Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

IUKWC Workshop Nov16: Developing Hydro-climatic Services for Water Security – Session 6 – Item 5 Priya

65 views

Published on

IUKWC Workshop Nov16: Developing Hydro-climatic Services for Water Security – Session 6.5 Priya P

Published in: Environment
  • Be the first to comment

  • Be the first to like this

IUKWC Workshop Nov16: Developing Hydro-climatic Services for Water Security – Session 6 – Item 5 Priya

  1. 1. 11/08/1629 November – 1 December 2016, IITM, Pune, India Priya P PhD Student Email: priya@tropmet.res.in IUKWC Workshop on “Developing Hydro-climatic Services for Water Security”
  2. 2. 2010 Pakistan Floods Introduction Motivation Objective Methodology Results Conclusions Event could have been predicted two weeks in advance (Webster et. al. 2011) Northwest India-Pakistan flood 29 July 2010 TRMM3b42 Precipitation ERA Interim wind at 700hPa Webster et al,2011 mm/d
  3. 3. Introduction Motivation Objective Methodology Results Conclusions 2010 CLIM Mean sea level pressure (hPa) for JJAS 2010  Connection with Russian heat wave–wildfires (Lau and Kim , 2012)  Interaction between mid-latitude disturbance and monsoon surges (Hong et al., 2011)  Persistent increase in conditional instabilities (Wang et al. 2011) Convection of ocean character (Houze et al. 2011) Westward shift of West Pacific Subtropical High associated with LaNina (Mujumdar et al. 2012) Hong et al. 2011 Mujumdar et al. (2012)
  4. 4. TRMM (Rainfall) & NCEP (Moisture Transport) JJAS Climatology TRMM (Rainfall) & NCEP (Moisture Transport) “2010” JJAS Anomalies • Strong east-west rainfall gradient over equatorial west Pacific • Suppressed rainfall over equatorial Indian Ocean • Suppressed rainfall activity over Bay of Bengal and Central India • Anomalous northward moisture transport over Arabian Sea • Enhanced seasonal rainfall over northwest India-Pakistan region Anomalous features of 2010 Boreal Summer Monsoon Season Introduction Motivation Objective Methodology Results Conclusions
  5. 5. (0 C)  Strong SST gradient between Central & western equatorial Pacific  Basin wide type of warming  Developing Negative IOD over southeast Indian Ocean Anomalous SST patterns over Pacific & Indian Ocean regions were unique during 2010 La Nina. SST Anomaly for JJAS 2010 Unique features of 2010 La Nina Introduction Motivation Objective Methodology Results Conclusions  Previous studies discussed the anomalous Atmospheric and Oceanic features associated with 2010 Indo- Pak extreme rainfall events. Though, slowly varying tropical SSTs can modulate synoptic, sub- synoptic and meso-scale variabilities, “specific roles of remote (ENSO) and regional (ENSO-unrelated) boundary forcings in the evolution of 2010 summer monsoon heavy rainfall events” was unexplored.
  6. 6. Decomposition of 2010 SST (Compo & Sardeshmukh, 2010 personnel communication) To delineate the role of ENSO and ENSO-unrelated factors, ensemble simulation experiments were carried out with different SSTs forcing using variable resolution AGCM (LMDZ4). Introduction Motivation Objective Methodology Results Conclusions 2010 ENSO ENSO-Unrelated
  7. 7. LMDZ grid setup for South Asia (shaded region has grid-size < 35 km) 2012 (0-Equator, 45-110E) Introduction Motivation Objective Methodology Results Conclusions
  8. 8. Extreme convective events & Weibull Distribution  Statistics of extreme convective events over Indus basin is captured (Priya et al 2015). ProbabilityDensity Vertical Velocity (Pa s-1 ) LMDZ4 AGCM Simulation using Climatological SST ensemble mean Introduction Motivation Objective Methodology Results Conclusions (Priya et al 2015, J. Climate). Northwest India-Pakistan region (70°-74°E, 30°-36°N)
  9. 9. Introduction Motivation Objective Methodology Results Conclusions Extreme convective events & Weibull Distribution  The “large-scale” summer monsoon climatology is realistically simulated (Sabin et al 2013).  Statistics of extreme convective events over Indus basin is captured (Priya et al 2015). SST boundary forcings for the different sets of LMDZ simulation experiments Serial No. Experiment SST boundary condition 1 C-SST Climatological SST 2 R-SST Real SST for 2010 3 E-SST ENSO-related SST for 2010 4 NE-SST ENSO-unrelated SST for 2010 5 NE-IO-SST ENSO-unrelated SST for 2010 over Indian Ocean
  10. 10. Rainfall and Moisture Transport Anomalies for JJAS 2010 Observation TRMM (Rainfall) & NCEP (Moisture Transport) Simulation LMDZ4 AGCM R-SST ensemble mean Introduction Motivation Objective Methodology Results Conclusions Vertical Velocity (Pa s-1 ) ProbabilityDensity (70-74ºE & 30-36ºN)Weibull Distribution & Extreme Convection
  11. 11. Introduction Motivation Objective Methodology Results Conclusions OBS (NCEP) MODEL (R-SST) Western Indian Ocean Eastern Indian Ocean Meridional cell averaged over (60°-75°E) Meridional cell averaged over (85°-110°E) Rainfall and Moisture Transport Anomalies JJAS 2010 -OBS Rainfall and Moisture Transport Anomalies JJAS 2010 -LMDZ
  12. 12. Introduction Motivation Objective Methodology Results Conclusions Near Equatorial region OBS (NCEP) MODEL (R-SST) Zonal-cell averaged over (15°S-0°) ?Roles of ENSO and ENSO-unrelated SSTs on the northwest Indo-Pak rainfall events ? Rainfall and Moisture Transport Anomalies JJAS 2010 -OBS Rainfall and Moisture Transport Anomalies JJAS 2010 -LMDZ The LMDZ model experiment using 2010 real SST simulates observed atmospheric circulation features and rainfall anomalies over the Indo-Pak region
  13. 13. Introduction Motivation Objective Methodology Results Conclusions E-SST NE-SST NE-IO-SST NE-SST & NE-IO-SST simulations reproduces extreme convective activities and anomalous positive rainfall over northwest India-Pakistan region. Vertical Velocity (Pa s-1 ) ProbabilityDensity Specific roles of Indo-Pacific SSTs SST boundary forcings for the different sets of LMDZ simulation experiments Serial No. Experiment SST boundary condition 1 C-SST Climatological SST 2 R-SST Real SST for 2010 3 E-SST ENSO related SST for 2010 4 NE-SST ENSO-unrelated SST for 2010 5 NE-IO-SST ENSO-unrelated SST for 2010 over Indian Ocean
  14. 14. E-SSTNE-SST Introduction Motivation Objective Methodology Results Conclusions E-SSTNE-SST Meridional cell averaged over (60°-75°E) Western Indian Ocean Near Equatorial region Zonal-cell averaged over (15° S-0°) E-SST NE-SST
  15. 15. Introduction Motivation Objective Methodology Results Conclusions Conclusion This study points to the key-role of Indian Ocean SST anomaliesrole of Indian Ocean SST anomalies in inducing the northward moisture transport from AS into sub-tropical Indo-Pak region in the background of modulated large-scale Indo-Pacific summer monsoon circulation by Pacific SST anomalies during 2010. DD CC DD CC SST Precipitation CC DD CC DDCC CC SST Precipitation La Nina SST over Pacific Westward shift of the West Pacific Subtropical High Weaker convection over Bay of Bengal Indian Ocean SST Cyclonic convergence over south-eastern Indian Ocean Divergence over central and western equatorial Indian Ocean Enhanced convection and northward moisture transport over northern Arabian Sea Heavy rainfall activity over north-west India Pakistan region during 2010
  16. 16. 11/08/16 Introduction Motivation Objective Methodology Results Conclusions Northwest India-Pakistan flood 29 July 2010 TRMM3b42 Precipitation ERA Interim wind at 700hPa Heavy precipitation activity over Western Himalaya  Midlatitude trough activity  Southerly wind over Arabian Sea  Moisture flux convergence over WH  Trend in frequency of Extreme rain events ( R > 99th pctl) APHRODITE Precipitation data 1951-2007
  17. 17. 11/08/16  Weakening trend of the monsoon large-scale facilitated the enhancement of cyclonic trough activity over the WH and increases moisture convergence over the WH region associated with stronger southerly flows from the Arabian Sea during the recent decades.  These two results suggest an increasing probability of the type of extreme precipitation event that results from the combination of large-scale moisture flux (associated with a westward extended monsoonal trough) and a southward protruding mid-latitude westerly trough. Introduction Motivation Objective Methodology Results Conclusions Results highlight the importance of a detailed monitoring of the Indian Ocean variability andthe importance of a detailed monitoring of the Indian Ocean variability and conditions,conditions, through dedicated observation systems, for improving the accuracy of “extended- range” prediction of future heavy rainfall events in the Indian Ocean and adjacent subtropicalprediction of future heavy rainfall events in the Indian Ocean and adjacent subtropical areasareas, which are projected to be more frequent in the future warming climate Thank You.!

×