the global precipitation climatology centre (() ggpcc...

The Global Precipitation Climatology Centre (GPCC) Serving ( ) g

the Hydro-Climatology Community

Bruno Rudolf, Andreas Becker, Udo Schneider, , , ,Anja Meyer-Christoffer, Markus Ziese, Peter Finger

D t h W tt di tDeutscher WetterdienstDepartment of Hydrometeorology

Global Precipitation Climatology Centre 1

GPCCGPCC

Outline

• Background and functions of the Global Precipitation Climatology Centre• Background and functions of the Global Precipitation Climatology Centre (GPCC)

• GPCC data base and provenancep

• Methods in use for QC and gridding

• GPCC Products

• Sampling error vs. high-resolution products and trend analysis

• Frequencies of extreme eventsq

• Outlook


GPCCGPCC

Outline




• GPCC Products



• Outlook


GPCCGPCC

The Global Precipitation Climatology Centre (GPCC)

Established by the World Meteorological Organization WMO in the year 1988

undertaken by Deutscher Wetterdienst DWD

contributes to the Global Climate Observing System GCOS and the World Climate Research Programme WCRPg thousands of users world-wide scientific task: quantitative assessment of global precipitationq g p p

and investigation of the global water cycle


GPCCGPCC

The functions of the GPCC

collection of observed precipitation data world-wide

data processing, quality control, storage

data analysis, production of gridded data fields

distribution of the gridded data fields distribution of the gridded data fields

contribution to international programs contribution to international programs


GPCCGPCC

Outline




• GPCC Products



• Outlook


data sourcesGPCC data sources

Near real-time regularly exchanged data

GPCC

• hourly/daily weather reports (SYNOP)

Near real time regularly exchanged datavia the WMO Global Main Telecommunication Network

hourly/daily weather reports (SYNOP) ca. 6,500 stations

• monthly climatological totals (CLIMAT)o t y c ato og ca tota s (C ) ca. 2,300 stations

ca. 8,000 stations ca. 8,000 stations

Non real-time:Non real time:Additional data received from ca. 190 countries

• Historical data collections (CRU FAO GHCN)plus: • Historical data collections (CRU, FAO, GHCN)• International project data (GEWEX and other)

plus:

totally more than 64 000 stations


totally more than 64,000 stations

GPCC data baseGPCC data base

Data coverageData coverageby country


GPCC data baseGPCC data base

More than 64,000 stations providing normal means – status 2010More than 64,000 stations providing climatic means – status 2010/10


Data used as climatologic background for GPCC gridded data sets

GPCCGPCC

Outline




• GPCC Products



• Outlook


GPCC quality controlSeparate storage of the data from different sources

GPCC quality control

The source specific storage of the data serves an important basis for quality control as well as p q yfor understanding, traceability and later re-production


GPCC quality controlQuality-control with 4 levels:


1a: Pre-control of SYNOPs 1b: Pre-control of CLIMATs 1c: Format check of individual1c: Format-check of individual data sets 2: Overall visual control of2: Overall visual control of individual data sets 3: Check of station meta data during the loading process

4: Semi-automatic QC of

monthly precipitation data: monthly precipitation data: Statistical pre-control and visual check of questionables


griddingGPCC

Gridding of the station data for individual months

griddingGPCC

Gridding of the station data for individual monthsLong term mean monthly precipitation ‘normals’

Monthly precipitation anomaly gridded from station anomaliesprecipitation normals gridded from station anomalies

Gridded monthly precipitation totals


precipitation totals

GPCCGPCC

Outline




• GPCC Products



• Outlook


GPCC products

GPCC near real-time products

GPCC products

pRoutinely produced gridded data setsavailable within: application: number of stations:

5 days First Guess Anomalies drought monitoring FAO ~ 6,500

available within: application: number of stations:

2 months Monitoring Product WCRP/GEWEX early reference ~ 7,500

Additional information provided for monitoring product• Number of stations per grid box

S li• Sampling error• Stochastic error• Systematic error assessment• Systematic error assessment

This information is updated every month


This information is updated every month

GPCC products

Schedule for the release of new products

GPCC products

Schedule for the release of new products Global Precipitation Mean Climatology

i d 1951 2000- period 1951-2000- based on about 64,000 stations Nov 2010

Full Data Reanalysis Version 5- period 1901-2009

b d ll il bl d t (64 000 t ti ) N 2010- based on all available data (64,000 stations) Nov 2010

Trend analysis for selected data time-series - period 1951-2005- based on complete data time-series (~ 16,000 stations) early 2011

publication of the methods used and results to be submitted early 2011


to be submitted early 2011

GPCC data baseTemporal data coverage Full Data Product Version 4 and Version 5

GPCC data base


GPCCGPCC Product examples: GPCC Product examples:

GPCC

a) First Guess Analysis for August 2010 (total & anomaly)a) First Guess Analysis for July 2010 (total

Global total patterns typical for La Nina season


Global total patterns typical for La Nina seasonAnomalies across Indian sub-continent contain precipitation causing Pakistan flooding

GPCC P d t lGPCCGPCC Product examples:

b) Monitoring (top row) and (c) Full Data Product El Nino Winter 1997/98

GPCC

Please note the excellent overall quality of the monitoring product available 2 months


Please note the excellent overall quality of the monitoring product available 2 months after the fact, but also the improvement in the Full Data Product across central Africa!

GPCCGPCC

Outline




• GPCC Products



• Outlook


sampling errorGPCC sampling errorGPCC

Monthly precipitationStatistical error < 10%

16 stations per grid required

Daily precipitationDaily precipitationStatistical error < 20%

40 stations per grid40 stations per grid required !!

Figure: GPCC after Jenne and Joseph


Jenne and Joseph,WMO-No. 115, 1985

station densityGPCC station densityGPCC

Monthly precipitationerror < 10%error < 10%

16 stations per grid,per grid,

i.e. approximately 40 000 stations

required globallyq g y

GPCC Climatology 1951-2000: Number of stations per 1º grid cellgy p g


Areas in dark green and blue = Sufficient station density

station densityGPCC station densityGPCC

DailyDaily precipitationerror < 20%

40 stations per grid required !!

i e approximatelyGPCC, Monitoring Product, Sep 2009: No. of stations per 2,5º grid cell i.e. approximately100 000 stations

required globally!!

, g , p p , g


globally!!Areas in blue = Sufficient station density

Daily data analysisDaily data analysis

- 0.40

- 0.31

- 0.04

0 04

Linear trend (slope) for number of days with daily precipitation of- 0.04 daily precipitation of 30 mm/d or more

i d 1931 2008- 0.17- 0.24

period 1931-2008

- 0.55

- 0.18

0 78 decreasearea size ca. 50x50 km2- 0.78

- 0.18

decrease ca. 50x50 km2200 - 400 msl


Daily data analysis

+ 0 55

Daily data analysis

+ 0.92+ 0.55

+ 1 05

+ 0.15

+ 0 07

Linear trend (slope) for number of days with daily precipitation of

+ 0.36 + 0.30

+ 1.05

+ 1.37+ 0.52+ 0.34

+ 0.07 daily precipitation of 30 mm/d or more

i d 1931 2008+ 0.26 + 0. 73

+ 1 55

+ 1.62 period 1931-2008

+ 0.33+ 1.55+ 2.03

+ 0.80+ 0.95

+ 0 86

+ 0.46

+ 0.46+ 0.29

+ 0.86

+ 0.65+ 0 17

increase area size ca. 50x50 km2

+ 0.45+ 0.17 ca. 50x50 km2

200 - 400 msl


Daily data analysis

+ 0 55

Daily data analysis

- 0.40

- 0.31

- 0.04

0 04

+ 0.92+ 0.55

+ 1 05

+ 0.15

+ 0 07

Linear trend (slope) for number of days with daily precipitation of

+ 0.36

- 0.04

+ 0.30

+ 1.05

+ 1.37+ 0.52+ 0.34

+ 0.07 daily precipitation of 30 mm/d or more

i d 1931 2008+ 0.26 + 0. 73

- 0.17- 0.24

+ 1 55

+ 1.62 period 1931-2008

all 37 stations

+ 0.33- 0.55

- 0.18

+ 1.55+ 2.03+ 0.80+ 0.95

+ 0 86

0 78 + 0.46

+ 0.46+ 0.29

+ 0.86

+ 0.65+ 0 17

increasedecrease

area size ca. 50x50 km2- 0.78

- 0.18

+ 0.45+ 0.17 decrease ca. 50x50 km2

200 - 400 msl


GPCCGPCC

Outline




• GPCC Products



• Outlook


1955-1964 1965-1974 1975-1984 1985-1994 1995-2004

SUUMMER Number of days with heavy rain (i.e. days with totals exceeding 60 mm) for decades

WIINTTE


R

1955-1964 1965-1974 1975-1984 1985-1994 1995-2004

SUUMMER Number of dry days (i.e. days with totals less than 1 mm) for decades

WIINTTE


R

GPCCGPCC

Outline




• GPCC Products



• Outlook


GPCCGPCC

Further Outlook:•GPCC Climatology 2010 and Full Data Product Version 5 (almost done)•Peer-reviewed publication on GPCC data base (ASAP)•Peer-reviewed publication on GPCC data base (ASAP)•Upload to IPCC portal – Contribution to IPCC (Q1 2011)

•Selection of homogeneous time series for assembling a new homogenizedSelection of homogeneous time series for assembling a new homogenized precipitation re-analysis (HOMPRA) (Year 2011)

•Commence near real-time daily SYNOP-based Products (Year 2011)•Extend daily analysis to re-analysis of historical data (from 2011 ongoing)


GPCC Web siteAccess to GPCC‘s Precipitation Products

GPCC Web sitep

http://gpcc.dwd.de


Email: [email protected]

GPCCGPCC

GPCC staff members:

Dr. Andreas Becker (scientist, head of GPCC)Udo Schneider (scientist)( )Anja Meyer-Christoffer (scientist)Markus Ziese (scientist new member)Markus Ziese (scientist, new member)Peter Finger (programmer)P t St d (t h i i )Peter Stender (technician)Astrid Heller (technician)Jan Niclas Breidenbach (technician)Dr. Bruno Rudolf (supervisor, dir. dept. hydrometeorology)


…

GPCCGPCC

Additional Material:


GPCC data basThe data base Jan 1901 – Oct 2010 for gridded products

GPCC data basg


GPCC data sourcesTemporal data coverage of the eight different data sources and the total

GPCC data sources

GTS = near realtime


near realtimeSYNOP, CLIMAT

GPCC gridding

Gridding of the stations monthly long-term mean data

GPCC gridding

g y g1. Interpolation of station based monthly normals to gridpoint normals

(distance of the grid-points 0.25° lat/lon)

2. Calculation of area-mean precipitation for regular grid-boxes for all continents and islands(grid si e 0 5° lat b 0 5° lon 1 0° lat b 1 0° lon and 2 5° lat b 2 5° lon

Gridding of the gauge data for individual months (e.g. July 2010)

(grid size 0.5° lat by 0.5° lon, 1.0° lat by 1.0° lon, and 2.5° lat by 2.5° lon

1. Calculation of precipitation (mm/month) anomalies on the stations usingall available data

2 Interpolation of station based monthly anomalies to grid point anomalies2. Interpolation of station based monthly anomalies to grid-point anomalies and calculation of area means on the grid-boxes (as above)

3. Calculation of area-mean precipitation totals for the grid-boxes bybi ti f th idd d li d lcombination of the gridded anomalies and normals

The anomaly-based interpolation is used at the GPCC since 2008


The anomaly based interpolation is used at the GPCC since 2008

GPCC quality controlLoading new data – check station meta data against the existing data


Station with new data

base

he d

ata

bon

s in

thst

atio

decision support

optio

ns

Questionable Meta Data Expert Decision


o Expert Decision

GPCC quality controlGPCC quality control

Metadata and precipitation observation data are intensively

lit t ll d d if

Major challenges:• Incorrect station location;

S ti f i i quality controlled and – if necessary – corrected by GPCC based on automatic as well as

• Separation of missing values from 0 mm;

• Separation of true from


manual QC procedures false extremes;

GPCC quality controlGPCC quality controlData errors discovered by comparisons and homogeneity tests

Barisal, Maijde Court, Comilla/BGD: GHCN data

Save/BEN: Reg. data for 1922-1924 and1927 1936 too large by a factor of 2 54!!

, j ,for 1991-2000 too small by a factor*10!!

Puna/BOL: FAO and GHCN data 1930-

1927-1936 too large by a factor of 2.54!!

Puna/BOL: FAO and GHCN data 1930-1948 do not belong there!! Cantillan/PHL: Nat. data

1977-1982 all „0“!!

Puerto Puyuhuapi, Coyhaique/CHL:Nat. data 1992-1995 all „0“!!


GPCC

Free access to GPCC gridded data sets via internet

GPCC

g

http://gpcc.dwd.de


Number of contacts 2002 - 2008

the global precipitation climatology centre (() ggpcc...

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