Overview of the MOSAiC expedition: Atmosphere

Elementa Science of the Anthropocene, Journal Year: 2022, Volume and Issue: 10(1)

Published: Jan. 1, 2022

With the Arctic rapidly changing, needs to observe, understand, and model changes are essential. To support these needs, an annual cycle of observations atmospheric properties, processes, interactions were made while drifting with sea ice across central during Multidisciplinary Observatory for Study Climate (MOSAiC) expedition from October 2019 September 2020. An international team designed implemented comprehensive program document characterize all aspects system in unprecedented detail, using a variety approaches, multiple scales. These measurements coordinated other observational teams explore cross-cutting coupled Ocean, ice, ecosystem through physical biogeochemical processes. This overview outlines breadth complexity research program, which was organized into 4 subgroups: state, clouds precipitation, gases aerosols, energy budgets. Atmospheric variability over revealed important influences persistent large-scale winter circulation pattern, leading some storms pressure winds that outside interquartile range past conditions suggested by long-term reanalysis. Similarly, MOSAiC location warmer wetter summer than reanalysis climatology, part due its close proximity edge. The comprehensiveness characterizing analyzing phenomena is demonstrated via case study examining air mass transitions vertical evolution. Overall, successfully met objectives most measurement date conducted ice. obtained data will broad coupled-system scientific provide foundation advancing multiscale modeling capabilities Arctic.

Language: Английский

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Overview of the MOSAiC expedition: Physical oceanography

Elementa Science of the Anthropocene, Journal Year: 2022, Volume and Issue: 10(1)

Published: Jan. 1, 2022

Arctic Ocean properties and processes are highly relevant to the regional global coupled climate system, yet still scarcely observed, especially in winter. Team OCEAN conducted a full year of physical oceanography observations as part Multidisciplinary drifting Observatory for Study Climate (MOSAiC), drift with sea ice from October 2019 September 2020. An international team designed implemented program characterize system unprecedented detail, seafloor air-sea ice-ocean interface, sub-mesoscales pan-Arctic. The oceanographic measurements were coordinated other teams explore ocean physics linkages ecosystem. This paper introduces major components complements overviews MOSAiC observational program. OCEAN’s sampling strategy was around hydrographic ship-, ice- autonomous platform-based improve understanding circulation mixing processes. Measurements carried out both routinely, regular schedule, response storms or opening leads. Here we present along-drift time series properties, allowing insights into seasonal evolution water column winter Laptev Sea early summer Fram Strait: freshening surface, deepening mixed layer, increase temperature salinity Atlantic Water. We also highlight presence Canada Basin deep intrusions surface meltwater layer most likely comprehensive ever over ice-covered Ocean. While data analysis interpretation ongoing, acquired datasets will support wide range multi-disciplinary research. They provide significant foundation assessing advancing modeling capabilities

Language: Английский

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Seasonality and timing of sea ice mass balance and heat fluxes in the Arctic transpolar drift during 2019–2020

Elementa Science of the Anthropocene, Journal Year: 2022, Volume and Issue: 10(1)

Published: Jan. 1, 2022

Sea ice growth and decay are critical processes in the Arctic climate system, but comprehensive observations very sparse. We analyzed data from 23 sea mass balance buoys (IMBs) deployed during Multidisciplinary drifting Observatory for Study of Climate (MOSAiC) expedition 2019–2020 to investigate seasonality timing thermodynamic Transpolar Drift. The reveal four stages season: (I) onset basal freezing, mid-October November; (II) rapid growth, December–March; (III) slow April–May; (IV) melting, June onward. Ice ranged 0.64 1.38 m at a rate 0.004–0.006 d–1, depending mainly on initial thickness. Compared buoy close MOSAiC setup site September 2012, total was about twice as high, due relatively thin thickness sites. top, caused by surface flooding subsequent snow-ice formation, observed two sites likely linked dynamic processes. Snow reached maximum depth 0.25 ± 0.08 May 2, 2020, had melted completely 25, 2020. early melt 7 (±10 d), 2019, can be partly attributed unusually advection floes towards Fram Strait. oceanic heat flux, calculated based bottom, 2.8 1.1 W m–2 December–April, increased gradually onward, reaching 10.0 2.6 mid-June Subsequently, under-ice ponds formed most connection with increasing permeability. Our analysis provides crucial information future studies related beyond.

Language: Английский

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Arctic sea ice albedo: Spectral composition, spatial heterogeneity, and temporal evolution observed during the MOSAiC drift

Elementa Science of the Anthropocene, Journal Year: 2022, Volume and Issue: 10(1)

Published: Jan. 1, 2022

The magnitude, spectral composition, and variability of the Arctic sea ice surface albedo are key to understanding numerically simulating Earth’s shortwave energy budget. Spectral broadband albedos were spatially temporally sampled by on-ice observers along individual survey lines throughout sunlit season (April–September, 2020) during Multidisciplinary drifting Observatory for Study Climate (MOSAiC) expedition. seasonal evolution MOSAiC year was constructed from averaged values each line. Specific locations identified as representative types, including accumulated dry snow, melting bare ice, refreezing ponded sediment-laden ice. area-averaged progression total recorded showed remarkable similarity that 22 years prior on multiyear Surface Heat Budget Ocean (SHEBA) In accord with these other previous field efforts, relatively thick, snow-free, shows invariance across location, decade, type. particular, indistinguishable second-year suggesting highly scattering layer forms summer is robust stabilizing. contrast, observed be variable at visible wavelengths. Notable temporal changes in documented melt freeze onset, formation deepening ponds, While model simulations show considerable agreement progression, disparities suggest need improve how both thin, simulated.

Language: Английский

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Thermodynamic and dynamic contributions to seasonal Arctic sea ice thickness distributions from airborne observations

Elementa Science of the Anthropocene, Journal Year: 2022, Volume and Issue: 10(1)

Published: Jan. 1, 2022

Sea ice thickness is a key parameter in the polar climate and ecosystem. Thermodynamic dynamic processes alter sea thickness. The Multidisciplinary drifting Observatory for Study of Arctic Climate (MOSAiC) expedition provided unique opportunity to study seasonal changes same ice. We analyzed 11 large-scale (∼50 km) airborne electromagnetic surface roughness surveys from October 2019 September 2020. Data mass balance position buoys additional information. found that thermodynamic growth decay dominated cycle with total mean increase 1.4 m (October June 2020) 1.2 (June 2020 2020). Ice dynamics deformation-related processes, such as thin formation leads subsequent ridging, broadened distribution contributed 30% These caused 1-month delay between maximum EM measurements bridged scales local floe-scale Arctic-wide satellite observations model grid cells. spatial differences Central (<10 MOSAiC Distributed Network (<50 were negligible fall only 0.2 late winter, but relative abundance thick varied. One unexpected outcome was large thickening regime where divergence prevailed on average western Nansen Basin spring. suggest due mobile, unconsolidated pack periodic, sub-daily motion. demonstrate this Lagrangian data set well suited validating existing redistribution theory models. Our comprehensive description valuable interpreting time series across disciplines can be used reference advance modeling.

Language: Английский

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Spatiotemporal evolution of melt ponds on Arctic sea ice

Elementa Science of the Anthropocene, Journal Year: 2022, Volume and Issue: 10(1)

Published: Jan. 1, 2022

Melt ponds on sea ice play an important role in the Arctic climate system. Their presence alters partitioning of solar radiation: decreasing reflection, increasing absorption and transmission to ocean, enhancing melt. The spatiotemporal properties melt thus modify albedo feedbacks mass balance ice. Multidisciplinary drifting Observatory for Study Climate (MOSAiC) expedition presented a valuable opportunity investigate seasonal evolution through rich array atmosphere-ice-ocean measurements across spatial temporal scales. In this study, we characterize behavior variability snow, surface scattering layer, from spring autumn freeze-up using situ surveys auxiliary observations. We compare results satellite retrievals output two models: Community Earth System Model (CESM2) Marginal Ice Zone Modeling Assimilation (MIZMAS). During season, maximum pond coverage depth were 21% 22 ± 13 cm, respectively, with distribution corresponding roughness thickness. Compared observations, both models overestimate summer, values approximately 41% (MIZMAS) 51% (CESM2). This overestimation has implications accurately simulating feedbacks. observed freeze-up, weather events, including rain caused high-frequency snow depth, while remained relatively constant until continuous freezing ensued. Both simulate abrupt cessation during but dates differ. MIZMAS simulates date CESM2 one-to-two weeks earlier. work demonstrates areas that warrant future observation-model synthesis improving representation sea-ice processes properties, which can aid accurate simulations warming climate.

Language: Английский

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Continuous observations of the surface energy budget and meteorology over the Arctic sea ice during MOSAiC

Scientific Data, Journal Year: 2023, Volume and Issue: 10(1)

Published: Aug. 4, 2023

The Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) was a yearlong expedition supported by icebreaker R/V Polarstern, following Transpolar Drift from October 2019 to 2020. campaign documented an annual cycle physical, biological, and chemical processes impacting atmosphere-ice-ocean system. Of central importance were measurements thermodynamic dynamic evolution sea ice. A multi-agency international team led University Colorado/CIRES NOAA-PSL observed meteorology surface-atmosphere energy exchanges, including radiation; turbulent momentum flux; latent sensible heat snow conductive flux. There four stations on ice, 10 m micrometeorological tower paired with 23/30 mast radiation station three autonomous Atmospheric Surface Flux Stations. Collectively, acquired ~928 days data. This manuscript documents acquisition post-processing those provides guide researchers access use data products.

Language: Английский

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Surface temperature comparison of the Arctic winter MOSAiC observations, ERA5 reanalysis, and MODIS satellite retrieval

Elementa Science of the Anthropocene, Journal Year: 2023, Volume and Issue: 11(1)

Published: Jan. 1, 2023

Atmospheric model systems, such as those used for weather forecast and reanalysis production, often have significant systematic errors in their representation of the Arctic surface energy budget its components. The newly available observation data Multidisciplinary drifting Observatory Study Climate (MOSAiC) expedition (2019/2020) enable a range analyses validation order to advance our understanding potential deficiencies. In present study, we analyze deficiencies radiative over sea ice ERA5 global atmospheric by comparing against winter MOSAiC campaign data, well as, pan-Arctic level-2 MODIS temperature remote sensing product. We find that can simulate timing radiatively clear periods, though it is not able distinguish two observed states, opaquely cloudy, distribution net budget. has conditional error with positive bias conditions negative cloudy conditions. mean 4°C situations at up 15°C some parts Arctic. spatial variability temperature, given 4 sites MOSAiC, captured due resolution but represented satellite sensitivity analysis possible sources, using products snow depth thickness, shows during events are, large extent, caused insufficient thickness system. A characterizes regions greater than 1.5 m, while thinner partly compensated effect snow.

Language: Английский

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Sea Ice Remote Sensing—Recent Developments in Methods and Climate Data Sets

Surveys in Geophysics, Journal Year: 2023, Volume and Issue: 44(5), P. 1653 - 1689

Published: April 3, 2023

Abstract Sea ice monitoring by polar orbiting satellites has been developed over more than four decades and is today one of the most well-established applications space observations. This article gives an overview data product development from first sensors to state-of-the-art regarding retrieval methods, new products operational sets serving climate as well daily services including charting forecasting. Passive microwave longest history represents backbone global with already consistent observations concentration extent. Time series passive primary set document sea decline in Arctic. Scatterometer a valuable supplement data, particular retrieve displacement distinguish between firstyear multiyear ice. Radar laser altimeter become main method estimate thickness thereby fill gap observation essential variable. Data on allows estimation volume masses improvement forecasts. The use different altimetric frequencies also makes it possible measure depth snow covering Synthetic Aperture (SAR) work horse regional scale because high-resolution radar images are delivered year-round nearly all regions where national produce charts. important for research can be used observe number processes phenomena, like type dynamics, contribute knowledge about modelling forecasting navigation discussed. Finally, describes future plans observation.

Language: Английский

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Snowfall and snow accumulation during the MOSAiC winter and spring seasons

˜The œcryosphere, Journal Year: 2022, Volume and Issue: 16(6), P. 2373 - 2402

Published: June 17, 2022

Abstract. Data from the Multidisciplinary drifting Observatory for Study of Arctic Climate (MOSAiC) expedition allowed us to investigate temporal dynamics snowfall, snow accumulation and erosion in great detail almost whole season (November 2019 May 2020). We computed cumulative water equivalent (SWE) over sea ice based on depth density retrievals a SnowMicroPen approximately weekly measured depths along fixed transect paths. used derived SWE cover compare with precipitation sensors installed during MOSAiC. The data were also compared ERA5 reanalysis snowfall rates drift track. found an accumulated mass 38 mm between end October April 2020. initial first-year relative second-year increased 50 % 90 by investigation period. Further, we that Vaisala Present Weather Detector 22, optical sensor, railing top deck research vessel Polarstern, was least affected blowing showed good agreements transect. On contrary, OTT Pluvio2 pluviometer Parsivel2 laser disdrometer largely wind snow, leading too high rates. These are reduced when eliminating periods comparison. reveals timing events agreement ground measurements overestimation tendency. Retrieved ship-based Ka-band ARM zenith radar shows differences comparable those ERA5. Based results, suggest radar-derived as upper limit present weather detector RV Polarstern lower range. these findings, 72 107 loss due sublimation 47 68 %, time period 31 26 Extending this beyond available measurements, 98–114 mm.

Language: Английский

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