Overview of the MOSAiC expedition: Snow and sea ice

Elementa Science of the Anthropocene, Год журнала: 2022, Номер 10(1)

Опубликована: Янв. 1, 2022

Year-round observations of the physical snow and ice properties processes that govern pack evolution its interaction with atmosphere ocean were conducted during Multidisciplinary drifting Observatory for Study Arctic Climate (MOSAiC) expedition research vessel Polarstern in Ocean from October 2019 to September 2020. This work was embedded into interdisciplinary design 5 MOSAiC teams, studying atmosphere, sea ice, ocean, ecosystem, biogeochemical processes. The overall aim characterize cover comprehensively central over an entire annual cycle. objective achieved by detailed energy mass balance ice. By dynamics nested spatial scales centimeters tens kilometers, variability across can be considered. On-ice situ remote sensing different surface types all seasons will help improve numerical process climate models establish validate novel satellite methods; linkages accompanying airborne measurements, observations, results are discussed. We found large variabilities metamorphism thermal regimes impacting growth. conclude highly variable needs considered more detail (in sensing, models) better understand snow-related feedback revealed rapid transformations motions along drift seasons. number coupled ice–ocean interface observed expected guide upcoming respect changing

Язык: Английский

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Overview of the MOSAiC expedition: Physical oceanography

Elementa Science of the Anthropocene, Год журнала: 2022, Номер 10(1)

Опубликована: Янв. 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

Язык: 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, Год журнала: 2022, Номер 10(1)

Опубликована: Янв. 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.

Язык: Английский

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Spatiotemporal evolution of melt ponds on Arctic sea ice

Elementa Science of the Anthropocene, Год журнала: 2022, Номер 10(1)

Опубликована: Янв. 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.

Язык: Английский

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

Scientific Data, Год журнала: 2023, Номер 10(1)

Опубликована: Авг. 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.

Язык: Английский

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The winter central Arctic surface energy budget: A model evaluation using observations from the MOSAiC campaign

Elementa Science of the Anthropocene, Год журнала: 2023, Номер 11(1)

Опубликована: Янв. 1, 2023

This study evaluates the simulation of wintertime (15 October, 2019, to 15 March, 2020) statistics central Arctic near-surface atmosphere and surface energy budget observed during MOSAiC campaign with short-term forecasts from 7 state-of-the-art operational experimental forecast systems. Five these systems are fully coupled ocean-sea ice-atmosphere models. Forecast need simultaneously simulate impact radiative effects, turbulence, precipitation processes on atmospheric conditions in order produce useful system. focuses unique Arctic, such as, representation liquid-bearing clouds at cold temperatures a persistent stable boundary layer. It is found that contemporary models still struggle maintain liquid water temperatures. Given simple balance between net longwave radiation, sensible heat flux, conductive ground flux balance, bias one components manifests as compensating other terms. highlights different manifestations model potential implications Three general types challenges within evaluated: representing clouds, interaction fluxes sub-surface (i.e., snow ice properties), relationship stability turbulent fluxes.

Язык: 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, Год журнала: 2023, Номер 11(1)

Опубликована: Янв. 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.

Язык: Английский

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A central arctic extreme aerosol event triggered by a warm air-mass intrusion

Nature Communications, Год журнала: 2022, Номер 13(1)

Опубликована: Сен. 8, 2022

Abstract Frequency and intensity of warm moist air-mass intrusions into the Arctic have increased over past decades been related to sea ice melt. During our year-long expedition in remote central Ocean, a record-breaking increase temperature, moisture downwelling-longwave radiation was observed mid-April 2020, during an intrusion carrying air pollutants from northern Eurasia. The two-day intrusion, caused drastic changes aerosol size distribution, chemical composition particle hygroscopicity. Here we show how transformed low-particle environment area comparable central-European urban setting. Additionally, resulted explosive cloud condensation nuclei, which can direct effects on clouds’ radiation, their precipitation patterns, lifetime. Thus, unless prompt actions significantly reduce emissions source regions are taken, such events expected continue affect climate.

Язык: Английский

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Snowfall and snow accumulation during the MOSAiC winter and spring seasons

˜The œcryosphere, Год журнала: 2022, Номер 16(6), С. 2373 - 2402

Опубликована: Июнь 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.

Язык: Английский

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Arctic warming by abundant fine sea salt aerosols from blowing snow

Nature Geoscience, Год журнала: 2023, Номер 16(9), С. 768 - 774

Опубликована: Сен. 1, 2023

Abstract The Arctic warms nearly four times faster than the global average, and aerosols play an increasingly important role in climate change. In Arctic, sea salt is a major aerosol component terms of mass concentration during winter spring. However, mechanisms production remain unclear. Sea are typically thought to be relatively large size but low number concentration, implying that their influence on cloud condensation nuclei population properties generally minor. Here we present observational evidence abundant from blowing snow central Arctic. Blowing was observed more 20% time November April. sublimation generates high concentrations fine-mode (diameter below 300 nm), enhancing up tenfold above background levels. Using chemical transport model, estimate April north 70° N, produced accounts for about 27.6% total particle number, increases longwave emissivity clouds, leading calculated surface warming +2.30 W m −2 under cloudy sky conditions.

Язык: Английский

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