Summary
By analyzing 12-year (1979–1990) 200 hPa wind data from National Centers for Environmental Prediction-National Center for Atmospheric Research reanalysis, we demonstrate that the intraseasonal time scale (30–60 days) variability of the Tropical Easterly Jet (TEJ) reported in individual case studies occurs during most years. In the entrance region (east of ∼70° E), axis of the TEJ at 200 hPa is found along the near equatorial latitudes during monsoon onset/monsoon revivals and propagates northward as the monsoon advances over India. This axis is found along ∼5° N and ∼15° N during active monsoon and break monsoon conditions respectively. Examination of the European Centre for Medium Range Weather Forecasts reanalysis wind data also confirms the northward propagation of the TEJ on intraseasonal time scales.
During the intraseasonal northward propagations, axis of the TEJ is found about 10°–15° latitudes south of the well-known intraseasonally northward propagating monsoon convective belts. Because of this 10°–15° displacement, axis of the TEJ arrives over a location about two weeks after the arrival of the monsoon convection. Systematic shifting of the locations by convection, low level monsoon flow and TEJ in a collective way during different phases of the monsoon suggests that they all may be related.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
T-C Chen (1982) ArticleTitleOn the kinetic energy budget of the summer mean flow at 200 mb in the tropics Tellus 33 102–104
T Chen H van Loon (1987) ArticleTitleInterannual variation of the Tropical Easterly Jet Mon Wea Rev 115 1739–1759 Occurrence Handle10.1175/1520-0493(1987)115<1739:IVOTTE>2.0.CO;2
T Chen M-C Yen (1991) ArticleTitleIntraseasonal variations of the Tropical Easterly Jet during the 1979 northern summer Tellus 43A 213–225
De US, Lele RR, Natu JC (1998) Breaks in southwest monsoon. Prepublished scientific report no. 1998/3, pp 11. IMD, Pune (available from the Office of the ADGM (Research), India Meteorological Department, Pune 411005, India)
Dümenil L, Bauer H-S (1998) The Tropical Easterly Jet in a hierarchy of general circulation models and the reanalysis. MPI Report No. 243, 43 pp
H Flohn (1964) ArticleTitleInvestigations on the Tropical Easterly Jet Bonn Meteor Abh 4 1–83
Gibson JK, Kallberg P, Uppala S, Hernandez A, Nomura A, Serrano E (1997) ERA description. ECMWF Reanalysis Project Report 1, 72 pp
A Gruber AF Krueger (1984) ArticleTitleThe status of the NOAA outgoing longwave radiation data set Bull Amer Meteor Soc 65 958–962 Occurrence Handle10.1175/1520-0477(1984)065<0958:TSOTNO>2.0.CO;2
PV Joseph S Sijikumar (2004) ArticleTitleIntraseasonal variability of the low-level jet stream of the Asian summer monsoon J Climate 17 1449–1458 Occurrence Handle10.1175/1520-0442(2004)017<1449:IVOTLJ>2.0.CO;2
Kalnay E, Coauthors (1996) The NCEP/NCAR 40-year reanalysis project. Bull Amer Meteor Soc 77: 437–471
RN Keshavamurty (1973) ArticleTitlePower spectra of large-scale distributions of the Indian southwest monsoon Indian J Meteor Geophys 24 117–124
P Koteswaram (1958) ArticleTitleThe easterly jet stream in the tropics Tellus X 43–57
TN Krishnamurti P Ardanuy (1980) ArticleTitleThe 10–20 day westward propagating mode and breaks in the monsoons Tellus 32 15–26 Occurrence Handle10.1111/j.2153-3490.1980.tb01717.x
TN Krishnamurti HN Bhalme (1976) ArticleTitleOscillations of monsoon system. Part I. Observational aspects J Atmos Sci 33 1937–1954 Occurrence Handle10.1175/1520-0469(1976)033<1937:OOAMSP>2.0.CO;2
TN Krishnamurti PK Jayakumar J Sheng N Surgi A Kumar (1985) ArticleTitleDivergent circulations on the 30 to 50 day time scale J Atmos Sci 42 364–375 Occurrence Handle10.1175/1520-0469(1985)042<0364:DCOTTD>2.0.CO;2
TN Krishnamurti CM Kishtawal (2000) ArticleTitleA pronounced continental scale diurnal mode of the Asian summer monsoon Mon Wea Rev 128 462–473 Occurrence Handle10.1175/1520-0493(2000)128<0462:APCSDM>2.0.CO;2
K-M Lau HY Weng (1995) ArticleTitleClimate signal detection using wavelet transform: how to make a time series sing Bull Amer Meteor Soc 76 2391–2402 Occurrence Handle10.1175/1520-0477(1995)076<2391:CSDUWT>2.0.CO;2
Murakami T, Godbole R, Kelkar RR (1970) Numerical simulation of the monsoon along 80° E. Proc. Conf. on the Summer Monsoon of South East Asia, Norfolk, VA, Navy Weather Research Facility, pp 39–51
GB Pant K Rupakumar (1997) Climates of South Asia Wiley London
DR Pattanaik V Satyan (2000) ArticleTitleFluctuations of Tropical Easterly Jet during contrasting monsoons over India: a GCM study Meteorol Atmos Phy 75 51–60 Occurrence Handle10.1007/s007030070015
Raghavan K (1976) Tibetan anticyclone and Tropical Easterly Jet, RR-6. Indian Institute of Tropical Meteorology, Pune, pp 18 (available from Indian Institute of Tropical Meteorology, Pune 411008, India)
Ramamurthy K (1969) Monsoons of India. Some aspects of the breaks in the Indian southwest monsoon during July and August. FMU Report. No. IV-18-3, India Meteorological Department, New Delhi
BRS Rao DVB Rao VB Rao (2004) ArticleTitleDecreasing trend in the strength of Tropical Easterly Jet during the Asian summer monsoon season and the number of tropical cyclonic systems over Bay of Bengal Geophys Res Lett 31 L14103 Occurrence Handle10.1029/2004GL019817
DN Rao HR Singh JR Kulkarni AY Chandrika SVB Rao (2000) ArticleTitleVertical variation of Madden-Julian oscillations in the normal monsoon season as revealed through MST radar wind data Meteorol Atmos Phys 73 55–59 Occurrence Handle10.1007/s007030050064
Rao YP (1976) Southwest monsoon. Meteor Monogr Synoptic Meteor, No. 1/1976, India Meteorological Department, 376 pp
V Sathiyamoorthy (2005) ArticleTitleLarge scale reduction in the size of the Tropical Easterly Jet Geophys Res Lett 32 L14802 Occurrence Handle10.1029/2005GL022956
DR Sikka S Gadgil (1980) ArticleTitleOn the maximum cloud zone and the ITCZ over Indian longitudes during the Asian summer monsoon Mon Wea Rev 108 1840–1853 Occurrence Handle10.1175/1520-0493(1980)108<1840:OTMCZA>2.0.CO;2
PJ Webster VO Magana TN Palmer J Shukla RA Tomas M Yanani T Yasunari (1998) ArticleTitleMonsoons: processes, predictability, and the prospects for prediction J Geophys Res C7 14451–14510 Occurrence Handle10.1029/97JC02719
T Yasunari (1980) ArticleTitleA quasi–stationary appearance of the 30–40 day period in the cloudiness fluctuations during the summer monsoon over India J Meteor Soc Jpn 58 225–229
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Sathiyamoorthy, V., Pal, P. & Joshi, P. Intraseasonal variability of the Tropical Easterly Jet. Meteorol. Atmos. Phys. 96, 305–316 (2007). https://doi.org/10.1007/s00703-006-0214-7
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00703-006-0214-7