intrusion during June 2014 influence reduce the intensity - - PowerPoint PPT Presentation

▶
intrusion during june 2014 influence reduce
SMART_READER_LITE
LIVE PREVIEW

intrusion during June 2014 influence reduce the intensity - - PowerPoint PPT Presentation

Jul 19, 2023 212 likes •377 views

Outline of the talk A life cycle of a strong subtropical stratospheric intrusion during June 2014 influence reduce the intensity of Indian rainfall after onset. Analysis of all monsooon breaks days during 29 years (1979-2007)

slide-1
SLIDE 1
slide-2
SLIDE 2

 A life cycle of a strong subtropical stratospheric intrusion during June 2014 influence reduce the intensity of Indian rainfall after onset.  Analysis of all monsooon breaks days during 29 years (1979-2007) (Breaks days from Rajeevan et al., 2010)  Propose a hypothesis on “Linkages of Stratospheric Intrusion with deficit Indian rainfall”

Outline of the talk

Suvarna Fadnavis and Rajib Chattopadhyay, J. Clim, 2017

slide-3
SLIDE 3

 Ramasw swam amy (1962) 62) has propose

  • sed

d that the e intrusion rusion of the e mid latitu tude de trough gh may trigge ger monso nsoon

  • n deficit

cit rainf nfall l over er the e Indian dian region ion and lead d to developmen elopment of break eak monso nsoon

  • n condition.

ndition.  Mapes and d Zui uidem dema (1996); 96); Al Allen n et et al., , (2009) 09) deline ineate e invasion sion of dry y air from

  • m sub

ubtr tropi

  • pica

cal l up upper r tropos posphe phere re with th tropi pica cal l drou

  • ught

ghts. s.  Krishna shnan n et et al., (2000) 000) have e attri ribut buted ed monso nsoon

  • n brea

eaks ks to an abrup upt t movem emen ent t of anoma

  • malous

lous Rossb sby waves es origina ginati ting ng from

  • m Bay of Beng

ngal al travelin eling g into

  • north

thwest t and centra ntral l India. dia.

Background

Suvarna Fadnavis and Rajib Chattopadhyay, J. Clim, 2017

slide-4
SLIDE 4

Suvarna Fadnavis and Rajib Chattopadhyay, J. Clim, 2017

Deficit rainfall over India during June 2014

slide-5
SLIDE 5

Data a and Analysis ysis

Diagnostic Analysis: Bivariate Probability Distribution Function (BPDF) of the two variables (PV and rainfall) Specific humidity (q) (vertically averaged between 400hPa-200hPa) Vertical wind shear (i.e. difference in zonal winds (U) at 200hPa minus 850 hPa) Temperature anomaly (departure from climatology) index (Tanom_diff_index), (i.e. temperature anomaly at 200 hPa minus 850 hPa) Kinetic energy at 200 hPa (ke200 i.e. U*U) ERA-Interim Reanalysis data:

  • Potential Vorticity (PV)
  • temperature
  • winds
  • ozone
  • relative humidity (RH)
  • Indian summer monsoon rainfall (ISMR) from India Meteorological Department
slide-6
SLIDE 6

10 Jun une e 12 2 Jun une e 14 Jun une e 16 Jun une e 18 18 Jun une 10 Jun une e 12 Jun une e 14 Jun une e 16 Jun une e 18 18 Jun une Ed Eddy y shading ding from

  • m the

e RWB B over er the e Tibeta tan n Platea eau

Ver ertica ical di distrib ibut ution ion of Potenti ential Vorti tici city ty (PV)

PV PV PV PV

slide-7
SLIDE 7

Rossby wave breaking in the jet  migration of extra-tropical stratospheric PV (>2) over the Tibetan Plateau 10 Ju June e 12 Jun une e 14 4 Ju June 16 Jun une e 18 18June ne 20 0 Jun une

Rossb sby wave br e brea eakin ing g in in the e subtr tropica

  • pical

l Jet et (PV-35 350K) 0K)

PV

slide-8
SLIDE 8

Rossby Wave Breaking (RWB) at 370 K

Westward eddy shedding associated with RWB

10 June 12 June 14 June 16 June 18 18 June 20 June

Suvarna Fadnavis and Rajib Chattopadhyay, J. Clim, 2017 PV

slide-9
SLIDE 9

Intrusion of dry and ozone-rich air

RH 10 June 12 June 14 June 16 June 18 June 10 June 12 June 14 June 16 June 18 June

Ozone In the UT

RH < 30%

slide-10
SLIDE 10

RWB event associated with cold intrusion over the Tibetan Plateau from extra-

  • tropics. Cold air persisted for the rest of month - June 2014.

Suvarna Fadnavis and Rajib Chattopadhyay, J. Clim, 2017

Cold air intrusion over the Tibetan Plateau

slide-11
SLIDE 11

Stratosphe

  • spheric

ric in intrusi usion 10 10 Ju June ne 2014 col cold air and and dry in in th the UT UT for

  • r rest

est of

  • f the

the mon month th  Increa ease se in in stati tic stabil ability ty  may lead to to monso soon

  • n break.

Intrusi rusion

  • n of co

cold and dr dry air r : Implications plications on stat atic ic stabili ability ty

Suvarna Fadnavis and Rajib Chattopadhyay, J. Clim, 2017

slide-12
SLIDE 12

6/1/2014 6/8/2014 6/15/2014 6/22/2014 6/29/2014

  • 3
  • 2
  • 1

1 2 3 4 5 6

IMD Precipitation

PV at 200 hPa AIRS OLR Normalized Anomalies Time (month/day/year)

  • 3
  • 2
  • 1

1 2 3 4 5 6 7

Temp central India Temp Tibetan Plateau

Lin inkag kages of stratosp

  • spheric

eric in intrusion ion wit ith Indi dian r rain infall l

Stratospheric PV  negative anomalies in temperature over TP and CI high OLR  negative anomalies in rainfall

Suvarna Fadnavis and Rajib Chattopadhyay, J. Clim, 2017

slide-13
SLIDE 13

Bivariate Probability Distribution Function (BPDF) is negatively skewed, indicating a likelihood of deficit monsoon during stratospheric intrusions (PV>2). It indicates that subtropical stratospheric intrusions near the Indian region may be one

  • f the factors influencing ISMR deficit.

Stratosp

  • sphe

heri ric c Intr trusions usions dur uring ng mons

  • nsoo
  • on

n break ak days (1979-2007)

(a) Region-1 (27°N-35°N, 60°E-78°E) (b) Region-2 (27°N-35°N, 78°E-110°E).

slide-14
SLIDE 14

(a)

(b)

Hy Hypoth pothesi esis: s: Link nkag ages es of strat atosph

  • spheric

eric intrus usion ion with th Indian dian rainf infal all l de defici icit t

Suvarna Fadnavis and Rajib Chattopadhyay, J. Clim, 2017

slide-15
SLIDE 15

Fadnavis et al., 2017

Balloo loonson nsonde de measureme surement nts s at Nainital nital, , India ia (Aug ugust ust 2016)

Collabor aborat ation ion: IITM, TM, Pune, ETH, Zurich, h, DWD German any, ARIES ES, Nainit ital al

slide-16
SLIDE 16

Thank you !

suvarna@tropmet.res.in