Kristian Mogensen

Kristian Mogensen
European Center For Medium Range Weather Forecasts · Research Department

About

70
Publications
22,740
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4,408
Citations
Citations since 2016
16 Research Items
3092 Citations
20162017201820192020202120220100200300400500
20162017201820192020202120220100200300400500
20162017201820192020202120220100200300400500
20162017201820192020202120220100200300400500

Publications

Publications (70)
Article
We present an investigation of the performance of the ECMWF coupled atmosphere-waves-ocean model for different ocean and atmosphere resolutions on a series of tropical cyclones in the Western Pacific with the aim to better understand the coupled feedback mechanisms in these extreme conditions. For some of the test cases, we only find little impact...
Article
Full-text available
The drive to develop environmental prediction systems that are seamless across both weather and climate timescales has culminated in the development and use of Earth system models, which include a coupled representation of the atmosphere, land, ocean and sea ice, for medium-range weather forecasts. One region where such a coupled Earth system appro...
Preprint
The drive to develop environmental prediction systems that are seamless across both weather and climate timescales has culminated in the development and use of Earth system models, which include a coupled representation of the atmosphere, land, ocean and sea ice, for medium-range weather forecasts. One region where such a coupled Earth system appro...
Article
Full-text available
We present a detailed long-term (1982–2020) analysis of cyclone-induced surface cooling (i.e., cold wake) in the northeast Indian Ocean, which hosts about 6% of the annual tropical cyclones in the...
Article
Full-text available
The ECMWF OCEAN5 system is a global ocean and sea-ice ensemble of reanalysis and real-time analysis. This paper gives a full description of the OCEAN5 system, with the focus on upgrades of system components with respect to its predecessors, ORAS4 and ORAP5. An important novelty in OCEAN5 is the ensemble generation strategy that includes perturbatio...
Article
Full-text available
In this paper we describe SEAS5, ECMWF's fifth generation seasonal forecast system, which became operational in November 2017. Compared to its predecessor, System 4, SEAS5 is a substantially changed forecast system. It includes upgraded versions of the atmosphere and ocean models at higher resolutions, and adds a prognostic sea-ice model. Here, we...
Article
Full-text available
The ECMWF OCEAN5 system is a global ocean and sea-ice ensemble of reanalysis and real-time analysis. This manuscript gives a full description of the OCEAN5 system, with the focus on upgrades of system components with respect to its predecessors ORAS4 and ORAP5. An important novelty in OCEAN5 is the ensemble generation strategy that includes perturb...
Article
Full-text available
In this paper, we review the use of satellite-based remote sensing in combination with in situ data to inform Earth surface modelling. This involves verification and optimization methods that can handle both random and systematic errors and result in effective model improvement for both surface monitoring and prediction applications. The reasons fo...
Article
Full-text available
Tropical cyclones are some of the most devastating natural hazards and the “three beasts”—Harvey, Irma, and Maria—during the Atlantic hurricane season 2017 are recent examples. The European Centre for Medium-Range Weather Forecasts (ECMWF) is working on fulfilling its 2016–25 strategy in which early warnings for extreme events will be made possible...
Article
Full-text available
In this paper we describe SEAS5, ECMWF’s fifth generation seasonal forecast system, which became operational in November 2017. Compared to its predecessor, System 4, SEAS5 is a substantially changed forecast system. It includes upgraded versions of the atmosphere and ocean models at higher resolutions, and adds a prognostic sea ice model. Here, we...
Article
The effect of wind waves on water level and currents during two storms in the North Sea is investigated using a high-resolution Nucleus for European Modelling of the Ocean (NEMO) model forced with fluxes and fields from a high-resolution wave model. The additional terms accounting for wave-current interaction that are considered in this study are t...
Article
Coupled circulation (NEMO) and wave model (WAM) system was used to study the effects of surface ocean waves on water temperature distribution and heat exchange at regional scale (the Baltic Sea). Four scenarios—including Stokes-Coriolis force, sea-state dependent energy flux (additional turbulent kinetic energy due to breaking waves), sea-state dep...
Article
A coupled data assimilation system has been developed at the European Centre for Medium-Range Weather Forecasts (ECMWF), which is intended to be used for the production of global reanalyses of the recent climate. The system assimilates a wide variety of ocean and atmospheric observations and produces ocean-atmosphere analyses with a coupled model....
Technical Report
Full-text available
With the objective to develop and maintain one of the most advanced and flexible modelling infrastructures in Europe for operational, global NWP applications, recent advances and future challenges are described. A particular challenge arises from the need to achieve computationally and energy efficient solutions for operating global, complex, high-...
Technical Report
Full-text available
A new eddy permitting global ocean and sea-ice reanalysis has been developed in the ECMWF as a contribution to the EU FP7 MyOcean2 project. It is called ORAP5 (Ocean ReAnalysis Pilot 5), and it spans the period 1979 to 2012. Data from ORAP5 became publicly available from MyOcean portal from August 2014. ORAP5 is based on NEMO ocean model and NEMOVA...
Article
A coupled data assimilation system has been developed at the European Centre for Medium-Range Weather Forecasts (ECMWF), which is intended to be used for the production of global reanalyses of the recent climate. The system assimilates a wide variety of ocean and atmospheric observations and produces ocean-atmosphere analyses with a coupled model....
Article
Full-text available
The GODAE OceanView systems use various data assimilation algorithms, including 3DVar, EnOI, EnKF and the SEEK filter with a fixed basis, using different time windows. The main outputs of the operational data assimilation systems, the increments, have been compared for February 2014 in various regions. The eddy-permitting systems’ increments are si...
Article
Full-text available
This paper investigates the Atlantic Ocean influence on equatorial Pacific decadal variability. Using an ensemble of simulations, where the ICTPAGCM (“SPEEDY”) is coupled to the NEMO/OPA ocean model in the Indo-Pacific region and forced by observed sea surface temperatures in the Atlantic region, it is shown that the Atlantic Multidecadal Oscillati...
Article
Full-text available
We discuss the state of Arctic sea ice in the global eddy-permitting ocean reanalysis Ocean ReAnalysis Pilot 5 (ORAP5). Among other innovations, ORAP5 now assimilates observations of sea ice concentration using a univariate 3DVar-FGAT scheme. We focus on the period 1993–2012 and emphasize the evaluation of model performance with respect to recent o...
Article
A new eddy-permitting ocean reanalysis has been recently completed at ECMWF. It is called Ocean ReAnalysis Pilot 5 (ORAP5), and it spans the period 1979-2012. This work describes the new system, evaluates its performance, and investigates how the estimation of climate indices are affected by the assimilation system settings. ORAP5 introduces severa...
Article
Full-text available
The NEMO general circulation ocean model is extended to incorporate three physical processes related to ocean surface waves, namely the surface stress (modified by growth and dissipation of the oceanic wave field), the turbulent kinetic energy flux from breaking waves, and the Stokes-Coriolis force. Experiments are done with NEMO in ocean-only (for...
Article
Full-text available
Quantifying the effect of the seawater density changes on sea level variability is of crucial importance for climate change studies, as the sea level cumulative rise can be regarded as both an important climate change indicator and a possible danger for human activities in coastal areas. In this work, as part of the Ocean Reanalysis Intercomparison...
Article
Uncertainty in ocean analysis methods and deficiencies in the observing system are major obstacles for the reliable reconstruction of the past ocean climate. The variety of existing ocean reanalyses is exploited in a multi-reanalysis ensemble to improve the ocean state estimation and to gauge uncertainty levels. The ensemble-based analysis of signa...
Article
Full-text available
Uncertainty in ocean analysis methods and deficiencies in the observing system are major obstacles for the reliable reconstruction of the past ocean climate. The variety of existing ocean reanalyses is exploited in a multi-reanalysis ensemble to improve the ocean state estimation and to gauge uncertainty levels. The ensemble-based analysis of signa...
Article
Full-text available
Polar climate studies are severely hampered by the sparseness of the sea ice observations. We aim at filling this critical gap by producing two 5-member sea ice historical simulations strongly constrained by ocean and atmosphere observational data and covering the 1958–2006 and 1979–2012 periods. This is the first multi-member sea ice reconstructio...
Technical Report
Full-text available
We discuss the state of Arctic sea ice in ORAP5, a prototype for the ORAS5 ocean reanalysis, which was run as the ECMWF contribution to MyOcean2. Among other innovations, ORAP5 assimilates observations of sea ice concentration. For the period 1993-2012, we find that sea ice concentration fields in ORAP5 are very close to observations in general, wi...
Article
A new operational ocean reanalysis system (ORAS4) has been implemented at ECMWF. It spans the period 1958 to the present. This article describes its main components and evaluates its quality. The adequacy of ORAS4 for the initialization of seasonal forecasts is discussed, along with the robustness of some prominent climate signals. ORAS4 has been e...
Article
Full-text available
This paper explores the sensitivity of hindcasts of the Madden Julian Oscillation (MJO) to the use of differ-ent sea surface temperture (SST) products as lower bound-ary conditions in the European Centre for Medium-range Weather Forecasts (ECMWF) atmospheric model. Three sets of monthly hindcast experiments are conducted, starting from initial cond...
Article
Full-text available
This paper explores the sensitivity of the prediction of Madden Julian Oscillation (MJO) events to different aspects of the sea surface temperature (SST) in the European Centre for Medium-range Weather Forecasts (ECMWF) model. The impact of temporal resolution of SST on the MJO is first evaluated via a set of monthly hindcast experiments. The exper...
Article
The ECMWF monthly forecasting system is used for the forecast of the Madden-Julian Oscillation (MJO) event of the winter 1992-1993. The impact of the ocean- atmosphere coupling on the MJO forecast skill is assessed in parallel with sensitivity tests on the temporal resolution (daily, weekly and monthly) of Sea Surface Temperature (SST) forcing fiel...
Article
Full-text available
A 4-dimensional variational data assimilation (4D-Var) scheme for the HIgh Resolution Limited Area Model (HIRLAM) forecasting system is described in this article. The innovative approaches to the multi-incremental formulation, the weak digital filter constraint and the semi-Lagrangian time integration are highlighted with some details. The implicit...
Article
Full-text available
The latest operational version of the ECMWF seasonal forecasting system is described. It shows noticeably improved skill for sea surface temperature (SST) prediction compared with previous versions, particularly with respect to El Nino related variability. Substantial skill is shown for lead times up to 1year, although at this range the spread in t...
Article
Full-text available
Ocean data assimilation has reached a sufficient level of maturity such that observations are routinely combined with model forecasts to produce a variety of ocean products. Approaches to ocean data assimilation vary widely both in terms of the sophistication of the method and the observations assimilated, and also in terms of specification of the...
Article
Available from: http://www.ecmwf.int/sites/default/files/elibrary/2009/14605-newsletter-no120-summer-2009.pdf
Article
In 2003 the average summer temperature in Southern Europe exceeded the 1961-1990 European summer mean by 2.3~K. Many regions experienced a large number of deaths due to the elevated temperatures, and attribution studies have determined that human activity has at least doubled the risk of such a heatwave compared to a non-industrial scenario. Howeve...
Article
http://www.ecmwf.int/publications/library/ecpublications/_pdf/tm/501-600/tm503.pdf
Article
Two different approaches for improving the representation of background error standard deviations have been developed and introduced into the HIRLAM high-resolution limited area model 3-D variational data assimilation scheme. One of the methods utilizes a horizontally varying climatological background error standard deviation field, estimated from...
Article
KNMI works within the EUMETSAT NWP SAF on the processing of SeaWinds scatterometer data and distributes software and winds. The aim is to prepare the wind user community for the ASCAT scatterometer on METOP in 2006. Aspects of concern are spatial resolution and data quality and a trade-off is made. At www.knmi.nl/scatterometer a 100-km product is d...
Technical Report
Full-text available
A 4-dimensional variational data assimilation (4DVAR) scheme for the HIgh Res- olution Limited Area Model (HIRLAM) forecasting system will be described. The HIRLAM-4DVAR is based on the minimization of a cost function which measures the distance between the resulting 4-dimensional model state and a background field and observations. As HIRLAM-4DVAR...
Article
MAGIC (Meteorological Applications of GPS Integrated Column Water Vapor Measurements in the Western Mediterranean) is a 3 year project financed in part by the European Commission for research on deriving and validating robust GPS integrated water vapor (IWV) and zenith tropospheric delay (ZTD) data sets and developing methods to assimilate the data...
Article
We discuss aspects of how to derive precise estimates of zenith total delays (ZTD's) of the neutral atmosphere (its non-ionized constituents) from meteorological data in order to validate ZTD's derived from ground based GPS (Global Positioning System) observations. The goal is that a later stage GPS ZTD's may conversely be used in numerical weather...
Article
A 3-dimensional variational data assimilation (3D-Var) scheme for the High Resolution Limited Area Model (HIRLAM) forecasting system is described. The HIRLAM 3D-Var is based on the minimisation of a cost function that consists of one term, Jb, which measures the distance between the resulting analysis and a background field, in general a short-rang...
Article
Full-text available
ABSTRACT A 3-dimensional variational data assimilation (3D-Var) scheme for the High Resolution Limited Area Model (HIRLAM) forecasting system is described. The HIRLAM 3D-Var is based on the minimization of a cost function that consists of one term Jb, which measures the distance between the resulting analysis and a background field, in general a sh...
Article
In the past few years the numbers of ACARS (Aircraft Communication Addressing and Reporting System) and AMDAR (Aircraft Meteorological Data Reporting) aircraft observation data received at DMI have increased. We have made two sets of observational system experiments (OSE) with these observation types. One set has used the DMI HIRLAM Optimum Interpo...
Article
Electron capture cross sections for coherent elliptic Rydberg states have been measured as a function of eccentricity. The ion impact velocity was parallel to the minor axis of the associated, classical elliptic orbit and both clockwise and anticlockwise orbital motion of the electron were studied. The incoming ions were 2.5 keV 23Na+ and the Rydbe...
Article
The main objective of this research is to study the residual macroscopic stress in titanium-nitride, TiN, coatings deposited onto a tool steel substrate. The measurements were performed with a θ-θ decoupled X-ray diffractometer. The coatings were manufactured using an industrial pulsed-DC plasma-enhanced chemical vapour deposition (PECVD) technique...
Article
The plasma-assisted chemical vapour deposition process in a large-scale industrial plant for coating of TiN on tool steels was investigated by optical emission spectroscopy. Several atomic lines and molecular bands were identified. A parametric study of the dependence of bias voltage, total pressure and gas flows, H2, N2, Ar and TiCl4, on the plasm...
Article
Experimental studies of the time evolution of a pulsed-DC plasma for deposition of TIN were carried out. By use of optical emission spectroscopy and current measurements, delays in the plasma formation relative to the rise of the voltage were observed. A delay is observed only in cases where TiCl4, which like Cl is electronegative, is present in th...
Article
In order to design coatings with optimal wear and corrosion performance, knowledge of the structures and properties of the coatings and their dependence on the process parameters is required. Coatings of TiN deposited onto tool steels using an industrial, pulsed DC plasma-assisted chemical vapour deposition chamber were investigated. The process pa...
Article
Experimental relative cross sections for electron capture by singly charged ions (Na+) from coherent elliptic states of principal quantum number n=25 are presented. An interval of reduced impact velocities from about 1–2 is covered. Absolute reaction cross sections could not be determined precisely, but the eccentricity of the coherent elliptic sta...
Article
The cross section for charge transfer in fast collisions between Rydberg atoms in coherent elliptic states of n=25 and singly charged ions has been measured as a function of the eccentricity and the orientation of the initial state. Dramatic variations are seen. Theoretical results based on classical collision dynamics are in good qualitative agree...
Article
A detailed comparison between experimental lifetimes for Rydberg atoms formed by the adiabatic crossed-field method and corresponding theoretical lifetimes has been performed to document that the crossed-field method indeed may be used to generate and control coherent elliptic states of highly excited Rydberg atoms. It is found that core effects pl...
Article
Oriented elliptic Rydberg atoms have been formed in a thermal beam of Li atoms by the adiabatic crossed-field method. All coherent elliptic quantum states from linear to circular can be produced by this method. The orientation and eccentricity is controlled by the external fields. While the formation of circular states by the crossed-field method h...

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Project (1)
Archived project
HIgh Resolution Limited Area Modelling