CMA Global Reanalysis (CRA-40): Status and Plans

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Zhiquan (Jake) LiuChunxiang Shi, Zijiang Zhou, Lipeng Jiang, Xiao Liang,Tao Zhang, Jie Liao, Jingwei Liu, Mingyan Wang, ShuangYao, Zhishen Zhang, Lijuan Cao, Kaixi Hu, Hui Jiang, YaniZhu, Yizhou Yin, Bin Zhao, Dong Si, Chenghu Sun,

and others

5th International Conference on Reanalysis 13-17 Nov. 2017, Rome, Italy

Started in early 2014, led by the National Meteorological Information Center (NMIC) of CMA

Include Atmosphere and Land component

3 other CMA national centers and 3 outside institutes involved- National Meteorological Center (CMA/NMC) - National Satellite Meteorological Center (CMA/NSMC) - National Climate Center (CMA/NCC)- Institute of Atmospheric Physics, Chinese Academy of Sciences (CAS/IAP) - Beijing Normal University (BNU) - Nanjing University of Information Science & Technology (NUIST)

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Background

Goals

Produce 40-year datasets (1979-2018)：

– Ingested observations

– Grid products: ~30km, 6 hourly

– Obs. feedback datasets：departure from analysis & background

– Atmospheric Reanalysis uncertainty：from EnKF ensembles

Will then be continuously running in NRT for climate

monitoring

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CMA 40-year Global Reanalysis (CRA-40)

CRA-40 Roadmap

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Atmospheric Reanalysis System- Forecast Model: GFS

T574 (~ 34km), 64L, top at ~0.2hPa- Data Assimilation: GSI

3Dvar-FGAT, 6-h time windowVarBC for aircraft T and satellite radiances

Observations (see Poster by Jiang Lipeng)- Radiosondes & SYNOP: CFSR + more Chinese observations- Radiosonde T: applied “raobcore” bias correction- Aircraft data from CFSR, Met Office, and NMIC- Reprocessed AMV, GPS-RO, scatterometer ocean surface wind- Satellite Radiances from CFSR/GDAS observation Dataset

Production (finished middle October!) 2007.1 - 2016.12, 2.5year/stream, 6 months overlap between streams

Separate Land Reanalysis (see Poster by Liang Xiao) Based on NASA LIS and Noah3.3 LSM No soil data assimilation, forcing: SW radiation, precip., surface P/t/q/wind

10-year Interim Product (CRA-Interim)

2006.07

2010.072012.07

2014.07

2008.07

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5 streams

RadiancesfromCFSR/GDAS

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Conv.OBS &Satellite Retrievals

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Reprocesseddatasets

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Comparison of CRA-Interim and ERA-Interim against Radiosonde T

RMSE of ERA-Interim

RMSE of OMA RMSE of OMB

Smaller RMSE than ERA-Interim against radiosonde temperature

Precipitation Evaluation against rain gauge over China

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00h-06h

12h-18h

06h-12h

18h-24h

2014 heat wave event (July 4 – August 10)

Southeast of China and Sichuan Basin

ERA misses high T in Sichuan basin

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CRA-Interim/CFSR/JRA55 minus ERA-Interim

Global T Mean Global RH Mean

Global U MeanSouthern Hemi.Z Mean

Problem

Re-run exp. with CFSR’s GPSRO, compare to ERA5

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Mean 500 hPa Z difference w.r.t. ERA5 (Units: gpm)

CFSR’sGPSRO

ReprocessedGPSRO “Impact height” is

different betweenCFSR data andUCAR/COSMICreprocessed data

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Re-run exp. with CFSR’s GPSRO, compare to ERA5

Height-latitude distribution of U-wind and T mean difference between

ERA5 and other reanalyses

0-10 cm Soil T: July, 2007-2010 mean

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Range: 265 K – 305 K

ERAI/Land

0-10 cm Soil Q: July, 2007-2010 mean

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Range: 0 – 0.45 m3/m3

ERAI/Land

• Currently re-running 5 streams by replacing reprocessed GPSRO by CFSR’s GPSRO data – should finish in Feb. 2018

• Evaluate CRA-Interim and release in 2nd half of 2018

• Prepare for CRA-40 production- CMA new HPC expected in 2018, 8 Pflops,- GSI-4DEnVar/EnKF & GFS T574 or higher- Observation processing/pre-evaluation

• Expect to complete CRA-40 by 2020

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Future Plan