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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