Blar i Nansen Environmental and Remote Sensing Center (NERSC) på tittel
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On the Velocity Gradient in Stably Stratified Sheared Flows. Part 2: Observations and Models
(Peer reviewed; Journal article, 2010-05-12)Observations of the dependence of the dimensionless wind speed gradient φm as a function of the Monin–Obukhov stability parameter z/Lo under strong stability diverge from results of large-eddy simulation (LES) modelling. ... -
Open Boundary Conditions for the Extended Kalman Filter With a Quasi-Geostrophic Ocean Model
(Journal article, 1993-05-18)The formulation of consistent boundary conditions for the quasi-geostrophic (QG) model with an extended Kaiman filter in a data assimilation scheme is discussed. To form a well-posed boundary value problem for the QG model, ... -
Parameter Estimation Solving a Weak Constraint Variational Formulation for an Ekman Model
(Journal article, 1997-06-15)A weak constraint variational formulation is used for inverse calculations and parameter estimation in a one-dimensional Ekman model. When parameters in the model are allowed to contain errors, the inverse problem becomes ... -
Passive tracers and active dynamics - a model study of hydrography and circulation in the northern North Atlantic
(Journal article; Peer reviewed, 2006-08)A long-standing problem in oceanography has been to understand the relationship between what can be measured in the ocean, such as hydrography, and what cannot, such as the strength and structure of the complete Meridional ... -
A preliminary study on the relationship between Arctic Oscillation and daily SLP variance in the Northern hemisphere during wintertime
(Journal article; Peer reviewed, 2005-01-20)In the present study, the authors investigated the relationship between the Arctic Oscillation (AO) and the high-frequency variability of daily sea level pressures in the Northern Hemisphere in winter (November through ... -
Remote sensing of sea ice
(OceanObs’09 Community White Paper, Conference lecture, 2009-09) -
Resistance and heat-transfer laws for stable and neutral planetary boundary layers: old theory advanced and re-evaluated
(Journal article; Peer reviewed, 2005-07)The planetary boundary layer (PBL) resistance and heat-transfer laws express the surface fluxes of momentum and heat through the PBL governing parameters. Since the late sixties, the dimensionless coefficients (A, B and ... -
Satellite detection of natural films on the ocean surface
(Journal article; Peer reviewed, 1996-11-01)Natural films on the ocean surface influence air-sea fluxes of momentum, heat, and gas. It is therefore essential to be able to map the geographical extent and variability of such films to determine the resulting impact ... -
Sea ice investigations in the Laptev Sea area in late summer using SAR data
(Journal article; Peer reviewed, 2001-10)The Laptev Sea area, including the Vilkitsky Strait, is an important part of the Northern Sea Route where the presence of sea ice makes navigation difficult even in the summer season. The objective of this study was therefore ... -
Sea Ice Monitoring by Remote Sensing
(, Chapter, 2006) -
Sea ice monitoring in the Arctic using satellite SAR images
(NERSC thesis, Master thesis, 2007) -
Semi-empirical Algorithm for the Retrieval of Ecology-Relevant Water Constituents in Various Aquatic Environments
(Journal article, 2009-03-10)An advanced operational semi-empirical algorithm for processing satellite remote sensing data in the visible region is described. Based on the Levenberg-Marquardt multivariate optimization procedure, the algorithm is ... -
Sequential data assimilation with a nonlinear quasi-geostrophic model using Monte Carlo methods to forecast error statistics
(Journal article, 1994-05-15)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 ... -
Spatial heterogeneity of greening and browning between and within bioclimatic zones in northern West Siberia
(Journal article; Peer reviewed, 2016-10-26)Studies of the normalized difference vegetation index (NDVI) have found broad changes in vegetation productivity in high northern latitudes in the past decades, including increases in NDVI (‘greening’) in tundra regions ... -
Subpolar Gyre Index and the North Atlantic Meridional Overturning Circulation in a Coupled Climate Model
(Journal article, 2008-11-16)The subpolar gyre index (SPG), derived from the analysis of sea surface height (SSH), is proposed to be a potential indicator for the North Atlantic Meridional Overturning Circulation (AMOC) based on observation as well ... -
Surface Atmospheric Temperature as Indicator of Climate Change in the Arctic
(Conference poster, 2005-12)Surface atmospheric temperature (SAT) is one of the most reliable atmospheric characteristics used to quantify climate change. Contrary to what has been always implicitly assumed, changes in the SAT have loose relations ... -
Toward an optimal inversion method for synthetic aperture radar wind retrieval
(Journal article; Peer reviewed, 2002-08-01)In recent years, particular efforts have been made to derive wind fields over the oceans from synthetic aperture radar (SAR) images. In contrast with the scatterometer, the SAR has a higher spatial resolution and therefore ... -
Two-phase, near-field modeling of purposefully released CO2 in the ocean
(Journal article; Peer reviewed, 2001-01-15) -
Universal Dependences between Turbulent and Mean Flow Parameters in Stably and Neutrally Stratified Planetary Boundary Layers
(Journal article; Peer reviewed, 2006-05-08)We consider the resistance law for the planetary boundary layer (PBL) from the point of view of the similarity theory. In other words, we select the set of the PBL governing parameters and search for an optimal way to ... -
Using the Extended Kalman Filter with a Multilayer Quasi-Geostrophic Ocean Model
(Journal article, 1992-11-15)The formulation of the extended Kalman filter for a multilayer nonlinear quasi-geostrophic ocean circulation model is discussed. The nonlinearity in the ocean model leads to an approximative equation for error covariance ...