scholarly journals Meteorological and cloud conditions during the Arctic Ocean 2018 expedition

2021 ◽  
Vol 21 (1) ◽  
pp. 289-314 ◽  
Author(s):  
Jutta Vüllers ◽  
Peggy Achtert ◽  
Ian M. Brooks ◽  
Michael Tjernström ◽  
John Prytherch ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
High Frequency ◽  
Heat Budget ◽  
Mixed Boundary ◽  
The Arctic ◽  
Central Arctic Ocean ◽  
Surface Water Chemistry ◽  
Near Surface ◽  
The Arctic Ocean ◽  
Arctic Summer

Abstract. The Arctic Ocean 2018 (AO2018) took place in the central Arctic Ocean in August and September 2018 on the Swedish icebreaker Oden. An extensive suite of instrumentation provided detailed measurements of surface water chemistry and biology, sea ice and ocean physical and biogeochemical properties, surface exchange processes, aerosols, clouds, and the state of the atmosphere. The measurements provide important information on the coupling of the ocean and ice surface to the atmosphere and in particular to clouds. This paper provides (i) an overview of the synoptic-scale atmospheric conditions and their climatological anomaly to help interpret the process studies and put the detailed observations from AO2018 into a larger context, both spatially and temporally; (ii) a statistical analysis of the thermodynamic and near-surface meteorological conditions, boundary layer, cloud, and fog characteristics; and (iii) a comparison of the results to observations from earlier Arctic Ocean expeditions – in particular AOE1996 (Arctic Ocean Expedition 1996), SHEBA (Surface Heat Budget of the Arctic Ocean), AOE2001 (Arctic Ocean Experiment 2001), ASCOS (Arctic Summer Cloud Ocean Study), ACSE (Arctic Clouds in Summer Experiment), and AO2016 (Arctic Ocean 2016) – to provide an assessment of the representativeness of the measurements. The results show that near-surface conditions were broadly comparable to earlier experiments; however the thermodynamic vertical structure was quite different. An unusually high frequency of well-mixed boundary layers up to about 1 km depth occurred, and only a few cases of the “prototypical” Arctic summer single-layer stratocumulus deck were observed. Instead, an unexpectedly high amount of multiple cloud layers and mid-level clouds were present throughout the campaign. These differences from previous studies are related to the high frequency of cyclonic activity in the central Arctic in 2018.

scholarly journals Meteorological and cloud conditions during the Arctic Ocean 2018 expedition

2020 ◽  
Author(s):  
Jutta Vüllers ◽  
Peggy Achtert ◽  
Ian M. Brooks ◽  
Michael Tjernström ◽  
John Prytherch ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
High Frequency ◽  
Mixed Boundary ◽  
The Arctic ◽  
Atmospheric Conditions ◽  
Central Arctic Ocean ◽  
Surface Exchange ◽  
Surface Water Chemistry ◽  
Near Surface ◽  
The Arctic Ocean

Abstract. The Arctic Ocean 2018 (AO2018) expedition took place in the central Arctic Ocean in August and September 2018. An extensive suite of instrumentation provided detailed measurements of surface water chemistry and biology, sea ice and ocean physical and biogeochemical properties, surface exchange processes, aerosols, clouds, and the state of the atmosphere. The measurements provide important information on the coupling of the ocean and ice surface to the atmosphere and in particular to clouds. This paper provides: (i) an overview of the synoptic-scale atmospheric conditions and its climatological anomaly to help interpret the process studies and put the detailed observations from AO2018 into a larger context, both spatially and temporally; (ii) a statistical analysis of the thermodynamic and near-surface meteorological conditions, boundary layer, cloud, and fog characteristics; (iii) a comparison of the results to observations from earlier Arctic Ocean expeditions, in particular AOE96, SHEBA, AOE2001, ASCOS, ACSE, and AO2016, to provide an assessment of the representativeness of the measurements. The results show that near-surface conditions were broadly comparable to earlier experiments, however the thermodynamic vertical structure was quite different. An unusually high frequency of well-mixed boundary layers up to about 1 km depth occurred, and only a few cases of the prototypical Arctic summer single-layer stratocumulus deck were observed. Instead, an unexpectedly high amount of multiple cloud layers and mid-level clouds was present throughout the campaign. These differences from previous studies are related to the high frequency of cyclonic activity in the central Arctic in 2018.

scholarly journals An Evaluation of Surface Atmospheric Changes over the Arctic Ocean for 2000–09 Using Recent Reanalyses

2015 ◽  
Vol 19 (2) ◽  
pp. 1-18 ◽  
Author(s):  
Ayan H. Chaudhuri ◽  
Rui M. Ponte
Keyword(s):  
Arctic Ocean ◽  
Extreme Event ◽  
Longwave Radiation ◽  
Remotely Sensed ◽  
Surface Radiation ◽  
Shortwave Radiation ◽  
The Arctic ◽  
Near Surface ◽  
The Arctic Ocean ◽  
Ice Retreat

Abstract The authors examine five recent reanalysis products [NCEP Climate Forecast System Reanalysis (CFSR), Modern-Era Retrospective Analysis for Research and Applications (MERRA), Japanese 25-year Reanalysis Project (JRA-25), Interim ECMWF Re-Analysis (ERA-Interim), and Arctic System Reanalysis (ASR)] for 1) trends in near-surface radiation fluxes, air temperature, and humidity, which are important indicators of changes within the Arctic Ocean and also influence sea ice and ocean conditions, and 2) fidelity of these atmospheric fields and effects for an extreme event: namely, the 2007 ice retreat. An analysis of trends over the Arctic for the past decade (2000–09) shows that reanalysis solutions have large spreads, particularly for downwelling shortwave radiation. In many cases, the differences in significant trends between the five reanalysis products are comparable to the estimated trend within a particular product. These discrepancies make it difficult to establish a consensus on likely changes occurring in the Arctic solely based on results from reanalyses fields. Regarding the 2007 ice retreat event, comparisons with remotely sensed estimates of downwelling radiation observations against these reanalysis products present an ambiguity. Remotely sensed observations from a study cited herewith suggest a large increase in downwelling summertime shortwave radiation and decrease in downwelling summertime longwave radiation from 2006 and 2007. On the contrary, the reanalysis products show only small gains in summertime shortwave radiation, if any; however, all the products show increases in downwelling longwave radiation. Thus, agreement within reanalysis fields needs to be further checked against observations to assess possible biases common to all products.

Wie genau sind universelle Funktionen bei stark stabiler Schichtung?

2021 ◽  
Author(s):  
Thomas Foken ◽  
Christof Lüpkes ◽  
Dörthe Handorf
Keyword(s):  
Arctic Ocean ◽  
Heat Budget ◽  
Surface Heat ◽  
The Arctic ◽  
The Arctic Ocean ◽  
Surface Heat Budget

<p>Der Datensatz des <em>Surface Heat Budget of the Arctic Ocean (SHEBA) </em>Experimentes 1997/98 wird häufig für die Berechnung von universellen Funktionen für stabile Schichtung herangezogen. Für eine nicht-iterative Modellierung (Louis-Ansatz) können diese Funktionen neu berechnet werden. Allerdings haben diese Funktionen viele empirische Faktoren, die sich aus der Anpassung an den ursprünglichen Datensatz ergeben. Ein interessantes Ergebnis bei der Analyse der Daten des SHEBA-Experimentes ist, dass die Daten für die oberen Messpunkte des Experiments einer lokalen Skalierung mit den klassischen universellen Funktionen folgen, während die Daten der unteren Messpunkte eine große Streuung aufweisen. Somit könnten für den oberen Teil des Profils ein allgemein üblicher Louis-Ansatz verwendet werden. Es ist davon auszugehen, dass unter besonderen Bedingungen der untere Teil des Profils vom oberen Teil entkoppelt ist, wie es bei anderen Experimenten bereits gezeigt werden konnte. Ein einfacher Test für die Entkopplung durch Vergleich der experimentellen Daten mit einem hydrodynamischen Modellansatzes wird in der Präsentation gezeigt. Es wird daher empfohlen, den SHEBA Datensatz auf Entkopplung zu testen und eine wahrscheinlich viel einfachere universelle Funktion zu erstellen. Allerdings ist der Umgang mit entkoppelten Situationen noch im Bereich der Forschung. Es ist allerdings für die meisten Fälle zu erwarten, dass bei Berücksichtigung der Entkopplung kleinere Flüsse bestimmt würden.</p>

Arctic Ocean State-Changes: Self Interests and Common Interests

2009 ◽  
Vol 1 (1) ◽  
pp. 511-525
Author(s):  
Paul Arthur Berkman
Keyword(s):  
Arctic Ocean ◽  
The Arctic ◽  
International Governance ◽  
State Change ◽  
Central Arctic Ocean ◽  
Nation States ◽  
Free Region ◽  
The Arctic Ocean ◽  
Challenges And Opportunities ◽  
State Changes

Abstract Environmental and geopolitical state-changes are the underlying first principles of the diverse stakeholder positioning in the Arctic Ocean. The Arctic Ocean is changing from an ice-covered region to an ice-free region during the summer, which is an environmental state-change. As provided under the framework of the United Nations Convention on the Law of the Sea (UNCLOS), the central Arctic Ocean currently involves “High-Seas” (beyond the “Exclusive Economic Zones”) and the underlying “Area” of the deep-sea floor (beyond the “Continental Shelves”). Governance applications of this ‘donut’ demography – with international space surrounded by sovereign sectors – would be a geopolitical state-change in the Arctic Ocean. International governance strategies and applications for the central Arctic Ocean have far-reaching implications for the stewardship of other international spaces, which between Antarctica and the ocean beyond national jurisdictions account for nearly 75 percent of the Earth’s surface. In view of planetary-scale strategies for humankind, with frameworks such as climate, the Arctic Ocean underscores the challenges and opportunities to balance the governance of nation states and international spaces centuries into the future.

scholarly journals Circulation and transformation of Atlantic water in the Eurasian Basin and the contribution of the Fram Strait inflow branch to the Arctic Ocean heat budget

2015 ◽  
Vol 132 ◽  
pp. 128-152 ◽  
Author(s):  
Bert Rudels ◽  
Meri Korhonen ◽  
Ursula Schauer ◽  
Sergey Pisarev ◽  
Benjamin Rabe ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
Heat Budget ◽  
Atlantic Water ◽  
The Arctic ◽  
Fram Strait ◽  
The Arctic Ocean ◽  
Eurasian Basin

scholarly journals Regional sensible and radiative heat flux estimates for the winter Arctic during the Surface Heat Budget of the Arctic Ocean (SHEBA) experiment

2000 ◽  
Vol 105 (C6) ◽  
pp. 14093-14102 ◽  
Author(s):  
James E. Overland ◽  
S. Lyn McNutt ◽  
Joanne Groves ◽  
Sigrid Salo ◽  
Edgar L. Andreas ◽  
...  
Keyword(s):  
Heat Flux ◽  
Arctic Ocean ◽  
Radiative Heat ◽  
Heat Budget ◽  
Surface Heat ◽  
Radiative Heat Flux ◽  
The Arctic ◽  
The Arctic Ocean ◽  
Surface Heat Budget

scholarly journals Arctic sea-ice area and volume production:1996/97 versus 1997/98

2002 ◽  
Vol 34 ◽  
pp. 447-453 ◽  
Author(s):  
Ron Kwok
Keyword(s):  
Arctic Ocean ◽  
Large Scale ◽  
Heat Budget ◽  
Ice Cover ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Ice Thickness ◽  
The Arctic Ocean ◽  
Volume Production ◽  
Area And Volume

AbstractThe RADARSAT geophysical processor system (RGPS) produces measurements of ice motion and estimates of ice thickness using repeat synthetic aperture radar maps of the Arctic Ocean. From the RGPS products, we compute the net deformation and advection of the winter ice cover using the motion observations, and the seasonal ice area and volume production using the estimates of ice thickness. The results from the winters of 1996/97 and 1997/98 are compared. The second winter is of particular interest because it coincides with the Surface Heat Budget of the Arctic Ocean (SHEBA) field program. The character of the deformation of the ice cover from the two years is very different. Over a domain covering a large part of the western Arctic Ocean (~2.5 × 106 km2), the net divergence of that area during the 6 months of the first winter was 2.7% and for the second winter was 49.3%. In a subregion where the SHEBA camp was located, the net divergence was almost 38% compared to a net divergence of the same subregion of ~9% in 1996/97. The resulting deformation created a much larger volume of seasonal ice than in the earlier year. The net seasonal ice-volume production is 1.6 times (0.38 m vs 0.62 m) that of the first year. In addition to the larger divergence, this part of the ice cover advected a longer distance toward the Chukchi Sea over the same time-span. The total coverage of multi-year ice remained almost identical at ~2.08 × 106 km2, or 83% of the initial area of the domain. In this paper, we compare the behavior of the ice cover over the two winters and discuss these observations in the context of large-scale ice motion and atmospheric-pressure pattern.

Sign in / Sign up

Export Citation Format

Share Document