scholarly journals A 1 year sea surface heat budget in the northeastern Atlantic basin during the POMME experiment: 1. Flux estimates

2005 ◽  
Vol 110 (C7) ◽  
Author(s):  
G. Caniaux
Keyword(s):  
Heat Budget ◽  
Surface Heat ◽  
Sea Surface ◽  
Atlantic Basin ◽  
Surface Heat Budget ◽  
Northeastern Atlantic

scholarly journals Evaluating the impact of atmospheric forcing and air–sea coupling on near-coastal regional ocean prediction

Ocean Science ◽  
2019 ◽  
Vol 15 (3) ◽  
pp. 761-778 ◽  
Author(s):  
Huw W. Lewis ◽  
John Siddorn ◽  
Juan Manuel Castillo Sanchez ◽  
Jon Petch ◽  
John M. Edwards ◽  
...  
Keyword(s):  
Heat Budget ◽  
Global Scale ◽  
Ocean Model ◽  
Surface Heat ◽  
Wind Forcing ◽  
Sea Surface ◽  
Atmospheric Forcing ◽  
Convective Scale ◽  
The Impact ◽  
Surface Heat Budget

Abstract. Atmospheric forcing applied as ocean model boundary conditions can have a critical impact on the quality of ocean forecasts. This paper assesses the sensitivity of an eddy-resolving (1.5 km resolution) regional ocean model of the north-west European Shelf (NWS) to the choice of atmospheric forcing and atmosphere–ocean coupling. The analysis is focused on a month-long simulation experiment for July 2014 and evaluation of simulated sea surface temperature (SST) in a shallow near-coastal region to the south-west of the UK (Celtic Sea and western English Channel). Observations of the ocean and atmosphere are used to evaluate model results, with a particular focus on the L4 ocean buoy from the Western Channel Observatory as a rare example of co-located data above and below the sea surface. The impacts of differences in the atmospheric forcing are illustrated by comparing results from an ocean model run in forcing mode using operational global-scale numerical weather prediction (NWP) data with an ocean model run forced by a convective-scale regional atmosphere model. The value of dynamically representing feedbacks between the atmosphere and ocean state is assessed via the use of these model components within a fully coupled ocean–wave–atmosphere system. Simulated SSTs show considerable sensitivity to atmospheric forcing and to the impact of model coupling in near-coastal areas. A warm ocean bias relative to in situ observations in the simulation forced by global-scale NWP (0.7 K in the model domain) is shown to be reduced (to 0.4 K) via the use of the 1.5 km resolution regional atmospheric forcing. When simulated in coupled mode, this bias is further reduced (by 0.2 K). Results demonstrate much greater variability of both the surface heat budget terms and the near-surface winds in the convective-scale atmosphere model data, as might be expected. Assessment of the surface heat budget and wind forcing over the ocean is challenging due to a scarcity of observations. However, it can be demonstrated that the wind speed over the ocean simulated by the convective-scale atmosphere did not agree as well with the limited number of observations as the global-scale NWP data did. Further partially coupled experiments are discussed to better understand why the degraded wind forcing does not detrimentally impact on SST results.

A study of surface heat fluxes in the Ross Sea (Antarctica)

2000 ◽  
Vol 12 (2) ◽  
pp. 243-254 ◽  
Author(s):  
Giorgio Budillon ◽  
Giannetta Fusco ◽  
Giancarlo Spezie
Keyword(s):  
Heat Loss ◽  
Ross Sea ◽  
Heat Budget ◽  
Ice Cover ◽  
Surface Heat ◽  
Heat Fluxes ◽  
Total Heat ◽  
Sea Surface ◽  
Conductive Heat ◽  
Surface Heat Budget

In the polar regions, dynamical and thermodynamical interactions between atmosphere and ocean are strongly influenced by the presence or absence of the ice cover, which forms an insulating layer over the ocean, hindering sensible heat fluxes and forming an effective barrier to evaporation and thus preventing latent heat loss. In the framework of the CLIMA (Climatic Long-term Interactions for the Mass-balance in Antarctica) project of the Italian PNRA (National Program for Antarctic Research) we focused our attention on the evaluation of the heat fluxes between the ocean and the atmosphere in the Ross Sea, where the ice covers the sea for many months of the year. Wherever the ice cover is absent all year round, such as in leads or polynyas, the air-sea fluxes can be very large, especially in winter when the air-sea temperature differences are strong. In this work heat exchanges between sea and atmosphere, whether ice cover was present or not, were calculated from climatological data obtained from the European Centre for Medium Range Weather Forecasts, while sea ice data were collected from the US National Ice Center and National Climatic Data Center. Each of the terms in the sea surface heat budget were computed for 1994 with a temporal resolution of six hours and a spatial resolution of 0.5° using bulk formulae and obtaining monthly averaged horizontal distributions. The surface heat budget is dominated in November, December, January and February by shortwave radiation, while for the other months the turbulent and conductive heat fluxes dominate the heat exchange between the atmosphere and the sea surface. The annual total heat loss at the surface in 1994 has been estimated at about −90 W m−2 with the highest heat loss occurring close to the coast; the maximum heat loss occurred in May (−217 W m−2) while in January the heat gain by the ocean was 196 W m−2. In addition, weekly averaged values over the whole Ross Sea from 1994 to 1997 were calculated with the same parameterisation in order to study the temporal variability in this basin of each individual component and of the total surface heat budget. For this purpose only the data inside the continental shelf of the Ross Sea were considered in calculating the averaged fluxes. The 1994–97 total heat budget ranges from −87 to −107 W m−2with an average of −96 W m−2; this amount of heat loss was supposed to be compensated for by the heat advected by the Circumpolar Deep Water and its transport was estimated at about 2.9 Sv.

scholarly journals A Climatology of Ocean–Atmosphere Heat Flux Estimates over the Great Barrier Reef and Coral Sea: Implications for Recent Mass Coral Bleaching Events

2008 ◽  
Vol 21 (15) ◽  
pp. 3853-3871 ◽  
Author(s):  
Evan Weller ◽  
Manuel Nunez ◽  
Gary Meyers ◽  
Itsara Masiri
Keyword(s):  
Heat Flux ◽  
Great Barrier Reef ◽  
Coral Bleaching ◽  
Heat Budget ◽  
Surface Heat ◽  
Sea Surface ◽  
Barrier Reef ◽  
Surface Measurements ◽  
Surface Heat Budget ◽  
Rms Errors

Abstract A regional-scale estimate of the surface heat budget of the Great Barrier Reef and Coral Sea (10°–26°S, 142°–155°E) has been developed for the period 1995–2005 in the hope of understanding the trends of sea surface temperatures and the surface heat balance. This report describes the methodology to acquire input parameters from satellite observations, the resultant individual components of the surface heat budget, and their validation with existing datasets and surface measurements. The accuracy of individual flux components of the heat budget were analyzed with an array of surface measurements. Derived monthly averaged latent and sensible heat flux estimates show RMS errors of approximately 25.2 and 3.4 W m−2, respectively. Monthly averaged longwave and shortwave radiation flux estimates show RMS errors of approximately 6.7 and 13.3 W m−2, respectively. These improved estimates allow a higher confidence in studies that examine recent sea surface temperature (SST) trends and observed mass coral bleaching for the region. It is proposed that the greatest uptake of heat occurs over the spring/summer period in the central and southern regions of the Great Barrier Reef, agreeing well with areas where anomalously high sea surface temperatures are observed and where the most significant coral bleaching has occurred, and not in the most northern, more tropical region, as might be expected. The surface heat budget climatology was used to examine the mass bleaching episode that occurred in 2002. Results show that areas of maximum and minimum bleaching are better discriminated by the anomaly from mean seasonal values in the net surface heat flux (QNET), with accuracy of 86% and 79%, respectively, than by absolute QNET, absolute SST, or SST anomaly. Possible reasons for this are discussed.

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>

scholarly journals Surface Heat Budget over the North Sea in Climate Change Simulations

Atmosphere ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 272 ◽  
Author(s):  
Christian Dieterich ◽  
Shiyu Wang ◽  
Semjon Schimanke ◽  
Matthias Gröger ◽  
Birgit Klein ◽  
...  
Keyword(s):  
Climate Change ◽  
Heat Flux ◽  
North Sea ◽  
Heat Budget ◽  
Coupled Model ◽  
Surface Heat ◽  
The North ◽  
The North Sea ◽  
Rcp 8.5 ◽  
Surface Heat Budget

An ensemble of regional climate change scenarios for the North Sea is validated and analyzed. Five Coupled Model Intercomparison Project Phase 5 (CMIP5) General Circulation Models (GCMs) using three different Representative Concentration Pathways (RCPs) have been downscaled with the coupled atmosphere–ice–ocean model RCA4-NEMO. Validation of sea surface temperature (SST) against different datasets suggests that the model results are well within the spread of observational datasets. The ensemble mean SST with a bias of less than 1 ∘ C is the solution that fits the observations best and underlines the importance of ensemble modeling. The exchange of momentum, heat, and freshwater between atmosphere and ocean in the regional, coupled model compares well with available datasets. The climatological seasonal cycles of these fluxes are within the 95% confidence limits of the datasets. Towards the end of the 21st century the projected North Sea SST increases by 1.5 ∘ C (RCP 2.6), 2 ∘ C (RCP 4.5), and 4 ∘ C (RCP 8.5), respectively. Under this change the North Sea develops a specific pattern of the climate change signal for the air–sea temperature difference and latent heat flux in the RCP 4.5 and 8.5 scenarios. In the RCP 8.5 scenario the amplitude of the spatial heat flux anomaly increases to 5 W/m 2 at the end of the century. Different hypotheses are discussed that could contribute to the spatially non-uniform change in air–sea interaction. The most likely cause for an increased latent heat loss in the central western North Sea is a drier atmosphere towards the end of the century. Drier air in the lee of the British Isles affects the balance of the surface heat budget of the North Sea. This effect is an example of how regional characteristics modulate global climate change. For climate change projections on regional scales it is important to resolve processes and feedbacks at regional scales.

scholarly journals Seasonality of Decadal Sea Surface Temperature Anomalies in the Northwestern Pacific

2006 ◽  
Vol 19 (12) ◽  
pp. 2953-2968 ◽  
Author(s):  
Takashi Mochizuki ◽  
Hideji Kida
Keyword(s):  
Heat Flux ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Mixed Layer ◽  
Surface Heat Flux ◽  
Heat Budget ◽  
Surface Heat ◽  
Sea Surface ◽  
Northwestern Pacific ◽  
Sst Anomaly

Abstract The seasonality of the decadal sea surface temperature (SST) anomalies and the related physical processes in the northwestern Pacific were investigated using a three-dimensional bulk mixed layer model. In the Kuroshio–Oyashio Extension (KOE) region, the strongest decadal SST anomaly was observed during December–February, while that of the central North Pacific occurred during February–April. From an examination of the seasonal heat budget of the ocean mixed layer, it was revealed that the seasonal-scale enhancement of the decadal SST anomaly in the KOE region was controlled by horizontal Ekman temperature transport in early winter and by vertical entrainment in autumn. The temperature transport by the geostrophic current made only a slight contribution to the seasonal variation of the decadal SST anomaly, despite controlling the upper-ocean thermal conditions on decadal time scales through the slow Rossby wave adjustment to the wind stress curl. When averaging over the entire KOE region, the contribution from the net sea surface heat flux was also no longer significantly detected. By examining the horizontal distributions of the local thermal damping rate, however, it was concluded that the wintertime decadal SST anomaly in the eastern KOE region was rather damped by the net sea surface heat flux. It was due to the fact that the anomalous local thermal damping of the SST anomaly resulting from the vertical entrainment in autumn was considerably strong enough to suppress the anomalous local atmospheric thermal forcing that acted to enhance the decadal SST anomaly.

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