Hans Visser

15 mei

1

Flexible trends in hydrological time series(and how to publicise ..)

1.Global mean sea level in IPCC2.Trends water temperatures3.Kwaliteit oppervlaktewater4.Elfstedentocht5.Simultaneous confidence limits6.Sea level rise Den Helder

1 Fouten opsporen in IPCC rapporten

2

20 september, Bilthoven3

Characterization of errors (E1,E2, C1, …,C7):

C2 Insufficiently transparent and/or founded statement

The generalization in a SYR statement is not justifiable (E.g., impacts in one country or sector are extrapolated to include entire regions and/or additional sectors.)

The reasoning behind a statement is not accessible to a non-expert reviewer.

Insufficiently clear on what facts or figures a statement is basedNote: a lack of transparency does not imply the judgment to be wrong

Provide reasoning and if possible and alternative solution

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Global mean sea level rise: SPM and main text

20 september, Bilthoven5

Note: ‘from a linear trend’ and accelerations?

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What is the basis of the data? Table Chapter 3

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2 Trends schatten: zeer veel smaken

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Temperaturen Rijn en Maas: Compendium

20 september, Bilthoven9

Trends in kwaliteit oppervlaktewater

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Fosfaat, gemiddelde 2006-2010, 5x5 grids

20 september, Bilthoven11

20 september, Bilthoven12

Alles samengevat in één Eutrophication index:

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Trends in bevroren water

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16

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Index koudste 15 dagen - Log-trafo gebruikt - Let op 2012 ..

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1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2020Jaar

0.0

0.1

0.2

0.3

0.4

0.5

Eens per 5 jaarEens per 4 jaar

Eens per 10 jaar

Kan

s op

een

Elfs

tede

ntoc

ht

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Simultaneous or pointwise confidence limits?

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20 september, Bilthoven23

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Artikel hierover tweemaal mislukt …

Prachtig NWO-promotie-voorstel ook mislukt…

Het voorstel was te statistisch.

25

Modeling trend plus explanatory variables

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1860 1880 1900 1920 1940 1960 1980 2000 2020

6600

6700

6800

6900

7000

7100Den Helder - annual data Full time-series modelTrend component

Year

Rel

ativ

e w

ater

leve

l (m

m)

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1860 1880 1900 1920 1940 1960 1980 2000 2020

-2.0

0.0

2.0

4.0

6.0

Tren

d in

crem

ent

(mm

/yea

r)Trend increment with 95% confidence limits

Artikel afgekeurd..

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Impacts weather-related disasters

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