Ice Flux Research Articles

Thickness of Ruth Glacier, Alaska, and depth of its Great Gorge from ice-penetrating radar and mass conservation

Abstract Ruth Glacier is situated in the Central Alaska Range, with the Don Sheldon Amphitheater comprising much of its broad accumulation area, directly adjacent to North America's tallest mountain, Denali. From there it funnels through the ‘Great Gorge,’ flanked by steep valley walls reaching over 1500 m. We combine airborne and ground-based radar measurements of ice thickness with satellite-derived surface velocities to constrain ice flux above and below the gorge, and employ a mass conservation approach to estimate the glacier's thickness within the gorge. We measure ice thickness in the amphitheater to reach 950 m, and estimate centerline thickness in the gorge to range from 610 to 960 m. Our estimates are up to two times greater than those suggested by global models, and allow us to confirm that the Great Gorge rivals Hells Canyon as the deepest gorge in North America. We found that the geometry of the gorge prevents radar measurements of ice thickness there since returns from the subglacial valley walls would precede and potentially occlude nadir bed returns. The same may be true of other unmapped mountain glaciers; however, thickness may be determined using appropriately located flux gates where radar sounding is feasible, combined with mass conservation methods.

Melt sensitivity of irreversible retreat of Pine Island Glacier

Abstract. In recent decades, glaciers in the Amundsen Sea Embayment in West Antarctica have made the largest contribution to mass loss from the entire Antarctic Ice Sheet. Glacier retreat and acceleration have led to concerns about the stability of the region and the effects of future climate change. Coastal thinning and near-synchronous increases in ice flux across neighbouring glaciers suggest that ocean-driven melting is one of the main drivers of mass imbalance. However, the response of individual glaciers to changes in ocean conditions varies according to their local geometry. One of the largest and fastest-flowing of these glaciers, Pine Island Glacier (PIG), underwent a retreat from a subglacial ridge in the 1940s following a period of unusually warm conditions. Despite subsequent cooler periods, the glacier failed to recover back to the ridge and continued retreating to its present-day position. Here, we use the ice-flow model Úa to investigate the sensitivity of this retreat to changes in basal melting. We show that a short period of increased basal melt was sufficient to force the glacier from its stable position on the ridge and undergo an irreversible retreat to the next topographic high. Once high melting begins upstream of the ridge, only near-zero melt rates can stop the retreat, indicating a possible hysteresis in the system. Our results suggest that unstable and irreversible responses to warm anomalies are possible and can lead to substantial changes in ice flux over relatively short periods of only a few decades.

Diverse behaviors of marine ice sheets in response to temporal variability of the atmospheric and basal conditions

Abstract The observed retreat of the grounding line of the present-day ice sheets and the simulated grounding-line retreat of ice sheets under changing climate conditions are often interpreted as indications of marine ice-sheet instability (MISI), driven by a positive feedback between the ice discharge and conditions at the grounding line. However, the arguments that support this feedback are valid only for steady-state conditions. Here, we assess how unconfined marine ice sheets may behave if atmospheric conditions and basal conditions evolve with time. We find that the behavior of grounding lines can exhibit a range from unstoppable advance and retreat to irregular oscillation irrespective of the stability of the corresponding steady-state configurations obtained with time-invariant conditions. Our results show that numerical simulations with a parameterization of the ice flux through the grounding line used in large-scale ice-sheet models produce markedly different results from simulations without the parameterization. Our analysis demonstrates that the grounding-line migration can be driven by the temporal variability in the atmospheric and basal conditions and not by MISI, which assumes unchanging conditions. Instead, the grounding-line advance or retreat is determined by interactions between ice flow, basal processes and environmental conditions throughout the length of a marine ice sheet in addition to the circumstances at its grounding line.

Lightning NOx in the 29–30 May 2012 Deep Convective Clouds and Chemistry (DC3) Severe Storm and Its Downwind Chemical Consequences

AbstractA cloud‐resolved storm and chemistry simulation of a severe convective system in Oklahoma constrained by anvil aircraft observations of NOx was used to estimate the mean production of NOx per flash in this storm. An upward ice flux scheme was used to parameterize flash rates in the model. Model lightning was also constrained by observed lightning flash types and the altitude distribution of flash channel segments. The best estimate of mean NOx production by lightning in this storm was 80–110 mol per flash, which is smaller than many other literature estimates. This result is likely due to the storm having been a high flash rate event in which flash extents were relatively small. Over the evolution of this storm a moderate negative correlation was found between the total flash rate and flash extent and energy per flash. A longer‐term simulation at 36‐km horizontal resolution with parameterized convection was used to simulate the downwind transport and chemistry of the anvil outflow from the same storm. Convective transport of low‐ozone air from the boundary layer decreased ozone in the anvil outflow by up to 20–40 ppbv compared with the initial conditions, which contained stratospheric influence. Photochemical ozone production in the lightning‐NOx enhanced convective plume proceeded at a rate of 10–11 ppbv per day in the 9–11 km outflow layer over the 24‐hr period of downwind transport to the Southern Appalachians. Photochemical production plays a large role in the restoration of upper tropospheric ozone following deep convection.

Evaluation of Lightning Flash Rate Parameterizations in a Cloud‐Resolved WRF‐Chem Simulation of the 29–30 May 2012 Oklahoma Severe Supercell System Observed During DC3

AbstractEighteen lightning flash rate parameterization schemes (FRPSs) were investigated in a Weather Research and Forecasting model coupled with chemistry cloud‐resolved simulation of the 29–30 May 2012 supercell storm system observed during the Deep Convective Clouds and Chemistry (DC3) field campaign. Most of the observed storm's meteorological conditions were well represented when the model simulation included both convective damping and lightning data assimilation techniques. Newly‐developed FRPSs based on DC3 radar observations and Lightning Mapping Array data are implemented in the model, along with previously developed schemes from the literature. The schemes are based on relationships between lightning and various kinematic, structural, and microphysical thunderstorm characteristics (e.g., cloud top height, hydrometeors, reflectivity, and vertical velocity) available in the model. The results suggest the model‐simulated graupel and snow/ice hydrometeors require scaling factors to more closely represent proxy observations. The model‐simulated lightning flash trends and total flashes generated by each scheme over the simulation period are compared with observations from the central Oklahoma Lightning Mapping Array. For this supercell system, 13 of the 18 schemes overpredicted flashes by >100% with the group of FRPSs based on storm kinematics and structure (particularly updraft volume) performing slightly better than the hydrometeor‐based schemes. During the storm's first 4 hr, the upward cloud ice flux FRPS, which is based on the combination of vertical velocity and hydrometeors, well represents the observed total flashes and flash rate trend; while, the updraft volume scheme well represents the observed flash rate peak and subsequent sharp decline in flash rate.

A time-dependent ice accretion model for trap-setting fishing vessels with filigree structures

This paper describes a time-dependent methodology for calculating the rate of ice accretion on vessels with filigree structures. It combines Newton’s Second Law for spray droplet trajectories with time varying flow velocities determined using computational fluid dynamics (CFD). The mass flux of ice is determined by solving a set of partial differential equations describing the conservation of mass, heat, and salt in the boundary layer of brine near the ice surface. Icing predictions numerically generated by this approach areevaluated against current stability regulations for fishing vessels.

Reconstructing dynamics of the Baltic Ice Stream Complex during deglaciation of the Last Scandinavian Ice Sheet

Abstract. Landforms left behind by the last Scandinavian Ice Sheet (SIS) offer an opportunity to investigate controls governing ice sheet dynamics. Terrestrial sectors of the ice sheet have received considerable attention from landform and stratigraphic investigations. In contrast, despite its geographical importance, the Baltic Sea remains poorly constrained due to limitations in bathymetric data. Both ice-sheet-scale investigations and regional studies at the southern periphery of the SIS have considered the Baltic depression to be a preferential route for ice flux towards the southern ice margin throughout the last glaciation. During the deglaciation the Baltic depression hosted the extensive Baltic Ice Lake, which likely exerted a considerable control on ice dynamics. Here we investigate the Baltic depression using newly available bathymetric data and peripheral topographic data. These data reveal an extensive landform suite stretching from Denmark in the west to Estonia in the east and from the southern European coast to the Åland Sea, comprising an area of 0.3 million km2. We use these landforms to reconstruct aspects of the ice dynamic history of the Baltic sector of the ice sheet. Landform evidence indicates a complex retreat pattern that changes from lobate ice margins with splaying lineations to parallel mega-scale glacial lineations (MSGLs) in the deeper depressions of the Baltic Basin. Ice margin still-stands on underlying geological structures indicate the likely importance of pinning points during deglaciation, resulting in a stepped retreat signal. Over the span of the study area we identify broad changes in the ice flow direction, ranging from SE–NW to N–S and then to NW–SE. MSGLs reveal distinct corridors of fast ice flow (ice streams) with widths of 30 km and up to 95 km in places, rather than the often-interpreted Baltic-wide (300 km) accelerated ice flow zone. These smaller ice streams are interpreted as having operated close behind the ice margin during late stages of deglaciation. Where previous ice-sheet-scale investigations inferred a single ice source, our mapping identifies flow and ice margin geometries from both Swedish and northern Bothnian sources. We anticipate that our landform mapping and interpretations may be used as a framework for more detailed empirical studies by identifying targets to acquire high-resolution bathymetry and sediment cores and also for comparison with numerical ice sheet modelling.

Sea ice transport and replenishment across and within the Canadian Arctic Archipelago, 2016–2022

Abstract. The Canadian Arctic Archipelago (CAA) serves as both a source and a sink for sea ice from the Arctic Ocean, while also exporting sea ice into Baffin Bay. We use observations from Sentinel-1, RADARSAT-2, the RADARSAT Constellation Mission (RCM), and CryoSat-2, together with the Canadian Ice Service ice charts, to quantify sea ice transport and replenishment across and within the CAA from 2016 to 2022. We also provide the first estimates of the ice area and volume flux within the CAA from the Queen Elizabeth Islands to Parry Channel, which spans the central region of the Northwest Passage shipping route. Results indicate that the CAA primarily exports ice to the Arctic Ocean and Baffin Bay, with an average annual (October to September) ice area flux of 137 ± 72 × 103 km2 and a volume flux of 58 ± 68 km3. The CAA contributes a larger area but smaller volume of ice downstream to the North Atlantic than what is delivered via Nares Strait. The average annual ice area flux from the Queen Elizabeth Islands to Parry Channel was 27 ± 10 × 103 km2 and the volume flux was 34 ± 12 km3, with a majority occurring through Byam Martin Channel, which is directly above the central region of Northwest Passage. Over our study period, annual multi-year ice (MYI) replenishment within the CAA was resilient, with an average of 14 ± 38 × 103 km2 imported from the Arctic Ocean and an average of 56 ± 36 × 103 km2 of first-year ice (FYI) retained following the melt season. The considerable ice flux to Parry Channel, together with sustained MYI replenishment, emphasizes the continued risk that sea ice poses to practical utilization of key shipping routes in the CAA, including the Northwest Passage.

Mechanisms of Offshore Solid and Liquid Freshwater Flux from the East Greenland Current

Abstract The mechanisms that control the export of freshwater from the East Greenland Current, in both liquid and solid form, are explored using an idealized numerical model and scaling theory. A regional, coupled ocean–sea ice model is applied to a series of calculations in which key parameters are varied and the scaling theory is used to interpret the model results. The offshore ice flux, occurring in late winter, is driven primarily by internal stresses and is most sensitive to the thickness of sea ice on the shelf coming out of Fram Strait and the strength of alongshore winds over the shelf. The offshore liquid freshwater flux is achieved by eddy fluxes in late summer while there is an onshore liquid freshwater flux in winter due to the ice–ocean stress, resulting in only weak annual mean flux. The scaling theory identifies the key nondimensional parameters that control the behavior and reproduces the general parameter dependence found in the numerical model. Climate models predict that winds will increase and ice export from the Arctic will decrease in the future, both of which will lead to a decrease in the offshore flux of sea ice, while the influence on liquid freshwater may increase or decrease, depending on the relative changes in the onshore Ekman transport and offshore eddy fluxes. Additional processes that have not been considered here, such as more complex topography and synoptic wind events, may also contribute to cross-shelf exchange. Significance Statement The purpose of this study is to provide a basic understanding of what controls the flux of sea ice and low-salinity water from the East Greenland shelf into the interior of the Greenland and Iceland Seas. This is a potentially important process since it has been shown that sufficient freshening of the surface waters in the interior of the Nordic seas can inhibit deep convection and the associated air–sea heat flux and water mass transformation. A combination of idealized computer models and basic theory indicates that the fluxes of liquid and solid freshwater are controlled by different mechanisms and occur at different times of the year. Accurate representation in climate models will require representation of small-scale processes such as mesoscale eddies and gradients of ice thickness across the shelf.

The importance of sub-meter-scale snow roughness on conductive heat flux of Arctic sea ice

Abstract The conductive heat flux through the snow and ice is a critical component of the mass and energy budgets in the Arctic sea ice system. We use high horizontal resolution (3–15 cm) measurements of snow topography to explore the impacts of sub-meter-scale snow surface roughness on heat flux as simulated by the Finite Element method. Simulating horizontal heat flux in a variable snow cover modestly increases the total simulated heat flux. With horizontal heat flux, as opposed to simple 1D-vertical heat flux modeling, the simulated heat flux is 10% greater than that for uniform snow with the same mean snow thickness for a 31.5 × 21 m region of sea ice (the largest region we studied). Vertical-only (1D) heat flux simulates just a 6% increase for the same region. However, this is highly dependent on observation resolution. Had we measured the snow cover at 1 m horizontal spacing or greater, simulating horizontal heat flux would not have changed the net heat flux from that simulated with vertical-only heat flux. These findings suggest that measuring and modeling snow roughness at sub-meter horizontal scales may be necessary to accurately represent horizontal heat flux on level Arctic sea ice.

Ejection of porous dust–ice agglomerates from the surface of the cometary nucleus

This paper presents two problems related to the ejection of particles from the surface of the cometary nucleus. The first problem is related to the phase of quiet sublimation. This part of the paper discusses the influence of the water ice sublimation flux on the size of particles that are lifted into the coma. In these considerations, three formulas were used to describe the water ice sublimation flux. The calculations show that the size of the particle lifted into the coma depends on its density and the sublimation flux of water ice. The second mechanism is related to the cometary outburst phase. In this part of the paper, it was proposed that the cometary outburst as a high-energy process may significantly contribute to explaining the presence of small particles in the coma. Based on the calculations performed, it was shown that the dimensions of these particles depend on the adopted value of the power index in the power law. Based on the considerations presented in this paper, the presence of both large and fine dust particles observed in the coma during the Rosetta mission can be explained.

The influence of hemispherical albedo on the dynamics of cometary particles

ABSTRACT This paper presents a new approach to determining the dimensions of particles that can be lifted to a coma by the sublimation flux of water ice. Due to the diverse colour of the cometary surfaces, in the presented calculations we take into account the influence of the reflectance coefficient (hemispherical albedo) on the size of particles lifted from the surface of the nucleus. A Cary 5000 spectrometer was used to measure hemispherical albedo. Spectroscopic measurements used dust particles that consisted of pure silicate or were a mixture of pure silicate and organic compounds such as charcoal, soot, and ash. In addition, these admixtures acted as a means of darkening the tested sample. Depending on the colour of the sample and the wavelength, the measured value of hemispherical albedo oscillated in the range from 4.93 per cent to 48.65 per cent. A thermodynamic model of cometary matter emission was developed based on the results of hemispherical albedo measurements. The performed numerical simulations show that the temperature decreases with the increase of the hemispherical albedo, which translates into the sublimation flux and the dynamics of the dust-ice particles present on the surface of the cometary nucleus. Taking into account the extreme values of the hemispherical albedo, the differences in the size of particles carried away from the surface of the nucleus are in the order of centimeters.

An improvement in accuracy and spatial resolution of the pattern-matching sea ice drift from SAR imagery

ABSTRACTSea ice drift is a crucial parameter for sea ice flux, atmospheric and ocean circulation, and ship navigation. Pattern matching is widely used to retrieve sea ice drift from Synthetic Aperture Radar (SAR) data, but it often yields mismatched vectors and coarse spatial resolution. This study presents a framework to enhance the spatial resolution and accuracy of pattern-matching sea ice drift derived from SAR images. The framework employs the Accelerated-KAZE feature extraction method and Brute-Force feature matcher to extract feature-tracking sea ice drift vectors from SAR data, with mismatched vectors subsequently removed. The pattern-matching vectors are then refined by fusing with these feature-tracking vectors, using a Co-Kriging algorithm. Using the sea ice drift product from the Technical University of Denmark space as the pattern-matching vector field for refinement, the framework's effectiveness is evaluated by comparing the refined vectors with buoy displacements and pattern-matching vectors across five selected regions. Results show a reduction in velocity and direction root mean square error (RMSE) by 0.47 km/d (22%) and 4.97° (28%), respectively, and an enhanced spatial resolution from 10 km to 1 km. The findings demonstrate the framework's success in improving the accuracy and resolution of pattern-matching sea ice drift from SAR imagery.

Impacts of tidewater glacier advance on iceberg habitat

Abstract Icebergs in proglacial fjords serve as pupping, resting and molting habitat for some of the largest seasonal aggregations of harbor seals (Phoca vitulina richardii) in Alaska. One of the largest aggregations in Southeast Alaska occurs in Johns Hopkins Inlet, Glacier Bay National Park, where up to 2000 seals use icebergs produced by Johns Hopkins Glacier. Like other advancing tidewater glaciers, the advance of Johns Hopkins Glacier over the past century has been facilitated by the growth and continual redistribution of a submarine end moraine, which has limited mass losses from iceberg calving and submarine melting and enabled glacier thickening by providing flow resistance. A 15-year record of aerial surveys reveals (i) a decline in iceberg concentrations concurrent with moraine growth and (ii) that the iceberg size distributions can be approximated as power law distributions, with relatively little variability and no clear trends in the power law exponent despite large changes in ice fluxes over seasonal and interannual timescales. Together, these observations suggest that sustained tidewater glacier advance should typically be associated with reductions in the number of large, habitable icebergs, which may have implications for harbor seals relying on iceberg habitat for critical life-history events.

Provenance and transport of supraglacial debris revealed by variations in debris geochemistry on Khumbu Glacier, Nepal Himalaya

AbstractThe origin of supraglacial debris covers is often conceptualised as the formation of a surface lag by melt‐out of englacial debris from slow‐moving ice, where complexity arises from feedback between debris thickness and sub‐debris ice melt. Here, we examine the origin of a debris cover from the perspective of debris provenance and changing tributary supply in a high‐elevation compound valley glacier. Geochemical analysis of 11 major elements in 21 debris samples from six tributaries of Khumbu Glacier (Nepal) shows unambiguous statistical differentiation of debris sources reflecting lithological differences between tributary catchments. Twenty‐four samples from transects across the ablation area are partitioned according to their source areas using the FR2000 sediment unmixing model. We estimate the age of ice at each transect using a higher order ice flow model. The results show greater proportions of debris from lateral tributaries in downglacier locations that have experienced longer flowline histories. More recently, ice from the Main Himalayan Divide (Western Cwm) has become relatively more important. This suggests a change in the state of the lower glacier's structure depending on the relative ice discharges of lateral and divide sources. Ice flux from lower elevation tributaries was more important probably prior to a weakening of the Indian Summer Monsoon at around 1420 CE. The lower elevation tributaries lie within the range of late Holocene equilibrium line altitude variation and therefore respond most sensitively to climatic drivers of the glacier's flow structure. Negative glacier mass balance since around 1900 CE caused tributary glaciers to detach and high‐elevation catchments to re‐establish as the dominant ice source to Khumbu Glacier.

Ice flux of alpine glaciers controls erosion and landscape in the Nianbaoyeze Shan, northeastern Tibetan Plateau

Ice flux of alpine glaciers controls erosion and landscape in the Nianbaoyeze Shan, northeastern Tibetan Plateau

Migration of the Shear Margins at Thwaites Glacier: Dependence on Basal Conditions and Testability Against Field Data

AbstractProjections of global sea level depend sensitively on whether Thwaites Glacier, Antarctica, will continue to lose ice rapidly. Prior studies have focused primarily on understanding the evolution of ice velocity and whether the reverse‐sloping bed at Thwaites Glacier could drive irreversible retreat. However, the overall ice flux to the ocean and the possibility of irreversible retreat depend not only on the ice speed but also on the width of the main ice trunk. Here, we complement prior work by focusing specifically on understanding whether the lateral boundaries of the main ice trunk, termed shear margins, might migrate over time. We hypothesize that the shear margins at Thwaites Glacier will migrate on a decadal timescale in response to continued ice thinning and surface steepening. We test this hypothesis by developing a depth‐averaged, thermomechanical free‐boundary model that captures the complex topography underneath the glacier and solves for both the ice velocity and for the position of the shear margins. We find that both shear margins are prone to migration in response to ice thinning with basal strength and surface slope steepening determining their relative motion. We construct four end‐member cases of basal strength that represent different physical properties governing friction at the glacier bed and present two cases of ice thinning to contrast the effects of surface steepening and ice thinning. We test our model by hindcasting historic data and discuss how data from ongoing field campaigns could further be used to test our model.

The geomorphological record of an ice stream to ice shelf transition in Northeast Greenland

AbstractUnderstanding ice stream dynamics over decadal to millennial timescales is crucial for improving numerical model projections of ice sheet behaviour and future ice loss. In marine‐terminating settings, ice shelves play a critical role in controlling ice‐stream grounding line stability and ice flux to the ocean, but few studies have investigated the terrestrial lateral geomorphological imprint of ice shelves during deglaciation. Here, we document the terrestrial deglacial landsystem of Nioghalvfjerdsfjorden Glacier (79N) in northeast Greenland, following the Last Glacial Maximum, and the margin's lateral transition to a floating ice shelf. High‐elevation areas are influenced by local ice caps and display autochthonous to allochthonous blockfields that mark the interaction of local ice caps with the ice stream below. A thermal transition from cold‐ to warm‐based ice is denoted by the emplacement of erratics onto allochthonous blockfields. Below ~600 m above sea level (a.s.l.) glacially abraded bedrock surfaces and assemblages of lateral moraines, ‘hummocky’ moraine, fluted terrain, and ice‐contact deltas record the former presence of warm‐based ice and thinning of the grounded ice stream margin through time. In the outer fjord a range of landforms such as ice shelf moraines, dead‐ice topography, and ice marginal glaciofluvial outwash was produced by an ice shelf during deglaciation. Along the mid‐ and inner‐fjord areas this ice shelf signal is absent, suggesting ice shelf disintegration prior to grounding line retreat under tidewater conditions. However, below the marine limit, the geomorphological record along the fjord indicates the expansion of the 79N ice shelf during the Neoglacial, which culminated in the Little Ice Age. This was followed by 20th century recession, with the development of a suite of compressional ice shelf moraines, ice‐marginal fluvioglacial corridors, kame terraces, dead‐ice terrain, and crevasse infill ridges. These mark rapid ice shelf thinning and typify the present‐day ice shelf landsystem in a warming climate.

Managing plastic pollution in the Arctic ocean: An integrated quantitative flux estimate and policy study

Abstract Plastic pollution in the Arctic marine system is sparsely quantified, and few enforceable policies are in place to ameliorate the issue. With an inflow-outflow budget for the Arctic Ocean, we identify gateways through which plastic enters and exits the Arctic marine system. While estimating the flux of plastic through rivers, sea ice, and ocean, we also quantify marine plastic pollution from Arctic shipping and fishing. Plastic fluxes are calculated using horizontal volume fluxes of water and ice and combining them with plastic waste concentration data; flux from fishing and shipping is generated through combining waste estimates with estimated ship traffic. We estimate that fishing and shipping contribute 105 tonnes of plastic flux per annum, compared to 10−1 tonnes per annum from river inflow. The ocean has a far smaller net outflow, dwarfed by that of ice, at 10−8 to 10−7 and 10−5 to 10−3 tonnes per annum, respectively. We examine how a suite of proposed policy interventions would quantitatively change those concentrations, and how the current governance environment makes each feasible; we find interventions targeting vessel traffic most effective. These interventions include a prohibition on the use of certain plastics in fishing as well as a Polar Code permitting scheme.

The evolution of the Fram Strait sea ice volume export decomposed by age: estimating with parameter-optimized sea ice-ocean model outputs

Sea ice export through the Fram Strait is crucial in the dynamic evolution of Arctic sea ice and can further modulate Arctic sea ice mass balance as well as the ocean thermohaline circulation. In this study, based on outputs from a parameter-optimized and fully physical ocean–sea ice coupled model and sea ice age observation, we estimate sea ice volume (SIV) flux and its age evolution via the Fram Strait. The estimate of mean annual SIV flux is about 1605 315 km3 yr−1 without a significant trend for 1979–2021. Combining with sea ice age data, the variation of the sea ice age and its corresponding SIV flux are obtained for 1984–2020. The SIV flux of 1st-year ice significantly increases as expected, but it still contributes very little to the total flux in the 2010s with a proportion of 3.5%. SIV fluxes of different ages in multi-year ice present diverse variations. The proportions of 2nd-year ice and 3rd-year ice in the annual SIV flux show an extreme increase from 6.8% and 25.0% in the 1980s to 49.0% and 38.8% in the 2010s, respectively, while the proportions of 4th-year ice and 5th-year and older (5+ year) ice significantly decrease from 22.8% and 45.0% in the 1980s to 7.1% and 1.6% in the 2010s, respectively. Meanwhile, the prevailing age of annual volume export via Fram Strait shifts from 4th-year and 5+ year ice to 2nd-year and 3rd-year ice around 2007/2008. It is worth noticing that the variation in Fram Strait ice export modulates the variation in Arctic SIV prior to 2008, but the reverse is true after 2008, indicating a decreasing influence of Fram Strait SIV export on Artic SIV variability with decreasing sea ice age. The results are beneficial to promote the understanding of the evolution of Fram Strait SIV export under the warming Arctic.