1 / 22

BENCHMARK DATASET HOMOGENIZATION. A first test.

BENCHMARK DATASET HOMOGENIZATION. A first test. Contribution to the Working Groups Meeting of COST-HOME action, Tarragona, 9-11 March 2009. Enric Aguilar, Center on Climate Change, URV, Tarragona. C3-SNHT APPLICATION. New software (F95) ‏

tad-higgins
Download Presentation

BENCHMARK DATASET HOMOGENIZATION. A first test.

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. BENCHMARK DATASET HOMOGENIZATION. A first test. • Contribution to the Working Groups Meeting of COST-HOME action, Tarragona, 9-11 March 2009 • Enric Aguilar, Center on Climate Change, URV, Tarragona.

  2. C3-SNHT APPLICATION • New software (F95)‏ • Detection (done) and taylored correction modules (almost done) • Reference selection (distance, correlation, overlap) • One homogenization for station: for each station/element/month-season-annual a special “network” is created and only the results for the main candidate are retained • Series are split until the most recent significant break is found and the remaining series is tested until no more breaks are found or the segment is too small • Breaks need to be inspected and a correction pattern created. This is better done with annual and seasonal averages (problem with benchmark; run over anomalies?)‏ • R-code for output inspection • WORK IN PROGRESS: • feed breaks to HOM; use weather types to calculate daily factors

  3. VISUAL INSPECTION STATISTICAL DETECTION BREAKS VALIDATION Network TEMP/SUR1/000001

  4. VISUAL INSPECTION • Saint-Cornier (06): large break around 1959 & missing 1945 • Chartres (03): large break around 1950 • Saint Georges (01): break around 1970 & missing 1945 • Groix (02) : break around 1955 & and missing 1945 • Rennes (04): break around 1985 & missing 1940

  5. STATISTICAL DETECTION • Monthly results are confusing and noisy • Seasonal are better (only 4!)‏ • Annual, optimum to start

  6. PLOTS FOR BREAK VALIDATION HOMOGENIZATION FOR SAINT-CORNIER Data series for main candidate and references. Red lines indicate breaks

  7. PLOTS FOR BREAK VALIDATION HOMOGENIZATION FOR SAINT-CORNIER Zeta-series for main candidate and references. Red lines indicate breaks

  8. PLOTS FOR BREAK VALIDATION HOMOGENIZATION FOR SAINT-CORNIER Data and Zeta-series for main candidate

  9. PLOTS FOR BREAK VALIDATION HOMOGENIZATION FOR SAINT-CORNIER test-values and break location

  10. PLOTS FOR BREAK VALIDATION HOMOGENIZATION FOR SAINT-CORNIER Histogram of Detected breaks, in all homogenizations where this station has participated

  11. PLOTS FOR BREAK VALIDATION HOMOGENIZATION FOR SAINT-CORNIER Detected breaks, drawn proportional to the largest one

  12. SAINT-GEORGES • Large break in 1948 • Smaller breaks after 1970 • Pattern: • BREAK 1948 • TREND 1948-1981 or BREAK 1970

  13. GROIX • Annual detects nothing • Z-plots point to 1950-1960 • Histogram plot indicates 1949 and 1955 or 1956 • They're detected in summer • Pattern: • BREAK 1949 • BREAK 1956

  14. GROIX • Question: is my decision influenced by the existence of larger breaks? • Plot 1 = no • Plot 2 = maybe!

  15. CHARTRES • Looking at annual + Spring (plotted)‏ • BREAK 1980 • BREAK 1948 (Clear)‏ • BREAK 1926 • BREAK 1919 (?)‏

  16. CHARTRES • SUMMER: non detected outlier (level is 3.5 sd) going in the oposite direction of a potential break: no detection!

  17. RENNES • ANNUAL: • BREAK 1990 • BREAK 1951 • OTHER POSSIBLE BREAKS: • 1919 & 1926 ... (remember last slide?) Influenced by others or margin effect? • ~ 1979 -1984 ==> forced by outlier

  18. GIEVRES • Breaks are small • BREAK 1985 • BREAK 1943 • MAYBE TREND 1943-END?

  19. SAINT CORNIER • BREAKS 1994 • BREAK 1959 • BREAK 1942 (missing?)‏ • BREAK 1928 (?)‏ Annual Summer: detection around 1935, but seems to be ~ 1928

  20. ILE-YEU • Annual does not detect breaks, but there is an evident (short) problem between 1931-1934 (2 breaks?)‏ • Winter (shown bottom pannel) and Spring identify: • BREAK 1963

  21. LA MOTE-ACHARD • Breaks have small amplitude. Visual inspecetion of z-series suggests: • TREND 1951-1980? • BREAK 1951 • BREAK 1939

  22. BIARD • BREAK ~ 1970? • BREAK 1943 • MANY OUTLIERS FOUND

More Related