The Inter-Relations of Monsoon Rainfall in Different Sub-Divisions of India

Subbaramayya, I.

doi:10.2151/jmsj1965.46.2_77

Cited by 21 publications

(7 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In confirmation of Subbaramayya's (1968) earlier work, there is a strong spatial coupling between annual rainfall in Northwestern and Central India, while these regions have little affinity with the Northeast and Southeast.…”

Section: Discussionsupporting

confidence: 84%

See 1 more Smart Citation

Patterns of India monsoon rainfall anomalies

Hastenrath¹,

Rosen²

1983

Tellus A

View full text Add to dashboard Cite

Pattern characteristics of annual rainfall anomalies over India during 1900–72 are studied from precipitation records of 31 regional subdivisions and series of annual cyclone frequency and number of break monsoon days. Methods include spatial correlation, pattern stratification, and principal component and spectral analyses. Pattern stratification with respect to an all‐India rainfall index yields largest concordant departures in the Central and Western portions of the country. Pattern stratification with respect to the largest annual frequency of cyclonic storms in the Bay of Bengal and Arabian Sea show large positive rainfall departures over Eastern. Southeastern and Western India, and negative departures in the North and a limited area of the Southwest: for the collective of years with smallest storm frequency a partly inverse rainfall anomaly pattern is obtained. Pattern stratification with respect to the years of most numerous break monsoon days yields deficient rainfall in a large, broadly zonally oriented band across Central India, and positive departures in most other parts of ther country. Stratification with respect to the least numerous break monsoon days yields a broadly inverse pattern. The first eight principal component patterns account for 74% of the total variance. The first component resembles the pattern obtained by stratification with respect to the all‐India rainfall index, the two time series being highly positively correlated. The third component is approximately inverse to the pattern constructed from stratification with respect to the most numerous break monsoon days, the two time series being negatively correlated. The seventh component is similar to the pattern derived from stratification with respect to the largest frequency of cyclonic storms: this is consistent with the positive correlation between the two time series. No physical significance is apparent for the other principal components. The combination of the various analysis techniques thus serves to identify spatial and temporal pattern characteristics of possible physical significance.

show abstract

Section: Discussionsupporting

confidence: 84%

“…While precipitation varies greatly from year t o year. rainfall anomalies are not uniform over the subcontinent (Subbaramayya, 1968). Such spatial diversity must be accounted for in diagnosing the circulation mechanisms of anomalies in monsoon rainfall.…”

Section: Introductionmentioning

confidence: 99%

Patterns of India monsoon rainfall anomalies

Hastenrath¹,

Rosen²

1983

Tellus A

View full text Add to dashboard Cite

show abstract

“…It is felt intuitively that for regional studies of the summer monsoon variations, the entire area north of 21 °N and west of 80°E can make one zone. Over the northwest and northeast the summer monsoon rainfall fluctuations are negatively correlated (Subbaramayya, 1968;Singh et al, 1992). Over the same zonal belt that is north of 21 °N emergence of a third zone (North Central India) between two large zones (North West India and North East India) is a natural one.…”

Section: The Cluster Analysismentioning

confidence: 99%

Longest instrumental regional and all-India summer monsoon rainfall series using optimum observations: reconstruction and update

Sontakke

Singh

1996

The Holocene

View full text Add to dashboard Cite

Long period June-to-September total rainfall series are vital for the study of summer monsoon/climatic variability over the Indian region. Owing to high spatial variability in rainfall, the representativeness of the summer monsoon rainfall series for the entire country is limited. In order to develop an effective system for monsoon rainfall studies, the country has been divided into six zones, named as North West India (NWI), North Central India (NCI), North East India (NEI), West Peninsular India (WPI), East Peninsular India (EPI) and South Peninsular India (SPI). Fluctuation, empirical orthogonal function (EOF) and cluster analyses of the summer monsoon rainfall of the period AD 1871-1984 of 306 raingauges are carried out for this classification. Updating the different zonal rainfall series on a real-time basis from all the gauges is a difficult task. In the present study, an objective technique is applied to select a subset of gauges whose mean showed the highest correlation with the all-gauges mean series; a total of 116 raingauge stations (19 for NWI, 27 for NCI, 15 for NEI, 18 for WPI, 14 for EPI and 23 for SPI) maintained by the India Meteorological Department (IMD) have been identified for updating the different zonal series. The different zonal series are extended as far as possible backward (prior to AD 1871) by applying an objective technique to the available gauges. The NEI and the EPI series are extended back to 1848, the NWI to 1844, the NCI to 1842, the WPI to 1817 and the SPI to 1813. Though of limited practical value, the all-India series is widely used in studies of long-range monsoon forecasting, teleconnections and large-scale climate dynamics. The all-India monsoon rainfall series from AD 1871 onwards is therefore calculated from the area-weighted mean of the six zones. The series is also extended back to AD 1813 by applying the objective technique on the available gauges. The different reconstructed series for the longest instrumental period are reported.

show abstract

“…

…”

mentioning

confidence: 99%

Principal components of monsoon rainfall

Bedi

Bindra

1980

Tellus A: Dynamic Meteorology and Oceanography

View full text Add to dashboard Cite

Monsoon rainfall over India during the 120-day period from the beginning of June to the end of September exhibits interesting oscillations over the country. According to an analysis by Subbramayya (1968), there is a negative correlation in rainfall between the north-eastern and west-central parts of India. But his analysis does not indicate how much of the total variance of rainfall is explained by different rainfall patterns. We examined this aspect by expressing rainfall as a linear combination of orthogonal functions. This technique was suggested by Lorenz (1956). It was later used by Kutzbach (1967) and Weare (1977) to evaluate the principal components of sea-level pressure over the northern hemisphere, and sea surface temperature over the Atlantic Ocean.Let P be a n x m matrix of monsoon rainfall over m stations and a series of n years. The elements (p,) of P represent departures of rainfall from their mean values for the sth station and the rth year. We used the data of 70 evenly distributed stations for a period of 60 years ). As P represents the time and space variability of rainfall, we put P = QF (1) Where the matrices Q and F represent, respectively, the time and space variation of rainfall. The elements of P are m = qrk(l) x&(X,y)(2) k== I As F is an orthonQrma1 matrixWhere F' is the transpose of F and Z is the identity matrix.To determine F and Q from P we define a matrixWhere D is a diagonal matrix. The columns of F are now the eigenvectors of S, while the elements of D are the eigenvalues of S. Each element of Q represents the amplitude of eigenvector, and every element of D is a measure of the percentage variance explained by the corresponding eigenvector. F and D were determined from S by Jacobi's method (Greenstadt, 1960). This is an iterative process which utilizes successive rotations of each element of S. It was observed that the process converged sufficiently after about 2500 iterations. A tolerance of was used before stopping further iterations.Figs. 1 -4 depict the first four principal components of P. A total of 15 components were examined. This accounted for 72% of the total variance of monsoon rain, but the first four components by themselves were able to explain 47 % of the variance. The contributions by components beyond the 15th were negligibly small. The amplitudes of each component are shown at the bottom of each figure.The opposition between northeast and western India appears to be the dominant feature of monsoon rain. This explained 26.9% of the total variance. We also observed that positive and negative amplitudes were evenly distributed over the last 60 years, with a tendency for more rapid oscillations in the two decades following 1950, but oo40-2826/80/030296-03$02.50/0 0 1980 Munksgaard, Copenhagen Tellus 32 (1980), 3

show abstract

The Inter-Relations of Monsoon Rainfall in Different Sub-Divisions of India

Cited by 21 publications

References 3 publications

Patterns of India monsoon rainfall anomalies

Patterns of India monsoon rainfall anomalies

Longest instrumental regional and all-India summer monsoon rainfall series using optimum observations: reconstruction and update

Principal components of monsoon rainfall

Contact Info

Product

Resources

About