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The Numerical Predicition Division (NPD) of Japan Meteorological Agency (JMA) has been working on TDCF migration of both surface and upper-air reports.

Surface

Use in NWP

  • Assimilation of BUFR SYNOP reports was started on 16 October 2013.
  • Currently coordinates (latitude, longitude, and elevation) in BUFR is ignored and replaced by coordinates from Volume A, WMO Pub. 9.
  • Current implementation picks BUFR if TAC for the same station is absent;  the weight of BUFRs is little now but will grow when TAC reports are stopped
  • Figure below is the number of stations reporting Any SYNOP (black), Only TAC (red), TAC and BUFR (purple), and Only BUFR (blue), observed at NWP system in JMA.  The number of BUFR (purple + blue) firstly exceeds 50 % of entire SYNOP reports in mid-October 2014.  But there are still 40+% of stations which does not (probably cannot) send BUFR.

 

Image Added

Trouble cases

Missing pressure for geopotential height

Starting at 11Z 23 January 2014, the SYNOP BUFR reports from the station 07497 BOURG ST-MAURICE contained:

  • missing value for 0-07-004 PRESSURE, follewd by
  • extremely large value for 0-10-009 GEOPOTENTIAL HEIGHT.

These values were decoded into 16 bit signed integers.  The missing value was converted to minimum possible value (-32768e1 Pa).  Unfortunately that was treated as valid value since geopotential was not missing.  Then that caused floating point exception in computation of power of (now negative!) pressure.  In the TAC (traditional alphanumeric) reports it was safely assumed geopotential is always missing when pressure is missing.  We are not monitoring later reports regarding this issue, as the NWP system was fixed immediately.  We also contacted the originating country, and they say it will be fixed.

Upper-air

Analysis of incoming data

Format/Headers/Stations as of 2015-01-13

description of algorithm to tell code form and parts

Use in NWP

  • BUFR TEMP in U.S. was once used in assimilation from April 25 2013
  • But it was stopped February 2014 (migration back to TAC)
  • Starting the end of October 2014, the system uses BUFR if TAC is missing for the station/ship

Trouble cases

Geopotential height for US TEMP BUFR

Starting February 2014, most of U.S. TEMP BUFR reports contained unnatural geopotential height.  This issue is explained detail in Errors in BUFR radiosonde data page by FNMOC.

Japan's TEMP BUFR

A few problems were found in TEMP BUFR reports sent from Tokyo.  The TAC-BUFR conversion at RTH Tokyo has to be amended to get rid of the situation, and it is not possible to show specific schedule for now.

  • When the geopotential height of 700 hPa goes below 2400 m, it is reported 1000 m higher than actual.
  • When there are significant levels below or equal to 1000 hPa level (i.e. pressure >= 1000), the pressure is reported 1000 hPa less than actual. This problem was fixed effective 2015-08-18T12Z.
  • When the geopotential height of 1000 hPa goes below MSL, the reported value is same to coded digits in TAC TEMP (512 means 12 m). This problem was fixed effective 2014-02-24T12Z.

The issues are "missing top digit of data", lost in TAC encoding.

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吾輩(わがはい)は猫である。名前はまだ無い。
 どこで生れたかとんと見当(けんとう)がつかぬ。何でも薄暗いじめじめした所でニャーニャー泣いていた事だけは記憶している。吾輩はここで始めて人間というものを見た。しかもあとで聞くとそれは書生という人間中で一番獰悪(どうあく)な種族であったそうだ。この書生というのは時々我々を捕(つかま)えて煮(に)て食うという話である。しかしその当時は何という考もなかったから別段恐しいとも思わなかった。ただ彼の掌(てのひら)に載せられてスーと持ち上げられた時何だかフワフワした感じがあったばかりである。掌の上で少し落ちついて書生の顔を見たのがいわゆる人間というものの見始(みはじめ)であろう。この時妙なものだと思った感じが今でも残っている。第一毛をもって装飾されべきはずの顔がつるつるしてまるで薬缶(やかん)だ。その後(ご)猫にもだいぶ逢(あ)ったがこんな片輪(かたわ)には一度も出会(でく)わした事がない。のみならず顔の真中があまりに突起している。そうしてその穴の中から時々ぷうぷうと煙(けむり)を吹く。どうも咽(む)せぽくて実に弱った。これが人間の飲む煙草(たばこ)というものである事はようやくこの頃知った。
 この書生の掌の裏(うち)でしばらくはよい心持に坐っておったが、しばらくすると非常な速力で運転し始めた。書生が動くのか自分だけが動くのか分らないが無暗(むやみ)に眼が廻る。胸が悪くなる。到底(とうてい)助からないと思っていると、どさりと音がして眼から火が出た。それまでは記憶しているがあとは何の事やらいくら考え出そうとしても分らない。
 ふと気が付いて見ると書生はいない。たくさんおった兄弟が一疋(ぴき)も見えぬ。肝心(かんじん)の母親さえ姿を隠してしまった。その上今(いま)までの所とは違って無暗(むやみ)に明るい。眼を明いていられぬくらいだ。はてな何でも容子(ようす)がおかしいと、のそのそ這(は)い出して見ると非常に痛い。吾輩は藁(わら)の上から急に笹原の中へ棄てられたのである。