Empirical statistical monsoon prediction
Download
1 / 22

Empirical/Statistical Monsoon Prediction - PowerPoint PPT Presentation


  • 100 Views
  • Uploaded on

Empirical/Statistical Monsoon Prediction. Long History Blanford (1884) Walker (1918,1924) Normand (1953) And many studies in the recent decades…. Sir. Gilbert Walker. Geographical Location of some of the important precursors of Indian Monsoon Rainfall.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Empirical/Statistical Monsoon Prediction' - ashton-villarreal


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Empirical statistical monsoon prediction
Empirical/Statistical Monsoon Prediction

Long History

Blanford (1884)

Walker (1918,1924)

Normand (1953)

And many studies in the

recent decades…

Sir. Gilbert Walker




Current practices of dynamical monsoon rainfall prediction
Current Practices of Dynamical Monsoon Rainfall Prediction of

  • 2-tiered approach wherein SSTs are predicted first using a coupled model and then the AGCMs are forced using these SST fields

  • Use persistent SSTs to run AGCMs

  • Dynamical Downscaling using Regional Climate Models taking lateral boundary values from AGCM Simulations


Skills of the present generation of agcms reproduced from the iri website
Skills of the Present Generation of AGCMs of(Reproduced from the IRI Website)


We set out to examine the skills of monsoon rainfall in detail by involving long simulations made using observed SSTs with a suite of multi-model, multi-member ensemble runs.


Research questions
Research Questions..? detail by involving long simulations made using observed SSTs with a suite of multi-model, multi-member ensemble runs.

  • How skillful are the AGCMs in simulating Monsoon Rainfall over the Indian region?

  • Is specifying SSTs a constraint on realistic monsoon simulations?

  • How sensitive are monsoon simulations to initial conditions?

  • What is the impact of coupling on Monsoon-ENSO relationships?

  • Are the ENSO related western Indian Ocean SSTs acting as negative feed-back on Monsoon-ENSO relations?


Details of agcms used
Details of AGCMs Used detail by involving long simulations made using observed SSTs with a suite of multi-model, multi-member ensemble runs.


Simulation of tropical rain bands during djf in agcms
Simulation of Tropical Rain bands during DJF in AGCMs detail by involving long simulations made using observed SSTs with a suite of multi-model, multi-member ensemble runs.


Simulation of tropical rain bands during jja in agcms
Simulation of Tropical Rain bands during JJA in AGCMs detail by involving long simulations made using observed SSTs with a suite of multi-model, multi-member ensemble runs.


Climatology of monsoon rainfall
Climatology of Monsoon Rainfall detail by involving long simulations made using observed SSTs with a suite of multi-model, multi-member ensemble runs.


Monsoon enso relation in agcm simulations
Monsoon-ENSO Relation in AGCM Simulations detail by involving long simulations made using observed SSTs with a suite of multi-model, multi-member ensemble runs.


Pdfs of correlations 1 obs vs model ens 2 perprog
PDFs of Correlations detail by involving long simulations made using observed SSTs with a suite of multi-model, multi-member ensemble runs.(1) Obs. Vs. Model ENS (2) PERPROG


Impact of initial conditions on monsoon simulations
Impact of Initial Conditions on Monsoon Simulations detail by involving long simulations made using observed SSTs with a suite of multi-model, multi-member ensemble runs.


Monsoon enso teleconnections coupled vs uncoupled models
Monsoon-ENSO Teleconnections: Coupled vs. Uncoupled Models detail by involving long simulations made using observed SSTs with a suite of multi-model, multi-member ensemble runs.


GOGA: Obs SSTs globally detail by involving long simulations made using observed SSTs with a suite of multi-model, multi-member ensemble runs.DTEPOGA: Obs SSTs in Deep Tropical East Pacific and Climatological SSTs elsewhereDTEPOGA_MLM: Same as DTEPOGA but a Mixed Layer Model used in the Indian Ocean


Progressive Improvement in Monsoon Rainfall Simulation Skills:1. Un-coupled AMIP 2.Un-coupled AMIP only in eastern tropical Pacific and Climatological SSTs elsewhere 3.AMIP in the Pacific and Mixed Layer Model in the Indian Ocean


Summary
Summary Skills:

  • The skills of current generation AGCMs in simulating monsoon rainfall in India even when forced with observed SSTs are very low.

  • However, there appears to be much higher predictive potential as evidenced by the large PERPROG skills.

  • No clear hint of higher skills either for models with better monsoon climatology or when multi-model-super ensembles are involved.

  • Specification of SSTs in the Indian Ocean appears to be the main reason for the low-skills.

  • An interactive ocean-atmosphere in the Indian Ocean (using even a simple mixed layer ocean model) produces more realistic monsoon simulations compared to specifying actual or climatological SSTs.

  • General belief that the ENSO related SSTs in the Indian Ocean (particularly the western Indian Ocean and the Arabian Sea) might act as a negative feedback on Monsoon-ENSO teleconnections appears to be wrong based on the above observations.

  • In general the monsoon-ENSO links are much stronger in fully coupled models compared to the AGCMs forced with observed/predicted SSTs.

  • The 2-tiered approach currently being pursued in seasonal forecasting needs immediate revision to achieve higher forecast skills for the Indian region. We also believe, this might be true for some other countries located in the warm pool region in the west Pacific and the Indian Ocean.


Thank You!!! Skills:


ad