AOPC-Meeting XX GPCC Report Report from the Global Precipitation Climatology Centre (GPCC) Report to...

AOPC-Meeting XX GPCC Report

Report from the Global Precipitation Climatology Centre (GPCC)

Report to AOPC-XX, Zurich, 17-20 March 2015Doc. 7.4 - Agenda item 7.4

Andreas BeckerHead, Precipitation Monitoring Unit & GPCCDepartment of Hydrometeorology

Deutscher Wetterdienst (DWD), Offenbach am Main, Germany

25 Years, 1989-2014

KU42 Unit

GPCC Team: 1 Head3 Scientists, 1 Proj. Scientist1 Programmer,3 TAs

RADOLAN Team2 Scientists2 Proj. Scientists1 Programmer2 TAs

From left to right: M.Sc. Elke Rustemeier, Dr. Markus Ziese, Heinz-Jörn Müller, Dipl. Met. Udo Schneider, Jan-Nicolas Breidenbach, Astrid Heller, Cathleen Sterker, Mario Hafer, Dr. Tanja Winterrath, Peter Stender, Dipl. Met. Elmar Weigl, Dipl. Met. Anja Meyer-Christoffer, Peter Finger, Dr. Andreas Becker, M.Sc. Thomas Junghänel, M.Sc. Anna Schmitt

KU42/GPCC Staff

A. Becker, Beobachtung und Bewertung extremer Niederschlagsereignisse. Quo Vadis DWD? ; Besuch PIK-Potsdam, 3. Februar 2015

4 von 45

• hourly/daily weather reports (SYNOP) up to 7,500 stations

• monthly climatological totals (CLIMAT) up to 2,900 stations

up to 8,800 unique stations

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

Non real-time:

Additional data received from ca. 190 countries

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

plus:

> 95,000 stations in total

GPCC data sources

5Global Precipitation Climatology Centre, AOPC XIX – 9 - 11 April 2014 - Agenda Item 5.3

WMO Data Request for the GPCC

Global Precipitation Climatology Centre, AOPC XX – 17 - 20 March 2015 - Agenda Item 7.4

Steps of quality control at GPCC

GTS-Data (SYNOP reports):

check of precipitation amounts against the weather information

consistency check of reports overlapping in time

(fill gaps without precipitation, if weather group indicates no precipitation)

Delivered data

Check station location within country and over land

Coding of missing values (sometimes 0 is used)

Data from existing station or new one (check of meta data)

precipitation data checked against background statistics for the station or, if not available, for the corresponding 2.5° grid (since 2009)

data being flagged as questionable (below the 5% or above the 95% percentile), checked manually

7Global Precipitation Climatology Centre, AOPC XX – 17 - 20 March 2015 - Agenda Item 7.4

Stations are sometimes located in the ocean or outside of the boundaries of the country

Unusual annual cycle or extreme outliers of monthly precipitation

Temporal shifts in the data

Factor*10 errors

Typing or coding errors

Errors in the conversion of inch, mm etc. (mostly with historical data)

Incorrect flagging of missing precipitation observations (might be misinterpreted as „0“)

QC: Errors typically detected


Features of gridded precipitation data as required by the users:

· Homogeneity (for climate change and variability analysis)

All of these requirements cannot be met by one single gridded data set

==>A portfolio of different analysis products has been designed and optimized with respect to the application purposes

User requirements

· Timeliness (for drought monitoring)

· High resolution (for regional structures in global maps)

· High accuracy (for verification of model results)



Break in 1986 because of initial start of data acquisition almost homogenized

Data base for different monthly GPCC products

Station data base of GPCC‘s Precipitation Climatology V.2011 (V.2015) as basis for anomaly analyses ca. 67,200 (75,000)

GPCC Climatological data base


Monthly GPCC Products (Becker et al, 2013, ESSD 5, 71-99)

First Guess Product (DOI: 10.5676/DWD_GPCC/FG_M_100)based SYNOP data, automated QC, Resolution 1.0 degavailable within 3 to 5 days after the end of each month

Monitoring Product (Version 4, DOI: 10.5676/DWD_GPCC/MP_M_V4_100)based on CLIMAT and SYNOP data, enhanced QC, Resolutions 1.0° & 2.5°available within two month after the analyzed month

Climatology (Version 2011, DOI: 10.5676/DWD_GPCC/CLIM_M_V2011_025) based on about 67200 stations, Resolutions 0.25°, 0.5°, 1.0° and 2.5° target reference period 1951 – 2000, stations with at least 10 years of databackground climatology for GPCC products

Full Data Reanalysis (Version 6, 10.5676/DWD_GPCC/FD_M_V6_050)uses same stations as Climatology, Resolutions 0.5°, 1.0° and 2.5°available from 1901 to 2010 (2013 with V7)


Utilization of Full Data Reanalysis for ERA_CLIM2 Project


Steps of quality control at GPCC

GTS-Data (SYNOP reports):

check of precipitation amounts against the weather information

consistency check of reports overlapping in time

(fill gaps without precipitation, if weather group indicates no precipitation)

Delivered data

Check station location within country and over land

Coding of missing values (sometimes 0 is used)

Data from existing station or new one (check of meta data)

precipitation data checked against background statistics for the station or, if not available, for the corresponding 2.5° grid (since 2009)

data being flagged as questionable (below the 5% or above the 95% percentile), checked manually


Stations are sometimes located in the ocean or outside of the boundaries of the country

Unusual annual cycle or extreme outliers of monthly precipitation

Temporal shifts in the data

Factor*10 errors

Typing or coding errors

Errors in the conversion of inch, mm etc. (mostly with historical data)

Incorrect flagging of missing precipitation observations (might be misinterpreted as „0“)

QC: Errors typically detected


Absolute Precipitation Anomaly in year 2014

17

Fig. 5 in „WMO State of the Climate 2014“



To appear soon in „BAMS SoC 2014“ d.3

Globally averaged precipitation anomalies (mm yr-1, 1961-1990 base period) for three in situ data sets over land.

R. S. Vose, K. Hilburn, X. Yin, M. Kruk, and A. Becker

Additional products available from GPCC

I. Analyses of daily land-surface precipitation

• First Guess Daily: automated QC, based on SYNOP reports; near real-time (within five days)

II. Bi-decadal (1988-2008) global analysis of daily precipitation utilized to study extremes with ETCCDI package

III. Additional products:

• GPCC drought index: combination of SPI-DWD and SPEI with nearly global coverage


• Interpolated with ordinary block Kriging

• Interpolation of relative values – fraction of daily total in relation to

monthly total (only stations with monthly total could be used, at least 70% data coverage required)

• Released together with First Guess Product

• netCDF-files containing total precipitation, standard deviation regarding Yamamoto (2000), Kriging error and number of stations per grid

• Described in Schamm et al. (2014): “Global Gridded Precipitation over Land: A description of the new GPCC First Guess Daily product”, Earth Syst. Sci. Data, 6, 49-60, DOI:10.5194/essd-6-49-2014

GPCC‘s First Guess Daily Productdoi: 10.5676/DWD_GPCC/FG_D_100


GPCC First Guess Daily product elements

precipitation standard deviation

number of stations Kriging error


Additional work at GPCC for historic daily data

participating DAPACLIP (global DAily Precipitation Analyses for the validation of medium-range CLImate Predictions)

Daily precipitation analyses for 1988 to 2008 over land

Acquisition of daily data

Developing QC scheme for daily data (including comparison to monthly total)

Loading data into data bank focusing 1988 to present

Testing and optimization of interpolation schemes including error estimation

Test of optimization possibilities of QC → detection of shift by one or two days


Overview of the daily data collected by GPCC

23

Daily data loading focusing on 1988 to present, earlier data available at GPCC


II. Bi-Decadal Global Daily Data Set, 1988-2008


II. Bi-Decadal Global Daily Data Set, 1988-2008

25

Example to characterize the bi-decadal DAPACLIP daily data set (Dietzsch et al., 2015) through the precipitation related indices of the ETCCDI package compiled by Klein Tank et al. (2009).Here RX1day (maximum daily precipitation) for the second decade (1998-2008) is shown.


III. GPCC drought index GPCC_DI: gridded drought index with nearly global coverage combination of SPI-DWD and SPEI precipitation data from GPCC; First Guess Product monthly mean temperature from CPC uses mean of SPI-DWD and SPEI, if both can be calculated, otherwise the

one which can be computed parameters derived from Full Data Reanalysis V.6, period 1961-1990 several averaging intervals: 1, 3, 6, 9, 12, 24 and 48 months using gridded fields, no interpolations → areas with no data possible analysis from January 2013 until present provided as netCDF-files updated 10 to 13 days after each month DOI: 10.5676/DWD_GPCC/DI_M_100


III. Example GPCC drought index, January 2013, 1 Month

SPI-DWD SPEI

GPCC_DI

+

=>

normalwetter thandrier than


III. GPCC drought index here for 01.05.-31.01.2015

30

• Sao Paolo


GPCC comments on AOPC-XVIII (GCOS-169) actions and recommendations:

1. Referring to Action Item 26, GPCC is grateful for the acknowledgement received.

2. Referring to Action item 27, GPCC would like to express its gratitude for the continued support of the WMO Secretariat with regard to GPCC’s activities in the field of data acquisition. In the 2nd half of year 2015 GPCC will liaise with GCOS on an optimized data request letter that shall contain better incentives to the data providers and offers additional ways of daily data provision through an XML based data standard.

3. Referring to Action item 28 GPCC remains open to joint efforts in data acquisition, as demonstrated with ECMWF and KNMI/ECA&D past year with regard to the daily precipitation data originally sent to ECMWF for model verification. The proposed solution to gather the data through ECA&D mechanisms while requesting for co-use by GPCC is a good example for a joint activity. The issue on a too quick re-assignment of stations Identifiers (IDs) from closed stations challenging maintenance of the WMO catalogue remains open. Action from the WMO WWW might be needed to provide sufficient blocks of station IDs.


GPCC suggestions for AOPC XIX action: Continue GPCC data acquisition support via WMO Secretariat (e.g. WCP) in

case of GPCC communication problems with WMO members; Cooperation with GCOS in 2015 on an updated and optimized data request letter utilized for the communication.

Support alternate ways of joint daily data acquisition in cooperation with scientific projects and with activities of the GEO community. In particular the inclusion of OGC compliant XML standards should be considered constructively due to their enormous potential for data mobilization.

Reliable meta information is key for systematic error correction and correct station association. The latter is challenged in countries of WMO members that have to re-assign station Id’s from closed stations too quickly, challenging the WMO catalogue maintenance. WMO WWW activity might be needed in this context, e.g. to provide for an additional block of station Id’s for those members being short on this;

Consideration of web-services for data and product dissemination should become an appropriate priority level for the WMO Secretariat. DWD and GPCC are ready and open for exchange of requirements and plans.


GPCC plans for next year Issuance of the next generation of monthly re-processing products (GPCC

Full Data Reanalysis Version 7, GPCC Climatology Version 2014, GPCC Monitoring Product Version 5) in spring 2015. For the Monitoring Product the re-processing shall start already in 1986, allowing also for the provision of the systematic error fields (due to snow and wind) for the entire period 1986-today. (So far this was only available since 2007).

Continuation of loading of daily data and development and generation quality assured daily data products. After completion of import from existing distributions (GHCN-daily and ECA&D) a new initiative to enhance the daily data compartment from national contributions (WMO NHMS) will be started in the 2nd half of 2015 through an updated data request letter making better incentives towards data providers with regard to GPCC’s capabilities in backup services and provision of feedback to data providers as for GPCCs results of quality checks.

Continuous enlargement of the GPCC daily database concerning the entire instrumentation periods.


GPCC plans for next year GPCC is up to address the data requirements of WCRP GC on Weather

and Climate Extremes. Tasks and deliverables have been defined at the Workshop in Sydney, Australia, 25-27 February 2015 and encompass for the GPCC – inter alia - the identification and combination of unique sources of precipitation data, guidance documents and ultimately the development of improved data sets more ready to study extremes.

Along with the WCRP GC on Weather and Climate Extremes GPCC will continue its efforts towards improved GPCC products derived from historic daily precipitation data information through an elaboration of ETCCDI kinds of extreme indices

Development and release of a new Homogenized Precipitation Re-Analysis (HOMPRA) Product (adjusted for climate variability and trend analyses) covering the time period 1951-2005 at spatial resolutions 0.5°, 1.0°, and 2.5°, HOMPRA is planned to become available in a Europe only version in course of year 2015 and in a global version later on. (Delayed from 2013).

Technically GPCC will add an import pre-processor for the OGC compliant XML standard Water ML 2.0 to its data base import software in order to explore data sources and providers beyond the WMO NMHSs


http://gpcc.dwd.deftp://ftp-anon.dwd.de/pub/data/gpcc/html/download_gate.html


http://gpcc.dwd.de/

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AOPC-Meeting XX GPCC Report Report from the Global Precipitation Climatology Centre (GPCC) Report to...

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