scholarly journals Does the Western-Ghats play any dynamical role in the distance effect of vortex over the Bay of Bengal on the enhancement of monsoon rainfall over Pune?

MAUSAM ◽  
2021 ◽  
Vol 57 (4) ◽  
pp. 567-578
Author(s):  
SOMENATH DUTTA ◽  
S. I. LASKAR ◽  
M. MAITI
Keyword(s):  
Bay Of Bengal ◽  
West Coast ◽  
Western Ghats ◽  
Monsoon Season ◽  
Distance Effect ◽  
Southwest Monsoon ◽  
The Other ◽  
Dynamical Model ◽  
Considerable Depth ◽  
The Western Ghats

lkj & bl ’kks/k i= esa nf{k.k&if’pe ekulwu _rq ¼,l-MCY;w-,e-,l-½ ds nkSjku caxky dh [kkM++h esa mBs coaMj ds nwjorhZ izHkko ds QyLo:Ik iq.ks esa o"kkZ esa gqbZ o`f) esa if’peh ?kkV ¼MCY;w-th-½ dh xR;kRed Hkwfedk ¼;fn dksbZ gks rks½ dh tk¡p djus dk iz;kl fd;k x;k gSA bldh tk¡p djus ds fy, e/; ekiØe vojks/k ds Åij ok;q&izokg ds ,d xR;kRed ekWMy dk mi;ksx fd;k x;k gSA N% ?kVukvksa ds v/;;u ls ;g Kkr gqvk gS fd caxky dh [kkM+h esa coaMj mBus dh fLFkfr esa iq.ks esa gqbZ o"kkZ esa o`f) ns[kh xbZ gSA bu N% ?kVukvksa esa ls pkj  ?kVukvksa esa ;g ns[kk x;k gS fd xR;kRed ekWMy iq.ks esa o"kkZ dh izsf{kr ?kV&c<+ ¼deh&cs’kh½ dk irk yxkus esa xq.kkRed :Ik ls lQy jgk gSA bu pkjksa ?kVukvksa esa if’peh iousa if’pe rV ds fdukjs m/okZ/kj esa vis{kkÑr dkQh rhoz FkhaA vU; nks ?kVukvksa esa ls ,d ?kVuk esa ;g ekWMy o"kkZ dh vf/kdrk dks] de ls de xq.kkRed :Ik esa] irk yxkus esa lQy jgk gS ijUrq o"kkZ esa deh dk irk yxkus esa vlQy jgk gSA ,d vU; ?kVuk esa ;g ekWMy iq.ks esa o"kkZ dh ?kV&c<+ Kkr djus esa xq.kkRed :Ik ls Hkh iw.kZr;k vlQy jgk gSA vafre nks ?kVukvksa esa if’pe rVh; LVs’ku ij if’peh iou detksj ,oa lrgh FkhA   An attempt has been made to examine the dynamical role (if any) played by the Western Ghats (WG), in the distance effect of vortex over the Bay of Bengal (BOB) on the rainfall enhancement over Pune, during southwest monsoon season (SWMS). To examine it, a dynamical model of airflow over a meso-scale barrier has been used. Six cases have been studied, in which enhancement of rainfall over Pune in presence of vortex over the Head Bay are noticed. Out of these six cases, in four cases it is found that the dynamical model can capture, at least qualitatively, the observed fluctuation (rise and fall) of rainfall over Pune. In these four cases westerly along west coast was strong with considerable depth in vertical. In one of the other two cases, the model has been able to capture, at least qualitatively, the observed rise in rainfall but failed to capture the observed fall in rainfall. In the other case the model has failed completely to capture, even qualitatively, the fluctuation in observed rainfall over Pune. In the last two cases, westerly along west coast station was weak and shallow.  

Precipitation modes over the Western Ghats orography during the summer monsoon season

2021 ◽  
Author(s):  
Jayesh Phadtare ◽  
Jennifer Fletcher ◽  
Andrew Ross ◽  
Andy Turner ◽  
Thorwald Stein ◽  
...  
Keyword(s):  
Summer Monsoon ◽  
West Coast ◽  
Western Ghats ◽  
Monsoon Season ◽  
Radiosonde Data ◽  
Summer Monsoon Season ◽  
The West ◽  
Radiosonde Station ◽  
Westerly Flow ◽  
The Western Ghats

&lt;p&gt;Precipitation distribution around an orographic barrier is controlled by the Froude Number (Fr) of the impinging flow. Fr is essentially a ratio of kinetic energy and stratification of winds around the orography. For Fr &gt; 1 (Fr &lt;1), the flow is unblocked (blocked) and precipitation occurs over the mountain peaks and the lee region (upwind region). While idealized modelling studies have robustly established this relationship, its widespread real-world application is hampered by the dearth of relevant observations. Nevertheless, the data collected in the field campaigns give us an opportunity to explore this relationship and provide a testbed for numerical models. A realistic distribution of precipitation over a mountainous region in these models is necessary for flash-flood and landslide forecasting. The Western Ghats region is a classic example where the orographically induced precipitation leads to floods and landslides during the summer monsoon season. In the recent INCOMPASS field campaign, it was shown that the precipitation over the west coast of India occurred in alternate offshore and onshore phases. The Western Ghats received precipitation predominantly during the onshore phase which was characterized by a stronger westerly flow. Here, using the radiosonde data from a station over the Indian west coast and IMERG precipitation product, we show that climatologically, these phases can be mapped over an Fr-based classification of the monsoonal westerly flow. Classifying the flow as 'High Fr' (Fr &gt;1), 'Moderate Fr' ( 0.5 &lt; Fr &amp;#8804; 1) and 'Low Fr' ( Fr &amp;#8804; 0.5 ) gives three topographical modes of precipitation -- 'Orographic', 'Coastal' and 'Offshore', respectively. &amp;#160;Moreover, these modes are not sensitive to the choice of radiosonde station over the west coast.&lt;/p&gt;

scholarly journals Dragonflies and Damselflies (Insecta: Odonata) of Aryanad Grama Panchayat, Kerala, India

2021 ◽  
Vol 13 (14) ◽  
pp. 20153-20166
Author(s):  
Reji Chandran ◽  
A. Vivek Chandran
Keyword(s):  
Species Richness ◽  
Western Ghats ◽  
Monsoon Season ◽  
Southwest Monsoon ◽  
Regional Level ◽  
Southern India ◽  
Peninsular India ◽  
Small Streams ◽  
Southwest Monsoon Season ◽  
The Western Ghats

A year-long study to document the diversity and seasonality of odonates was conducted at Aryanad Grama Panchayat, Thiruvananthapuram district, Kerala, southern India. A total of 93 species (56 dragonflies and 37 damselflies) belonging to 12 families were recorded. Twenty-four species of odonates recorded are endemic to the Western Ghats, three to peninsular India and one to India. Small streams showed the highest species richness, hosting 69 species and ponds the lowest with 59 species. Species richness showed a peak during the southwest monsoon season and a dip in winter. The study highlights the importance of biodiversity documentation at regional level. 

scholarly journals Beaching patterns of plastic debris along the Indian Ocean rim

2020 ◽  
Author(s):  
Mirjam van der Mheen ◽  
Erik van Sebille ◽  
Charitha Pattiaratchi
Keyword(s):  
Indian Ocean ◽  
Bay Of Bengal ◽  
Plastic Material ◽  
Monsoon Season ◽  
Southwest Monsoon ◽  
Plastic Waste ◽  
Ocean Dynamics ◽  
Global Ocean ◽  
The Indian Ocean ◽  
Southwest Monsoon Season

Abstract. A large percentage of global ocean plastic waste enters the northern hemisphere Indian Ocean (NIO). Despite this, it is unclear what happens to buoyant plastics in the NIO. Because the subtropics in the NIO is blocked by landmass, there is no subtropical gyre and no associated subtropical garbage patch in this region. We therefore hypothesise that plastics "beach" and end up on coastlines along the Indian Ocean rim. In this paper, we determine the influence of beaching plastics by applying different beaching conditions to Lagrangian particle tracking simulation results. Our results show that a large amount of plastic likely ends up on coastlines in the NIO, while some crosses the equator into the southern hemisphere Indian Ocean (SIO). In the NIO, the transport of plastics is dominated by seasonally reversing monsoonal currents, which transport plastics back and forth between the Arabian Sea and the Bay of Bengal. All buoyant plastic material in this region beaches within a few years in our simulations. Countries bordering the Bay of Bengal are particularly heavily affected by plastics beaching on coastlines. This is a result of both the large sources of plastic waste in the region, as well as ocean dynamics which concentrate plastics in the Bay of Bengal. During the intermonsoon period following the southwest monsoon season (September, October, November), plastics can cross the equator on the eastern side of the NIO basin into the SIO. Plastics that escape from the NIO into the SIO beach on eastern African coastlines and islands in the SIO or enter the subtropical SIO garbage patch.

RECORDS OF SOME SPECIES OF POLYCHAETA NEW TO BRITISH COLUMBIA AND OF EXTENSIONS IN DISTRIBUTION OF SOME OTHERS

1966 ◽  
Vol 44 (5) ◽  
pp. 839-849 ◽  
Author(s):  
C. Berkeley
Keyword(s):  
British Columbia ◽  
North America ◽  
West Coast ◽  
Vancouver Island ◽  
The Other ◽  
The West ◽  
New Subspecies ◽  
Northeast Pacific ◽  
Considerable Depth ◽  
Geographical Locations

Twenty-five species of Polychaeta recently collected off the coast of British Columbia are discussed. Most were taken in waters of considerable depth off the west coast of Vancouver Island. Sixteen are new to British Columbia. Most of these are known from farther south on the west coast of North America, but some from much shallower depths than those from which they are now recorded; two of them are new to the northeast Pacific; one is a new subspecies. The other nine have been previously known from British Columbia, but they are now recorded from much greater depths than hitherto, or in new geographical locations.

Two Notes on Ptolemy's Geography of India

1941 ◽  
Vol 73 (3) ◽  
pp. 208-222 ◽  
Author(s):  
E. H. Johnston
Keyword(s):  
West Coast ◽  
Western Ghats ◽  
The West ◽  
Market Town ◽  
The City ◽  
The Town ◽  
Good Access ◽  
The Western Ghats ◽  
Market Towns

The Periplus Marts Erythræ describes the seaports below Barygaza in the following way according to Schoff's translation: “The market-towns of this region are, in order, after Barygaza: Suppara, and the city of Calliena, which in the time of the elder Saraganus became a lawful market-town; but since it came into the possession of Sandares [an unjustified conjecture for the text's Sandanes] the port is much obstructed, and Greek ships landing there may chance to be taken to Barygaza under guard. Beyond Calliena there are other market-towns of this region; Semylla.…” Suppara is now Sopara on the coast above Bassein, Semylla is Cemūla of two inscriptions, now Chaul, and Calliena is Kalyāṇa. This last, situated at the foot of the two regular ascents of the Western Ghats leading towards Nasik and Poona respectively and with good access to the sea, was the natural outlet for the commerce of the Andhra dominions on the west coast, and the notice, just quoted, shows how its trade was stifled, as the Kṣaharātas extended their rule southwards from Broach. It is unnecessary here to consider who are the kings alluded to in this passage or in the earlier one mentioning Nambanus (a conjecture for the text's Mambarus), but clearly we are dealing with the rivalry of the Western Satraps and the Andhra kings. That the former were successful in their policy towards Kalyāṇa is shown by Ptolemy's omission of the town. The order he gives (taking Renou's text) is Souppara mouth of the River Goaris, Dounga, mouth of the River Bêndas, Semyla.

Evidence of new particle formation during post monsoon season over a high-altitude site of the Western Ghats, India

2017 ◽  
Vol 99 (4) ◽  
pp. 652-664 ◽  
Author(s):  
Parakkatt Parambil Leena ◽  
Vasudevan Anil Kumar ◽  
Kundan. K. Dani ◽  
Sunil. M. Sombawne ◽  
Palani Murugavel ◽  
...  
Keyword(s):  
High Altitude ◽  
Western Ghats ◽  
Monsoon Season ◽  
Particle Formation ◽  
New Particle Formation ◽  
Post Monsoon ◽  
Post Monsoon Season ◽  
The Western Ghats

scholarly journals Characteristics of Summer Precipitation around the Western Ghats and the Myanmar West Coast

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Dibas Shrestha ◽  
Rashila Deshar ◽  
Kenji Nakamura
Keyword(s):  
West Coast ◽  
Western Ghats ◽  
Large Scale ◽  
Summer Precipitation ◽  
Tropical Rainfall Measuring Mission ◽  
Precipitation Radar ◽  
Maximum Rainfall ◽  
Trmm Precipitation ◽  
The Western Ghats ◽  
Coastal Mountain

Characteristics of summer (June–August) precipitation over two coastal mountain regions in South Asia (Western Ghats: WG and Myanmar West Coast: MWC) with a focus on topographic impact are analyzed using the 13-year (1998–2010) high spatial resolution (0.05° × 0.05°) version 6 data obtained from the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR). A relationship between precipitation patterns and topography was observed in the coastal mountains. In both the WG and MWC, maximum rainfall along a tight line on the upwind side of the coastal mountains is primarily attributed to rain frequency. However, intense precipitation was observed over the offshore regions. Compared with the WG, deeper and large-scale precipitation systems develop over the MWC, producing more intense rainfall. It is suggested that insufficient humidity deters large-scale convection over the WG, and the atmosphere is sufficiently moist over the MWC.

scholarly journals Small carnivores of Silent Valley National Park, Kerala, India

2018 ◽  
Vol 10 (8) ◽  
pp. 12091 ◽  
Author(s):  
Devika Sanghamithra ◽  
P. O. Nameer
Keyword(s):  
Western Ghats ◽  
National Park ◽  
Niche Partitioning ◽  
Common Species ◽  
Camera Trap ◽  
The Other ◽  
Southern Western Ghats ◽  
Prionailurus Bengalensis ◽  
The Western Ghats

A study on the small carnivores in Silent Valley National Park (SVNP), southern Western Ghats, Kerala, India was conducted from September 2015 to April 2016, using the camera trap technique.  Seven species of small carnivores were recorded during the study.  The most common species of small carnivore of SVNP was Viverricula indica (44%) followed by Paradoxurus jerdoni (20%) and Herpestes vitticollis (17%). The other small carnivores found at SVNP were Herpestes fuscus (7%), Prionailurus bengalensis (6%), Aonyx cinereus (5%) and Martes gwatkinsii (1%).  P. jerdoni and M. gwatkinsii are endemic to the Western Ghats.  We discuss the niche partitioning among small carnivores in SVNP.  

scholarly journals Characteristics of Mudbanks along the Southwest Coast of India

2021 ◽  
Vol 4 (1) ◽  
Keyword(s):  
West Coast ◽  
Carbon Sink ◽  
Monsoon Season ◽  
Southwest Monsoon ◽  
The South ◽  
Coastal Regions ◽  
West Coast Of India ◽  
South West ◽  
South West Coast ◽  
Southwest Monsoon Season

Mudbank is a unique phenomenon observed along the south-west coast of India among all the Indian coastal regions during the Southwest Monsoon Season. The scientific reasons behind the formation and its persistence are vague. Mudbank is considered as a boon to the fishermen of Kerala, as they are getting reasonable catches during the occurrence of mudbanks using indigenous boats from the calm sea, which otherwise is in a fury during the rough Southwest Monsoon Season. Since the region, the Arabian Sea, is significant as a carbon sink due to its very high productivity because of different coastal ocean features, variations in the smaller and highly restricted coastal processes due to climate change can have a significant impact on the rates of global warming. Here, we consolidate the previous publications on various aspects of mudbanks with the reports of the occurrence of mudbanks on the south-west coast of India. A model for the prediction of the formation and location of mudbanks, inclusive of all the intrinsic and extrinsic parameters involved, through an extensive study is much relevant as far as the socio-economic and food security significance is concerned. Here, we discuss the most conducive factors for the formation of mudbank and its characteristics with special reference to Alappuzha, where the frequency of occurrence of mudbanks is maximum among the Indian coastal regions.

scholarly journals Intraseasonal Variability of Air–Sea Fluxes over the Bay of Bengal during the Southwest Monsoon

2018 ◽  
Vol 31 (17) ◽  
pp. 7087-7109 ◽  
Author(s):  
Alejandra Sanchez-Franks ◽  
Elizabeth C. Kent ◽  
Adrian J. Matthews ◽  
Benjamin G. M. Webber ◽  
Simon C. Peatman ◽  
...  
Keyword(s):  
Bay Of Bengal ◽  
Monsoon Season ◽  
Intraseasonal Variability ◽  
Surface Flux ◽  
Southwest Monsoon ◽  
Heat Fluxes ◽  
In Situ Data ◽  
Flux Variables ◽  
Southwest Monsoon Season

In the Bay of Bengal (BoB), surface heat fluxes play a key role in monsoon dynamics and prediction. The accurate representation of large-scale surface fluxes is dependent on the quality of gridded reanalysis products. Meteorological and surface flux variables from five reanalysis products are compared and evaluated against in situ data from the Research Moored Array for African–Asian–Australian Monsoon Analysis and Prediction (RAMA) in the BoB. The reanalysis products: ERA-Interim (ERA-I), TropFlux, MERRA-2, JRA-55, and CFSR are assessed for their characterization of air–sea fluxes during the southwest monsoon season [June–September (JJAS)]. ERA-I captured radiative fluxes best while TropFlux captured turbulent and net heat fluxes Qnet best, and both products outperformed JRA-55, MERRA-2, and CFSR, showing highest correlations and smallest biases when compared to the in situ data. In all five products, the largest errors were in shortwave radiation QSW and latent heat flux QLH, with nonnegligible biases up to approximately 75 W m−2. The QSW and QLH are the largest drivers of the observed Qnet variability, thus highlighting the importance of the results from the buoy comparison. There are also spatially coherent differences in the mean basinwide fields of surface flux variables from the reanalysis products, indicating that the biases at the buoy position are not localized. Biases of this magnitude have severe implications on reanalysis products’ ability to capture the variability of monsoon processes. Hence, the representation of intraseasonal variability was investigated through the boreal summer intraseasonal oscillation, and we found that TropFlux and ERA-I perform best at capturing intraseasonal climate variability during the southwest monsoon season.

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