Overview of the MOSAiC expedition: Atmosphere

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

Опубликована: Янв. 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.

Язык: Английский

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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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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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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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Sea Ice Melt Pond Fraction Derived From Sentinel‐2 Data: Along the MOSAiC Drift and Arctic‐Wide

Geophysical Research Letters, Год журнала: 2023, Номер 50(5)

Опубликована: Март 4, 2023

Abstract Melt ponds forming on Arctic sea ice in summer significantly reduce the surface albedo and impact heat mass balance of ice. Therefore, their areal coverage, which can undergo rapid change, is crucial to monitor. We present a revised method extract melt pond fraction (MPF) from Sentinel‐2 satellite imagery, evaluated by MPF products higher‐resolution helicopter‐borne imagery. The analysis evolution during MOSAiC campaign 2020, shows split Central Observatory (CO) into level highly deformed part, latter exhibits exceptional early formation compared vicinity. Average CO MPFs are 17% before 23% after major drainage. Arctic‐wide for years 2017–2021 consistent seasonal cycle all regions years.

Язык: Английский

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Surface impacts and associated mechanisms of a moisture intrusion into the Arctic observed in mid-April 2020 during MOSAiC

Frontiers in Earth Science, Год журнала: 2023, Номер 11

Опубликована: Апрель 11, 2023

Distinct events of warm and moist air intrusions (WAIs) from mid-latitudes have pronounced impacts on the Arctic climate system. We present a detailed analysis record-breaking WAI observed during MOSAiC expedition in mid-April 2020. By combining Eulerian with Lagrangian frameworks using simulations across different scales, we investigate aspects mass transformations via cloud processes quantify related surface impacts. The is characterized by two distinct pathways, Siberian Atlantic. A static energy transport Circle above climatological 90th percentile found. Observations at research vessel Polarstern show transition radiatively clear to cloudy state significant precipitation positive balance (SEB), i.e., warming. parcels reach first near tropopause, only 1–2 days later lower altitudes. In 5 prior event, latent heat release formation triggers maximum diabatic heating rates excess 20 K d -1 . For some poleward drifting parcels, this facilitates strong ascent up 9 km. Based model experiments, explore role key cloud-determining factors. First, test moisture availability reducing lateral inflow 30%. This does not significantly affect liquid water path, therefore SEB, central Arctic. cause are counteracting mechanisms along trajectory. Second, impact increasing Cloud Condensation Nuclei concentrations 10 1,000 cm -3 (pristine highly polluted), which enhances content. Resulting stronger longwave cooling top makes entrainment more efficient deepens atmospheric boundary layer. Finally, strongly effect SEB. mainly driven turbulent fluxes over ocean, but radiation sea ice. also contributes large fraction Arctic, reaching 30% total 9-day period site. However, measured varies substantially between platforms. Therefore, estimates subject considerable observational uncertainty.

Язык: Английский

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Thin and transient meltwater layers and false bottoms in the Arctic sea ice pack—Recent insights on these historically overlooked features

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

Опубликована: Янв. 1, 2023

The rapid melt of snow and sea ice during the Arctic summer provides a significant source low-salinity meltwater to surface ocean on local scale. accumulation this on, under, around floes can result in relatively thin layers upper ocean. Due small-scale nature these upper-ocean features, typically order 1 m thick or less, they are rarely detected by standard methods, but nevertheless pervasive critically important summer. Observations Multidisciplinary drifting Observatory for Study Climate (MOSAiC) expedition 2020 focused evolution such made advancements understanding their role coupled system. Here we provide review Arctic, with emphasis new findings from MOSAiC. Both prior recent observational datasets indicate an intermittent yet long-lasting (weeks months) layer 0.1 1.0 thickness, large spatial range. presence impacts physical system reducing bottom allowing formation via false growth. Collectively, bottoms reduce atmosphere-ocean exchanges momentum, energy, material. far-reaching, including acting as barrier nutrient gas exchange impacting ecosystem diversity productivity.

Язык: Английский

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A full year of aerosol size distribution data from the central Arctic under an extreme positive Arctic Oscillation: insights from the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition

Atmospheric chemistry and physics, Год журнала: 2023, Номер 23(1), С. 389 - 415

Опубликована: Янв. 11, 2023

Abstract. The Arctic environment is rapidly changing due to accelerated warming in the region. trend driving a decline sea ice extent, which thereby enhances feedback loops surface energy budget Arctic. aerosols play an important role radiative balance and hence climate response region, yet direct observations of over Ocean are limited. In this study, we investigate annual cycle aerosol particle number size distribution (PNSD), concentration (PNC), black carbon (BC) mass central during Multidisciplinary drifting Observatory for Study Climate (MOSAiC) expedition. This first continuous, year-long data set PNSD ever collected Ocean. We use k-means cluster analysis, FLEXPART simulations, inverse modeling evaluate seasonal patterns influence different source regions on population. Furthermore, compare land-based sites across Arctic, using both long-term measurements year MOSAiC expedition (2019–2020), interannual variability give context characteristics from within Our analysis identifies that, overall, exhibits typical aerosols, including anthropogenic haze winter secondary processes summer. pattern corresponds global radiation, air temperature, timing melting/freezing, drive changes transport processes. winter, Norilsk region Russia/Siberia was dominant signals BC observations, contributed higher accumulation-mode PNC concentrations than at observatories. also show that wintertime Oscillation (AO) phenomenon, reported achieve record-breaking positive phase January–March 2020, explains unusual magnitude compared longer-term observations. summer, PNCs nucleation Aitken modes enhanced; however, were notably lower pack further south. presented herein provides current snapshot characterized by rapid changes, will be crucial improving model predictions, understanding linkages between environmental processes, investigating impacts change future studies.

Язык: Английский

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The MOSAiC Distributed Network: Observing the coupled Arctic system with multidisciplinary, coordinated platforms

Elementa Science of the Anthropocene, Год журнала: 2024, Номер 12(1)

Опубликована: Янв. 1, 2024

Central Arctic properties and processes are important to the regional global coupled climate system. The Multidisciplinary drifting Observatory for Study of Climate (MOSAiC) Distributed Network (DN) autonomous ice-tethered systems aimed bridge gaps in our understanding temporal spatial scales, particular with respect resolution Earth system models. By characterizing variability around local measurements made at a Observatory, DN covers both interactions involving ocean-ice-atmosphere interfaces as well three-dimensional ocean, sea ice, atmosphere. more than 200 instruments (“buoys”) were varying complexity set up different sites mostly within 50 km Observatory. During an exemplary midwinter month, observations captured atmospheric on sub-monthly time but less so monthly means. They show significant snow depth ice thickness, provide temporally spatially resolved characterization motion deformation, showing coherency scale smaller scales. Ocean data background gradient across dependent due mixed layer sub-mesoscale mesoscale processes, influenced by variable cover. second case (May–June 2020) illustrates utility during absence manually obtained providing continuity physical biological this key transitional period. We examples synergies between extensive MOSAiC remote sensing numerical modeling, such estimating skill drift forecasts evaluating modeling. has been proven enable analysis atmosphere-ice-ocean potential improve model parameterizations important, unresolved future.

Язык: Английский

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Isotopic signatures of snow, sea ice, and surface seawater in the central Arctic Ocean during the MOSAiC expedition

Elementa Science of the Anthropocene, Год журнала: 2024, Номер 12(1)

Опубликована: Янв. 1, 2024

The Arctic Ocean is an exceptional environment where hydrosphere, cryosphere, and atmosphere are closely interconnected. Changes in sea-ice extent thickness affect ocean currents, as well moisture heat exchange with the atmosphere. Energy water fluxes impact formation melting of sea ice snow cover. Here, we present a comprehensive statistical analysis stable isotopes various hydrological components central obtained during Multidisciplinary drifting Observatory for Study Climate (MOSAiC) expedition 2019–2020, including understudied winter. Our dataset comprises >2200 water, snow, samples. Snow had most depleted variable isotopic composition, δ18O (–16.3‰) increasing consistently from surface (–22.5‰) to bottom (–9.7‰) snowpack, suggesting that metamorphism wind-induced transport may overprint original precipitation isotope values. In Ocean, also help distinguish between different types, whether there meteoric contribution. composition salinity seawater indicated relative contributions freshwater sources: lower (approximately –3.0‰) salinities were observed near eastern Siberian shelves towards center Transpolar Drift due river discharge. Higher –1.5‰) associated Atlantic source when RV Polarstern crossed Gakkel Ridge into Nansen Basin. These changes driven mainly by shifts within carried across Ocean. highlights importance investigating fractionation effects, example, melting. A systematic full-year sampling strengthens our understanding cycle provides crucial insights interaction atmosphere, ice, their spatio-temporal variations MOSAiC.

Язык: Английский

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