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GRAS SAF Status & Next Steps

Kent B. Lauritsen

Danish Meteorological Institute

Copenhagen, Denmark

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Contents

- Short introduction to the GRAS SAF system

- Status of refractivity product

- Next upgrades of the system

- 1dvar products and ROPP_PP processing

- ROPP software and plans

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GRAS Satellite Application Facility Consortium

Leading Entity:Danish Meteorological Institute (Copenhagen, Denmark)Kent B. Lauritsen, Hans Gleisner, Kjartan Kinch, Johannes K. Nielsen, Frans

Rubek, Stig Syndergaard, Hallgeir Wilhelmsen

Partners: ECMWF (Reading, UK)Sean Healy

Institute d’Estudis Espacials de Catalunya (IEEC, Barcelona, Spain)

Estel Cardellach, Santi Oliveras

Met Office (Exeter, UK)Dave Offiler, Chris Burrows, Ian

Culverwell

Occultation Antenna

UKMO x

DMIx

IEECx

EUMETSATx

ECMWFx

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The GRAS SAF objectives

Operational processing and archiving center for GRAS radio occultation (RO) data:- including additional third party RO data being processed by EUMETSAT CAF;- including reprocessing of RO data from EUMETSAT CAF and other data providers;

Products and software deliverables:

Near-real time (NRT) radio occultation products- operational products in NRT (refractivity, temperature, pressure, humidity);

Offline/climate radio occultation products- offline profile products (monthly), and reprocessed profiles;- offline gridded products (monthly), and reprocessed data sets: gridded data of bending angle, refractivity, temperature, humidity, geopotential height;

Radio Occultation Processing Package (ROPP)- routines for assimilation and processing of RO data;

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NRT, Offline, and Climate processing overviewPhase, amplitude,

ground station observations,near-real time orbits

Phase, amplitude,ground station observations,

NRT/offline data

Bending angle profiles(L1, L2, LC)

Refractivity profiles

1D-Var algorithm

Ancillarytemperature, pressure,

and humidity, fromECMWF forecasts

Temperature,pressure, and

humidity profiles

GRAS SAFNRT Products

Bending angle profiles(ionosphere corrected and

statistically optimized)

Refractivity profiles

1D-Var algorithm

Temperature,pressure, and

humidity profiles

GRAS SAFOffline Products

Level 1a

Level 1b

Level 2

Produced byEUMETSAT CAF

Geometric optics inversion algorithm

Bending angle profiles(statistically optimized)

Abel transformalgorithm

CT2algorithm

Abel transformalgorithm

Level 2

Level 2

Re-processed data(zero/single/double diff.):

Phase, amplitude

Other RO data(COSMIC, CHAMP, ...):

Phase, amplitude

Bending angle profiles(ionosphere corrected and

statistically optimized)

Refractivity profiles

1D-Var algorithm

CT2algorithm

Abel transformalgorithm

Temperature,pressure, and

humidity profiles

Climate algorithms

Bending angle, refractivity,temperature, humidity, andgeopotential height grids

GRAS SAFClimate/Gridded Data

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Recent and planned system upgrades

GRIB2 format- upgrading of GPAC to handle ECMWF’s new GRIB-2 format- done on May 17, 2011

L2 extrapolation and BA thinning- upgrade done in coordination with EUMETSAT- updated code running at EUMETSAT CGS GS2- planned for June/July (TBC)

Production, dissemination, and archiving of 1DVar products- code prepared, testing- upgrade planned for TBD

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NRT refractivity product (GRM-01)

Produced from geometric optics (GO) level 1b bending angles (BAs) from GRAS/Metop-A data from EUMETSAT CAF

Limited information contents at low altitudes (due to GO and no RS data) Product version: 1.3 Number of registered GTS users: 19

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REF statistics for the first 10 days of Dec 2010

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NRT refractivity product (GRM-01): Plans

Plans:- L2 extrapolation: will increase penetration depth- Improve statistical optimization (SO) by using an enhanced

background climatology - Validate against COSMIC data processed to BA and Refractivity- Comparisons of ROPP_PP vs OCC/Invert- Switch to using ROPP_PP code in operations

Status on issues related to PPF upgrade preparations at DMI:- Analyses focusing on the inclusion of thinned bending angles in the PFS

files (done in Dec 2010 using PPF2.16 GS2 data)

- Analyses focusing on extrapolation of L2 bending angles with higher SLTA configuration (done in Feb 2011 using PPF2.17 offline data)

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Penetration statistics with L2 extrapolation

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NRT 1DVar products: T and q

Status Produced from refractivity from (currently) geometric optics (GO) bending

angles Limited information content at low altitudes Limited information about humidity Product version: 1.0 Number of GTS users: n/a

Plans/ongoing:- Upgrade operational system with NRT 1DVar products: in preparation- Processing and comparison of GRAS and COSMIC data- Re-assess temperature and humidity information in the lower

troposphere - Handle cases with super saturation- Scientific assessment of prototype GRAS data for check-point review

in Jan 2012

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ROPP_PP processing of GRAS RS data

All processed GRAS RS profiles from 30 Sept 2007 included;

Comparison of ROPP_PP and Michael Gorbunov’s OCC codes for different choices of coordinates;

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ROPP package overview

GRAS Level 1b(CGS)

EPS/PFS

netCDFeps2netcdf

GRASLevel 2(SAF)

ropp2bufr(Thin or Full Level 1b/2)

BUFR

ropp_1dvar(for Q/C)

ropp_fm(as part of 3/4-D Var)

NWP VAR system

NWP User

netCDFropp_pp

ropp2bufr(Thin Level 1b)

ropp2bufr(Thin Level 2)

ropp_1dvar

netCDF

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Next release: ROPP-5 

• ROPP-5 improvements over ROPP v4.1:• Inclusion of non-ideal gas effects (compressibility factors) in ropp_fm and

ropp_1dvar;

• Enhanced BUFR support in ropp_io – interfaces also with ECMWF library;

• Various bugfixes (including some in ropp_pp/OCC);

• Beta version built and put on website at end of March 2011.

• DRI review held at Met Office on 20 May 2011.

• ROPP-5 scheduled to be released early July 2011 after close-out meeting/telecon later in June.

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Plan for ROPP-6

• ROPP-6 in plan for release before end of CDOP in February 2012(Public release: Feb 2012; DRI: Dec 2011; Beta: Oct/Nov 2011)

• New/improved science to include: Ionosphere Correction

• New technical enhancements:• potentially netCDF-4/HDF5

• updated format for ECM’s (error covariance matrices)

• Tuning of ROPP_PP for GRAS offline data

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ROPP and data registered users

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Improving the timeliness of Metop-A global data

Using NASA's McMurdo station in Antarctica, near the South Pole;

Antarctic Data Acquisition (ADA) User trials in e.g. April, 2011:

Below is shown data from 19 April from 7:30z to 15:30z;

GRAS SAF system can handle higher data rates (but to get

the full increase in timeliness, system has to be “reconfigured”)

Figure from EUMETSAT

Min: 1h 28min

Min: 0h 41min

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fin