scholarly journals Heavy rain at Chennai and its relation to cyclonic disturbances

MAUSAM ◽  
2021 ◽  
Vol 51 (1) ◽  
pp. 17-24
Author(s):  
G. S. GANESAN ◽  
A. MUTHUCHAMI ◽  
A. S. PONNUSWAMY
Keyword(s):  
Bay Of Bengal ◽  
Heavy Rainfall ◽  
Heavy Rain ◽  
Total Rainfall ◽  
Cyclonic Storm ◽  
North East ◽  
The North ◽  
The Mean ◽  
Cyclonic Disturbances ◽  
Severe Cyclonic Storm

In this paper an attempt is made to study the characteristics of Heavy Rainfall (HR) and Very Heavy Rainfall (VHR) over Chennai in the North East Monsoon month of October, November and December and the period considered is 1964 to 19%. It is observed that it is mainly the duration which determines whether rainfall would be heavy or very heavy. Defining a system as Depression or Cyclonic Storm or Severe Cyclonic Storm in the Bay of Bengal, the mean rainfall in a System-affected day is 1.5 times that of Non-system-affected day in October and November. No striking differences could be found in intensity and duration characteristics of rainfall between system- affected days and non-system affected days. Even if system induced. heavy rainfall does not occur other thing being normal, the total rainfall of this season can continue to be normal.

scholarly journals Evaluation of Indian summer monsoon rainfall features using TRMM and KALPANA-1 satellite derived precipitation and rain gauge observation

MAUSAM ◽  
2021 ◽  
Vol 61 (3) ◽  
pp. 317-336
Author(s):  
V. R. DURAI ◽  
S. K. ROY BHOWMIK ◽  
B. MUKHOPADHYAY
Keyword(s):  
Summer Monsoon ◽  
Western Ghats ◽  
Heavy Rainfall ◽  
Heavy Rain ◽  
Rain Gauge ◽  
Summer Monsoon Rainfall ◽  
North East ◽  
The North ◽  
Western Ghats Of India ◽  
The Western Ghats

The study provides a concise and synthesized documentation of the current level of skill of the satellite (3B42RT, 3B42V-6, KALPANA-1) products over Indian regions based on the data gathered during the summer monsoon seasons of 2006, 2007 and 2008. The inter-comparison of satellite products with the rain gauge observations suggests that the TRMM 3B42V6 product could distinctly capture characteristic features of the summer monsoon, such as north–south oriented belt of heavy rainfall along the Western Ghats with sharp gradient of rainfall between the west coast heavy rain region and the rain shadow region to the east, pockets of heavy rainfall along the location of monsoon trough, over the east central parts of the country, over north-east India, along the foothills of Himalayas and over the north Bay of Bengal. The KALPANA-1 and 3B42RT products reproduce only the broadest features of mean monsoon seasonal rainfall. The near real-time products 3B42RT and KALPANA-1 underestimate the orographic heavy rainfall along the Western Ghats of India. The precipitation estimates from TRMM 3B42V6 product, when accumulated over the whole season, could reproduce the observed pattern. However, the TRMM 3B42RT and KALPANA-1 estimates are comparatively lower than the observed rainfall over most parts of the country during the season. Inter comparison reveals that the TRMM 3B42V6 product showed better skill in estimating the daily and seasonal mean rainfall over all India and also over four homogeneous regions of India.  

scholarly journals On tho proportions of the prevailing winds, the mean temperature, and depth of rain in the climate of London, computed through a cycle of Eighteen Years, or periods of the Moon’s declination

1843 ◽  
Vol 4 ◽  
pp. 300-300
Keyword(s):  
The Moon ◽  
Fair Weather ◽  
North West ◽  
West Wind ◽  
North East ◽  
East Wind ◽  
The North ◽  
The Common ◽  
The Mean ◽  
Solar Influence

In this paper the author investigates the periodical variations of the winds, rain and temperature, corresponding to the conditions of the moon’s declination, in a manner similar to that he has already followed in the case of the barometrical variations, on a period of years extending from 1815 to 1832 inclusive. In each case he gives tables of the average quantities for each week, at the middle of which the moon is in the equator, or else has either attained its maximum north or south declination. He thus finds that a north-east wind is most promoted by the constant solar influence which causes it, when the moon is about the equator, going from north to south; that a south-east wind, in like manner, prevails most when the moon is proceeding to acquire a southern declination ; that winds from the south and west blow more when the moon is in her mean degrees of declination, going either way, than with a full north or south declination ; and that a north-west wind, the common summer and fair weather wind of the climate, affects, in like manner, the mean declination, in either direction, in preference to the north or south, and most when the moon is coming north. He finds the average annual depth of rain, falling in the neighbourhood of London, is 25’17 inches.

Heavy rainfall in the northern coast of Ecuador in the aftermath of El Niño 2015/2016 and its predictability 

2021 ◽  
Author(s):  
Luis E. Pineda ◽  
Juan Changoluisa ◽  
Ángel G. Muñoz
Keyword(s):  
Heavy Rainfall ◽  
Heavy Rain ◽  
Rainfall Anomaly ◽  
Precipitation Event ◽  
Lead Times ◽  
Northern Coast ◽  
Atmospheric Conditions ◽  
The North ◽  
Ensemble Mean ◽  
Rainfall Anomalies

<p>In January 2016, a high precipitation event (HPE) affected the northern coast of Ecuador leading to devastating flooding in the Esmeraldas’ river basin. The HPE appeared in the aftermath of the 2015/2016 El Niño as an early onset of heavy rainfalls otherwise expected in the core rainy season (Mar-Apr). Using gauge data, satellite imagery and reanalysis we investigate the daily and ‘weather-within-climate’ characteristics of the HPE and its accompanying atmospheric conditions. The convective storms developed into a mesoscale convective complex (MCC) during nighttime on 24<sup>th</sup> January. The scale size of the heavy rainfall system was about 250 km with a lifecycle lasting 16 hours for the complete storm with 6 hours of convective showers contributing to the HPE. The genesis of the MCC was related to above-normal moisture and orographic lifting driving convective updrafts; the north-south mountain barrier acted as both a channel boosting upslope flow when it moves over hillslopes; and, as a heavy-rain divide for inner valleys. The above normal moisture conditions were favored by cross-time-scale interactions involving the very strong El Niño 2015/2016 event, an unusually persistent Madden–Julian oscillation (MJO) in phases 3 and 6, remotely forced by tropical synoptic scale disturbances. In the dissipation stage, a moderate low-level easterly shear with wind velocity of about 10 m/s moved away the unstable air and the convective pattern disappear on the shore of the Esmeraldas basin.</p><p> </p><p>We use ECMWF re-forecast from the Sub-seasonal to Seasonal (S2S) prediction project dataset and satellite observations to investigate the predictability of the HPE. Weekly ensemble-mean rainfall anomaly forecasts computed from raw (uncorrected) S2S reforecast initialized on 31st Dec 2015, 7th, 14th and 21st Jan 2016 are used to assess the occurrence of rainfall anomalies over the region. The reforecast represents consistently, over all lead times, the spatial pattern of the HPE. Also, the ensemble-mean forecast shows positive rainfall anomalies at times scales of 1-3 weeks (0-21 days) at nearly all initialization dates and lead times, predicting this way successfully the timing and amplitude of the highest HPE leading the 25th January flood.</p>

scholarly journals Effect of blended learning on students’ ability level and achievement in senior secondary geography in three education zones in niger state, Nigeria

2020 ◽  
Vol 1 (1) ◽  
pp. 21-26
Author(s):  
Abubakar Yahya Ibrahim
Keyword(s):  
Achievement Scores ◽  
High Ability ◽  
Ability Level ◽  
Significant Interaction Effect ◽  
North East ◽  
The North ◽  
Achievement Score ◽  
Significant Difference ◽  
The Mean ◽  
Low Ability

Purpose of the study: The purpose of this study was to determine the effect of student ability levels on the average value (x̄) of academic achievement of students in geography and the influence of method interactions and abilities on the average achievement score (x̄) of students in geography Methodology: The research design for the study was Quasi-experimental. Niger is one of the 36 States in Nigeria, the state is bordered by Zamfara State in the North, Kebbi State and Benin Republic in North West, Kaduna State in           the North East, In the South it is bordered by Kogi State, South West by Kwara State and South East by Federal Capital Territory (FCT) Abuja (Source: Geography Department FUT, Minna and Ministry of Land and Survey-Niger State, Minna). Main Findings: High ability level students had higher mean (x̄) achievement score that the low ability level students Also there is a significant difference between the mean (x̄) the achievement scores of low and high ability level students. Low ability level students who were taught geography using BLM had higher mean gain achievement score than the low ability level students taught using lecture methods while the high level ability students who were taught using BLM had higher mean gain achievement score than the high ability students taught using lecture method. It was further revealed that there is no significant interaction effect of method and ability level on the mean achievement scores in Geography.

Characteristics of Very Severe Cyclonic Storm “SIDR” over the Bay of Bengal During 11-16 November 2007

2009 ◽  
pp. 327-337
Author(s):  
Ajit Tyagi ◽  
M. Mohapatra ◽  
B. K. Bandyopadhyay ◽  
Charan Singh ◽  
Naresh Kumar
Keyword(s):  
Bay Of Bengal ◽  
Cyclonic Storm ◽  
Severe Cyclonic Storm

scholarly journals Evaluation of Rainfall Forecasts with Heavy Rain Types in the High-Resolution Unified Model over South Korea

2019 ◽  
Vol 34 (5) ◽  
pp. 1277-1293 ◽  
Author(s):  
Hwan-Jin Song ◽  
Byunghwan Lim ◽  
Sangwon Joo
Keyword(s):  
High Resolution ◽  
South Korea ◽  
Korean Peninsula ◽  
Heavy Rainfall ◽  
Rainfall Intensity ◽  
Heavy Rain ◽  
Unified Model ◽  
Moderate Intensity ◽  
Local Data ◽  
Total Rainfall

Abstract Heavy rainfall events account for most socioeconomic damages caused by natural disasters in South Korea. However, the microphysical understanding of heavy rain is still lacking, leading to uncertainties in quantitative rainfall prediction. This study is aimed at evaluating rainfall forecasts in the Local Data Assimilation and Prediction System (LDAPS), a high-resolution configuration of the Unified Model over the Korean Peninsula. The rainfall of LDAPS forecasts was evaluated with observations based on two types of heavy rain events classified from K-means clustering for the relationship between surface rainfall intensity and cloud-top height. LDAPS forecasts were characterized by more heavy rain cases with high cloud-top heights (cold-type heavy rain) in contrast to observations showing frequent moderate-intensity rain systems with relatively lower cloud-top heights (warm-type heavy rain) over South Korea. The observed cold-type and warm-type events accounted for 32.7% and 67.3% of total rainfall, whereas LDAPS forecasts accounted for 65.3% and 34.7%, respectively. This indicates severe overestimation and underestimation of total rainfall for the cold-type and warm-type forecast events, respectively. The overestimation of cold-type heavy rainfall was mainly due to its frequent occurrence, whereas the underestimation of warm-type heavy rainfall was affected by both its low occurrence and weak intensity. The rainfall forecast skill for the warm-type events was much lower than for the cold-type events, due to the lower rainfall intensity and smaller rain area of the warm-type. Therefore, cloud parameterizations for warm-type heavy rain should be improved to enhance rainfall forecasts over the Korean Peninsula.

Ocean Primary Productivity Variation due to the Cyclone: A Case Study at Bay of Bengal

2014 ◽  
Vol 71 (5) ◽  
Author(s):  
N. S. Sabarudin ◽  
M. L. R. Sarker
Keyword(s):  
Climate Change ◽  
Global Climate Change ◽  
Primary Productivity ◽  
Bay Of Bengal ◽  
Global Climate ◽  
Health Study ◽  
Cyclonic Storm ◽  
Chl A ◽  
Severe Cyclonic Storm ◽  
Ocean Primary Productivity

Monitoring ocean primary productivity especially Chlorophyll-a (Chl-a) concentration is important as it contributes to the carbon cycle, global climate change and ocean health study.  This study aims to examine the effects of cyclone events on the ocean productivity in the Bay of Bengal (BOB) considering its importance on global climate change.  Level 2 SeaWiFS daily data from 2001 to 2010 were used to determine Chl-a concentration and data from the Indian Meteorological Department (IMD) were used to get information and locations of the cyclone events.  Variation of Chl-a concentration was determined from the Chl-a concentration maps (pre-, during, and post-cyclone) using several transect lines parallel to the cyclone passages.  Results indicated that there is a relationship between the variation of Chl-a concentration and the cyclone events at the BOB but the effect is varied according to the type of cyclone where very severe cyclonic storm (VSCS) has higher impact on Chl-a concentration compared to cyclonic storm (CS) and severe cyclonic storm (SCS).  In most cases, Chl-a concentration was increased right after the cyclone event and the influence was observed over a wide area surrounding the cyclone passage.Monitoring ocean primary productivity especially Chlorophyll-a (Chl-a) concentration is important as it contributes to the carbon cycle, global climate change and ocean health study.  This study aims to examine the effects of cyclone events on the ocean productivity in the Bay of Bengal (BOB) considering its importance on global climate change.  Level 2 SeaWiFS daily data from 2001 to 2010 were used to determine Chl-a concentration and data from the Indian Meteorological Department (IMD) were used to get information and locations of the cyclone events.  Variation of Chl-a concentration was determined from the Chl-a concentration maps (pre-, during, and post-cyclone) using several transect lines parallel to the cyclone passages.  Results indicated that there is a relationship between the variation of Chl-a concentration and the cyclone events at the BOB but the effect is varied according to the type of cyclone where very severe cyclonic storm (VSCS) has higher impact on Chl-a concentration compared to cyclonic storm (CS) and severe cyclonic storm (SCS).  In most cases, Chl-a concentration was increased right after the cyclone event and the influence was observed over a wide area surrounding the cyclone passage.Monitoring ocean primary productivity especially Chlorophyll-a (Chl-a) concentration is important as it contributes to the carbon cycle, global climate change and ocean health study.  This study aims to examine the effects of cyclone events on the ocean productivity in the Bay of Bengal (BOB) considering its importance on global climate change.  Level 2 SeaWiFS daily data from 2001 to 2010 were used to determine Chl-a concentration and data from the Indian Meteorological Department (IMD) were used to get information and locations of the cyclone events.  Variation of Chl-a concentration was determined from the Chl-a concentration maps (pre-, during, and post-cyclone) using several transect lines parallel to the cyclone passages.  Results indicated that there is a relationship between the variation of Chl-a concentration and the cyclone events at the BOB but the effect is varied according to the type of cyclone where very severe cyclonic storm (VSCS) has higher impact on Chl-a concentration compared to cyclonic storm (CS) and severe cyclonic storm (SCS).  In most cases, Chl-a concentration was increased right after the cyclone event and the influence was observed over a wide area surrounding the cyclone passage.

scholarly journals Numerical simulation of storm surge associated with severe cyclonic storms in the Bay of Bengal during 2008-11

MAUSAM ◽  
2022 ◽  
Vol 64 (1) ◽  
pp. 193-202
Author(s):  
S.K. DUBE ◽  
JISMY POULOSE ◽  
A.D. ADRAO
Keyword(s):  
Storm Surge ◽  
Bay Of Bengal ◽  
Storm Surges ◽  
Eastern Coast ◽  
Property Damage ◽  
Cyclonic Storm ◽  
Recent Developments ◽  
Precise Prediction ◽  
Orissa Coast ◽  
Severe Cyclonic Storm

tc Hkh m".kdfVca/kh; pØokr vkrk gS rc Hkkjr vkSj blds fudVorhZ {ks=ksa esa rwQkuh leqnzh rjaxksa dh vkinkvksa ds dkj.k tku vkSj eky dh Hkkjh gkfu] rVh; <k¡pksa dh {kfr vkSj —f"k dks gkfu igq¡prh gSA uoEcj 1970 esa caxykns’k ¼igys iwohZ ikfdLrku½ esa vk, ,d vR;ar iapaM pØokr dh otg ls yxHkx 3]00]000 yksxksa dh tkus xbZaA uoEcj 1977 esa vkU/kz esa vk, pØokr us Hkkjr ds iwohZ rV dks rgl ugl dj fn;k ftlesa yxHkx 10]000 yksxksa dh tkus xbZaA vDrwcj 1999 esa Hkkjr ds mM+hlk ds rV ij ,d izpaM pØokrh rwQku vk;k ftlls ml {ks= esa laifRr dh vR;kf/kd gkfu gksus ds vfrfjDr 15]000 ls Hkh vf/kd yksxksa dh tkus xbZaA gky gh esa ebZ 2008 esa vk, pØokr uxhZl ls E;kaekj esa yxHk.k 1]40]000 yksxksa dh tkusa xbZa vkSj laifRr dk vR;f/kd ek=k esa uqdlku gqvkA ;s fo’o dh lcls cM+h ekuoh; vkink;sa eq[;r% m".kdfVca/kh; pØokrksa ls lac) gaS o leqnzh rwQkuh rjaxksa ls izR;{k:i  ls tqMh gSA vr% ml {ks= esa laf{kIr iwokZuqeku vkSj leqnzh rwQkuh rjaxksa dh iwoZ psrkouh nsus dk izko/kku ml {ks= ds fgr esa gksrk gSA bl 'kks/k i= dk eq[; mÌs’; caxky dh [kkM+h vkSj vjc lkxj esa mBus okyh leqnzh rwQkuh rjaxksa dk iwokZuqeku djus ds fy, gky gh esa fodflr fd, x, ekWMyksa dks izdk’k esa ykuk gSA bl 'kks/k&i= esa o"kZ 2008 ls 2011 ds nkSjku caxky dh [kkM+h esa cus izpaM pØokrksa ls tqM+h leqnzh rjaxksa dk iwokZuqeku [email protected] djus esa fun’kZ ds fu"iknu dk Hkh mYys[k fd;k x;k gSA Storm surge disasters cause heavy loss of life and property, damage to the coastal structures and the losses of agriculture in India and its neighborhood whenever a tropical cyclone approaches. About 3,00,000 lives were lost in one of the most severe cyclone that hit Bangladesh (then East Pakistan) in November 1970. The Andhra Cyclone devastated the eastern coast of India, killing about 10,000 persons in November 1977. Orissa coast of India was struck by a severe cyclonic storm in October 1999, killing more than 15000 people besides enormous loss to the property in the region. More recently the Nargis cyclone of May 2008 killed about 1,40,000 people in Myanmar as well as caused enormous property damage. These and most of the world's greatest human disasters associated with the tropical cyclones have been directly attributed to storm surges. Thus, provision of precise prediction and warning of storm surges is of great interest in the region. The main objective of the present paper is to highlight the recent developments in storm surge prediction model for the Bay of Bengal and the Arabian Sea. Paper also describes the performance of the model in forecasting/simulating the surges associated with severe cyclones formed in the Bay of Bengal during 2008 to 2011.  

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