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Sensor Web Observing System Simulator (SWS) Project

September 9, 2008Glenn J. Higgins (Northrop Grumman)Michael Seablom (NASA Goddard)

High Fidelity Weather ModelingHigh Performance ComputingNetwork of Observing Systems

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Agenda

• Overview and Background

• Architecture

• Example Use Cases

• Limited Simulation Example

• Plans

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Overview

• Sensor Web Observing System Simulator (SWS) is an ongoing NASA project contractually supported by Northrop Grumman (NG)

• Outgrowth of NASA Earth Science Technology Office (ESTO)-funded activity leading to two major reports

• Goal is to quantify impact of candidate changes to weather forecast system on weather forecast accuracy– Support trade studies prior to investment, leading to cost savings

• SWS creates test-bed for simulating future weather forecasting concepts, e.g., new sensors, targeted observing, etc.– Extension to climate monitoring observing systems desired– NRC decadal missions highest priority– Support Mission PI’s in defining mission requirements and impacts– Computationally intensive and large data sets

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Genesis of SWS

• ESTO Weather Architecture Studies (2002† & 2004‡) – Fundamental improvement in predictive skill may be obtained by incorporation

of an additional feedback between the forecast model and the observing system

• Existing technology can provide:– More frequent data collection in or near regions where the forecast model

predicts development of a significant feature (e.g., GOES rapid scan mode)

• New technology will be needed to enable, especially if resources limited:– Changing the observing mode of a satellite (power, slewing)– Dynamic asset deployment (e.g., UAVs)– Communication between the model and the sensor– Data collection in a more intelligent manner– Cloud-free lines of sight assessment– Higher density data collection in sensitive regions; lower density elsewhere

• SWS project launched to provide simulation environment to test these ideas and ultimately facilitate trade studies

Clausen, M., Kalb, M., McConaughy, G., Muller, R., Neeck, S., Seablom, M., Steiner, M., 2002: Advanced Weather Prediction Technologies: NASA’s Contribution to the Operational Agencies, ESTO Technical Report.

Higgins, G., Kalb, M.,Lutz, R., Mahoney, R., Mauk, R., Seablom, M., Talabac, S., 2004: Advanced Weather Prediction Technologies: Two-Way Interactive Sensor Web & Modeling System, ESTO Technical Report.

SWS High Level Architecture

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Needs to accommodate current system and future concepts

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Some Potential Use Cases: Quantifying Impact of Proposed Changes to Forecasting System on Forecast Accuracy

Doppler Lidar- 3D Winds

UAV measurements to improve hurricane track/

intensity forecasts

Impact of new CONOPS

Impact of different forecasts models

XOVWM- sea surface winds

(XOVWM: Extended Ocean Wind Vector Winds Mission)

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Example of Integrating SWS and SensorModels

ScenarioDefinition

Candidate Sensor

Data

Measure-ment

Simulation

Data Assimilation

ModelGSI

Forecast Model

GEOS5

Forecast Parameters

Truth Data

(Nature Run)

Performance Analysis

Forecast Quality

Performance Metrics

Each forecast cycle

NG EVEREST

Core SWS Components

Measurement Uncertainties

Of Other Sensors

SWS + EVEREST enable end-to-end sensor impact studies, including measurement accuracy-to-forecast accuracy

EVEREST: Environmental Product VErification and Remote Sensing Testbed

Simulated Weather DataReal Weather ModelsSimulated Weather Data for New SensorsHPC

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TIME SERIES of monthly mean anomaly correlations for 5-day forecasts of 500hPa heights for various operational models (CDAS frozen as of 1995) - Northern Hemisphere

Improvements in predictive skill over the past several decades have been gradual; the sensor web provides an opportunity for a

“revolutionary” impact

An expression of how well predicted anomalies correspond to observed anomalies

One metric of predictive skill of weather forecasts

“Anomaly Correlation”

Evolution of Weather Forecast Predictive Skill- a metric for comparing

Source: Fanglin Yang, Environmental Modeling Center, National Centers for Environmental Prediction, NOAA

Use Case: Decadal Survey Mission 3D Wind Lidar

Source: Kakar, R., Neeck, S., Shaw, H., Gentry, B., Singh, U., Kavaya, M., Bajpayee, J., 2007: An Overview of an Advanced Earth Science Mission Concept Study for a Global Wind Observing Sounder.

Global Wind Observing Sounder (GWOS)

Telescope Modules (4)

Life: 6 billion shots

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Application of Sensor Web Concepts

• Simulation: Extend Mission Life via Power Modulation

• Conserve power / extend instrument life by using aft shots only when there is “significant” disagreement between model first guess line-of-sight winds and winds measured by fore shots– Lidar engineers have recently suggested reduced duty cycles may

increase laser lifetimes– Duty cycles that are on the order of 10 minutes “on” and 80

minutes “off” may be very beneficial to mission lifetime

• Some combination of space/ground processing would be required– Requires engineering trades be performed for on-board

processing, storage, power, weight, communications

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Simulation Results

Lidar data deleted when there is “adequate” agreement with the

numerical model’s first guess wind fields

Designed to simulate suppression of the aft shot

of the lidar

Result: Nearly 30% of the lidar’s duty cycle may be reduced -- IF

there is no discernible impact to forecast skill!

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Simulation 1 Results

Northern Hemisphere

Southern Hemisphere

Forecast HourForecast Hour

Impact of duty cycle reduction on forecast skill, 20 day assimilation with 5-day forecasts launched at 00z each day. Results represent an aggregate over all forecasts

Full lidar set and targeted lidar set are

nearly identical -- indicating a reduced duty cycle may be

possible

Results in the Southern Hemisphere are more

ambiguous; some indication of degradation due to targeting

is evident

Simulation Results (cont.)

Anomaly Correlation versus Forecast hour

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Computational Requirements for the simulation functionality demonstration

• Computer System: NCCS (NASA Center for Computational Sciences) Palm System (SGI Altix)

• Number of processors used: 64 CPUs

• Global Model Resolution: 1x1 deg 72 levels

• Wall Clock: 10 Simulation Days/ Day

• Number of Days Processed: 20 days

• Data Requirements:– Input: 10 GB/simulation day– Output: 10+ GB/simulation day

• Note: Higher resolution simulations over longer times periods are planned requiring more computational resources

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Status and Plans

• Improve user interface, automate production, increase scope of simulation capability

• Conduct new simulations – GOES-R (Geostationary Operational Environmental Satellite-R)– GWOS (Global Wind Observing Sounder)– XOVWM (Extended Ocean Wind Vector Winds Mission)– PATH (Precipitation and All-Weather Temperature and Humidity)

Mission

• Integrate NG Everest sensor modeling capabilities through collaboration with NGIT and NGST, brings– NPOESS (National Polar-orbiting Operational Environmental

Satellite System)– Other sensors

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Q & A

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Backup

Data Assimilation Today

1. Observations are collected at “routine” locations in space &

time

3. Numerical forecast is executed

2. Data analysis is performed

“Survey Mode” Data Collection

Data Assimilation with Intelligent Sensor Webs

1. Observations are collected at specified locations in space & time

3. Numerical forecast is executed

2. Data analysis is performed

Autonomous and On-Demand Targeting to Collect “Best” Observations

Adaptive Targeting

Automated / Manual

Sensor Web Feedback LoopSensor Web Feedback Loop

4. Forecast error is estimated

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Adapting SWS for other Decadal Missions

• Decadal Missions have multiple purposes:– Climate research and monitoring– Health issues related to the environment– Ecosystem research and monitoring– Water resources monitoring– Weather prediction and research

• The current SWS simulator design is aimed at modeling proposed changes to the forecast system and their impact on weather forecasting skill– It is not limited to changes in the observing system

• The application of the SWS to other focus areas of the decadal missions, such as climate monitoring, requires additional use cases to further drive the design