scientific advisory committee (sac) review: 2010

SScientific cientific AAdvisory dvisory CCommittee ommittee (SAC) Review: 2010(SAC) Review: 2010

SScientific cientific AAdvisory dvisory CCommittee ommittee (SAC) Review: 2010(SAC) Review: 2010

Characterization of “Atmospheric Boundary Layer” with the aid of Numerical Atmospheric Models

and Field Experiments:

Research Highlights (2009-2010)

Characterization of “Atmospheric Boundary Layer” with the aid of Numerical Atmospheric Models

and Field Experiments:

Research Highlights (2009-2010)

D. Bala SubrahamanyamBoundary Layer Physics and Atmospheric Modelling

Space Physics Laboratory, VSSC, Thiruvananthapuram

D. Bala SubrahamanyamBoundary Layer Physics and Atmospheric Modelling

Space Physics Laboratory, VSSC, Thiruvananthapuram

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Organization of the PresentationOrganization of the Presentation

HRM Simulations in support of GSLV/PSLV

TOTAL SOLAR ECLIPSE:Response of ABL

MOKSHA Field Experiment:

ABL Response to SW-Monsoon

W-ICARB: New Insights

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W-ICARB Field Experiment: New InsightsWinter Phase - Integrated Campaign for Aerosols, gases and Radiation Budget

W-ICARB Field Experiment: New InsightsWinter Phase - Integrated Campaign for Aerosols, gases and Radiation Budget

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W-ICARB (MABL Component): ContributorsW-ICARB (MABL Component): Contributors

Ocean Segment (Onboard ORV-SK):D. Bala Subrahamanyam, N. V. P. Kiran KumarC. B. S. Dutt, Sherine Rachael John, S. S. Prijith

J. Subbarao, Poonaram Sinha

Thumba and ABLN&C Segment:P. K. Kunhikrishnan, Mannil Mohan, T. J. Anurose,

S. Indira Rani, S. Siji Kumar, Sandhya K. Nair, Santosh Muralidharan, Denny P. Alappattu, Marina Aloysius

Pisharoty Receiver and AWS Instrumentation:R. Gopakumar, S. Satyanarayana, K. Somayaji, R. Venkatesh

Ocean Segment (Onboard ORV-SK):D. Bala Subrahamanyam, N. V. P. Kiran KumarC. B. S. Dutt, Sherine Rachael John, S. S. Prijith

J. Subbarao, Poonaram Sinha

Thumba and ABLN&C Segment:P. K. Kunhikrishnan, Mannil Mohan, T. J. Anurose,

S. Indira Rani, S. Siji Kumar, Sandhya K. Nair, Santosh Muralidharan, Denny P. Alappattu, Marina Aloysius

Pisharoty Receiver and AWS Instrumentation:R. Gopakumar, S. Satyanarayana, K. Somayaji, R. Venkatesh

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(W-ICARB: MABL Component)(W-ICARB: MABL Component)Objectives and Plan-ExecutionObjectives and Plan-Execution

(W-ICARB: MABL Component)(W-ICARB: MABL Component)Objectives and Plan-ExecutionObjectives and Plan-Execution

Objectives/Requirements Plan ExecutionNorth-South Latitudinal Gradients in the

Air-Sea Interaction ParametersCruise Track was designed in accordance.

Vertical Structure of the MABLSystematic ascents of 108 Balloon-borne

GPS Pisharoty Sondes

Diurnal Variability in the

Air-Sea Interaction Parameters

Three Time-Series Measurements

(~ 18 Hrs each)

Offshore structure of the

Sea/Land Breeze Circulation and TIBL

Concurrent Measurements from ORV-SK

and Thumba

ABL Structure over Land vs. OceanConcurrent Measurements from ORV-SK

and ABLN&C Network Stations

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W-ICARB Data AnalysisW-ICARB Data Analysis

Air-Sea Interaction Processes over the Bay of Bengal(DATABASE)

(Meteorological Sensors mounted on a retractable boom)+

(Manual Measurements of SST and other meteorological fields)+

(GPS aided position of the ship, its speed and head angle)

Air-Sea Interaction Processes over the Bay of Bengal(DATABASE)

(Meteorological Sensors mounted on a retractable boom)+

(Manual Measurements of SST and other meteorological fields)+

(GPS aided position of the ship, its speed and head angle)

Vertical Structure of the MABL over the Bay of Bengal(DATABASE)

(Upper air meteorological observations obtained from Balloon-borne Pisharoty GPS Sondes)

Vertical Structure of the MABL over the Bay of Bengal(DATABASE)

(Upper air meteorological observations obtained from Balloon-borne Pisharoty GPS Sondes)

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Meteorological Instruments Mounted on

Retractable Boom

Meteorological Instruments Mounted on

Retractable Boom

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Estimation of Air-Sea Interaction Parameters(Iterative Bulk Aerodynamic Algorithm)#

Estimation of Air-Sea Interaction Parameters(Iterative Bulk Aerodynamic Algorithm)#

SSTSSTATAT

RHRHWSWS

PRESPRES

LHFLHFSHFSHF MFMF

INPUTS

OUTPUTS

#Subrahamanyam et al., (Ann. Geophy., 2007; Bound.Layer.Met., 2008; Atmos.Res., 2009)

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Spatial Heterogeneity in Air-Sea Interaction Parameters

over the Bay of Bengal during W-ICARB

Spatial Heterogeneity in Air-Sea Interaction Parameters

over the Bay of Bengal during W-ICARB

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Barring Wind Speed, rest of the

meteorological parameters had a

distinct North-South latitudinal gradient;However it was not so prominent in the case of surface layer turbulent fluxes of heat, moisture and

momentum.

Barring Wind Speed, rest of the

meteorological parameters had a

distinct North-South latitudinal gradient;However it was not so prominent in the case of surface layer turbulent fluxes of heat, moisture and

momentum.

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Diurnal Variability in Air-Sea Interaction Parameters

over the Bay of Bengal during W-ICARB:

How does the 24 Hrs evolution look like ?What are the timings when a parameter peaks ?

Diurnal Variability in Air-Sea Interaction Parameters

over the Bay of Bengal during W-ICARB:

How does the 24 Hrs evolution look like ?What are the timings when a parameter peaks ?

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SHF High during Night and Low during Noon Hrs!!!

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Unusual Nocturnal Peaks !!!Unusual Daytime Peak !!!

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Defining a “New Index” to quantify the diurnal variabilities....

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Statistical Interpretation of Data distribution in terms of

Skewness and Kurtosis

Statistical Interpretation of Data distribution in terms of

Skewness and Kurtosis

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Balloon-borne Pisharoty GPS

Ascents (108 Nos.)

Balloon-borne Pisharoty GPS

Ascents (108 Nos.)

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Balloon-borne Pisharoty GPS Sonde Data Analysis (Quality Checks and Data Processing)

(Raw Data → Sigma Filter → Running Mean → Regridding)

Balloon-borne Pisharoty GPS Sonde Data Analysis (Quality Checks and Data Processing)

(Raw Data → Sigma Filter → Running Mean → Regridding)

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Time-Series Measurements during W-ICARB: Mixed Layer Height Evolution

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Third Time Series Measurements closer to Thumba: Formation of “Thermal Internal Boundary Layer”

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Vertical profiles of VPT over Thumba

corresponding to 1323 LT showed formation

of TIBL, which gradually changed to

Residual Layer by 2016 LT profile.

Over Ocean, such clear formation of any

internal boundary layer was not

prominent and MABL showed a weak diurnal

evolution.

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Magnitudes of Sea Breeze Component (SBC) was marginally higher over Thumba.

Evolution of compensating return flow at higher altitudes (1 – 3 kms) was clear over Thumba as well as over the Ocean.

OVER TO NEXT THEME: TOTAL SOLAR ECLIPSE --->

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““Atmospheric Boundary Layer” Atmospheric Boundary Layer” Response to the Response to the Total Solar EclipseTotal Solar Eclipse

Event on January 15, 2010 Event on January 15, 2010

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Automatic Weather Station(Atmospheric Surface Layer Measurements)

(Round the Clock)

Balloon-borne Pisharoty GPS Ascents(14-15 January 2010)

(Upper Air Meteorological Measurements)

0800 LT1000 LT1230 LT1430 LT

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Reduction in incoming

solar radiation by a magnitude of about 600

Wm-2

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Delayed Onset of Sea Breeze on TSE Day !!!

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Shrinking of Sea Breeze Front (Vertical Thickness) due to TSEControl Day ~ 700 m; TSE Day ~ 300 m

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Shrinking of Sea Breeze Front (Vertical Thickness) due to TSE gradually vanished after the eclipse

Control Day ~ 500 m; TSE Day ~ 400 m

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Rapid Fall in the altitude of maximum convection (corresponding to minimum in delta theta)

OVER TO NEXT THEME: MOKSHA ---->

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Monsoon Onset over Kerala through Systematic Horizontal Advection

(MOKSHA)

Monsoon Onset over Kerala through Systematic Horizontal Advection

(MOKSHA)

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MOKSHA: Motivation and Background...Normal Dates of Onset of South-West Monsoon

Courtesy: IMD Website

(www.imd.gov.in)

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MOKSHA: Motivation and BackgroundMOKSHA: Motivation and Background

Courtesy: IMD Website

(www.imd.gov.in)

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MOKSHA: Motivation and Background...Advancement of Indian South-West Monsoon


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MOKSHA: Objectives ...MOKSHA: Objectives ...

➢What is the response of “Atmospheric Boundary Layer” to the Indian Summer Monsoon during its onset phase over Kerala ?

➢Whether the intrusion of moisture within the ABL from neighboring oceans during the onset phase of SW-monsoon is really systematic resulting into subsequent rainfalls (As shown through onset dates !!!)

➢What could be the possible role of ABL dynamics in SW-monsoon associated precipitation and whether both have got any feedback mechanism governing the rainfall intensities ?

....

Essentially MOKSHA does not aim at prediction of Monsoon !!!!

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MOKSHA: Science Plan Conceived ...MOKSHA: Science Plan Conceived ...

Preliminary Earmarked Objectives:-

➢Investigation in modulations in mixed layer heights and ABL characteristics over the Kerala Coast with the onset of SW-monsoon.

➢Study of spatial homogeneity/heterogeneity in rainfall during onset phase of SW-monsoon over Kerala.

➢Quantitative Investigation of intrusion of moisture from Oceans to landmass (Kerala) during onset phase of SW-monsoon with the aid of Regional Atmospheric Models.

➢Generation (Gathering) of ABL measurements database during onset phase of SW-monsoon.

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MOKSHA: Pilot Phase (2009)MOKSHA: Pilot Phase (2009)

Database:May 20 – June 01, 2009:One Pisharoty Sonde per day simultaneously from TERLS (Thumba) and SNOM (Cochin)

May 15 – Sept 15, 2009:Surface layer meteorological observations from about 37 ISRO AWS stations within Kerala under PRWONAM Network

++ All other ABL instruments at ATS, TERLS.

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How systematic was the horizontal advection of moisture and associated rainfall over Kerala in SW-monsoon (2009) !!!


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Formal Date of SW-Monsoon Onset: 23 May 2009

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Rainfall Vs. Mixed Layer Heights

OVER TO NEXT THEME: HRM ---->

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High-resolution Regional Model (HRM) Simulations in support of GSLV-D3 and

PSLV-C14 Launch:

Towards improvements in Model Simulations

Anurose T. J. and D. Bala Subrahamanyam

High-resolution Regional Model (HRM) Simulations in support of GSLV-D3 and

PSLV-C14 Launch:

Towards improvements in Model Simulations

Anurose T. J. and D. Bala Subrahamanyam

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End Users

Provided for HRM by DWD

Topographical Data

Initial data (Analysis)

Lateral Boundary Data

ModelProducts

RegionalNWP

System: HRM

General Structure of Regional NWP System: High-resolution Regional Model (HRM): An Overview

General Structure of Regional NWP System: High-resolution Regional Model (HRM): An Overview

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Launch Commit Criteria Requirements ...

(1) Probability of Occurrence of thunderstorms during different stage fuel fillings(2) Location of Thunderstorms in the near-proximity of launch site(3) Rainfall Intensity and duration (4) Maximum Possible magnitudes of surface layer winds during movement of launch vehicle(5) Maximum expected change in altitudinal profiles of winds over SHAR....

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+18 Hrs Forecast

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+24 Hrs Forecast

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HRM Predictions Vs. NCEP/NCAR Reanalysis

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Impact of high-resolution topography in Regional Atmospheric Models....

Two Different Cases: Case 1: HRM Orography is higher than the GME Orography

(A mountain's realistic elevation is under-estimated in Global Model)

Case 2: HRM Orography is lower than the GME Orography(A Flat ground is over-estimated as an elevated mountain in Global Model)

ps1HRM

psGME

psGME

ps1HRM

Case1: (No Problem) Case2: Just assumptions !!!

Mean height difference (m) GME - HRM: -0.0329

Minimum height difference (m) GME - HRM: -638.8944 Minimum at gridpoint j1: 82 j2: 107

Maximum height difference (m) GME - HRM: 507.7585 Maximum at gridpoint j1: 83 j2: 107

Impact of high-resolution topography in Regional Atmospheric Models....

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Sensitivity of Vertical Winds to Topography..

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Tiedtke Convective Scheme Bechtold Convective Scheme

Sensitivity of Precipitation to Convective Schemes..

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Experiences Gained:

Choice of Model Domain: How to avoid Steep topography ??

Choice of Topography (Expense: Model Run Time): Global Model to Regional Models

Choice of Convective Schemes: Widespread rainfall over isolated rainfall ?

Choice of Grid Size (and Model Time Step): As per Users' Need

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FUTURE PROJECTIONS ....HRM Verification studies with three different topographical datasets (0.25, 0.10 and 0.0625 deg. resolutions)

Data Assimilation (TEMP, SYNOP + Satellite Observations) in HRM for improving the forecast quality...

Continuation of Sea/Land Breeze Circulation Study (Observations + Model) with special emphasis on the dynamics of formation of the return flow (++ AACCR)

MOKSHA – Next Phase (++ ADB)

Indigestion of Field Experiments Database into the Model

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FUTURE PROJECTIONS (Long Terms....)

Our Preparedness for Future Generation Global Models (Global Centres are pushing the regional centres for smaller and smaller grid size models)

Let us no more remain “just” the Users of a “model”.....Lets us contribute something (HRM Scheduler...)

Expansion of ABLN&C network stations and to augment the basic minimum experimental set-up and their usage in Regional Climate Models

Coupling Mechanisms from ABL to Ionosphere ...

scientific advisory committee (sac) review: 2010

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