RIC-Tsukuba (Japan) Intercomparison of Thermometer Screens/Shields

in 2009 – 2010

AOSHIMA Tadayoshi NAKASHIMA Kouichi KAWAMURA HiroshiAOSHIMA Tadayoshi, NAKASHIMA Kouichi, KAWAMURA Hiroshi, KUMAMOTO Mariko, SAKAI Takeshi, KAWANO Saeko and JOKO Minoru

RIC-Tsukuba, Japan Meteorological Agency (JMA)

29 July 201029 July, 2010

1. Introduction

windwindsunshine

rain

[℃ ] Temperature Climatological Normals （1971–2000）

Fig. 2 Climatological normals for Tsukuba (upper: monthly temperature; lower: precipitation)

accurate

various screen/shelter

10

15

20

25

30

35

Temperature Climatological Normals （1971 2000）

Max

Mean

Min

measurement of air temperature

Radiation‐10

‐5

0

5

Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Dec. Nov. Dec.

[mm]

80100120140160180200

[mm]Precipitation Climatological  Normals（1971–2000）

PrecipitationJapan Tsukuba●To aid accurate measurement of air temperature, various screens/shields have been designed and

0204060

Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Dec. Nov. Dec.

Tokyo

36°3.4’N140°7.5’E

shields have been designed and used to protect thermometers from sunshine, radiation, rain and wind and so on.

・Tsukuba has a temperate rainy

Fig. 1 Location of Tsukuba

climate and high temperatures in summer (Cfa) according to the Köppen-Geiger climate classification.

2

2. Intercomparison Overview 2.1 Type of screens/shields tested and sensors

・Reference is JMA-95(A), the screen/shield is used on operational

Photo. 1 Location of screens/shields in the intercomparison field(north – south side view)

E 834 Z1(A) PFT 02(A) PVC 02(A)

screen/shield is used on operational surface observation.

・This experiment was carried out in summer season, and in winter and

DTR503A(N)JS-256(A)

E-834-Z1(A)

TV-150(A)

PFT-02(A)

PVC-03(A)

PVC-02(A) spring season.

・unified platinum resistence thermometer Pt 100Ω（the size is 3mm in diameter）because we wanted to

AV-040(N) YG-41003L(N)

）evaluate only screens effect.

Intercomparison field ( west – east side view)

JMA-W1(N)

( )

3

2.1 Type of screens/shields tested and sensors

Artificially ventilated screens/shields

Photo. 2 Pictures of screens/shields (upper: side view; lower: view from underneath)

JMA-95(A) JS-256(A) E-834-Z1(A) TV-150(A) PVC-03(A) PVC-02(A) PFT-02(A)

Naturally ventilated screens/shieldsAV-040(N) YG-41003L(N) DTR503A(N) JMA-W1(N)

upper: side view

lower: view from underneath

4

3. Results3.1 Statistical values 95 ％

75 ％

Maximum

Fig. 3 Tdev (temperature deviation) of daily temperature (reference: JMA-95(A)) Capitalize first letter of “Maximum/Average/Minimum” (same rule below for all graph legends).

(a) maximum temperature (b) minimum temperature (c) average temperature 6months

25 ％

75 ％

5 ％

Average

Minimum

1.2

1.6

2.0 Tdev of daily Tmax    Aug.  (Summer)

1.2

1.6

2.0

Tdev of daily Tmin    Jan.  (Winter)

1.2

1.6

2.0

Tdev of daily Tmean    for 6 months( ) p

Aug. 2009 (summer)( ) p

Jan. 2010 (winter) (Aug., Dec., Jan., Feb., Mar. and Apr.)

-0.4

0.0

0.4

0.8

Tdev [℃]

-0.4

0.0

0.4

0.8

Tdev [℃]

-0.4

0.0

0.4

0.8

Tdev [℃]

-2.0

-1.6

-1.2

-0.8

) ) ) ) ) ) ) ) ) )

-2.0

-1.6

-1.2

-0.8

) ) ) ) ) ) ) ) ) )

-2.0

-1.6

-1.2

-0.8

A)

A)

A)

A)

A)

A)

N)

N)

N)

N)

JS-256(A)

E-834-Z1(A)

TV-150(A)

PVC-03(A)

PVC-02(A)

PFT-02(A)

AV-040(N)

YG-41003L(N)

DTR503A(N)

JMA-W1(N)

JS-256(A)

E-834-Z1(A)

TV-150(A)

PVC-03(A)

PVC-02(A)

PFT-02(A)

AV-040(N)

YG-41003L(N)

DTR503A(N)

JMA-W1(N)

JS-256(A

E-834-Z1(A

TV-150(A

PVC-03(A

PVC-02(A

PFT-02(A

AV-040(N

YG-41003L(N

DTR503A(N

JMA-W1(N

Y Y

Artificiallyventilated

screen/shield

Naturallyventilated

screen/shield

Artificiallyventilated

screen/shield

Naturallyventilated

screen/shield

Artificiallyventilated

screen/shield

Naturallyventilated

screen/shield

5

3.2 Influences of global solar radiation

A tifi i ll til t d / hi ld

95 ％

25 ％

75 ％

5 ％

Maximum

Average

Minimum

2.5 3.0 3.5

JS-256(A)2 53.0 3.5

PVC-02(A)2 53.0 3.5

PFT-02(A)2.5 3.0 3.5

PVC-03(A)

Fig. 4 Tdev differences related to global solar radiation depending on each screen/shield, Aug. 2009Artificially ventilated screens/shieldbut no insulator → positive influences

-1 5-1.0 -0.5 0.0 0.5 1.0 1.5 2.0

Tdev [℃]

-1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5

Tdev [℃]

1 5-1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5

Tdev [℃]

-1 5-1.0 -0.5 0.0 0.5 1.0 1.5 2.0

Tdev [℃]

-3.5 -3.0 -2.5 -2.0 1.5

10-

100-

200-

300-

400-

500-

600-

700-

800-

900-

1000-

1100-

1200-

1300-

-3.5 -3.0 -2.5 -2.0 -1.5

10-

100-

200-

300-

400-

500-

600-

700-

800-

900-

1000-

1100-

1200-

1300-

-3.5 -3.0 -2.5 -2.0 -1.5

10-

100-

200-

300-

400-

500-

600-

700-

800-

900-

1000-

1100-

1200-

1300-

-3.5 -3.0 -2.5 -2.0 1.5

10-

100-

200-

300-

400-

500-

600-

700-

800-

900-

1000-

1100-

1200-

1300-

Naturally ventilated screens/shieldM t t d i ti +3 4℃

global solar radiation ［W/㎡］ global solar radiation ［W/㎡］

2.0 2.5 3.0 3.5

2.0 2.5 3.0 3.5

2.0 2.5 3.0 3.5

2.0 2.5 3.0 3.5

global solar radiation ［W/㎡］global solar radiation ［W/㎡］Max temperature deviation +3.4℃

20-1.5 -1.0 -0.5 0.0 0.5 1.0 1.5

Tdev [℃]

2 0-1.5 -1.0 -0.5 0.0 0.5 1.0 1.5

Tdev [℃]

2 0-1.5 -1.0 -0.5 0.0 0.5 1.0 1.5

Tdev [℃]

2 0-1.5 -1.0 -0.5 0.0 0.5 1.0 1.5

Tdev [℃]

-3.5 -3.0 -2.5 -2.0

10-

100-

200-

300-

400-

500-

600-

700-

800-

900-

1000-

1100-

1200-

1300-

l b l l di ti ［W/㎡］

AV-040(N)-3.5 -3.0 -2.5 -2.0

10-

100-

200-

300-

400-

500-

600-

700-

800-

900-

1000-

1100-

1200-

1300-

l b l l di ti ［W/㎡］

YG-41003L(N)-3.5 -3.0 -2.5 -2.0

10-

100-

200-

300-

400-

500-

600-

700-

800-

900-

1000-

1100-

1200-

1300-

global solar radiation ［W/㎡］

DTR503A(N)

-3.5 -3.0 -2.5 -2.0

10-

100-

200-

300-

400-

500-

600-

700-

800-

900-

1000-

1100-

1200-

1300-

JMA-W1(N)

global solar radiation ［W/㎡］ global solar radiation ［W/㎡］ global solar radiation ［W/㎡］global solar radiation［W/㎡］

6

3.3 Influences of radiation budgetFig. 6 Time series representations of monthly mean Tdev and radiation budget

400

500

600

700

[W/m2]

400

500

600

700

[W/m2]

Aug. 2009 (summer) Jan. 2010 (winter)I (a) Radiation budget II (a) Radiation budget

-100

0

100

200

300

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Radiation

[h]

Upward shortwave radiation Downward shortwave radiation

-100

0

100

200

300

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Radiation

[h]

Upward shortwave radiation Downward shortwave radiation・Largest negative Tdev → AV-040(N)Upward shortwave radiation Downward shortwave radiation

Upward longwave radiation Downward longwave radiation

Radiation budget

0 60.81

1.2

0 60.81

1.2

Upward shortwave radiation Downward shortwave radiation

Upward longwave radiation Downward longwave radiation

Radiation budget

(b) Tdev of naturally ventilated screens/shields (b) Tdev of naturally ventilated screens/shields

g g ( )・around sunrise and sunset Tdev changes remarkably

‐0.8‐0.6‐0.4‐0.2

00.20.40.6

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Tdev [℃]

‐0.8‐0.6‐0.4‐0.2

00.20.40.6

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Tdev [℃]

[h]

0.60.81

1.2

℃]

0 60.81

1.2

℃]

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 [h]

DTR503A(N) AV-040(N) YG-41003L(N) JMA-W1(N)

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 [h]

DTR503A(N) AV-040(N) YG-41003L(N) JMA-W1(N)

(c) Tdev of artificially ventilated screens/shields (c) Tdev of artificially ventilated screens/shields

‐0.8‐0.6‐0.4‐0.2

00.20.40.6

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Tdev [℃

[h]

‐0.8‐0.6‐0.4‐0.2

00.20.40.6

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Tdev  [℃

[h]

JS-256(A) TV-150(A) E-834-Z1(A)

PFT-02(A) PVC-03(A) PVC-02(A)

JS‐256(A) TV‐150(A) E‐834‐Z1(A)

PFT‐02(A) PVC‐03(A) PVC‐02(A)7

Reference: JMA-95(A). The dotted line in (c) includes missing data over periods of two days or more.

3.4 Influences of rainfall 95 ％

25 ％

75 ％

5 ％

Maximum

Average

Minimum

1580 764 194 53 9 7 40.5

0.6

count

1580 764 194 53 9 7 40.5

0.6

count

1580 764194 53 9 7 40.5

0.6

count

1558 715 175 52 9 7 40.5

0.6

count Index of Rainfall per

Fig. 7 Tdev differences related to rainfall intensity depending on each screen/shield for 31 days when the total rainfall was 10 mm per day or more

5 ％Minimum

-0 1

0.0

0.1

0.2

0.3

0.4

dev[℃]

count

0 1

0.0

0.1

0.2

0.3

0.4

v[℃]

count

0.0

0.1

0.2

0.3

0.4

ev[℃]

count

0 1

0.0

0.1

0.2

0.3

0.4

ev[℃]

count

0 >0.5

1 0.5

2 1～1.5

Index of

rainfall

class

Rainfall per

10 min.

[mm/10min.］

-0.6

-0.5

-0.4

-0.3

-0.2

0.1 T

JS-256(A)

-0 6

-0.5

-0.4

-0.3

-0.2

-0.1

Tdev

PVC-02(A)

-0 6

-0.5

-0.4

-0.3

-0.2

-0.1 Td

PFT-02(A)

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

TdePVC-03(A)

3 2～3

4 3.5～4.5

5 5～6.5

6 7≦

0 1 2 3 4 5 6

Index of rainfall class

0.6

0 1 2 3 4 5 6

Index of rainfall class

0.6

0 1 2 3 4 5 6

Index of rainfall class

0.6

0 1 2 3 4 5 6

Index of rainfall class

1101 559 135 28 4 3 10 5

0.6 1228 630157 37 5 4 1

0 5

0.6 1228 630 15737 5 4 1

0 5

0.6 1580 764 19453 9 7 4

0 5

0.6

largest negative Tdev→ DTR503A

0.0

0.1

0.2

0.3

0.4

0.5

ev [℃]

count

0.0

0.1

0.2

0.3

0.4

0.5

ev [℃]

count

0.0

0.1

0.2

0.3

0.4

0.5

ev [℃]

DTR503A(N)count

0.0

0.1

0.2

0.3

0.4

0.5

ev [℃]

JMA-W1(N)countMAX0.7

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1 Td

AV-040(N)

-0 6

-0.5

-0.4

-0.3

-0.2

-0.1 Td

YG-41003L(N)

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1 Td

-0 6

-0.5

-0.4

-0.3

-0.2

-0.1 Td

0.6

0 1 2 3 4 5 6

Index of rainfall class

0.6

0 1 2 3 4 5 6

Index of rainfall class

0.6

0 1 2 3 4 5 6

Index of rainfall class

0.6

0 1 2 3 4 5 6

Index of rainfall class 8

95 ％

25 ％

75 ％

Maximum

Average

3.5 Comprehensive evaluation 1/3Table 1 Characteristics and variation of Tdev related to various meteorological factors for each screen/shield

5 ％Minimum

JMA-95 (A)

(JS-258)JS-256 (A) E-834-Z (A) TV-150 (A) PVC-03 (A) PVC-02 (A) PFT-02 (A) AV-040 (N) YG-41003L (N) DTR503A (N) JMA-W1 (N)

Ogasawara Ogasawara Yokogawa Ogasawara Prede Prede Prede Ogasawara R. M. Young Vaisala Hidakosya

Horizontal type Horizontal type 10 plates (flat）

14 plates (dish

upside down） 12 plates (dish） Roof blinds base:

Ventilation Artificially Natural

Type

Manufacturer

FormHorizontal type

(pole）

Horizontal type

(roof）

10 plates (flat）

＋snow umbrella

upside down）

inner: curved

downward

12 plates (dish）

rim: flat

Roof, blinds, base:

duplication

Inside structure

Insulator/underneath

shield plate

MaterialStainless steel

Stainless steel

(SUS304）Stainless steel Stainless steel

Stainless steel

(SUS304） Stainless steel

Stainless steel

(Portion:Shade: aluminium

Arm: steel plate

UV stabilized white

thermoplastic plates

Polycarbonate

(20% glassfiber） Wood

Vertical type

Duplication tube

○

－

－

ructure of screen

－

Material (SUS304）

(SUS304）

Aluminium(SUS314） (SUS304） Portion:

aluminium

(SUS304） aluminium,

bakelite）

Arm: steel plate

［Steel］

thermoplastic plates

Arm: aluminium

(20% glassfiber）

Reverse: black

Wood

Diameter［mm］ 117 117 100 89 88 88 76 200 130～120 105

Length［mm］ 475 457 370 358 423 586 630 420 270 238

Measured 5.0 m/s 5.9 m/s 4.7 m/s * 4.3 m/s 2.0 m/s 2.5 m/s 3.6 m/s

Manufacturer 4 - 7 m/s 4 - 7 m/s 4 - 8 m/s 4 - 7 m/s About 3 m/s About 3-4 m/s About 3 m/s

-0 1 - 0 0 -0 1 - 0 0 -0 1 - 0 0 -0 1 - 0 0 -0 1 - 0 0 -0 1 - 0 0 -0 1 - +0 2 -0 1 - +0 1 -0 2 - 0 0 -0 1 - +0 1

1125 (W)

930 (L)

1511 (H)

－Ventilation

speed　*)

n Daily Tmean

St

0.1 0.0 0.1 0.0 0.1 0.0 0.1 0.0 0.1 0.0 0.1 0.0 0.1 +0.2 0.1 +0.1 0.2 0.0 0.1 +0.1

(-0.2 - +0.1) (-0.2 - +0.1) (-0.2 - +0.1) (-0.2 - +0.2) (-0.2 - +0.2) (-0.3 - +0.3) (-0.3 - +0.5) (-0.2 - +0.3) (-0.4 - +0.2) (-0.3 - +0.3)

Daily Tmax Aug. 0.0 - +0.1 -0.1 - +0.2 -0.2 - +0.1 0.0 - +0.3 +0.2 - +0.5 +0.4 - +0.6 +1.1 - +1.4 +0.4 - +0.6 +0.1 - +0.3 +0.1 - +0.3

Daily Tmin Jan. -0.3 - 0.0 -0.3 - 0.0 -0.2 - 0.0 -0.3 - -0.1 -0.3 - -0.1 -0.4 - -0.2 -0.7 - -0.4 -0.3 - -0.1 -0.5 - -0.3 -0.1 - +0.1

Effect of global solar

radiation Aug. *2)-0.1 - +0.1 -0.1 - +0.1 -0.2 - 0.0 0.0 - +0.3 +0.1 - +0.5 +0.2 - +0.6 +0.9 - +1.4 +0.3 - +0.7 0.0 - +0.3 +0.2 - +0.5

Effect of radiation

budget Jan *3)-0.3 - -0.1 -0.3 - -0.1 -0.3 - -0.1 -0.4 - -0.2 -0.4 - -0.2 -0.4 - -0.2 -0.9 - -0.4 -0.6 - -0.2 -0.7 - -0.4 -0.4 - -0.1v

: Temperature deviation

［℃］

Daily Tmean

6 months　*1)

Standard

budget Jan. *3)

Effect of rainfall *4) 0 -0.1 - 0.0 -0.1 - 0.0 0.0 -0.2 - -0.1 -0.1 - 0.0 -0.1 -0.1 - 0.0 -0.3 - -0.2 -0.1 - +0.1

Pt 3 mmφ

HMP155 etc.Pt 3 mmφ

Pt 3 mmφ

HMP155 etc.Pt 6 mmφ

Pt 3 mmφ

HMP155 etc.HMP155

Pt 3 mmφ

HMP155

JMA-95 for

synoptic station

JMA-89 for

old AWS

JMA-04 for

AWS

Horizontal type

alike PVC-03

JMA-1

louvered screen

Pt 3 mmφ Pt 6 mmφ

Notes

Thermometer recommended

Tdev

*1) For the artificially ventilated screens/shields the ventilation speed was measured using a Pitot tube indoors This tube is the same length (100*1) For the artificially ventilated screens/shields, the ventilation speed was measured using a Pitot tube indoors. This tube is the same length (100 mm) as the thermometer (Pt 100 Ω (3 mm in diameter)). In most cases, a 3.2 mm in diameter type was used. However, in case where this size could not be fixed, a shorter 3.1 mm in diameter tube was used.*2) Tdev is in a range between 25% and 75% assuming that the maximum value is 100% and the minimum is 0% for each meteorologicalelement. Positive Tdev is shown in pink and negative in light blue in cases where the value is more than ±0.2 °C. *3) Daily average temperature for 6 months (August, December, January, February, March and April) from the 10-sec. data. The values in ( ) show the minimum and maximum.

9

*4) 1 minute average global solar radiation data when the global solar radiation was 700 W/m2 or more in Aug. *5) 10-min. mov. ave. data when the radiation budget was −50 W/m2 or less in Jan. *6) 10-min. mov. ave. data when the rainfall intensity was Class 3 or higher (i.e., 2 mm or more for 10 minutes) for the 31 days when the total rainfall was 10 mm per day or more.

3.5 Comprehensive evaluation 3/3

Artificially ventilated Naturally ventilatedVentilation

Type

Table 2 Comparative table of operationally effective elements for each screen/shield

Category JMA-95(A) JS-256(A) E-834-Z1(A) TV-150(A) PVC-03(A) PVC-02(A) PFT-02(A) AV-040(N) YG-41003L(N) DTR503A(N) JMA-W1(N)

Electric power supply △ △ △ △ △ △ △ ◎ ◎ ◎ ◎

Periodic replacement

Costperformance

Item

Periodic replacementparts

△ △ △ △ △ △ △ ◎ ◎ ◎ ◎

Ease of installation △ △ ○ ○ ○ ○ ○ ◎ ◎ ◎ △

Thermometer cleaningwork

△ △ ○ ○ ○ ○ △ ◎ ◎ ◎ ◎

performance

Maintenance

Ease of maintenance △ △ ○ ○ ○ ○ △ ◎ ◎ ◎ ◎

Corrosion resistance ◎ ◎ ◎ ◎ △ △ △ △ ◎ ◎ △

Resistance toultraviolet radiation

◎ ◎ ◎ ◎ ◎ ◎ ◎ ◎ △ △ ◎Weatherresistance

Insect resistance ◎ ◎ ○ ○ ○ △ △ △ △ △ △

◎ better ○ normal △ not so good

10

3.5 Comprehensive evaluation 2/3

95 ％

25 ％

75 ％

5 ％

Maximum

Average

Minimum

Fig. 10 Radar charts of Tdev differences related to various meteorological factors for each screen/shield

Artificially ventilated screens/shields

0246810

Tx

SRRa

JS-256(A)

0246810

Tx

SRRa

E-834-Z1(A)

0246810

Tx

SRRa

TV-150(A)

0

2

4

6

8

10

Tx

SRRa

PVC-03(A)

0

2

4

6

8

10

Tx

SRRa

PVC-02(A)

0

2

4

6

8

10

Tx

SRRa

PFT-02(A)

ERTn ERTn ERTn ERTn ERTn ERTn

Naturally ventilated screens/shields Item Tx SR Tn ER Rain

0246810

Tx

SRRa

AV-040(N)

0246810

Tx

SRRa

YG-41003L(N)

0246810

Tx

SRRa

DTR503A(N)

0246810

Tx

SRRa

JMA-W1(N)　　Tdev [℃]

Class

Daily

Tmax

(Aug.)

Concerning

global

solar

radiation

(Aug.)

Daily Tmin

(Jan.)

Concerning

radiation

budget

(Jan.)

Concerning

rainfall

109

0 - 0 - +0.1 - -0.1 -

0 -

0

ERTn

0

ERTn

0

ERTn

0

ERTn

87654 +0.6 - -0.6 -

+0.3 - -0.3 -+0.4 - -0.4 -+0.5 - -0.5 -

+0.2 - -0.2 - -0.1 -

-0.2 -

-0.3 - 321 +0.9 - -0.9 -

+0.7 - -0.7 -+0.8 - -0.8 - -0.4 -

11

4. Discussion

(1) Influences of global solar radiation in August :

● Naturally ventilated screens/shields,

・A maximum positive Tdev of +3.4°C for AV-040(N) is seen.

・This influence produces the largest positive Tdev for AV-040(N) and the smallest for DTR503A(N)

→ The reasons for this are that the screen/shield material has good insulation and the plates on the reverse are black

● Artificially ventilated screens/shields, Tdev for PFT-02(A), PVC-02(A) and PVC-03(A) shows some influence

→ as these screens/shields have no layer of insulating material.

(2) Influences of radiation budget:

● Naturally ventilated screens/shields, a negative Tdev is seen. These negative values are observed for AV-040(N), DTR503A(N) and YG-41003L(N), in that order.

→ The reason is that the influence of radiative cooling differs because they have different thermal capacities and insulating materials.

A ifi i ll il d / hi ld i Td i● Artificially ventilated screens/shields, some negative Tdev is seen

→ due to differences in thermal capacity, insulating layers and the rate of ventilation.

(3) Influences of rainfall:

● Naturally ventilated screens/shields, higher rainfall intensity values give a more remarkably negative Tdev for y , g y g y gDTR503A(N).

→ The reason is that its structure allows the internal thermometer to be seen between the plates from outside, and

that it has a structure in which raindrops tend to remain on the flat edges of the plates.

The structure of YG 41003L(N) in which no influence from rainfall is seen has an internal thermometer covered by

12

The structure of YG-41003L(N), in which no influence from rainfall is seen, has an internal thermometer covered by plates, In addition, the plates gradually become smaller from top to bottom and have an inverted dish shape,

● Artificially ventilated screens/shields, no difference in the influence of rainfall is seen.

5. Conclusions

● Naturally ventilated screens/shields

・ superior in terms of economy and ease of maintenance.superior in terms of economy and ease of maintenance.

・ However, in cases where they are used in low-latitude regions, care is required because some types might be affected by strong global solar radiation.

・ It is also necessary to carefully consider the influence of the radiation budget.It is also necessary to carefully consider the influence of the radiation budget.

・ as some are penetrated by rainwater and do not allow accurate temperature measurement.

Such screens/shields should also be used with a good understanding of their structure andSuch screens/shields should also be used with a good understanding of their structure and characteristics,

● Artificially ventilated screens/shieldsy /

・ an essential requirement to minimize the influence of global solar radiation and the radiation budget is an appropriate insulation structure (insulation material/a heat-insulating layer of air).

・In addition, the horizontal type of artificially ventilated screens/shields requires care on rainy days because its configuration means that it is easily penetrated by wind and

i t

13

rainwater.

ReferencesReferences

・ Brandsma T., van der Meulen J.P., 2007: Thermometer screen intercomparison in De Bilt (the Netherlands), part II: Description and modeling of mean temperature differences and extremes, International Journal of Climatology.

SO ( S O ) f・ ISO (International Standardization Organization), 2007: Meteorology - Air temperature measurements - Test methods for comparing the performance of thermometer shields/screens and defining important characteristics (ISO 17714), First edition.

・ Lacombe Muriel, 2008: Acquisition system used by the Algerian ONM for WMO combined intercomparison of thermometer screens/shields in conjunction with humidity measuring instruments, TECO-2008.

・ WMO, 2008: Guide to meteorological instruments and methods of observation, seventh edition, WMO-No. 8.

Thank you for your time.Thank you for your time.

We would like to measure temperature more accurately all over the world, for our and children’saccurately all over the world, for our and children s

future on the earth.

http://iss.jaxa.jp/shuttle/flight/sts99/photo_hdtv.htmlhttp://photojournal.jpl.nasa.gov/catalog/PIA11066

3.2 Influences of global solar radiation

Fig. 5 Time series representations of temperature for various screens/shields and solar radiation, 16 Aug. 2009 (summer)

( ) T t 3132 33 34

E-834-Z1(A)

PFT-02(A)

PVC-02(A)

(a) Temperature by various

screens/shields

2021 22 23 24 25 26 27 28 29 30 31

［℃］

PVC-03(A)

YG-41003L(N)

AV-040(N)

DTR503A(N)

JMA-W1(N)

TV-150(A)

JS-256(A)

JMA-95(A)

(b) Tdev for naturally ventilated screens/shields

20

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

0 0

0.5

1.0

1.5

2.0

2.5

3.0

℃］

YG-41003L(N)

AV-040(N)

DTR503A(N)

JMA-W1(N)

[h]

screens/shields

-3.0

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

［℃

[h]

(c) Tdev for artificially ventilated screens/shields

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

［℃］

E-834-Z1(A) PFT-02(A)

PVC-02(A) PVC-03(A)

TV-150(A) JS-256(A)

(d) Total global solar

-3.0

-2.5

-2.0

-1.5

1.0

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

600

900

1200

／ｍ2] Global solar radiation

(d） [h]

15

radiation0

300

600

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

［Ｗ／