 2000
"... This note addresses the meander enumeration problem: “Count all topologically inequivalent configurations of a closed planar non selfintersecting curve crossing a line through a given number of points”. We review a description of meanders introduced recently in terms of the coupling to gravity of ..."
Abstract
 Add to MetaCart
This note addresses the meander enumeration problem: “Count all topologically inequivalent configurations of a closed planar non selfintersecting curve crossing a line through a given number of points”. We review a description of meanders introduced recently in terms of the coupling to gravity
Meanders and the TemperleyLieb algebra
, 1996
"... The statistics of meanders is studied in connection with the TemperleyLieb algebra. Each (multicomponent) meander corresponds to a pair of reduced elements of the algebra. The assignment of a weight q per connected component of meander translates into a bilinear form on the algebra, with a Gram ma ..."
Abstract

Cited by 34 (3 self)
 Add to MetaCart
The statistics of meanders is studied in connection with the TemperleyLieb algebra. Each (multicomponent) meander corresponds to a pair of reduced elements of the algebra. The assignment of a weight q per connected component of meander translates into a bilinear form on the algebra, with a Gram
Results 1  10
of
17,475