Indian Ocean Dipole modulated wave climate of eastern Arabian Sea

Anoop, T. R.; Kumar, V. Sanil; Shanas, P. R.; Glejin, Johnson; Amrutha, M. M.

doi:10.5194/os-12-369-2016

Cited by 30 publications

(22 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…13a). The reduction in wave height in the study area during positive IOD is due to weaker zonal wind shear (Cherchi and Navarra, 2013) and reduction in wind seas, as observed by Anoop et al (2016).…”

Section: Influence Of Enso Iod and Sammentioning

confidence: 60%

“…The Anoop et al (2016) study highlights the role of IOD in wave climate variability due to changes in the equatorial SST and sea level pressure. Since the wind is the major generating force of surface waves in the ocean, the wind anomaly caused by IOD (Schott et al, 2009) induces the change in wave climate.…”

Section: Influence Of Enso Iod and Sammentioning

confidence: 99%

“…The interannual variations in wave spectra at Honavar from 2009 to 2012 were examined by Sanil Kumar and Anjali Nair (2015) and observed that the seasonal average wave spectrum during the ISM was single peaked and were double peaked during rest of the period. Anoop et al (2016) reported about an intrinsic mode of variability that has a significant role in driving climate oscillations in the ocean and demonstrated the influence of the climate variability -IOD on the waves in the eastern AS during October.…”

Section: Study Areamentioning

confidence: 99%

“…Variability in wave climate to the large-scale atmospheric circulation patterns, referred to as teleconnection patterns (e.g. ENSO) are studied (Hemer et al, 2010;Stopa and Cheung, 2014;Anoop et al, 2016). The variability of wave heights in the North Atlantic are linked to the North Atlantic Oscillation (NAO) (Izaguirre et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Influence of Indian summer monsoon variability on the surface waves in the coastal regions of eastern Arabian Sea

Kumar

George

2016

Ann. Geophys.

View full text Add to dashboard Cite

Abstract. We assess the influence of monsoon variability on the surface waves using measured wave data covering 7 years and reanalysis data from 1979 to 2015 during the Indian summer monsoon (JJAS) in the eastern Arabian Sea. The interannual comparison shows that the percentage of higher wave heights ( > 2.5 m) is higher (∼ 26%) in 2014 than in other years due to the higher monsoon wind speed (average speed ∼ 7.3 m s −1 ) in 2014. Due to the delayed monsoon, monthly average significant wave height (H m0 ) of June was lowest (∼ 1.5 m) in 2009. The spectral peak shifted to lower frequencies in September due to the reduction of wind seas as a result of decrease in monsoon intensity. The study shows high positive correlation (r ∼ 0.84) between average lowlevel jet (LLJ) for the block 0-15 • N, 50-75 • E and H m0 of eastern Arabian Sea in all the months except in August (r ∼ 0.66). The time series data on wave height shows oscillations with periods 5 to 20 days. Wavelet coherence analysis indicates that the LLJ and H m0 are in-phase related (phase angle 0 • ) almost all the time and LLJ leads H m0 . The monsoon seasonal anomaly of H m0 is found to have a negative relationship with the Oceanic Niño Index indicating that the monsoon average H m0 is relatively low during the strong El Niño years.

show abstract

Section: Influence Of Enso Iod and Sammentioning

confidence: 60%

Section: Influence Of Enso Iod and Sammentioning

confidence: 99%

Section: Study Areamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Influence of Indian summer monsoon variability on the surface waves in the coastal regions of eastern Arabian Sea

Kumar

George

2016

Ann. Geophys.

View full text Add to dashboard Cite

show abstract

“…In the Indian Ocean, Lopez and Kirtman () observed a nonlinear influence of the ENSO on large wave height events. The above studies show that wave heights of different regions of world ocean are correlated with climate indices; (a) NAO (Dodet et al, ), (b) SAM (Hemer et al, ), (c) ENSO (Gulev and Grigorieva, 2004; Hemer et al, ; Lopez and Kirtman, ) and (d) IOD (Anoop et al, ). The two modes, namely ENSO and IOD, are patterns which have significant impacts on winds in the Indian Ocean (Girishkumar and Ravichandran, ).…”

Section: Introductionmentioning

confidence: 97%

Features of locally and remotely generated surface gravity waves in the inner‐shelf region of northwestern Bay of Bengal

Nair

Kumar

Amrutha

et al. 2018

Intl Journal of Climatology

Self Cite

View full text Add to dashboard Cite

In this article, we studied the characteristics of locally and remotely generated wind waves in the inner‐shelf region of northwestern Bay of Bengal (BoB) based on the measured wave data. Two well‐differentiated wave systems, one young sea from the east‐southeast and another more developed swell from the south lead to bimodality in the wave spectrum. Wind‐sea predominance is not observed in the monthly average wave spectrum and in all the months swells dominated indicating a swell‐driven wave regime. During the monsoon (JJAS), the wave climate is dominated by long‐period swell from the south‐southeast and the short fetch during the northeast monsoon (ONDJ) leads to weaker easterly swells, while the effects of the sea/land breeze influence on the wave generation are more relevant during this season. During November–April, diurnal variation of 0.15 m in significant wave height (SWH) is observed. The study based on seasonally averaged ERA‐Interim reanalysis data reveals a weak connection between the waves in the northwestern BoB and the El Niño Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) events. The waves are influenced by ENSO events during June–September and by IOD events during October–January, which consequently caused inter‐annual variations in monthly average SWH. The present study, however, did not show a significant inter‐annual variability in annual mean SWH during 1979–2015.

show abstract

Dipole behaviour in maximum significant wave height over the Southern Indian Ocean

Gupta

Bhaskaran

Dash

2017

Intl Journal of Climatology

View full text Add to dashboard Cite

The study reports on existence of a dipole pattern in maximum significant wave height (MSWH) as well in mean significant wave height over the Southern Indian Ocean (SIO) based on analysis using 24 years of satellite observations. Analysis using quality checked daily altimeter data from nine satellite missions for entire Indian Ocean region revealed the spatio-temporal variability of observed dipole phenomena. Interestingly, the second empirical orthogonal function (EOF) mode (EOF2) in monthly and monthly anomaly MSWH data clearly shows the prevalence of dipole over the SIO having a period of 6 months for monthly dataset Principal Component (PC) leading to a 3 months oscillation. The EOF of monthly anomaly dataset analysis also exhibited a similar dipole pattern for the EOF2 mode having a period of 2.1 years. In addition, the study also considered seasonal EOF analysis for four austral seasons December-January-February (DJF), March-April-May (MAM), June-July-August (JJA), and September-October-November (SON). The EOF2 for all seasons exhibits a similar dipole pattern in SIO basin, except for the DJF months. Based on seasonal EOF analysis, the DJF and JJA EOF2s have similar dipole pattern that reverses its polarity because of wind variability for the MAM and SON EOF2s justifying 3 months dipole oscillation obtained for monthly datasets. The Radon transform is used to investigate the orientation of this dipole, and for the first time this method is used in the field of climatology to study orientation and the degree of polarity of a dipole pattern. Furthermore, the study investigated possible correlation of dipole with various proven climate indices establishing the fact that Southern Annular Mode Index (SAMI) showed a significant correlation. The other seasonal datasets also correlated well with SAMI, except DJF months that do not show the dipole pattern, and it had a good correlation with Nino3 index representing the El Nino Southern Oscillation Index.

show abstract

Indian Ocean Dipole modulated wave climate of eastern Arabian Sea

Cited by 30 publications

References 40 publications

Influence of Indian summer monsoon variability on the surface waves in the coastal regions of eastern Arabian Sea

Influence of Indian summer monsoon variability on the surface waves in the coastal regions of eastern Arabian Sea

Features of locally and remotely generated surface gravity waves in the inner‐shelf region of northwestern Bay of Bengal

Dipole behaviour in maximum significant wave height over the Southern Indian Ocean

Contact Info

Product

Resources

About