Impact of the sea surface temperature forcing on hindcasts of  Madden-Julian Oscillation events using the ECMWF model

Abstract. This paper explores the sensitivity of the prediction of Madden Julian Oscillation (MJO) events to different aspects of the sea surface temperature (SST) in the European Centre for Medium-range Weather Forecasts (ECMWF) model. The impact of temporal resolution of SST on the MJO is first evaluated via a set of monthly hindcast experiments. The experiments are conducted with an atmosphere forced by persisted SST anomalies, monthly and weekly SSTs. Skill scores are clearly degraded when weekly SSTs are replaced by monthly values or persisted anomalies. The new high resolution OSTIA SST daily reanalysis would in principle allow to establish the impact of daily versus weekly SST values on the MJO prediction. It is found however that OSTIA SSTs provide lower skill scores than the weekly product. Further experiments show that this loss of skill cannot be attributed to either the mean state or the daily frequency of OSTIA SSTs. Additional diagnostics show that the phase relationship between OSTIA SSTs and tropical convection is not optimal with repspect to observations. Such result suggests that capturing the correct SST-convection phase relationship is a major challenge for the MJO predictions.

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Impact of the sea surface temperature forcing on hindcasts of Madden-Julian Oscillation events using the ECMWF model

Ocean Science ◽

10.5194/os-8-1071-2012 ◽

2012 ◽

Vol 8 (6) ◽

pp. 1071-1084 ◽

Cited By ~ 15

Author(s):

E. de Boisséson ◽

M. A. Balmaseda ◽

F. Vitart ◽

K. Mogensen

Keyword(s):

Surface Temperature ◽

Sea Surface Temperature ◽

Initial Conditions ◽

Lower Boundary ◽

Phase Relationship ◽

Atmospheric Model ◽

Sea Surface ◽

Madden Julian Oscillation ◽

Realistic Representation ◽

The Difference

Abstract. This paper explores the sensitivity of hindcasts of the Madden Julian Oscillation (MJO) to the use of different sea surface temperture (SST) products as lower boundary conditions in the European Centre for Medium-range Weather Forecasts (ECMWF) atmospheric model. Three sets of monthly hindcast experiments are conducted, starting from initial conditions from the ERA interim reanalysis. First, as a reference, the atmosphere is forced by the SST used to produce ERA interim. In the second and third experiments, the SST is switched to the OSTIA (Operational Sea Surface Temperature and Sea-Ice Analysis) and the AVHRR-only (Advanced Very High Resolution Radiometer) reanalyses, respectively. Tests on the temporal resolution of the SST show that monthly fields are not optimal, while weekly and daily resolutions provide similar MJO scores. When using either OSTIA or AVHRR, the propagation of the MJO is degraded and the resulting scores are lower than in the reference experiment. Further experiments show that this loss of skill cannot be attributed to either the difference in mean state or temporal variability between the SST products. Additional diagnostics show that the phase relationship between either OSTIA or AVHRR SST and the MJO convection is distorted with respect to satellite observations and the ERA interim reanalysis. This distortion is expected to impact the MJO hindcasts, leading to a relative loss of forecast skill. A realistic representation of ocean–atmosphere interactions is thus needed for MJO hindcasts, but not all SST products – though accurate for other purposes – fulfill this requirement.

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An Air–Sea Coupled Skeleton Model for the Madden–Julian Oscillation*

Journal of the Atmospheric Sciences ◽

10.1175/jas-d-12-0348.1 ◽

2013 ◽

Vol 70 (10) ◽

pp. 3147-3156 ◽

Cited By ~ 21

Author(s):

Fei Liu ◽

Bin Wang

Keyword(s):

Boundary Layer ◽

Surface Temperature ◽

Sea Surface Temperature ◽

Western Hemisphere ◽

Sea Surface ◽

Longitudinal Variation ◽

Madden Julian Oscillation ◽

Skeleton Model ◽

Planetary Scale ◽

The Mean

Abstract This work is an extension and improvement of the minimal Madden–Julian oscillation (MJO) “skeleton” model developed by Majda and Stechmann, which can capture some important features of the MJO—slow eastward propagation, quadrupole-vortex structure, and independence of frequency on wavelength—but is unable to produce unstable growth and selection of eastward-propagating planetary waves. With the addition of planetary boundary layer frictional moisture convergence, these deficiencies can be remedied. The frictional boundary layer “selects” the planetary-scale eastward propagation as the most unstable mode, but the dynamics remains confined to atmospheric processes only. Here the authors study the role of air–sea interaction by implementing an oceanic mixed-layer (ML) model of Wang and Xie into the MJO skeleton model. In this new air–sea coupled skeleton model, the features of the original skeleton model remain; additionally, the air–sea interaction under mean westerly winds is shown to produce a strong instability that selectively destabilizes the eastward-propagating planetary-scale waves. Although the cloud–shortwave radiation–sea surface temperature (CRS) feedback destabilizes both eastward and westward modes, the air–sea feedback associated with the evaporation and oceanic entrainment favors planetary-scale eastward modes. Over the Western Hemisphere where easterly background winds prevail, the evaporation and entrainment feedbacks yield damped modes, indicating that longitudinal variation of the mean surface winds plays an important role in regulation of the MJO intensity in addition to the longitudinal variation of the mean sea surface temperature or mean moist static stability. This theoretical analysis suggests that accurate simulation of the climatological mean state is critical for capturing the realistic air–sea interaction and thus the MJO.

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Impact of interactive sea surface temperature on convective clustering in radiative convective equilibrium

10.5194/egusphere-egu2020-14171 ◽

2020 ◽

Author(s):

Addisu Gezahegn Semie ◽

Adrian Mark Tompkins

Keyword(s):

Surface Temperature ◽

Sea Surface Temperature ◽

Radiative Forcing ◽

Wrf Model ◽

Ocean Model ◽

Surface Fluxes ◽

Sea Surface ◽

The Mean ◽

Slab Ocean ◽

The Impact

We present results of radiative convective equilibrium runs using the WRF model coupled to an interactive slab ocean model, for which a relaxation term removes energy to constrain the domain mean sea surface temperature to a target value over a given timescale. By using a short adjustment timescale of one minute, drift in the mean temperature is constrained and the impact of the slab ocean is only through the spatial heterogeneity in sea&#160; surface flux. We show how thin slabs slow the onset of organization, and conduct sensitivity experiments to determine the relative contributions of the radiative, sensible and latent surface fluxes, with surface fluxes key. Once clustering starts, the surface feedback acts to aid organization onset due to the drying atmosphere, although the speed of clustering onset is not significantly changed, indicating that it could be determined by a water vapour diffusive timescale as suggested by Windmiller and Craig.&#160; An additional set of experiments that permit the mean surface temperature to undergo a diurnal adjustment show how diurnal variations in SST oppose the atmospheric radiative forcing and also act to prevent clustering onset. We show the mechanism for this acts through the reduction of the diurnal variation of convective mass flux and the distance between updraft towers.

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Interannual Variability and Trends in Sea Surface Temperature, Lower and Middle Atmosphere Temperature at Different Latitudes for 1980–2019

Atmosphere ◽

10.3390/atmos12040454 ◽

2021 ◽

Vol 12 (4) ◽

pp. 454

Author(s):

Andrew R. Jakovlev ◽

Sergei P. Smyshlyaev ◽

Vener Y. Galin

Keyword(s):

Surface Temperature ◽

Sea Surface Temperature ◽

Lower Stratosphere ◽

Middle Atmosphere ◽

Southern Oscillation ◽

Lower Troposphere ◽

Reanalysis Data ◽

Sea Surface ◽

The Arctic ◽

The Impact

The influence of sea-surface temperature (SST) on the lower troposphere and lower stratosphere temperature in the tropical, middle, and polar latitudes is studied for 1980–2019 based on the MERRA2, ERA5, and Met Office reanalysis data, and numerical modeling with a chemistry-climate model (CCM) of the lower and middle atmosphere. The variability of SST is analyzed according to Met Office and ERA5 data, while the variability of atmospheric temperature is investigated according to MERRA2 and ERA5 data. Analysis of sea surface temperature trends based on reanalysis data revealed that a significant positive SST trend of about 0.1 degrees per decade is observed over the globe. In the middle latitudes of the Northern Hemisphere, the trend (about 0.2 degrees per decade) is 2 times higher than the global average, and 5 times higher than in the Southern Hemisphere (about 0.04 degrees per decade). At polar latitudes, opposite SST trends are observed in the Arctic (positive) and Antarctic (negative). The impact of the El Niño Southern Oscillation phenomenon on the temperature of the lower and middle atmosphere in the middle and polar latitudes of the Northern and Southern Hemispheres is discussed. To assess the relative influence of SST, CO2, and other greenhouse gases’ variability on the temperature of the lower troposphere and lower stratosphere, numerical calculations with a CCM were performed for several scenarios of accounting for the SST and carbon dioxide variability. The results of numerical experiments with a CCM demonstrated that the influence of SST prevails in the troposphere, while for the stratosphere, an increase in the CO2 content plays the most important role.

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The impact of climate model sea surface temperature biases on tropical cyclone simulations

Climate Dynamics ◽

10.1007/s00382-018-4577-5 ◽

2018 ◽

Vol 53 (1-2) ◽

pp. 173-192 ◽

Cited By ~ 5

Author(s):

Wei-Ching Hsu ◽

Christina M. Patricola ◽

Ping Chang

Keyword(s):

Tropical Cyclone ◽

Surface Temperature ◽

Sea Surface Temperature ◽

Climate Model ◽

Sea Surface ◽

The Impact

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STUDY ON CYCLONE INDUCED PHYTOPLANKTON BLOOM IN THE ARABIAN SEA THROUGH GAP-FREE RECONSTRUCTED CHLOROPHYLL-A DATA

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xliii-b3-2020-1391-2020 ◽

2020 ◽

Vol XLIII-B3-2020 ◽

pp. 1391-1396

Author(s):

R. Shunmugapandi ◽

S. Gedam ◽

A. B. Inamdar

Keyword(s):

Surface Temperature ◽

Sea Surface Temperature ◽

Chlorophyll A ◽

Arabian Sea ◽

Phytoplankton Bloom ◽

Suitable Condition ◽

Sea Surface ◽

Cyclone Track ◽

Chl A ◽

The Impact

Abstract. Ocean surface phytoplankton responses to the tropical cyclone (TC)/storms have been extensively studied using satellite observations by aggregating the data into a weekly or bi-weekly composite. The reason behind is the significant limitations found in the satellite-based observation is the missing of valid data due to cloud cover, especially at the time of cyclone track passage. The data loss during the cyclone is found to be a significant barrier to efficiently investigate the response of chl-a and SST during cyclone track passage. Therefore it is necessary to rectify the above limitation to effectively study the impact of TC on the chlorophyll-a concentration (chl-a) and the sea surface temperature (SST) to achieve a complete understanding of their response to the TC prevailed in the Arabian Sea. Intending to resolve the limitation mentioned above, this study aims to reconstruct the MODIS-Aqua chl-a, and SST data using Data Interpolating Empirical Orthogonal Function (DINEOF) for all the 31 cyclonic events occurred in the Arabian Sea during 2003-2018 (16 years). Reconstructed satellite retrieved data covering all the cyclonic events were further used to investigate the chl-a and SST dynamics during TC. From the results, the exciting fact has been identified that only two TC over the eastern-AS were able to induce phytoplankton bloom. On investigating this scenario using sea surface temperature, it was disclosed that the availability of nutrients decides the suitable condition for the phytoplankton to proliferate in the surface ocean. Relevant to the precedent criterion, the results witnessed that the 2 TC (Phyan and Ockhi cyclone) prevailed in the eastern AS invoked a suitable condition for phytoplankton bloom. Other TC found to be less provocative either due to less intensity, origination region or the unsuitable condition. Thereby, gap-free reconstructed daily satellite-derived data efficiently investigates the response of bio-geophysical parameters during cyclonic events. Moreover, this study sensitised that though several TC strikes the AS, only two could impact phytoplankton productivity and SST found to highly consistent with the chl-a variability during the cyclone passage.

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A numerical study of the windstorm Klaus: sensitivity to sea surface temperature

Annals of Geophysics ◽

10.4401/ag-6466 ◽

2014 ◽

Vol 57 (5) ◽

Author(s):

Nazario Tartaglione ◽

Rodrigo Caballero

Keyword(s):

Surface Temperature ◽

Sea Surface Temperature ◽

Numerical Study ◽

Heat Fluxes ◽

Sea Surface ◽

Moisture Convergence ◽

Convective Precipitation ◽

Limited Area ◽

Weather Forecasts

This article investigates the role of sea surface temperature (SST) as well as the effects of evaporation and moisture convergence on the evolution of cyclone Klaus, which occurred on January 23 and 24, 2009. To elucidate the role of sea surface temperature (SST) and air–sea fluxes in the dynamics of the cyclone, ten hydrostatic mesoscale simulations were performed by Bologna Limited Area Model (BOLAM). The first one was a control experiment with European Centre for Medium-Range Weather Forecasts (ECMWF) SST analysis. The nine following simulations are sensitivity experiments where the SST are obtained by adding a constant value by 1 to 9 K to the ECMWF field. Results show that a warmer sea increases the surface latent heat fluxes and the moisture convergence, favoring the development of convection in the storm. Convection is affected immediately by the increased SST. Later on, drop of mean sea level pressure (MSLP) occurs together with increasing of surface winds. The cyclone trajectory is not sensitive to change in SST differently from MSLP and convective precipitation.

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Experience in developing a method for long-term forecasting of the ice breakup time for the Vyatka River basin

Hydrometeorological research and forecasting ◽

10.37162/2618-9631-2020-4-99-111 ◽

2021 ◽

Vol 4 ◽

pp. 99-111

Author(s):

Y.A Pavroz . ◽

Keyword(s):

Surface Temperature ◽

Sea Surface Temperature ◽

River Basin ◽

Geopotential Height ◽

Sea Surface ◽

River Ice ◽

Northwest Pacific ◽

Ice Breakup ◽

The Impact ◽

Breakup Time

An attempt is made to develop a method for long-term forecasting of the ice breakup time for the Vyatka River basin, to identify the impact of the distribution of sea surface temperature and geopotential height in the informative regions at the levels H100 and H500 over the Northern Hemisphere on the river ice breakup. The location and boundaries of the informative regions in the fields of H100 and H500 were revealed by the discriminant analysis, the EOF expansion coefficients of the fields of anomalies of monthly mean values of H100 and H500 for January and February and the anomalies of monthly mean sea surface temperature in the North Atlantic and Northwest Pacific were used as potential predictors. The stepwise regression analysis allowed deriving good and satisfactory (S/σ = 0.45–0.73) complex prognostic equations for forecasting the ice breakup time for the Vyatka River basin. The essential influence of H100 and H500 geopotential height fields and the spatial distribution of sea surface temperature anomalies in the North Atlantic and Northwest Pacific in January and February on the river ice breakup time is revealed. It is proposed to improve the method by considering the impact of air temperature, maximum ice thickness per winter, and other indirect characteristics on the processes of river ice breakup in the Vyatka River basin. Keywords: ice regime, long-range forecast, river ice breakup, expansion coefficients, geopotential height fields, spring ice phenomena, energy-active zones of the oceans, complex prognostic equation

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The Role of Sea Surface Temperature Forcing in the Life-Cycle of Mediterranean Cyclones

Remote Sensing ◽

10.3390/rs12050825 ◽

2020 ◽

Vol 12 (5) ◽

pp. 825 ◽

Cited By ~ 1

Author(s):

Christos Stathopoulos ◽

Platon Patlakas ◽

Christos Tsalis ◽

George Kallos

Keyword(s):

Life Cycle ◽

Surface Temperature ◽

Sea Surface Temperature ◽

Early Warning Systems ◽

Life Cycles ◽

Heat Fluxes ◽

Sea Surface ◽

Mediterranean Cyclones ◽

The Mediterranean ◽

The Impact

Air–sea interface processes are highly associated with the evolution and intensity of marine-developed storms. Specifically, in the Mediterranean Sea, the air–ocean temperature deviations have a profound role during the several stages of Mediterranean cyclonic events. Subsequently, this enhances the need for better knowledge and representation of the sea surface temperature (SST). In this work, an analysis of the impact and uncertainty of the SST from different well-known datasets on the life-cycle of Mediterranean cyclones is attempted. Daily SST from the Real Time Global SST (RTG_SST) and hourly SST fields from the Operational SST and Sea Ice Ocean Analysis (OSTIA) and the NEMO ocean circulation model are implemented in the RAMS/ICLAMS-WAM coupled modeling system. For the needs of the study, the Mediterranean cyclones Trixi, Numa, and Zorbas were selected. Numerical experiments covered all stages of their life-cycles (five to seven days). Model results have been analyzed in terms of storm tracks and intensities, cyclonic structural characteristics, and derived heat fluxes. Remote sensing data from the Integrated Multi-satellitE Retrievals (IMERG) for Global Precipitation Measurements (GPM), Blended Sea Winds, and JASON altimetry missions were employed for a qualitative and quantitative comparison of modeled results in precipitation, maximum surface wind speed, and wave height. Spatiotemporal deviations in the SST forcing rather than significant differences in the maximum/minimum SST values, seem to mainly contribute to the differences between the model results. Considerable deviations emerged in the resulting heat fluxes, while the most important differences were found in precipitation exhibiting spatial and intensity variations reaching 100 mm. The employment of widely used products is shown to result in different outcomes and this point should be taken into consideration in forecasting and early warning systems.

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