Blar i Geophysical Institute på emneord "VDP::Matematikk og Naturvitenskap: 400"
Viser treff 1-20 av 38
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Aircraft-based observations and high-resolution simulations of an Icelandic dust storm
(Peer reviewed; Journal article, 2012-11-16)The first aircraft-based observations of an Icelandic dust storm are presented. The measurements were carried out over the ocean near Iceland's south coast in February 2007. This dust event occurred in conjunction with an ... -
Arctic climate change: observed and modelled temperature and sea-ice variability
(Tellus A 56A(4), Peer reviewed; Journal article, 2004-07-09)Changes apparent in the arctic climate system in recent years require evaluation in a century-scale perspective in order to assess the Arctic's response to increasing anthropogenic greenhouse-gas forcing. Here, a new set ... -
Assessment of wind conditions at a fjord inlet by complementary use of sonic anemometers and lidars
(Peer reviewed; Journal article, 2015-12-02)Wind velocity measurement devices based on the remote optical sensing, lidars, are extensively applied in wind energy research and wind farm operation. The present paper demonstrates the relevance and potential of lidar ... -
The Atlantic Water flow along the Vøring Plateau: Detecting frontal structures in oceanic station time series
(Journal article, 2007-01-13)The topographic steering of the baroclinic western branch of the Norwegian Atlantic Current (NwAC) determines the extent of Atlantic Water and location of the Arctic Front in the Nordic Seas. In this paper the geographical ... -
Calving rates at tidewater glaciers vary strongly with ocean temperature
(Peer reviewed; Journal article, 2015-10-09)Rates of ice mass loss at the calving margins of tidewater glaciers (frontal ablation rates) are a key uncertainty in sea level rise projections. Measurements are difficult because mass lost is replaced by ice flow at ... -
Climate change in the North – past, present and future
(Journal article; Peer reviewed, 2008)The Nordic countries have produced famous polar explorers and researchers who have generated climate research schools at a variety of locations. The dependence of these countries with respect to the lifelihood of their ... -
Decreasing Arctic Sea Ice Mirrors Increasing CO2 on Decadal Time Scale
(Atmospheric and Oceanic Science Letters, Journal article, 2008-11-16)Arctic sea ice is a keystone indicator of greenhouse-gas induced global climate change, which is expected to be amplified in the Arctic. Here we directly compare observed variations in arctic sea-ice extent and CO2 since ... -
Diagnosing ocean tracer transport from Sellafield and Dounreay by equivalent diffusion and age
(Peer reviewed; Journal article, 2008-09-27)A simple approach for estimating the equivalent diffusion for diagnosing tracer transport is proposed. Two different expressions are derived; one is based directly on an analytical solution of the two-dimensional ... -
A diagram of wind speed versus air-sea temperature difference to understand the marine atmospheric boundary layer
(Peer reviewed; Journal article, 2015-08-28)This contribution reviews the dynamics in the marine atmospheric boundary layer (MABL) with a diagnostic diagram: wind speed versus air-sea temperature difference or U-ΔT. The diagram was first used by Alfred Woodcock in ... -
Direct ocean surface velocity measurements from space: Improved quantitative interpretation of Envisat ASAR observations
(Peer reviewed; Journal article, 2008-11-29)Previous analysis of Advanced Synthetic Aperture Radar (ASAR) signals collected by ESA’s Envisat has demonstrated a very valuable source of high-resolution information, namely, the line-of-sight velocity of the moving ocean ... -
Directly measured currents and estimated transport pathways of Atlantic Water between 59.58N and the Iceland-Faroes-Scotland Ridge
(Peer reviewed; Journal article, 2015-11-24)Using vessel-mounted acoustic Doppler current profiler data from four different routes between Scotland, Iceland and Greenland, we map out the mean flow of water in the top 400 m of the northeastern North Atlantic. The ... -
The European gravity field and steady-state ocean circulation explorer satellite mission: its impact on geophysics
(Journal article, 2003-07)Current knowledge of the Earth’s gravity field and its geoid, as derived from various observing techniques and sources, is incomplete. Within a reasonable time, substantial improvement will come by exploiting new approaches ... -
Evaluating two numerical advection schemes in HYCOM for eddy-resolving modelling of the Agulhas Current
(Ocean Science, Journal article, 2009-06-02)A 4th order advection scheme is applied in a nested eddy-resolving Hybrid Coordinate Ocean Model (HYCOM) of the greater Agulhas Current system for the purpose of testing advanced numerics as a means for improving the model ... -
The greater Agulhas Current system: an integrated study of its mesoscale variability
(Journal of Operational Oceanography, Journal article, 2008-02)For the purpose of developing an operational oceanography system for the greater Agulhas Current regime, a high resolution Hybrid Coordinate Ocean Model (HYCOM) has been set in a nested configuration. The intense and complex ... -
High northern latitude surface air temperature: comparison of existing data and creation of a new gridded data set 1900–2000
(Peer reviewed; Journal article, 2008-03)Detection, attribution and understanding of temperature changes in the high northern latitudes depend on constraining uncertainties and resolving apparent discrepancies in observational data sets. We quantitatively compare ... -
High resolution sea ice monitoring using space borne Synthetic Aperture Radar
(Doctoral thesis, 2017-12-06)Sea ice represents a major factor in the climate system and updated knowl- edge about sea ice conditions is important for shipping and offshore industry, local communities and others. Due to its remote location and strong ... -
Impact of springtime Himalayan-Tibetan Plateau snowpack on the onset of the Indian summer monsoon in coupled seasonal forecasts
(Peer reviewed; Journal article, 2016-02-20)The springtime snowpack over the Himalayan–Tibetan Plateau (HTP) region and Eurasia has long been suggested to be an influential factor on the onset of the Indian summer monsoon. To assess the impact of realistic initialization ... -
Lagrangian Measurement of Waves and Near Surface Turbulence from Acoustic Instruments
(Peer reviewed; Journal article, 2015-12-02)We demonstrate high-resolution measurements of upper ocean flow and turbulence using a Lagrangian drifter. A spherical buoy as a quasi-wave following drifter mitigate the contaminations induced by wave orbital velocities ... -
Multi-scale variability of winds in the complex topography of southwestern Norway
(Peer reviewed; Journal article, 2012-01-02)Multi-scale variability of winds in the complex terrain of southwestern Norway is investigated using up to 20yr of observations from nine automatic weather stations and reanalysis data. Significant differences between the ... -
North Atlantic storm track changes during the Last Glacial Maximum recorded by Alpine speleothems
(Peer reviewed; Journal article, 2015-02-27)The European Alps are an effective barrier for meridional moisture transport and are thus uniquely placed to record shifts in the North Atlantic storm track pattern associated with the waxing and waning of Late-Pleistocene ...