Evaluation of COST733 circulation classifications:

Persistence & synoptic-climatological applicability

Radan HUTH, Monika CAHYNOVÁ

Institute of Atmospheric Physics,

Prague, Czech Republic

1. Persistence (lifetime) of types

Persistence (lifetime) of types

• length of a sequence of days classified with one type

• can serve as a tool for assessing the usefulness of classifications

Data and methods

• all COST733 classifications except Litadve• additional: OGWL with a minimum 3-day

duration of CTs (…thanks to Paul James)• persistence of all types taken together• Domain 00 and 4 subdomains

0200

07

09

04

Data and methods02

00

07

09

04

HB

GW

L

PE

CZ

ELY

PE

RR

ET

SC

HU

EE

PP

ZA

MG

CE

C

ES

LPC

10

ES

LPC

30

EZ

500C

10

EZ

500C

30

GW

T

LIT

TC

LUN

D

LWT

2

NN

W

OG

WL

OG

WL-

3d+

P27

PC

AC

A

PC

XT

R

PC

XT

RK

M

PE

TIS

CO

SA

ND

RA

SA

ND

RA

S

TP

CA

07

TP

CA

V

WLK

C73

3

D00 23 23 12 9 20 25 154 87 163 61 18 10 24 11 28 14 22 17 19 18 19 20 32 22 30 21 12D02 15 36 16 54 54 12 10 15 8 46 8 19 14 14 10 15 16 14 15 13D04 18 52 30 60 42 11 9 19 8 39 9 20 15 12 8 15 17 15 14 12D07 30 77 33 57 50 17 11 16 10 58 9 26 16 12 9 13 20 17 15 10D09 25 103 37 164 82 13 11 21 8 41 11 50 13 19 11 20 20 16 16 9D00 5.3 1.7 1.7 1.3 1.6 2.8 4.7 3.1 6.1 3.2 1.7 1.4 2.5 1.5 1.7 1.7 4.8 1.8 2.2 1.9 2.0 2.2 2.4 3.2 3.0 2.2 1.5D02 2.0 2.5 1.8 3.6 2.4 1.3 1.3 1.6 1.2 1.9 1.3 2.4 1.5 1.5 1.3 1.5 2.0 1.7 1.4 1.3D04 2.0 2.7 2.0 3.5 2.4 1.4 1.3 1.9 1.2 1.9 1.3 2.6 1.5 1.5 1.3 1.5 2.0 1.7 1.5 1.3D07 2.0 2.8 2.0 3.9 2.6 1.4 1.3 1.6 1.2 2.4 1.3 2.8 1.5 1.6 1.4 1.5 2.0 1.7 1.6 1.3D09 2.1 3.6 2.2 4.9 2.9 1.5 1.4 1.9 1.2 2.4 1.4 3.4 1.6 1.7 1.4 1.7 2.3 2.0 1.7 1.3D00 5 1 1 1 1 2 2 1 2 2 1 1 2 1 1 1 4 1 2 1 1 2 2 2 2 2 1D02 1 1 1 2 1 1 1 1 1 1 1 2 1 1 1 1 1 1 1 1D04 1 1 1 2 1 1 1 1 1 1 1 2 1 1 1 1 2 1 1 1D07 1 1 1 2 1 1 1 1 1 2 1 2 1 1 1 1 2 1 1 1D09 1 2 1 2 1 1 1 1 1 2 1 2 1 1 1 1 2 1 1 1D00 2.5 1.3 1.1 0.6 1.2 2.3 11.5 5.7 11.5 4.5 1.2 0.8 2.1 0.9 1.4 1.1 2.2 1.3 1.7 1.4 1.6 1.8 2.0 2.5 2.6 1.7 1.0D02 1.6 2.8 1.5 5.3 3.1 0.8 0.7 1.2 0.6 1.9 0.7 1.8 0.9 1.0 0.8 1.0 1.5 1.2 0.9 0.7D04 1.6 3.5 2.1 5.2 3.1 0.9 0.8 1.6 0.6 1.9 0.7 2.4 1.0 1.0 0.7 1.0 1.5 1.3 1.0 0.7D07 1.6 4.0 2.1 5.7 3.6 0.8 0.7 1.1 0.5 2.8 0.7 2.6 1.0 1.1 0.8 1.0 1.6 1.3 1.1 0.7D09 1.7 5.9 2.4 9.8 4.9 0.9 0.8 1.4 0.6 2.8 0.8 4.1 1.1 1.3 0.8 1.2 1.8 1.5 1.2 0.7D00 29 13 31 40 43 10(40) 10 30 10 30 18 27 10 26 20 29 29 27 11 17 17 14 18 30 7 12 40D02 10(40) 10 30 10 30 18 27 10 26 20 27 4 12 12 25 21 30 7 11 40D04 10(40) 10 30 10 30 18 27 10 26 16 27 4 12 12 30 22 30 7 11 40D07 10(40) 10 30 10 30 18 27 10 26 12 27 4 12 12 28 23 30 7 9 40D09 10(40) 10 30 10 30 18 27 10 26 12 27 4 12 12 32 19 30 7 9 40

Objective

sigma

No. types

max

average

median

Manual

Basic statistics of persistence

Percentage of days in situations according to their length in D00

0

10

20

30

40

50

60

70

80

90

100

*SC

HU

EE

PP

LIT

TC

LWT

2

WL

KC

73

3

*ZA

MG

NN

W

GW

T

OG

WL

*PE

CZ

ELY

*PE

RR

ET

P2

7

PC

XT

R

PC

XT

RK

M

PE

TIS

CO

TP

CA

V

PC

AC

A

SA

ND

RA

ES

LP

C3

0

LU

ND

EZ

50

0C

30

CE

C

TP

CA

07

ES

LP

C1

0

SA

ND

RA

S

EZ

50

0C

10

OG

WL

-3d

+

*HB

GW

L

%

10-day CTs

9-day CTs

8-day CTs

7-day CTs

6-day CTs

5-day CTs

4-day CTs

3-day CTs

2-day CTs

1-day CTs

No. of days in events of given duration

Conclusions

• features of persistence of types are quite different among individual classifications

• Erpicum’s method is probably not useful – extremely long situations occur, esp. in summer (up to 164 days!!!)

2. Synoptic-climatological evaluation

GOAL

• assess the synoptic-climatological applicability of classifications

• i.e., how well they stratify surface weather (climate) conditions

TOOL

• 2-sample Kolmogorov-Smirnov test

• equality of distributions of the climate element under one type against under all the other types

- 1 0 - 5 0 5 1 0 1 5 2 0 2 54 0

4 5

5 0

5 5

6 0

- 1 0 - 5 0 5 1 0 1 5 2 0 2 54 0

4 5

5 0

5 5

6 0

- 1 0 - 5 0 5 1 0 1 5 2 0 2 54 0

4 5

5 0

5 5

6 0

- 1 0 - 5 0 5 1 0 1 5 2 0 2 54 0

4 5

5 0

5 5

6 0

- 1 0 - 5 0 5 1 0 1 5 2 0 2 54 0

4 5

5 0

5 5

6 0

- 1 0 - 5 0 5 1 0 1 5 2 0 2 54 0

4 5

5 0

5 5

6 0

- 1 0 - 5 0 5 1 0 1 5 2 0 2 54 0

4 5

5 0

5 5

6 0

- 1 0 - 5 0 5 1 0 1 5 2 0 2 54 0

4 5

5 0

5 5

6 0

x

- 1 0 - 5 0 5 1 0 1 5 2 0 2 54 0

4 5

5 0

5 5

6 0

TOOL

• at each station

• types for which the K-S test rejects the equality of distributions are counted

• the larger the count, the better the stratification, the better the synoptic-climatological applicability

ANALYSIS

• 20 objective class’s over domain 00 (whole Europe)

• + 6 subjective and objectivized catalogues (not assigned to any domain)

• from the v1.0 release of COST733 database• winter (DJF)• maximum temperature• 97 European stations (ECA&D database)• Jan 1958 – Feb 1993

- 2 0 - 1 0 0 1 0 2 0 3 0 4 03 5

4 0

4 5

5 0

5 5

6 0

6 5

7 0

7 5

S W Z

- 2 0 - 1 0 0 1 0 2 0 3 0 4 03 5

4 0

4 5

5 0

5 5

6 0

6 5

7 0

7 5N W Z

- 2 0 - 1 0 0 1 0 2 0 3 0 4 03 5

4 0

4 5

5 0

5 5

6 0

6 5

7 0

7 5H M

- 2 0 - 1 0 0 1 0 2 0 3 0 4 03 5

4 0

4 5

5 0

5 5

6 0

6 5

7 0

7 5T M

Example: Hess&Brez., 4 types

Summary over types: %age of test rejections

subjective + objectivized catalogues

- 2 0 - 1 0 0 1 0 2 0 3 0 4 03 5

4 0

4 5

5 0

5 5

6 0

6 5

7 0

7 5

H E S S & B R E Z O W S K Y 2 9

- 2 0 - 1 0 0 1 0 2 0 3 0 4 03 5

4 0

4 5

5 0

5 5

6 0

6 5

7 0

7 5

P E C Z E L Y ( H U ) 1 3

H E S S & B R E Z O W S K Y - o b j . 2 9

- 2 0 - 1 0 0 1 0 2 0 3 0 4 03 5

4 0

4 5

5 0

5 5

6 0

6 5

7 0

7 5

- 2 0 - 1 0 0 1 0 2 0 3 0 4 03 5

4 0

4 5

5 0

5 5

6 0

6 5

7 0

7 5

S C H U E P P ( C H ) 4 0

x

100 %

85-99 %

70-84 %

<70 %

Summary over types: %age of test rejections

objective catalogues

x

100 %

85-99 %

70-84 %

<70 %

- 2 0 - 1 0 0 1 0 2 0 3 0 4 03 5

4 0

4 5

5 0

5 5

6 0

6 5

7 0

7 5

E N K E & S P E K A T 1 0

- 2 0 - 1 0 0 1 0 2 0 3 0 4 03 5

4 0

4 5

5 0

5 5

6 0

6 5

7 0

7 5

B E C K 1 8

- 2 0 - 1 0 0 1 0 2 0 3 0 4 03 5

4 0

4 5

5 0

5 5

6 0

6 5

7 0

7 5

J E N K I N S O N - C O L L I S O N 2 6

- 2 0 - 1 0 0 1 0 2 0 3 0 4 03 5

4 0

4 5

5 0

5 5

6 0

6 5

7 0

7 5

S A N D R A 1 8- 2 0 - 1 0 0 1 0 2 0 3 0 4 0

3 5

4 0

4 5

5 0

5 5

6 0

6 5

7 0

7 5

T - M O D E P C A 1 2

RANKING OF CLASS’S

• methods ranked by the %age of rejected K-S tests (= well separated classes) at all stations individually

• higher %age better lower rank• ranks averaged over stations for each

classification• area mean rank ranking of the

classification

RANKING OF CLASS’S

• dependence on no. of classes• lower number larger class sizes smaller

difference necessary for significance more (higher %age) of rejections better stratification

Enke&Spekat 10 1 Jenk-Coll 26 10 k-means with iter’s 17 19 T-PCA 7 7 2 Sandra seq. 22 11 Schüepp 40 20 Beck 18 3 k-means no iter’s 17 12 Petisco 14 21 T-PCA var. 12 4 Erpicum SLP 10 10 13 Erpicum Z500 10 10 22 Peczely 13 5 Perret 31 14 DWD 37 23 Hess&Brez obj. 29 6 P-27 (Kruizinga) 27 15 Erpicum Z500 30 29 24 Lund 10 7 Litynski adv. 9 16 ZAMG 42 25 Hess&Brez 29 8 Litynski full 27 17 Erpicum SLP 30 30 26 Sandra 18 9 Ward 11 18

0 2 4 6 8 1 0 1 2 1 4 1 6 1 8 2 0 2 2 2 4 2 6c l a s s i f i c a t i o n ' s r a n k

5

1 0

1 5

2 0

2 5

3 0

3 5

4 0

4 5n

o. o

f cl

asse

s

RANKING OF CLASS’S

corr = 0.48

PRELIMINARY CONCLUSIONS

• synoptic-climatological applicability widely differs among class’s

• synoptic (& objectivized) catalogues compete successfully with objective methods (although not originally designed for the large domain)

• Hess-Brezowsky outperforms all objective methods with comparable no. of types

FURTHER WORK FOR ME

• other seasons (at least JJA)

• other climate elements (Tmin, precip, …)

• all domains

• gridded data ( averaging over stations may not be fair)

FURTHER WORK FOR WG2

• ranking is sensitive to no. of classes sensitivity should be removed if classification methods are compared

Therefore:• recalculate classifications

– for other numbers of types – preferably• low (around 10)• moderate (around 20)• high (around 30)

– at a selection of domains at least – CEC method (Enke&Spekat) – year-round

definition of types