A5090869107- Ocean Waves and Remote Sensing
- Oceanographic and Atmospheric Processes
- Climate variability and models
- Tropical and Extratropical Cyclones Research
- Meteorological Phenomena and Simulations
- Coastal and Marine Dynamics
- Arctic and Antarctic ice dynamics
- Marine and environmental studies
- Hydrological Forecasting Using AI
- Hydrology and Drought Analysis
- Seismic Waves and Analysis
- Wave and Wind Energy Systems
- Aeolian processes and effects
- Seismic Imaging and Inversion Techniques
- Geophysics and Gravity Measurements
Equinor (Norway)
2023-2024
Norwegian Meteorological Institute
2013-2023
University of Bergen
2011-2022
European Centre for Medium-Range Weather Forecasts
2013
A combined high-resolution atmospheric downscaling and wave hindcast based on the ERA-40 reanalysis covering Norwegian Sea, North Sea Barents is presented. The period covered from September 1957 to August 2002. dynamic performed as a series of short prognostic runs initialized blend previous run preserve fine-scale surface features model while maintaining large-scale synoptic field ERA-40. nested WAM consists coarse 50 km Atlantic forced with winds 10-11 resolution downscaled winds....
Abstract Trends in marine wind speed and significant wave height are investigated using the global reanalysis ERA-Interim over period 1979–2012, based on monthly-mean monthly-maximum data. Besides traditional reanalysis, authors include trends obtained at different forecast range, available up to 10 days ahead. Any model biases that corrected differently time likely introduce spurious of variable magnitude. However, increased range tends relax, being less affected by assimilation. Still,...
Abstract The 3-km Norwegian Reanalysis (NORA3) is a 15-yr mesoscale-permitting atmospheric hindcast of the North Sea, and Barents Sea. With horizontal resolution 3 km, nonhydrostatic numerical weather prediction model HARMONIE–AROME runs explicitly resolved deep convection yields fields that realistically downscale ERA5 reanalysis. wind field much improved relative to its host analysis, in particular mountainous areas along grid-resolving coastlines. NORA3 also performs better than earlier...
Abstract The trends in marine 10-m wind speed U 10 and significant wave height H s found two century-long reanalyses are compared against a model-only integration. Reanalyses show spurious due to the assimilation of an increasing number observations over time. comparisons between model that areas where discrepancies greatest also there is marked increase assimilated observations. Large differences yearly averages call into question quality by reanalyses, resulting unreliable before 1950s....
Abstract Historical trends in the direction and magnitude of ocean surface wave height, period, or are debated due to diverse data, time-periods, methodologies. Using a consistent community-driven ensemble global products, we quantify establish regions with robust multivariate fields between 1980 2014. We find that about 30–40% experienced seasonal mean extreme direction. Most Southern Hemisphere exhibited strong upward-trending heights (1–2 cm per year) periods during winter summer. Ocean...
Abstract Wind field ensembles from six CMIP5 models force wave model time slices of the northeast Atlantic over last three decades 20th and 21st centuries. The future climate is investigated by considering RCP4.5 RCP8.5 emission scenarios. selection based on their ability to reconstruct present (1971–2000) extratropical cyclone activity, but increased spatial resolution has also been emphasized. In total, study comprises 35 integrations, each about 30 years long, in total more than 1000...
There are numerous global ocean wave reanalysis and hindcast products currently being distributed used across different scientific fields. However, there is not a consistent dataset that can sample all existing based on standardized framework. Here, we present describe the first coordinated multi-product ensemble of present-day fields available to date. This dataset, produced through Coordinated Ocean Wave Climate Project (COWCLIP) phase 2, includes general extreme statistics significant...
The objective of this study is to compute 100-yr return value estimates significant wave height using a new hindcast developed by the Norwegian Meteorological Institute. This regional covers northeast Atlantic and spans period 1958–2009. are based upon three different stationary models commonly applied in extreme statistics: generalized (GEV) distribution, joint GEV distribution for r largest-order statistic (rLOS), Pareto (GP) distribution. Here, qualitative differences between their...
A method for estimating return values from ensembles of forecasts at advanced lead times is presented. Return significant wave height in the North-East Atlantic, Norwegian Sea and North are computed archived +240-h ECMWF ensemble prediction system (EPS) 1999 to 2009. We make three assumptions: First, each forecast representative a six-hour interval collectively data set then comparable time period 226 years. Second, model climate matches observed distribution, which we confirm by comparing...
Global return values of marine wind speed and significant wave height are estimated from very large aggregates archived ensemble forecasts at +240-h lead time. Long time ensures that the represent independent draws model climate. Compared with ERA-Interim, a reanalysis, yields higher estimates for both height. Confidence intervals much tighter due to size dataset. The period (9 yrs) is short enough be considered stationary even climate change. Furthermore, non-parametric 100-yr made order...
Storm surges can give rise to extreme floods in coastal areas. The Norwegian Meteorological Institute (MET Norway) produces 120-hour regional operational storm surge forecasts along the coast of Norway based on Regional Ocean Modeling System (ROMS), using a model setup called Nordic4-SS. Despite advances development models and computational capabilities, forecast errors remain large enough impact response measures issued alerts, particular, during strongest events. Reducing these will...
Abstract Accurate predictions of surface ocean waves in coastal areas are important for a number marine activities. In complex coastlines with islands and fjords, the quality wind forcing significantly affects results. We investigate role on wave conditions fjord system partly exposed to open sea. For this reason, we implemented model SWAN at west coast Norway using four different forcing. Wind estimates were compared observations from five measurement sites. The best results terms...
As atmospheric models move to higher resolution and resolve smaller scales, the maximum modeled wind speed also tends increase. Wave tuned coarser fields tend overestimate wave growth under strong winds. A recently developed semi-empirical parameterization of Charnock parameter, which controls roughness length over surface waves, substantially reduces aerodynamic drag waves in high winds (above a threshold 30 m/s). Here we apply formulation recent version model WAM (Cycle 4.7), uses modified...
The necessity to reduce C O 2 emissions in combination with the rising energy demand worldwide makes extensive use of renewable sources increasingly important. To that end, countries long coastlines, such as Norway, can exploit ocean wave produce large amounts power. In order facilitate these efforts well provide quantitative data on potential a specific area, it is essential analyze weather and climatic conditions detecting any variabilities. complex physical processes atmosphere-wave...
Abstract NORA10EI, a new atmosphere and wave hindcast for the Norwegian Sea, North Sea Barents is presented. The uses ERA‐Interim as initial boundary conditions covers period 1979–2017. earlier NORA10 used ERA‐40 before September 2002 operational analyses from European Centre Medium‐Range Weather Forecasts (ECMWF) in continuation. This change may lead to non‐stationarities bias random errors, it question of some concern whether this also leads spurious trends. We investigate by comparing two...
In-situ wave measurements are often required by marine industry standards and for verification of coastal forecasts. Obtaining is costly it would be advantageous to utilize existing platforms like navigational buoys designed environmental monitoring. In this study, a sensor module (MOTUS Wave Sensor, Aanderaa Data Instruments) installed on buoy (Tideland) (EMM2.0) validated against dedicated measurement (Waverider, Datawell). The validation based upon four months off the west coast Norway....
Abstract The future Stokes drift climate is investigated using a global wave projection (2071–2100) forced with EC-EARTH winds under the RCP8.5 scenario. run compared against historical (1976–2005). analyzed in terms of transport and surface drift. impact on from changes to wind, wind sea, swell identified. consequences for upper-ocean mixing circulation are studied by investigating turbulent Langmuir number depth. also hindcast ERA-Interim forcing. Systematic discrepancies due differences...
Extreme wave climate provides the basis for safe design of offshore structures and is crucial planning executing operations. Covariate modeling extremes significantly enriches improves estimates return levels exceedance probabilities extreme sea states. Based on novel observational hindcast datasets, we formulate a seasonal–directional value model individual heights present Ekofisk oil gas field, location in Central North Sea. Subsequently, elucidate how to downscale monthly daily maxima...
Abstract. Bootstrap resamples can be used to investigate the tail of empirical distributions as well return value estimates from extremal behaviour sample. Specifically, confidence intervals on or bounds in-sample statistics obtained using bootstrap techniques. However, non-parametric bootstrapping entire sample is expensive. It shown here that it suffices a small subset consisting highest entries in sequence make are essentially identical bootstraps Similarly, threshold found approximated...
Abstract On November 30, 2018, our attention was caught when analyzing wave profile time series measured by a platform mounted sensor (a SAAB REX radar) at Ekofisk, central North Sea. The 20-minute had not only one, but three consecutive waves with individual heights that all were more than twice the significant height, two last of them being almost equally high factor 2.35 to height 4m (from 4σ(η), over 20 minutes). Counting rogue in one sequence seems be very rare. In this study we analyze...
Knowledge about statistics for water level variations along the coast due to storm surge is important utilization of coastal zone. An open and freely available hindcast archive covering Norway adjacent sea areas spanning time period 1979–2022 presented. The model forced by wind stress mean pressure taken from non-hydrostatic NORA3 atmospheric hindcast. A dataset consisting observations more than 90 gauges coasts North Sea Norwegian compiled quality controlled, used assess performance...