Extended Range Forecast of Monsoon at Smaller Spatial Domains over India for Application in Agriculture

Author(s):  
D. R. Pattanaik ◽  
Ashish Alone ◽  
Praveen Kumar ◽  
R. Phani ◽  
Raju Mandal ◽  
...  

Abstract The performance of operational extended range forecast (ERF) issued by IMD is evaluated for the southwest monsoon 2020. The early onset of monsoon over the Bay of Bengal and the normal onset of monsoon over Kerala with slightly rapid progress northward are very well captured in the ERF with two to three weeks lead time. The ERF also captured very well the transitions from normal to weaker phase of monsoon in July, the active phase of monsoon in entire August was well anticipated in ERF with a lead time of 3 weeks. The active monsoon condition in the second half of September associated with delayed withdrawal from northwest India was also reasonably well captured in the ERF. Quantitatively, the ERF shows significant skill up to three weeks on all India levels. The spatial distribution of met-subdivision level mean forecast skill of predicting above normal, normal and below normal categories in terms of correct (forecast and observed category matching) and partially correct (forecast and observed category out by one category) for the 36 subdivisions during the entire monsoon season of 2020 is found to be 89%, 83%, 80% and 78% for week 1 to week 4 forecasts respectively. The wrong forecasts (forecast and observed category out by two categories) are found to be between 11% in week 1 to 22% in week 4 forecast. Thus, the met-subdivision level forecast shows useful skill and is being used operationally for agrometeorological advisory services of IMD.

2019 ◽  
Vol 34 (1) ◽  
pp. 81-101 ◽  
Author(s):  
Susmitha Joseph ◽  
A. K. Sahai ◽  
R. Phani ◽  
R. Mandal ◽  
A. Dey ◽  
...  

Abstract Under the National Monsoon Mission Project initiated by the government of India’s Ministry of Earth Sciences, an indigenous dynamical ensemble prediction system (EPS) has been developed at the Indian Institute of Tropical Meteorology based on the state-of-the-art Climate Forecast System Model version 2 (CFSv2) coupled model, for extended-range (~15–20 days in advance) prediction. The forecasts are generated for the entire year covering the southwest monsoon, the northeast monsoon, and the summer and winter seasons. As the forecast of rainfall is important during the southwest and northeast monsoon seasons, along with that of the temperature during the summer and winter seasons, the present study documents the deterministic as well as probabilistic skill of the EPS in predicting the results in the respective seasons, over various meteorological subdivisions throughout India, on a pentad-lead time scale. The EPS is found to be skillful in predicting rainfall during the southwest and northeast monsoon seasons, as well as temperature during the summer and winter seasons, across different subdivisions of India. In addition, the EPS is noted to be skillful in predicting selected extremes in rainfall and temperature. This affirms the reliability and usefulness of the present EPS from an operational perspective.


MAUSAM ◽  
2021 ◽  
Vol 71 (3) ◽  
pp. 523-552
Author(s):  
Editor Mausam

The rainfall over the country as a whole during the monsoon season (June-September) was 110% of its Long Period Average (LPA) and thus categorized as a normal* monsoon year. Seasonal rainfall over Central India region (1263.2 mm) was large excess with 129% of LPA rainfallwhich was third highest since 1901 after the years 1994 (1311.3 mm) and 1961 (1297 mm) for the broad geographical region of Central India. Rainfall over South Peninsula (116% of LPA) region was excess, over Northwest India (99% of LPA) was normal and East and Northeast Region remained deficient at 88% of LPA. Southwest monsoon reached parts over the Andaman Sea on 18 May, two days earlier than its normal date. However, it set in over Kerala on 8 June, 7 days later than its normal date and covered the entire country by 19 July with a delay of 4 days. Typically, the monsoon current begins to withdraw around 1 September, with the retreat completed by 15 October. This year, the retreat began on 9 October, marking the longest ever delay and was complete by 16 October in just 8 days. The withdrawal of Southwest monsoon from the entire country and the commencement of the Northeast monsoon rains occurred simultaneously on 16 October. Sometimes there is a gap of 10 days between the two seasons. Due to neutral ENSO conditions and weak Madden Julian Oscillation (MJO), their influence on the monsoon were nearly absent especially in the second half of the season. Positive Indian Ocean Dipole (IOD) episode was observed since the beginning of the monsoon season and its rapid strengthening to the strongest ever was observed by mid of the monsoon season.  


MAUSAM ◽  
2021 ◽  
Vol 57 (3) ◽  
pp. 459-474
Author(s):  
S. R. KALSI ◽  
RAJENDRA KUMAR JENAMANI ◽  
H. R. HATWAR

lkj & fiNys 14 o"kksZa ds nkSjku yxkrkj gqbZ vPNh ekulwu o"kkZ&_rq ds ckn Hkkjr esa o"kZ 2002 esa Hkh"k.k lw[kk iM+kA ;gk¡ rd fd ekfld le; eku ij Hkh 19 oha 'krkCnh ds e/; ls ysdj vc rd ds fjdkMZ ds bfrgkl esa tqykbZ dk eghuk o"kkZ dh n`f"V ls cgqr gh [kjkc eghuk jgk ftlesa vf[ky Hkkjrh; iSekus ij o"kkZ ds izfr’kr dk varj lkekU; ls 51-5 izfr’kr de jgkA ,d vU; egRoiw.kZ fo’ks"krk ;g jgh fd fiNys 133 o"kksaZ esa igyh ckj lEiw.kZ nf{k.kh if’peh ekulwu _rq ds nkSjku ,d Hkh vonkc vFkok pØokrh rwQku ugha cukA  Hkkjr esa ekulwu dbZ&dbZ fnuksa dh vo:)rk ds lkFk yxkrkj vkxs c<+kA 1960 ds ckn ls igyh ckj ,slk gqvk gS fd lqnwj mÙkjh&if’peh Hkkjr esa ekulwu] _rq ds iwok)Z esa ugha igq¡pkA bl 'kks/k&i= esa o"kZ 2002 ds nkSjku ekulwu ds fofHkUu y{k.kksa dh fo’ks"krkvksa tSls fd ekulwu dk vkjEHk] mldk vkxs c<+uk] :duk] fofHkUu flukWfIVd vkSj v)Z LFkk;h y{k.kksa rFkk nf{k.kh if’peh ekulwu o"kkZ _rq dh fo’ks"krkvksa dk foospu fd;k x;k gSA bu fo’ks"krkvksa dh rqyuk igys iMs+ lw[ks ds o"kksZa dh fo’ks"krkvksa  ds lkFk dh xbZ gSA tqykbZ 2002 ds nkSjku ekulwu o"kkZ dh Hkh"k.k deh ds laHkkfor dkj.kksa dk irk yxkus ds fy, fgan & iz’kkar ¼baMksislsfQd½ {ks= esa c`grLrjh; vkSlr ekfld vlkekU; egklkxjh; vkSj ok;qeaMyh; fLFkfr;ksa dh tk¡p dh xbZ gSA bl v/;;u ls izkIr gq, ifj.kkeksa ls ;g irk pyrk gS fd cgqr lh vlkekU; vkSj fof’k"V izdkj dh fo’ks"krkvksa ds dkj.k o"kZ 2002 ds nkSjku iwjs Hkkjr esa lw[kk iM+kA bl v/;;u ls ;g Hkh irk pyrk gS fd vuqdwy varjk&ekSleh {ks=h; fo’ks"krkvksa tSls fd ekulwu fo{kksHkksa vkSj v)Z LFkk;h ra=ksa] vR;ar ean yks ysoy tsV dh fo|ekurk] izcy e/; v{kka’kh; if’peh gokvksa ds izHkko] {ks= esa pØokr cuus dh vR;kf/kd vko`fr ds lkFk ekulwu _rq ds eghuksa ds nkSjku iz’kkar egklkxjh; fuuksa 4 {ks= esa vR;kf/kd m".k rhozrk ds lkFk ean ls lkekU; ,y fuuksa dk cuuk ,sls eq[; dkj.k gSa ftuds ifj.kkeLo:i  tqykbZ ds eghus esa o"kkZ dh vR;kf/kd deh gqbZ gSA India experienced severe drought in the year 2002 after 14 consecutive years of good monsoon. On the monthly time scale, July had the worst rainfall in the recorded history of monsoon dating back to middle of nineteenth century when the country as a whole registered rainfall deficiency of 51.5%. Another notable feature was that for the first time in the last 133 years, not a single depression or cyclonic storm formed during the whole southwest monsoon season. The advance of monsoon over India was accompanied with frequent as well as prolonged stagnations. The monsoon failed to arrive for the first time in extreme northwest India during the first half of the season since 1960. In the present study, various features of monsoon such as onset, progress, stagnation, different synoptic and semi-permanent features and characteristics of rainfall of southwest monsoon in 2002 over India have been discussed. A comparison of these features with those in the earlier drought years has been made. Large-scale mean monthly anomalous ocean and atmospheric conditions over Indo-Pacific region have also been investigated to find out the possible causes for drastic failure of the monsoon during July 2002. Results show that many abnormal and unique features during 2002 have resulted into all India drought. Study also shows that absence of favourable regional intra-seasonal features like monsoon disturbances and semi-permanent systems, presence of very weak low level jet, penetration of strong mid-latitude westerlies, weak to moderate El-Nino with most intense warming over Nino 4 region of Pacific Ocean during monsoon months together with higher frequency of typhoon formation over the region are the main causes that led to one of the highly pronounced rainfall deficiencies in the month of July.


MAUSAM ◽  
2022 ◽  
Vol 53 (4) ◽  
pp. 503-514
Author(s):  
R. SURESH

The total ozone derived from TOVS data from NOAA 12 satellite through one step physical retrieval algorithm of  International TOVS Processing Package (ITPP) version 5.0 has been used to identify  its diurnal, monthly, latitudinal and longitudinal variability during 1998 over the domain Equator to 26° N / 60-100° E. The linkage of  maximum total ozone with warmer tropopause and lower stratosphere has been re-established. The colder upper tropospheric temperature which is normally associated with maximum ozone concentration throughout the year elsewhere in the world  has also been identified in this study but the relationship gets reversed during southwest  monsoon months(June-September) over the domain considered. The moisture  available in abundance in the lower troposphere gets precipitated due to the convective instability prevailing in the atmosphere during monsoon season and very little moisture is only available for vertical transport into the upper troposphere atop 500 hPa. The latent heat released by the  precipitation processes warms up the middle and upper atmosphere. The warm and dry upper troposphere could be the reason for less depletion of ozone in the upper troposphere during monsoonal  months and this is supported by the positive correlation coefficient prevailing in monsoon season between  total ozone and upper tropospheric (aloft 300 hPa) temperature. The warmness in middle and upper troposphere which is associated with less depletion and/or production of more  ozone in the upper troposphere may  perhaps contribute  for the  higher total ozone during monsoon months than in other seasons over peninsular Indian region.  The minimum concentration is observed during January (226 DU) over 6° N and the maximum (283DU) over 18° N during August. Longitudinal variability is less pronounced than the latitudinal variability.


Author(s):  
S. Salihin ◽  
T. A. Musa ◽  
Z. Mohd Radzi

This paper provides the precise information on spatial-temporal distribution of water vapour that was retrieved from Zenith Path Delay (ZPD) which was estimated by Global Positioning System (GPS) processing over the Malaysian Peninsular. A time series analysis of these ZPD and Integrated Water Vapor (IWV) values was done to capture the characteristic on their seasonal variation during monsoon seasons. This study was found that the pattern and distribution of atmospheric water vapour over Malaysian Peninsular in whole four years periods were influenced by two inter-monsoon and two monsoon seasons which are First Inter-monsoon, Second Inter-monsoon, Southwest monsoon and Northeast monsoon.


2020 ◽  
Author(s):  
Mirjam van der Mheen ◽  
Erik van Sebille ◽  
Charitha Pattiaratchi

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.


Author(s):  
D. R. Pattanaik ◽  
Ashish Alone ◽  
Praveen Kumar ◽  
R. Phani ◽  
Raju Mandal ◽  
...  

MAUSAM ◽  
2022 ◽  
Vol 44 (3) ◽  
pp. 271-276
Author(s):  
H. N. SRIVASTAVA ◽  
K. C. SINHARAY ◽  
R. K. MUKHOPADHYAY

The study deals with the spatial and temporal variations of intra-seasonal oscillations in radio refractive index during southwest monsoon season over India and islands over Indian seas. Average daily radio refractive index data from 1 June to 30 September and that of the individual years for the period 1969-1986 were subjected to harmonic analysis to investigate the contributions of various periodicities in monsoon radio refractive index. The inter-annual variability of various intra-seasonal oscillations have been studied for each 5° latitudinal strip from 50 oN to 30° N with the help of variance explained by various frequency modes for different years. Variance explained by 30-60 day and 10-20 day modes were studied in relation to monsoon performance.   The northward and eastward propagation of30.60 day mod~ was noticed. The 10.20 day mode and seasonal mode dominate at latitudinal belts 5°N.10oN and 25°N-30°N respectively. Between 10°N and 25°N, both 30-60 day and 10-20 day modes occur.  


Author(s):  
Kanchan P. Rathoure

The area in question has diversified relief and amount of rainfall and soil types. It is dry region lies in east, irrigated region in north and tribal-dominant population dominant in the west. Ahmednagar district is situated partly in the upper Godavari basin and partly in the Bhīma basin occupying a somewhat central position in Maharashtra state. The climate of the district is characterized by a hot summer and general dryness throughout the year except during the southwest monsoon season (i.e., June to September). Physiographically the district forms part of Deccan Plateau. Part of Sahayadri hill ranges fall in the district. Here in this chapter, the author has elaborated about soil quality and ground water quality near IOCL Terminal Ahmednagar, Maharashtra, India.


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