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Seasonal and Extended Range Prediction Activities in India Using CFS. Suryachandra A. Rao (Surya). IITM, MoES , Government of India. Outline of the Presentation. Status of Seasonal Prediction of Indian Summer Monsoon (History and Present)
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Seasonal and Extended Range Prediction Activities in India Using CFS Suryachandra A. Rao (Surya) IITM, MoES, Government of India
Outline of the Presentation • Status of Seasonal Prediction of Indian Summer Monsoon (History and Present) • Status of Extended Range Prediction of Indian Summer Monsoon • Work in Progress to Improve Model Biases in CFS V2.0 • Monsoon Mission
HISTORY OF IMD OPERATIONAL FORECASTS ALL STATISTICAL MODELS 1924--1987 Forecast NW INDIA / PENINSULA 1988 16 –PARA MODEL All India Deterministic FORECASTS 1999 Forecasts for 3 REGIONS introduced 2003 8/10 Parameter Model for (Jun-Sept) & July F/C for India 2004 All India Forecast along with 4 Homogeneous Regions of India 2007 New Statistical Models Introduced 16 P Model Continued till 2002 8/10 Para Models Source: Rajeevan
Forecast Performance: 1932-1987 Gadgil, Rajeevan and Nanjundiah (2005, Current Science) Monsoon Prediction: Why yet another failure?
Correlation Coefficients between the observed and 5 AGCM MME hindcasted June-August precipitations (1979-1999) Wang et al. (2005)
Correlation Coefficients between the SST-Rainfall in observations and 5 AGCM MME (1979-1999) Wang et al. (2005) Observations AGCM
Seasonal Prediction of the Indian Monsoon (SPIM) Observed and simulated variation of all-India rainfall: 1985-2004 Note:(1988, 2001, 2002) – consistency among the models; 1994 – Models consistently fail to capture the observed anomaly Potential Prediction Skill is ~0.39
Details of Initialization (in ENSEMBLES) Atmospheric IC:ERA-40 Operational Analysis AMIP type Simulations Ocean IC: Ocean analysis with Wind/SST Perturbations
Details of Initialization (in CFS V2.0) (May Initial Conditions) CFS V2.0 hindcast results are evaluated for Feb., Mar., Apr., May., Initial Conditions.
Rainfall skill Land points (CGCMs) UKMO Depresys UKMO CFS V2.0 ECMWF
Prediction Skill of ISMR in CFS V2.0 CFS v2 Jan IC Correlation=0.37 CFS v2 Feb IC Correlation=0.59 CFS v2 Mar IC correlation=0.33 CFS v2 Apr IC Correlation=0.53 CFS v2 May IC correlation=0.36
Dynamical Seasonal Prediction of Indian Monsoon JJAS Rainfall – 2010 (CFS V1.0) Issues in April IITM CFS T62 IITM CFS T126 T126L64 T62L64 Central Indian drought predicted by CFS model Above normal rainfall over southern peninsular India IMD
Dynamical Seasonal Prediction of Indian Monsoon With Initial Conditions generated within India at (INCOIS & NCMRWF) JJAS Rainfall – 2011 (Issued in March) IITM CFS T62 IITM CFS V2.0 T126 T126L64 T62L64 Central Indian above normal rain predicted by CFS model Below normal rainfall over southern peninsular India IMD Upto 10th September
CFS V2 ISO Analysis Last 20 years of free run
East west space time spectra: OLR anomaly 10S:10N averaged OBS CFSV2
North-south space time spectra: OLR anomaly (20S-30N, 60-100E)
Lead lag correlation plot: PRECIPITATION Ref.series: 75-100E,10S-5N summer winter
Lead lag correlation plot:OLR Ref.series: 75-100E,10S-5N summer winter
Lead lag correlation plot: OLR Ref.series: 70-90E,12N-22N
Metric for summer ISO prediction and monitoring EEOF of rainfall averaged between 70oE-95oE
GPCP anomaly GPCP ISO PC1 of EEOF
Phase composite of precipitation anomaly
Interannual variability of Indian monsoon ISOs Behavior of ISOs during Jan-April
Climatology & climatological annual cycle of CFS V1 Averaged over 10N-25N; 70E-85E
45 day evolution of observation and forecast 2002 May 21 Initial condition 2003 2007 Observation _____ Model ---------- 2006
Forecast skill of CFS Model EOF1 EOF2
Rainfall Seasonal cycle Averaged over 10-30N, 70-100E Averaged over Indian land mass
Rainfall Difference (JJAS) CMAP - Noah CMAP - OSU Noah - OSU
Difference in Tropospheric Temperature Troposphere Cold bias
Average SWE from 200 Russian Station Delayed Snow Melt in CFS
Percentage Convective precipitation CFS V2 Observations
Percentage stratiform precipitation CFS V2 Observations
High resolution Seasonal Prediction Experiments T382 vs. T126 T382 model bias
ISO variance in T382 CFS V2.
SST Prediction Precip. Prediction
Monsoon Mission Vision All models have serious biases in simulating all aspects of monsoon such as Diurnal Variability Intreaseasonal Variability Seasonal Mean InterannualVariabilty These biases reflect in poor prediction skill of both monsoon weather (short-medium range) and climate (seasonal) Over the past 20 years, although we (India) have made some notable contribution in observational programs, we have made NO tangible contribution in model development/improvement! During the next 10 years we must invest much more resource and manpower in model development/improvement to be countable in the world community!!
The need of Monsoon Mission Weather on Short and Medium Range Climate , Seasonal Mean monsoon Climate Change Decadal prediction To improve forecasts in the country for
Effort started some time back • Made some progress • Still skill far below best in the world Weather on Short and Medium Range • Long history of empirical; No skill improvement • Dynamical Effort just has started now! • We are not counted in dynamical seasonal forecasts Climate , Seasonal Mean monsoon To improve forecasts, need to assess where we stand? Climate Change Decadal predict • We are just thinking of starting! • First effort is to build capacity to make reliable projection monsoon
Weather on Short and Medium Range • To take ourselves to a level comparable to the best in the world and be counted ! Climate ,Seasonal Mean monsoon Short Term Goal….2-3 years Climate Change Decadal predict.
Weather on Short & Medium Range • To become the best in the world! Climate ,Seasonal Mean monsoon Long Term Goal….3-10 years Climate Change Decadal predict.
Encourage basic research in a big way, Better understanding of mechanisms, parameterizations etc • Model Developments for improving forecasts Vigorous focused Basic Research What is required to achieve this Vision? • State-of-art HPC at operational and R&D Centres, petaflop comp. by 2-3yr • Equip Academic organizations with HPC to train, build capacity in modeling • Improvement of observations : Indoos and Modernization of IMD State of art Infrastructure Manpower Development : Training • Advanced, modernized training, job linked • Create jobs, induct laterally
Improving Prediction of Seasonal Mean Monsoon It is important that all development work should be done a specified model Coupled Model CFS 2.0 Model Development & Improvement in Physical Parameterization Basic Research Data Assimilation
Basic Research Mechanism of Interannual Variability • Teleconnection • Local Air-Sea Interaction • Internal Dynamics Parameterization of Physical Processes • Tropical Convection • Proportion of stratiform & Clouds IITM, IISc, IITs, NCMRWF, IMD, Universities