Diurnal variability of convection over northwest Indian subcontinent observed by the Doppler weather radar data
- 6 Downloads
Abstract
The diurnal cycle of convection over a sub-tropical semi-arid inland station—Delhi—has been analyzed in this study based on three different rainfall episodes. Two of these cases represent convection in association with low precipitable water content (< 40 mm) and moderate vertical wind shear (between 4 and 10 m/s) while the third case represents convection under high precipitable water content (> 60 mm) and low vertical wind shear (< 2 m/s). It has been noted that for all the three cases, convection was initiated during the morning hours in the form of single cells, which evolved into multi-cellular convection zones later on those days. The most common mesoscale organization of the clouds in all the three cases had been in the form of convective lines which moved along the mean steering flow in the lower troposphere. However, for case 1, squall line formation and movement were observed during a period of 6 h, which was aided by the high unidirectional shear in the lower-to-middle troposphere, that was absent in other cases. These squall lines were associated with severe surface winds. The convection zones were found to be short lived with less stratiform outflow for case 1, more stratiform outflow for case 2 and longest lifetimes and most stratiform outflow for case 3. This study also indicates that the primary peak of convection and associated rainfall over the region, irrespective of the season, is in the afternoon hours between 1730 Indian Standard Time (IST) and 2030 IST, and lags the diurnal temperature maximum (around 1430 IST) by 3–5 h. When there is sufficient moisture in the atmosphere and convection persists throughout the entire diurnal cycle, a second peak in convection and associated rainfall appears over the region in the early morning hours (between 0230 and 0530 IST). This night time-early morning peak has a greater fraction of stratiform clouds at the beginning of a rainfall episode. As the moisture build up in the atmosphere on day 2 and later of a long-lived episode, new convection was initiated in the night time with increase in the night time rainfall intensity. This implies that pre-monsoon convection over Delhi in the presence of low moisture is primarily unimodal, characterized by short bursts of intense convection with narrow and short-lived cells. Monsoon convection on the other hand, is essentially bimodal, with the early morning peak, often pre-dominating over the afternoon peak and characterized by longer lived cells which are less intense than cells of the pre-monsoon weather systems.
Notes
Acknowledgements
The authors would like to acknowledge helpful guidance of Dr. Mike Dixon at NCAR RAL (USA), for developing program to convert Delhi radar data in cfradial netcdf format and subsequently providing the “Radx” application for Cartesian conversion. The authors are also grateful to the Director General of Meteorology, India Meteorological Department, for constant encouragement during the course of this study. We are grateful to a large number of colleagues in Radar Division and NWP Division of India Meteorological Department, New Delhi. We also acknowledge the use of TRMM rainfall data from NASA Tropical Rainfall Measuring Mission’s Goddard Earth Sciences Data and Information Services Center (GESDISC) and radiosonde data from the University of Wyoming website http://weather.uwyo.edu/upperair/sounding.html.
References
- Barros AP, Lang TJ (2003) Monitoring the monsoon in the Himalayas: observations in central Nepal, June 2001. Mon Weather Rev 131(7):1408–1427CrossRefGoogle Scholar
- Basu BK (2007) Diurnal variation in precipitation over india during the summer monsoon season: observed and model predicted. Mon Weather Rev 135:2155–2167CrossRefGoogle Scholar
- Bhalotra YPR (1954) Statistical facts about squalls at Delhi. Mausam 5(4):551–555Google Scholar
- Bhattacharya A, Chakraborty A, Venugopal V (2017) Role of aerosols in modulating cloud properties during active–break cycle of Indian summer monsoon. ClimateDyn 49(5–6):2131–2145. https://doi.org/10.1007/s00382-016-3437-4 CrossRefGoogle Scholar
- Bluestein HB, Jain MH (1985) Formation of mesoscale lines of precipitation: severe squall lines in Oklahoma during the spring. J Atmos Sci 42(16):1711–1732CrossRefGoogle Scholar
- Chatterjee RN, Prakash P (1986) A radar study on the frequency of occurrence of cumulonimbus clouds around Delhi. Mausam 37(2):241–244Google Scholar
- Churchill Dean D, Houze RA Jr (1984) Development and structure of winter monsoon cloud clusters on 10 December 1978. J Atmos Sci 41(6):933–960CrossRefGoogle Scholar
- Dai A (2001) Global precipitation and thunderstorm frequencies. Part II: Diurnal variations. J Clim 14:1112–1128. https://doi.org/10.1175/1520-0442(2001)014%3c1112:GPATFP%3e2.0.CO;2 CrossRefGoogle Scholar
- Dai A, Giorgi F, Trenberth KE (1999) Observed and model simulated precipitation diurnal cycle over the contiguous United States. J Geophys Res 104:6377–6402CrossRefGoogle Scholar
- Davis C, Brown B, Bullock R (2006) Object-based verification of precipitation forecasts. Part I: Methodology and application to mesoscale rain areas. Mon Weather Rev 134(7):1772–1784CrossRefGoogle Scholar
- Dee DP, Uppala SM, Simmons AJ, Berrisford P, Poli P, Kobayashi S, Andrae U, Balmaseda MA, Balsamo G, Bauer P, Bechtold P, Beljaars ACM, van de Berg L, Bidlot J, Bormann N, Delsol C, Dragani R, Fuentes M, Geer AJ, Haimberger L, Healy SB, Hersbach H, Hólm EV, Isaksen L, Kållberg P, Köhler M, Matricardi M, McNally AP, Monge-Sanz BM, Morcrette JJ, Park BK, Peubey C, de Rosnay P, Tavolato C, Thépaut JN, Vitart F (2011) The ERA-Interim reanalysis: configuration and performance of the data assimilation system. Q J R Meteorol Soc 137:553–597. https://doi.org/10.1002/qj.828 CrossRefGoogle Scholar
- Deshpande NR, Goswami BN (2014) Modulation of the diurnal cycle of rainfall over India by intraseasonal variations of Indian summer monsoon. Int J Climatol 34:793–807. https://doi.org/10.1002/joc.3719 CrossRefGoogle Scholar
- Durai VR, Roy Bhowmik SK (2013) Prediction of Indian summer monsoon in short to medium range time scale with high resolution global forecast system (GFS) T574 and T382. Clim Dyn 42(5–6):1527–1551Google Scholar
- Giorgi F, Mearns LO (1999) Introduction to special section: regional climate modeling revisited. J Geophys Res Atmos (1984–2012) 104(D6):6335–6352CrossRefGoogle Scholar
- Houze RA Jr (1997) Stratiform precipitation in regions of convection: a meteorological paradox? Bull Am Meteorol Soc 78(10):2179–2196CrossRefGoogle Scholar
- Houze RA Jr (2014) Basic cumulus dynamics. Cloud dynamics, vol 104. Academic Press, Waltham, pp 166–167Google Scholar
- Houze RA Jr, Biggerstaff MI, Rutledge SA, Smull BF (1989) Interpretation of Doppler weather radar displays of midlatitudemesoscale convective systems. Bull Am Meteorol Soc 70(6):608–619CrossRefGoogle Scholar
- Houze RA Jr, Wilton DC, Smull BF (2007) Monsoon convection in the Himalayan region as seen by the TRMM precipitation radar. Q J R Meteorol Soc 133(627):1389–1411Google Scholar
- Huffman GJ, Adler RF, Bolvin DT, Gu G, Nelkin EJ, Bowman KP, Hong Y, Stocker EF, Wolff DB (2007) The TRMM multisatellite precipitation analysis (TMPA): quasi-global, multiyear, combined-sensor precipitation estimates at fine scales. J Hydrometeorol 8:38–55. https://doi.org/10.1175/JHM560.1 CrossRefGoogle Scholar
- Laing AG, Fritsch JM (1997) The global population of mesoscale convective complexes. Q J R Meteorol Soc 123(538):389–405CrossRefGoogle Scholar
- Laurent H, Machado LAT, Morales CA, Durieux L (2002) Characteristics of the Amazonian mesoscale convective systems observed from satellite and radar during the WETAMC/LBA experiment. J Geophys Res 107(D20):8054. https://doi.org/10.1029/2001JD000337 CrossRefGoogle Scholar
- Lin X, Randall DA, Fowler LD (2000) Diurnal variability of the hydrologic cycle and radiative fluxes: comparisons between observations and a GCM. J Clim 13(23):4159–4179CrossRefGoogle Scholar
- Maddox RA (1980) Mesoscale convective complexes. Bull Am Meteorol Soc 61:1374–1387CrossRefGoogle Scholar
- Maddox RA, Zhang J, Gourley JJ, Howard KW (2002) weather radar coverage over the contiguous United States. Weather Forecast 17:927–934. https://doi.org/10.1175/1520-0434(2002)017%3c0927:WRCOTC%3e2.0.CO;2 CrossRefGoogle Scholar
- Marshall JS, Palmer WM (1948) The distribution of raindrops with size. J Meteor 5:165–166. https://doi.org/10.1175/1520-0469(1948)005%3c0165:TDORWS%3e2.0.CO;2 CrossRefGoogle Scholar
- Mohr CG, Vaughan RL (1979) An economical procedure for Cartesian interpolation and display of reflectivity data in three-dimensionsal space. J Appl Meteorol 18:661–670CrossRefGoogle Scholar
- Mohr CG, Miller LJ, Vaughan RL (1981) An interactive software package for the rectification of radar data to three-dimensional Cartesian coordinates. Preprints 20th Conf. on radar meteorology, Boston, Am Meteorol Soc, pp 690–695Google Scholar
- Nair S, Srinivasan G, Nemani R (2009) Evaluation of multi-satellite TRMM derived rainfall estimates over a Western State of India. J Meteorol Soc Jpn 87:927–939. https://doi.org/10.2151/jmsj.87.927 CrossRefGoogle Scholar
- Nesbitt SW, Zipser EJ (2003) The diurnal cycle of rainfall and convective intensity according to three years of TRMM measurements. J Clim 16(10):1456–1475CrossRefGoogle Scholar
- Parker DJ, Burton RR, Diongue-Niang A, Ellis RJ, Felton M, Taylor CM, Thorncroft CD, Bessemoulin P, Tompkins AM (2005) The diurnal cycle of the West African monsoon circulation. Q J R Meteorol Soc 131(611):2839–2860CrossRefGoogle Scholar
- Peel MC, Finlayson BL, McMahon TA (2007) Updated world map of the Köppen–Geiger climate classification. Hydrol Earth Syst Sci Discuss 4(2):439–473CrossRefGoogle Scholar
- Puranik DM, Karekar RN (2009) Western disturbances seen with AMSU-B and infrared sensors. J Earth Syst Sci 118(1):27–39CrossRefGoogle Scholar
- Rahman SH, Sengupta D, Ravichandran M (2009) Variability of Indian summer monsoon rainfall in daily data from gauge and satellite. J Geophys Res 114:D17113. https://doi.org/10.1029/2008JD011694 CrossRefGoogle Scholar
- Ram S, Mohapatra M (2012) Some aspects of Squall over Indira Gandhi International Airport, New Delhi. Mausam 63(4):623–638Google Scholar
- Randall D, Krueger S, Bretherton C, Curry J, Duynkerke P, Moncrieff M, Ryan B, Starr D, Miller M, Rossow W, Tselioudis G (2003) Confronting models with data: the GEWEX cloud systems study. Bull Am Meteorol Soc 84(4):455–469CrossRefGoogle Scholar
- Rao YP, Srinivasan V (1968) Climatology of India and neighbourhood, 2: climate of India, FMU Report No. I-2, India Meteorological Department Forecasting Manual, New DelhiGoogle Scholar
- Romatschke U, Houze RA Jr (2011a) Characteristics of precipitating convective systems in the premonsoon season of South Asia. J Hydrometeorol 12:157–180. https://doi.org/10.1175/2010JHM1311.1 CrossRefGoogle Scholar
- Romatschke U, Houze RA Jr (2011b) Characteristics of precipitating convective systems in the South Asian monsoon. J Hydrometeorol 12(1):3–26CrossRefGoogle Scholar
- Romatschke U, Medina S, Houze RA Jr (2010) Regional, seasonal, and diurnal variations of extreme convection in the South Asian Region. J Clim 23:419–439. https://doi.org/10.1175/2009JCLI3140.1 CrossRefGoogle Scholar
- Roy Bhowmik SK, Sen Roy S, Srivastava K, Mukhopadhay B, Thampi SB, Reddy YK, Singh H, Venkateswarlu S, Adhikary S (2011) Processing of Indian Doppler Weather Radar data for mesoscale applications. Meteorol Atmos Phys 111(3–4):133–147CrossRefGoogle Scholar
- Schiemann R, Lüthi D, Schär C (2009) Seasonality and interannual variability of the westerly jet in the Tibetan Plateau region. J Clim 22(11):2940–2957CrossRefGoogle Scholar
- Sen Roy S, Sen Roy S (2011) Regional variability of convection over northern India during the pre-monsoon season. Theor Appl Clim 103(1–2):145–158. https://doi.org/10.1007/s00704-010-0289-4 CrossRefGoogle Scholar
- Sen Roy S, Sen Roy S (2014) Diurnal variation in the initiation of rainfall over the Indian subcontinent during two different monsoon seasons of 2008 and 2009. Theor Appl Clim 117(1):277–291. https://doi.org/10.1007/s00704-013-1006-x CrossRefGoogle Scholar
- Sen Roy S, Saha SB, Roy Bhowmik SK, Kundu PK (2014) Optimization of Nowcast Software WDSS-II for operational application over the Indian region. Meteorol Atmos Phys 124(3):143–166. https://doi.org/10.1007/s00703-014-0315-7 CrossRefGoogle Scholar
- Sen Roy S, Saha SB, Roy Bhowmik SK, Kundu PK (2015) Diurnal cycle of rainfall as predicted by WRF model: verification using model evaluation tools software. Mausam 66(3):349–360Google Scholar
- Serafin RJ, Wilson JW (2000) Operational weather radar in the United States: progress and opportunity. Bull Am Meteorol Soc 81:501–518. https://doi.org/10.1175/1520-0477(2000)081%3c0501:OWRITU%3e2.3.CO;2 CrossRefGoogle Scholar
- Shige S, Nakano Y, Yamamoto MK (2017) Role of orography, diurnal cycle, and intraseasonal oscillation in summer monsoon rainfall over Western Ghats and Myanmar coast. J Clim. https://doi.org/10.1175/JCLI-D-16-0858.1 CrossRefGoogle Scholar
- Steiner M, Houze RA Jr, Yuter SE (1995) Climatological characterization of three-dimensional storm structure from operational radar and rain gauge data. J Appl Meteorol 34:1978–2007CrossRefGoogle Scholar
- Sui CH, Lau KM, Takayabu YN, Short DA (1997) Diurnal variations in tropical oceanic cumulus convection during TOGA COARE. J Atmos Sci 54:639–655CrossRefGoogle Scholar
- Tokay A, Short DA (1996) Evidence from tropical raindrop spectra of the origin of rain from stratiform versus convective clouds. J Appl Meteorol 35:355–371CrossRefGoogle Scholar
- Trenberth KE, Fasullo JT (2010) Tracking Earth’s energy. Science 328(5976):316–317CrossRefGoogle Scholar
- Trenberth KE, Fasullo JT, Kiehl J (2009) Earth’s global energy budget. Bull Am Meteorol Soc 90(3):311–323CrossRefGoogle Scholar
- Weisman ML, Klemp JB (1982) The dependence of numerically simulated convective storms on vertical wind shear and buoyancy. Mon Weather Rev 110(6):504–520CrossRefGoogle Scholar
- Weisman ML, Klemp JB (1984) The structure and classification of numerically simulated convective stormsin directionally varying wind shears. Natl Center Atmos Res 112:2479–2498. https://doi.org/10.1175/1520-0493(1984)112%3c2479:TSACON%3e2.0.CO;2 CrossRefGoogle Scholar
- Yang GY, Slingo J (2001) The diurnal cycle in the tropics. Mon Weather Rev 129:784–801. https://doi.org/10.1175/1520-0493(2001)129%3c0784:TDCITT%3e2.0.CO;2 CrossRefGoogle Scholar
- Yang S, Smith EA (2008) Convective-stratiform precipitation variability at seasonal scale from 8 years of TRMM observations: implications for multiple modes of diurnal variability. J Clim 21:4087–4114. https://doi.org/10.1175/2008JCLI2096.1 CrossRefGoogle Scholar
- Yuter SE, Houze RA Jr (1995) Three dimensional kinematic and microphysical evolution of Florida cumulonimbus. Part III: vertical mass transport, mass divergence and synthesis. Mon Weather Rev 123:1964–1983CrossRefGoogle Scholar