Use Of NPP Data In The Joint Center For Satellite

Data Assimilation

Lars Peter Riishojgaard, JCSDA Director

IGARSS 2011 1July 25 2011

Overview

Introduction to JCSDA Weather prediction and satellite data

Motivation for R2O, NPP Preparation for new sensors NPP-related activities Summary

IGARSS 2011 2July 25 2011

IGARSS 2011 3

JCSDA History

July 25 2011

4

NASA/Earth Science Division

US Navy/Oceanographer andNavigator of the Navy and NRL

NOAA/NESDIS NOAA/NWS

NOAA/OAR

US Air Force/Director of Weather

Mission:

…to accelerate and improve the quantitative use of research and operational satellite data in weather, ocean, climate and environmental analysis and prediction models.

Vision:

An interagency partnership working to become a world leader in applying satellite data and research to operational goals in environmental analysis and prediction

JCSDA Partners, Vision, Mission

IGARSS 2011July 25 2011

IGARSS 2011 5

JCSDA Science Priorities

Radiative Transfer Modeling (CRTM) Preparation for assimilation of data from new instruments Clouds and precipitation Assimilation of land surface observations Assimilation of ocean surface observations Atmospheric composition; chemistry and aerosol

Driving the activities of the Joint Center since 2001, approved by the Science Steering Committee

Overarching goal: Help the operational services improve the quality of their prediction products via improved and accelerated use of satellite data and related research

July 25 2011

Slide 6

Satellite data now account for most of the skill

Impact of GOS components on 24-h ECMWF Global Forecast skill(courtesy of Erik Andersson, ECMWF)

500 hPa geopotential height anomaly correction from 01/09/2008-02/22/2008

1000 hPa geopotential height anomaly correction from 01/09/2008-02/22/2008

IGARSS 2011

Weather Prediction and the US Economy; A Macroscopic View

• Department of Commerce: “20% of overall US economy is weather sensitive”: ~$3 trillion/year

– Impact to air and surface transportation, agriculture, construction, energy production and distribution, etc.

• Assume that half of this is “forecast sensitive”: $1.5 trillion/year

• Assume that the potential savings due to weather forecasting amount to 5% of the “forecast sensitive total”: ~$75B/year

July 25 2011 8

IGARSS 2011

… a Macroscopic View … (II)

• Define now– “No forecast information” = 0 h useful forecast range – “Perfect forecast” = 336 h useful forecast forecast range

(two weeks traditonally used as limit of predictability)

• Next, assume that the potential savings up to the maximum of $75B are distributed linearly over the achieved forecast range for the global NWP system:– $75B/336h = $223M/hr

• This implies that the value to the United States economy of weather observations, dissemination, forecast products and services is >200M per hour of forecast range per year !

July 25 2011 9

NPP-related efforts in the Joint Center

July 25 2011 IGARSS 2011 10

Improved use of NPP precursor data; IR

AIRS/IASI water vapor channel improvement

Use of cloudy radiances Surface emissivity (land) Assimilation methodology studies Additional channels

July 25 2011 IGARSS 2011 11

Forecast impact of assimilation of AIRS cloud-cleared radiances

July 25 2011 IGARSS 2011 12

Improved use of NPP precursor data; Microwave

Ongoing CRTM improvements Surface emissivity, especially over

snow, ice,… Emissivity models Databases

Measurements affected by precipitation

July 25 2011 IGARSS 2011 13

July 25 2011 IGARSS 2011 14

Example of MW emissivity study (courtesy of Fuzhong Weng, NESDIS/STAR)

NPP Proxy Data

CrIS and ATMS proxy data generated by NESDIS on a routine basis (Barnet) Based on GFS model output, SARTA

radiative transfer model applied to model profiles

Streamed to JCSDA, ready for testing

July 25 2011 IGARSS 2011 15

CRTM status

CRTM ready for NPP sensors CrIS ATMS VIIRS

CRTM v. 2.1 released earlier this year Additional sensors Computational efficiency

July 25 2011 IGARSS 2011 16

500 hPa geopotential height anomaly correction from 01/09/2008-02/22/2008

1000 hPa geopotential height anomaly correction from 01/09/2008-02/22/2008

Observing System Simulation Experiments for NPP

Level 1 Experiments with simulated (proxy) data

from CrIS, ATMS along with existing data used in operations

Purpose here is to test data flow and data ingest rather than data impact

Level 2 Using the Joint OSSE system All data simulated; purpose is to assess and

optimize data impact

July 25 2011 IGARSS 2011 18

Post-launch activities

Passive monitoring Observation minus forecast residuals

monitored This effectively validates NPP data

against the rest of the Global Observing System

Active assimilation, off-line mode, impact assessment

Operational assimilationJuly 25 2011 IGARSS 2011 19

Summary The economic impact of Numerical Weather

Prediction and related activities are estimated to range in the tens of $B/year for the US alone

Satellite data are critical for NWP Upcoming launch of NPP marks the entry of a

new generation of operational meteorological satellites for the US

The Joint Center is heavily involved in preparing US operational users to benefit from these new data as soon as possible after launch

IGARSS 2011 20July 25 2011