409 Report E#ect of replacing the surface meteorological observation system at Syowa Station on the homogeneity of data Tatsuru Sato, Keishiro Higashijima, Kazuya Yasugahira and Eishin Murakata,**- / 0 ;,**- 3 +0 Abstract: The surface meteorological observation system was replaced over two years, +331 and +332, at Syowa Station in Antarctica. The new system has been formally operated since February +st +333. Operation of the old system was continued for one year afterward in order to compare data from both systems. The results of comparison of both systems are as follows: +) The observation data from both systems agree within the accuracy of the system. The homogeneity of old and new data has been preserved.,) However, some observed quantities show di#erences that cannot be disregarded although they are small. -) These di#erences originated from changes of sensor, data-processing method, and installation position. This paper reports the results considering di#erences in observational values obtained from the two systems, characteristics of data and homogeneity of data. : -3.* +331 +332, +333, + + +, - Janan Meteorological Agency, Otemachi +-chome, Chiyoda-ku, Tokyo +** 2+,,. Vol..1, No.-,.*3.1+,,**- Nankyoku Shiryô (Antarctic Record), Vol..1, No.-,.*3.1+,,**-,**- National Institute of Polar Research
410 +. -* +323, + Automated Meteorological Observation System-, AMOS-, AMOS, +33* -3 AMOS, JMA-3/ JMA3/ +332. +.* +333, +,**,;,**- JMA3/ +330 +330 JMA3/, JMA-2* AMOS, JMA-2* JMA3/ + AMOS, -.* +333, +,*** + -+ + AMOS, AMOS, JMA3/ JMA3/ AMOS, JMA3/ +333,***,.,.+. JMA3/ AMOS,
411 HK House Keeping, JMA3/,**, + JMA3/ DCP,,.,. AMOS, JMA3/ AMOS, +* mm JMA3/ -., mm Fig. +. + Schematic diagram of the surface meteorological observation system.
412, +332 Fig.,. Locations of meteorological instruments at Syowa Station. Barometer, sunshine duration meter, pyranometer Wind vane and anemometer, thermometer, hygrometer, visibility meter Sunshine duration meter, pyranometer Snow depth meter AMOS, JMA3/ AMOS, JMA3/ + AMOS, JMA3/ + +* 0 AMOS, + JMA3/ +*
413 JMA3/ AMOS, +, +322 +332,**,,.-.,.-.+.,.,,.-.,. AMOS, JMA3/ +333, +,,*** + +/* m 1 m,*** + JMA3/ JMA3/,.-.-.
414 + JMA3/ AMOS, +, Table +. Sensor specifications in JMA3/ and AMOS, (+/,).
+ JMA3/ AMOS,,, Table +. Sensor specifications in JMA3/ and AMOS, (,/,). 415
416, + - Table,. Data processing in conversion unit and processing unit (+/-).
,, - Table,. Data processing in conversion unit and processing unit (,/-). 417
418, - - Table,. Data processing in conversion unit and processing unit (-/-).
419 JMA3/ *, + + * +*, + + * /,.-... t t t R *.0-0- R + + exp t t. + +* t t i * +*,* + i j-/ j t i R i 0 R R.,, JMA3/ + +,.-./. JMA3/ + JMA3/ +m + AMOS,,.-.0.
420 AMOS, + + JMA3/ + +* JMA3/ AMOS, JMA3/ +m + JMA3/ +*,.-.1. +33*a + +, +* * *+,. ** 31* hpa -* -. +,.,,,.- -.+. AMOS, +333 1 +* +333, +
421 - *.* hpa min a +333, + +333 1 +* +2+*0+ b +333 1 ++,*** + -+,.++10 Fig. -. Percentage distribution of frequency of occurrence of di#erence of station pressure observed by JMA3/ and AMOS, (In case of rate of change in station-pressure *.* hpa/min). (a) Feb. +, +333 July +*, +333 (b) July ++, +333 Jan. -+,,*** 1 +* 1 ++,*** + -+ +,.-.- * -a b * *., hpa *.*, hpa *.+, hpa *.** hpa *.*2 hpa *.** hpa *.+* hpa + + -// AMOS, - + *.- hpa *., hpa, JMA3/ *.+. hpa *.+ hpa *.+ hpa -.,. -.,.+. +, JMA3/,.-.., -* +* *./* *.01 *.2- +.** 0-.* AMOS,,.-.. + +* *.33 +.** -* /*.* -- 0* -.,.,.. -.+ +,.-..
422. +333 1 ++,*** + -+ JMA3/ /* Fig... Relation between rate of change in station pressure observed by JMA3/ and di#erence of station pressure observed by JMA3/ and AMOS, (July ++, +333 Jan. -+,,***). /* AMOS, JMA3/ JMA3/ *.. hpa min + *.-/ hpa+ hpa min + -* + -/ -.,.+ -* JMA3/ AMOS, /* + *.+. hpa + 2.. hpa *.+ hpa *., hpa min *.0,-*+3*,3,*,. -.+ *
423 -.-. -.-.+. / -+ a b /a AMOS, JMA3/ *.+ hpa +../ - *.*0 hpa *.+- hpa,.-./ + AMOS, JMA3/ +m *.* hpa...2 AMOS, *.+ hpa.2., - *.*2 hpa *.+1 hpa /a - -.-.,.,.-.0 JMA3/ +m JMA3/ 3/./../ JMA3/ +m *.+ hpa - JMA3/ +m JMA3/ / a b a b Fig. /. Frequency distribution of di#erence of daily minimum sea-level pressure (a) and di#erence of its appearance time (b), observed by JMA3/ and AMOS,.
424 Table -. - The influence on extreme value with change in response time and sampling number. *.** hpa -.-.+ + -.-.-. /b JMA3/ AMOS, + -3 +, + 1.,- - AMOS, JMA3/ AMOS, JMA3/ +m JMA3/ +m JMA3/ +.* JMA3/ AMOS, +.- -.-... -., JMA3/ + AMOS, -.+ -., *.** hpa *.+* hpa AMOS,
425 AMOS, JMA3/ f x * JMA3/ n n + AMOS, JMA3/ X + X,X n Y Y AMOS, Y + X i f x Y g y g ynf y n + f x n +, - g y 0 n AMOS, n, *.+ hpa /* -+ +0 -.-.+./ +. n, -.-., AMOS,../ JMA3/ *.+ hpa *.+ hpa.2 -+ +..3 *.+ hpa +-..* /a 0 Fig. 0. n + - Succession of probability distribution of di#erence of observation value by change of length of constant pressure period.
426 AMOS, JMA3/ JMA3/ JMA3/ *.+ hpa n, 22 21 -... AMOS, JMA3/ * *., hpa *., hpa JMA3/ -* + -/ *.+ hpa JMA3/ AMOS, JMA3/ + + *.+ hpa../ +* *.+ hpa.2 *.+ hpa +- *.+ hpa 22 +.. + AMOS, +* mm JMA3/ -., mm,.,,,.-
427..+...+.+. +,.-.- * +2 1 *.+ C *.+ C *.. C *.+/ C *.++ C + + + --2 AMOS, JMA3/ *.+/ C + *.+/ C AMOS, JMA3/ 1 *.* C min Fig. 1. Frequency distribution of di#erence of temperatures observed by JMA3/ and AMOS, (in case of rate of change in temperature *.* C/min).
428..+.,.,**, +332 / +333 + AMOS, JMA3/ *.*1 C..+.+ JMA3/ +332. +, 0+/3 *.*/ C +..+.+ DT, AMOS,, JMA3/ Ta Tj Ta DTTj*.+/ +333.,,***. + TaTj DT *.*/ +332.. +332. +, DT*.*/ Ta Tj *.+* AMOS, JMA3/ *.+ C *.+ C *.+/ C AMOS, *.+/ C..,. 0 m s +* mm +,* +2* -., mm.* +330a +330 +* mm /.0 m s AMOS, -., mm..1 m s +330 -., mm. m s JMA3/. 1
429 m s..,.+.,.-.. +, 2 R.* R.*t.* R +2* t +2* R 1* t 1*.* +* + R.* JMA3/ 1* *.0-1* R.* +2* R +2* AMOS, 0* *./. *.,2 R +2* R.* 0* /,..,.,. 3 +.0,.-.. /* AMOS, JMA3/ AMOS, AMOS, JMA3/ 2 Fig. 2. R.*.* R +2* +2* R 1* 1* R.*.* +* + Response of temperature observed over time in response to a step-shaped input.
430 3 JMA3/ /* Fig. 3. Relation between rate of change in temperature observed by JMA3/ and di#erence of temperatures observed by JMA3/ and AMOS,. *.// *.*- C+ C min AMOS, JMA3/ + //..,.+..-...-.+.,.-./ + - JMA3/ + m AMOS, *.*+ C *.*/ C +..-.,.,.-.0 JMA3/ +m JMA3/ JMA3/ +m 3+.0 3+./ JMA3/ JMA3/ *.+ C 2.+ 2., *., C *.-
431 - JMA3/ +m JMA3/ *.*+ C +..-.-. +* DK a b AMOS, JMA3/ AMOS, +* a b Fig. +*. Frequency distribution of di#erence of time of daily extreme value. DK * AMOS, DK * AMOS, DK+ - AMOS, JMA3/ AMOS, JMA3/ +m JMA3/ +m JMA3/ JMA3/ + + *.- *./ JMA3/ JMA3/..-.....-.-
432..-.- JMA3/ + DK + ++ a AMOS, DK+ b DK+ c AMOS, DK +. AMOS, ++a AMOS,. AMOS, + + AMOS, ++b c ++ Fig. ++. a AMOS, b c JMA3/, JMA3/ 3 : : : : : : : : : Relation between temperature change pattern and time of daily maximum (or minimum) temperature.
433 Table... Di#erence of daily maximum (minimum) temperature. AMOS, JMA3/. AMOS, AMOS, JMA3/ *.*- C *.*0 C... AMOS, JMA3/ *.+ C *./ C AMOS, +2* JMA3/ 1* AMOS, JMA3/ 0* + // JMA3/ + + *.+ C
434 2.. 2./ +* AMOS, JMA3/ *.*- C *.*0 C AMOS, JMA3/ *.*1 C *.+0 C /. + AMOS, Dewcel JMA3/,.,, /.+. /.+.+. +302, +31, +0./ C *.* C +,./ C +330b +, +333 1,. 0 1,/ ++ +
435 +- 2*32 G G Fig. +,. +, +333 1,. *0 LT,/ ++ LT Example of observation of disorder of dew-point temperature caused by change of phase of LiCl aqueous solution (July,., +333, *0 LT July,/, +333, ++ LT). +- G.,3. G -.,2 Fig. +-. Scatter-diagram of dew-point temperature measured by Dewcel, and di#erence of dew-point temperature observed by electric hygrometer and Dewcel.
436 +- G G G,/ C *.. C *.- C +./ +.2 G+, C G G +/ C +, C + DHd DHe DHe DHd +- 3/DHe, +DHd * + DHd +-, /.+.,. /.+.+ /.+.+ G G P TDd DTD P TDd DTD PP -- +. P P G G TDd+/ C,/ C G G TDd+- C,* C * C +, D
437 +. +- G G +- G G a GG b G G Fig. +.. Succession of di#erences of dew-point temperature at time of change of phase. D G +/ PP TDd TDd PP DDTD DTD G G G G *.,. 3/ *.*1 +/ C + C +/ C /.+.-. +0 Washburn +3,-
438 +/ C + C +/ GG G G 3/ Fig. +/. Scatter-diagram of succession of dew-point temperatures with change of phase of LiCl aqueous solution. +0 Fig. +0. Di#erence between theoretical value and practical value of dew-point temperature at critical point of LiCl aqueous solution.
439 /.+., G G +/ C *.-. *.*. 3/ +/ +330b +1 C +,./ C G G +,./ C +32* /.+... +1 +* C / +* +, 1 +* /.,.,.-.0 JMA3/ + m JMA3/ 3,.1 1.- JMA3/ + m + - JMA3/ + m JMA3/ *.+ *.3 + AMOS, /.+
440 +1 Fig. +1. Comparison of monthly mean and minimum relative humidity observed by electric hygrometer and Dewcel. /.-. +/ C +* C / +* +, 1 +330b JMA3/ + + + 1.- +* 0. +
441 JMA3/, AMOS, +* JMA3/ +* +* 0.+. 0.+.+. JMA3/ +2, m s, m s *.., m s,*, m s +* m s +2 JMA3/ JMA3/ 2001 Fig. +2. Scatter-diagram of wind speed measured by JMA3/, and di#erence of wind speed observed by JMA3/ and AMOS,.
442 *.*+ m s *.++ m s +* m s AMOS, JMA3/,.* *.+ 33 / JMA3/ *., m s -.* +,**,,**, +332. + +333 +,/ JMA3/ AMOS, +1 JMA3/ 0.+.,. +3 +*,11 JMA3/ + +,/ m s +,/ m s +2.2 m s JMA3/.-.- m s / JMA3/ AMOS, Table /. Di#erence of daily maximum and mean wind speed observed by JMA3/ and AMOS,. +3 JMA3/ JMA3/ Fig. +3. Scatter-diagram of gust speed measured by JMA3/, and di#erence of gust speed observed by JMA3/ and AMOS,.
443.-,/ m s 0.+.-, m s *.0, m s *./- m s, m s +* m s *.+- m s *.,/ m s +* m s,/.0 m s AMOS, JMA3/ -.- *.+ 33 0.+.+ 0.+.-.,/ m s AMOS, AMOS, + +,11 AMOS,,* AMOS, a b + *.+ +.+ m s *.* m s AMOS,, m s +* m s + +,/ m s,/.,,/./ m s,/.0 m s,/ m s AMOS, +,* AMOS, a + b + Fig.,*. Frequency distribution of gust speed observed by AMOS,.
444 + AMOS, + + +,+,* m s +.,,/ +.+,* m s + +/ m s,/./ m s +.2 +,/./ m s,/./ m s -* m s,/ + + + AMOS,,/.0 m s /+., m s + AMOS,,**, -,+ AMOS, + + + + +,/ Fig.,+. Ratio of peak gust in last + min against instantaneous wind speed, observed by AMOS,.
445 0.,. -/- JMA3/,, JMA3/ +* JMA3/ V+ AMOS, JMA3/ V+, m s +* m s *.*+ m s *.++ m s +* m s AMOS, JMA3/ V+ +.3 *., 33 0.+.+ AMOS, JMA3/ +* m s AMOS, JMA3/ *.0 *.-,- JMA3/ V+,/ m s -* m s AMOS, JMA3/ +. -- AMOS, JMA 3/ +/ m s AMOS, +/ m s JMA3/ JMA3/ JMA3/ AMOS,,, Fig.,,. JMA3/ JMA3/ AMOS, JMA3/ AMOS, JMA3/ V+ +* m s Scatter-diagram of daily maximum wind speed measured by JMA3/, and di#erence of daily maximum wind speed observed by JMA3/ and AMOS,.
446,- AMOS, JMA3/ JMA3/ V+ Fig.,-. Number of days according to rank of daily maximum wind speed observed by JMA3/ and AMOS,. / AMOS, JMA3/ JMA3/ V+ *., m s 0.-. 0.-.+.,. +*,11 JMA3/, m s AMOS,, m s, m s / m s / m s JMA3/ AMOS, CW + /,* m s 0 2 / m s +1--1,/ JMA3/ -0 AMOS, JMA3/ CW CCW 3/
447,. JMA3/ -0 JMA3/ AMOS, JMA3/ Fig.,.. Wind roses, according to rank of wind speed as measured by JMA3/, observed by JMA3/ and AMOS,.,/ Fig.,/. JMA3/ / m s JMA3/ -0 3/ Distribution of wind direction by JMA3/, and di#erence of wind direction observed by JMA3/ and AMOS, (in case of wind speed / m/s or more). + - +* +/ / 3,,,1 1 2 *./ *.1
448 0.-.,.,0 JMA3/ +*,12 + + m s + -0 + -0* +/ +,./, +. -*./ / 2 AMOS,, -2 / 2 -*,/,0 + -0-0* +/ Fig.,0. Distribution of swaying width as a function of peak gust and the wind direction.
449 0..., m s *.., m s +* m s,.* JMA3/ JMA3/ *., m s -.*, m s *.0, m s +* m s -.- JMA3/ / 3-0 AMOS, JMA3/ *.1 CCW 1. AMOS,, +33* JMA3/ + +,,.-,.-., 1.+.,1a,*** + +/*,** 0,*** +
450 +*., h,.1 +333, +,,1./ h +.2 0,1,*** + a : : b : : Fig.,1. Distribution of di#erence of hourly sunshine duration as a function of solar position (January,***). (a) Comparison between tracking type which was installed on the roof of the meteorological instrument hut and on top of Hata hill. (b) Comparison at the same position at top of Hata hill between tracking type and rotating type. Size of plotted marks is proportionate to di#erence. Table 0. 0 Di#erence of sunshine duration with change of sensor and change of observation location.
451 1.,.,1b a,*** + 0,*** + -11.* h -1-., h -.2 h +.*,2 +333,,*** +,.-.- / --0* 0 +..* h *.2 1.,.+.,2,3,2 / Fig.,2. Frequency distribution of di#erence of hourly total sunshine duration between tracking type and rotating type (in case of solar elevation angle / or more).
452,3 / /* Fig.,3. Relation of sunshine duration observed by tracking type, and di#erence of hourly total sunshine duration observed by tracking type and rotating type (in case of solar elevation angle / or more). *.+ *.3 *.- *./ *.*/ *.- *./ 1.,.,. -* +333,,*** + a b a -+
453 +333,,*** + /, / + 0 +..* h *.2,*** + +.* -* a b Fig. -*. Solar positions where di#erence of sunshine duration observed by tracking type and rotating type occurred. -+ AMOS, / Fig. -+. Percentage of observations showing di#erence in sunshine duration with solar declination (only northerly sensor of AMOS, used; in case of solar elevation angle / or more).
454 0,/1 1.,.-.,+ *-,,/+-/ -* -*,1b 1.,... - +* - 1 * * +*,* - + 0 0. * +.,, + +* +* -* - + 33./ + /,-0+/ +*,* Table 1. 1 Di#erence of sunshine duration with change of sampling interval. 1.-. -,
455 -, / Fig. -,. Di#erence of monthly total sunshine duration observed by JMA3/ and AMOS,. / / +* ++ + +, +*,,*** + / +*,,*** + 1...,*** + +*., h,.1 *.2+.* +333, +* +,. +. h,*** +
456 2. +, JMA3/ + AMOS,, AMOS, JMA3/ JMA3/,.-., 2.+. -- a+ a-,*** + JMA3/ + +3 a+ a, a- *.* kj m, +.2 kj m, 2, 00./ 02.+,, 3,.+ 1.3 / *.. *./, *.,,.1 2
457 --,*** + + a JMA3/ JMA3/ a+ a, a- b +,* W m, JMA3/JMA3/ b+ b, b- Fig. --. Frequency distribution of di#erence of solar radiation observed at rooftop and hilltop (Jan.,***). (a+) (a-) +3 days in Jan.,***. (b+) (b-) Direct solar radiation less than +,* W/m,. +,*W m, -- a+ a- b+ b- 2 +.1 b+ b- a+ a- +.2 kj m, b+ b- 2
458,.* 3 JMA3/ AMOS,,*** + AMOS, JMA3/,./ JMA3/ -- JMA3/ -. JMA3/ JMA3/ JMA3/ a b 2 JMA3/,*** + +3 Table 2. Di#erence of solar radiation observed by JMA3/ during +3 days in January,***. 3 Table 3. AMOS, JMA3/ Global solar radiation observed by AMOS, and JMA3/.
459 -. JMA3/,*** + a b a b Fig. -.. Di#erence of global solar radiation observed by JMA3/ at rooftop and hilltop (Jan.,***). The abscissa is (a) solar elevation angle, (b) solar azimuth angle.,*** + +3 +.* h -.a +*-* -*. 2 -*..* +* -.b 2.,. -/, +/ AMOS, +/ JMA3/ -0 AMOS, JMA3/ JMA3/ a b
460 + +.* h a AMOS, --* -* b,/-/ -0a,*, * -/, AMOS, JMA3/ Fig. -/. Solar positions where di#erence of global solar radiation was, or more. -0 a b JMA3/ a --*-* b,/-/ Fig. -0. Di#erence of global solar radiation observed at rooftop. The abscissa is (a) solar elevation angle, (b) solar azimuth angle.
461-1 Fig. -1. Frequency distribution of di#erence of global solar radiation observed by JMA3/ and AMOS, at rooftop. -.a +/ -0b,1*-* AMOS, +./ -1 * AMOS, *.**/ MJ m, //1,,2.02 MJ m, *.1 3 2.-.,.1,*** + JMA3/ *.1 2 3.
462 AMOS, JMA3/ *.+ C AMOS, AMOS,,*** + JMA3/ AMOS, +.* +333, +333 +, JMA3/ +* AMOS, JMA3/ Table +*. Comparison of statistics of AMOS, and JMA3/(annual values).
++ AMOS, JMA3/ Table ++. Comparison of statistics of AMOS, and JMA3/ (monthly values). 463
464 AMOS, JMA3/ +* ++ 2 +* ++ +33*a 2 JMA3/,*** + +*. JMA3/ +*.+. +, + cm +333, +,*** + -+ +*.+.+. + + +** m + m -** m,* m +* m 3 + 3
465-2 +*.+.,. -2-3 NE -2 -** m +* m -3, m -2 +332 Fig. -2. Installation point of snow depth meter and snow pole at Syowa Station.
466 +*.+.-. S N +* cm /, +/ -* db +*,* db,* db +./, +333 1 + -3 +333 1 +, 2 +* +/ db 3 +* +* db -3 +333 1 +, Fig. -3. Time series of reliability level and noise level on snow depth meter (July +333 Dec. +333).
467 ++ *./ +*.+... +333, +,*** + -+.* -0/.0 *.10 *.-2 *.+- 33.* Fig..*. Comparison of snow depth between snow pole (above sea ice) and snow depth meter (Syowa Station).
468 +*.,. AMOS, WIVIS JMA3/ +,.+ -., +333 /,. JMA3/ WIVIS JMA3/, m WIVIS / m WIVIS JMA3/ WIVIS - km / - *0 LT WIVIS JMA3/ WIVIS JMA3/.011 +33*b.02*.02* JMA3/ +, Fig..+..+ JMA3/ Comparison of visibility range between observation by person and JMA3/.
469., JMA3/ WIVIS +333 /, +, LT /. ** LT JMA3/ WIVIS Fig..,. Comparison of visibility range with blizzard among JMA3/, WIVIS and observation by person (May,, +333, +, LT May., +333, ** LT). +, Table +,. Comparison of present weather between observation by person and weather sensor. JMA3/ JMA3/
470, - JMA3/ 31.+ -* 1/.3 21.0.,.3 2/.2, -3.*.*.+,**- :.* +333.1 +1+,1+.,**, : -3 +332.0 -+2-10. +33*a : +,. p. +33*b : 2.31 p. +330 : 0-,.-,20.,*** : +333 CD-ROM.,**, :,**, +2+ p. +31, : No..1+-. +332 : +332 +0* p.
471 +332 : JMA3/ +* +33* : /1,/-,03. +322 : +330 : 0-,/-,/0. +330a : +2/ +-,.. +330b : +2/,/ -0. Washburn, E.W. (+3,-): International Critical Tables of Numerical Data, Physics, Chemistry and Technology, -. London, U.S. National Research Council,... p. +32* : No. //*1.