Report on the Quality of Land Surface Observations in Region V

 

 

July  – December 2001

 

 

Report No. 10

 

 

 

 

 

 

 

 

 

 

 

 

 

 

WMC Melbourne

Lead Centre for Monitoring of the Quality of Land Surface Observation in RA-V

 

 

 

Data Management Section

Central Operations & Systems Branch

Bureau of Meteorology, Australia

 

 

Distribution List

Mr D. Schiessl Director, World Weather Watch, WMO
Dr A.I. Gusev President CBS
Dr E. I. Sarukhanian WWW Department, WMO
Mr S. L. Woon  President of RA V
Mr F. Lalaurette ECMWF
Mr I. Gitonga  Kenya Meteorological Department
Mr H. Sasaki Japanese Meteorological Agency
Mr A. Rabiolo Servicio Meteorologico Nacional, Argentina
Dr B. Ballish NCEP, Washington
Mr G. Verner Canadian Meteorological Centre
Mr B. Richter  Deutscher Wetterdienst, German
Mr H. Benichou  Meteo-France
Dr B. Macpherson UK Meteorological Office
Focal Points for Data Quality Monitoring in RA-V

 

 

For further information or comments on this report please contact:

 

Data Management Section

Central Operations & Systems Branch

Bureau of Meteorology

G.P.O. Box 1289K

Melbourne, VIC 3001          

Australia

 

Email: stdm@bom.gov.au

 

 

 

 

 

 

 

 

 

1.         Introduction

 

Within the Data Management Section of the Bureau of Meteorology lie responsibilities for collecting a full set of meteorological data in real-time from the WMO Global Observing System, and for making such data available to the Analysis-Prognosis models along with some indication as to reliability of report content.

 

Real-time judgement as to whether a reported element be assimilated by models relies largely on first guess fields, supplemented by observations from any neighbouring stations. Additionally, listings of platforms, which are currently considered suspect, are presented to the Analysis model.

 

To monitor platform performance, and also to expose likely positional errors, selected reported elements are paired with the interpolated first-guess value from the global model (6 hour forecast field) and analysed statistically each 6 months in a format which accords with the CBS recommended standards for the exchange of monitoring results. All observations used are unvalidated or "raw" data.  This report covers a consolidated list of the suspect stations for the period July to December 2001.  The locations of the suspect stations are shown in Figure1 and diagrams of the residuals for each of station are in Figures 2-7.

 

As part of WMO responsibilities as a WMC, copies of this report are made available to major GDPS Centres participating in data monitoring activities.

 

 

2.         Monitoring Methods

 

The decision as to whether a station is ‘suspect’ is from determination of the deviations of Mean Sea Level Pressure (MSLP) from the GASP first-guess fields (observation minus Guess), hereafter called O-G.  Deviations are accessed relative to the first guess fields.

 

To achieve more complete reporting profiles for the investigation of suspect stations, observations were not retrieved for statistical analysis until 24 hours after real-time, thus not

all values used in such computations may have been available to the assimilation processing.

 

The selection criteria for deciding whether a station is suspect or not are as follows:

 

Number of observations (NOBS) >= 120, and one or more of the following:

 

1. the mean of O-G    |BIAS| >= 3.0 hPa

2. the standard deviation of O-G     SD >= 5.0 hPa

3. the percentage of gross errors    PGE >= 25%

 

BIAS and SD are calculated excluding gross error data.

 

 

3          Monitoring Results

 

Table 1 contains a list of synoptic stations, which are considered to have reported suspect observations of mean sea level pressure (MSLP) during the 6 months.

 

WMO REGION 5        

 

 STN NO.   LAT    LONG  HT(M) TIME  ELEM   NOBS   NGE  PGE     SD    BIAS     RMS

 

  48632    4.5   101.4   1545  ALL  MSLP    263     0    0    1.5     3.9     4.2

  92010   -6.1   145.4   1587  ALL  MSLP    255     0    0    1.1     8.3     8.4

  94997  -53.1    73.7     13  ALL  MSLP    359     0    0    2.6    -3.0     4.0

  96947   -8.0   112.7    526  ALL  MSLP    220     0    0    1.2     3.1     3.4

  97008    3.6   125.5     38  ALL  MSLP    466     0    0     .7     3.1     3.2

  97378  -10.7   123.1      1  ALL  MSLP    266   211   79    1.2   -14.2    14.2

 

Table 1. List of land surface stations reporting suspect observations of mean sea level pressure over the period July to December 2001.

 

 

3.1 Suspect Stations

 

3.1.1 Retentions

 

The following stations have reappeared as suspect station from the previous six-month period.

 

92010 Goroka, New Guinea

A constant positive bias throughout the period indicates a possible incorrect station elevation, which should possible be lower than published.

 

97008 Tahuna, Indonesia

A constant positive bias of 3.1 hPa for the entire six months.

 

97378 Rote, Indonesia

With a large negative bias of –14.1 hPa and an elevation of only 1m, it is suggestive that there is a problem with the barometer readings or settings.

 

 

3.1.2 Additions

 

Several new suspect stations have appeared for the first time.

 

48632 Cameron Highlands, Malaysia

This station started reporting in September 2001, and from that date onwards displayed a consistent positive bias.

 

94977 Heard Island, Australia

The AWS has displayed an erratic negative bias during the entire period. The biases seem to shown some form of cyclicity, but this may be spurious. Not much can be done about this very remote station. It is quite possible that the model is incorrect, rather than the observations being in error, as there are no neighbouring stations for thousands of kilometers.

 

96947 Malang/Abdul Rahkman, Indonesia

Seems to be getting worse during the six-month period. The MSLP bias has always been positive, but started out being only 1 or 2  hPa high, but was closer to 3 or 4 hPa high by December.

 

3.1.3 Deteriorations and/or Improvements

 

There are no deteriorating stations or improving stations for this period.

 

3.1.4 Removals

 

Two suspect stations from the previous report have not reappeared:

 

96753 – Bogor/Dermaga, Indonesia

This station had a four month period, from August to November, when it reported no observations. There were only four observations reported for the entire month of December. All that can be said is that the negative 6.0 hPa bias for the previous six-months appears to be recurring in the few reports available this period.

 

97126 – Masamba, Indonesia

The negative bias for this station has dropped from 3.3 hPa during the last six months to less than 3.0 hPa during this period, so it no longer qualifies as a suspect station. However it should be noted that the bias this month is only just below the detection criteria.

 

4. Summary

 

Three new stations appear for the first time in this report, and three stations continue to be present.  Additionally two stations in the previous report are now removed from suspect

Status.

 

                                     

 

 

 

                            MONITORING OF SURFACE DATA

 

                               MONTHLY SUSPECT LIST

 

                         MONITORING CENTRE: NMC MELBOURNE

 

 

                              JULY to DECEMBER 2001

                              *********************

 

 

          MONITORING PROCEDURES   :-

 

 

          PERIOD                  :  SIX CALENDAR MONTHS

 

          DATA MONITORED          :  REPORTS FROM EACH UNIQUE IDENTIFIER

                                     FOR SYNOP

 

          AREA                    :  FULL GLOBAL

 

          STANDARD OF COMPARISON  :  +6H FIRST GUESS FIELD FROM THE AUSTRALIAN GLOBAL

                                     ASSIMILATION PREDICTION (GASP) MODEL

 

          OBSERVATION TIMES       :  00, 06, 12, 18 UTC

 

          ELEMENT MONITORED       :  MSLP - MEAN SEA LEVEL PRESSURE (hPa)

 

          PARAMETERS MONITORED    :-

 

 

                      NOBS        :  NUMBER OF OBSERVATIONS RECEIVED (WITH FIRST

                                     GUESS AVAILABLE) EXCLUDING DUPLICATES

 

                      NGE         :  NUMBER OF OBSERVATIONS WITH GROSS ERRORS

 

                      PGE         :  PERCENTAGE OF OBSERVATIONS WITH GROSS ERRORS

 

                      SD          :  STANDARD DEVIATION OF DIFFERENCE BETWEEN

                                     OBSERVATIONS AND BACKGROUND FIELD

                                     EXCLUDING OBSERVATIONS WITH GROSS ERRORS

 

                      BIAS        :  MEAN OF DIFFERENCE BETWEEN

                                     OBSERVATIONS AND BACKGROUND FIELD

                                     EXCLUDING OBSERVATIONS WITH GROSS ERRORS

 

                      RMS         :  ROOT MEAN SQUARE OF DIFFERENCE BETWEEN

                                     OBSERVATIONS AND BACKGROUND FIELD

                                     EXCLUDING OBSERVATIONS WITH GROSS ERRORS

 

          GROSS ERROR LIMIT       :  15.0 hPa

 

 

          SELECTION CRITERIA      :  NOBS >= 120  AND ONE OR MORE OF THE FOLLOWING:

                                     1. |BIAS| >=  3.0hPa

                                     2. SD     >=  5.0hPa

                                     3. PGE    >=  25%

 

           MONTHLY LIST OF SUSPECT LAND SURFACE STATIONS FOR JUL to DEC 2001

           -------------------------------------------------------------------

 

 WMO REGION 1        

 

 STN NO.   LAT    LONG  HT(M) TIME  ELEM   NOBS   NGE  PGE     SD    BIAS     RMS

 

  61492   16.1   -13.5     18  ALL  MSLP    249     0    0    1.8     4.5     4.8

  62271   24.2    23.3    436  ALL  MSLP    395     0    0    1.6     3.4     3.7

  63170    9.5    44.1   1326  ALL  MSLP    132     1    1    2.0     7.8     8.0

  63175    9.5    45.6   1032  ALL  MSLP    124     0    0    1.9     7.4     7.6

  63333   11.1    39.7   1903  ALL  MSLP    179     0    0    2.6     5.0     5.6

  63478    5.9    43.6    295  ALL  MSLP    152     1    1     .9     5.7     5.8

  68016  -19.3    12.7      0  ALL  MSLP    213     0    0    3.5     3.6     5.1

 

 WMO REGION 2        

 

 STN NO.   LAT    LONG  HT(M) TIME  ELEM   NOBS   NGE  PGE     SD    BIAS     RMS

 

  24671   64.0   135.9    402  ALL  MSLP    697     4    1    4.0     3.1     5.0

  24688   63.3   143.1    741  ALL  MSLP    708    62    9    5.0     3.5     6.1

  30967   49.9   115.8    623  ALL  MSLP    538     1    0    2.3    -5.9     6.3

  36096    0.0  1000.0  10000  ALL  MSLP    473    37    8    5.0     3.0     5.8

  38933   37.8    68.8    429  ALL  MSLP    476     2    0    2.2     5.6     6.0

  40700   39.7    48.1     45  ALL  MSLP    567     2    0    1.7    -4.6     4.9

  40726   36.8    45.7   1385  ALL  MSLP    582     0    0    2.3     3.1     3.8

  40741   36.5    61.2    236  ALL  MSLP    573     0    0    2.0    -4.2     4.6

  41396   16.0    49.0    700  ALL  MSLP    257     0    0    1.3     3.9     4.1

  44207   50.4   100.2   1687  ALL  MSLP    703    27    4    5.0     3.3     6.0

  44213   49.7    94.4   1232  ALL  MSLP    705    47    7    5.2     1.4     5.3

  44214   49.0    90.0   1714  ALL  MSLP    688    32    5    5.4     -.4     5.4

  44215   49.1    91.7   1591  ALL  MSLP    684    55    8    5.7      .6     5.7

  44218   48.0    91.7   1406  ALL  MSLP    707    46    7    6.1    -1.8     6.3

  44225   48.7    98.3   1723  ALL  MSLP    715   105   15    5.4     3.1     6.2

  44230   49.6   102.0   1236  ALL  MSLP    708    23    3    4.0     3.5     5.4

  44232   49.4   102.7    933  ALL  MSLP    713    16    2    4.4     3.1     5.4

  44265   46.1    91.6   1186  ALL  MSLP    668    63    9    4.4     5.4     7.0

  44272   47.8    96.8   1753  ALL  MSLP    706    10    1    5.7     -.6     5.7

  44275   46.8    98.1   2255  ALL  MSLP    701    34    5    5.8     1.6     6.0

  44284   46.7   100.1   2117  ALL  MSLP    709    74   10    5.4     3.9     6.7

  44285   46.9   102.8   1655  ALL  MSLP    708     7    1    4.8     3.1     5.7

  50727   47.2   119.9   1028  ALL  MSLP    731     0    0    2.2     3.0     3.8

  51156   46.8    85.7   1294  ALL  MSLP    729     0    0    2.7     3.6     4.5

  51334   44.6    82.9    321  ALL  MSLP    726     2    0    3.4     3.6     4.9

  51379   44.0    89.6    794  ALL  MSLP    726     3    0    3.8     3.2     5.0

  51463   43.8    87.6    919  ALL  MSLP    731     1    0    3.6     3.3     4.9

  51495   43.5    91.6    874  ALL  MSLP    727    57    8    2.6     7.7     8.1

  51818   37.6    78.3   1376  ALL  MSLP    727     7    1    3.5     3.1     4.6

  52378   41.4   102.4    960  ALL  MSLP    727     0    0    2.2     3.0     3.8

  52436   40.3    97.0   1527  ALL  MSLP    727     5    1    3.5     3.7     5.1

  52495   40.8   104.5   1329  ALL  MSLP    731     0    0    2.3     3.4     4.1

  52533   39.8    98.5   1478  ALL  MSLP    731     5    1    3.4     4.3     5.5

  52652   38.9   100.4   1483  ALL  MSLP    731     8    1    3.7     3.9     5.3

  53192   44.0   114.9   1128  ALL  MSLP    731     0    0    2.2     3.5     4.2

  53352   41.7   110.4   1377  ALL  MSLP    727     0    0    2.4     3.6     4.3

  53480   41.0   113.1   1416  ALL  MSLP    729     0    0    2.2     3.2     3.8

  54587   39.0   123.2     10  ALL  MSLP    716     3    0    1.3    -4.3     4.5

  56287   30.0   103.0    629  ALL  MSLP    731     0    0    1.9     3.2     3.7

 

 WMO REGION 3        

 

 STN NO.   LAT    LONG  HT(M) TIME  ELEM   NOBS   NGE  PGE     SD    BIAS     RMS

 

  80099    7.1   -70.7    128  ALL  MSLP    240     0    0    1.4    -5.5     5.6

  80315    3.0   -75.3    443  ALL  MSLP    477     0    0    2.1    -4.0     4.5

  82353   -3.2   -52.2     74  ALL  MSLP    461     0    0    1.2    -3.2     3.4

  82765   -7.3   -47.5    193  ALL  MSLP    510     0    0    1.5     4.3     4.6

  83214  -10.3   -54.9    285  ALL  MSLP    501     0    0    5.0    -4.5     6.7

  83319  -14.7   -52.3    315  ALL  MSLP    505     0    0    1.8     4.5     4.8

  83361  -15.6   -56.1    151  ALL  MSLP    496     0    0    1.7     3.5     3.9

  83773  -23.1   -48.9    793  ALL  MSLP    525     3    1    4.1    -7.5     8.6

  84401   -5.2   -80.6     55  ALL  MSLP    625     1    0    2.4     6.1     6.5

  84440   -6.1   -77.2    792  ALL  MSLP    124     0    0    2.9    -3.6     4.6

  84452   -6.8   -79.8     34  ALL  MSLP    611     1    0    1.5     3.7     4.0

  84455   -6.4   -76.4    282  ALL  MSLP    457     2    0    2.3     7.8     8.1

  84501   -8.1   -79.0     30  ALL  MSLP    467     0    0    1.3     5.4     5.6

  84628  -12.0   -77.1     13  ALL  MSLP    654     0    0    1.1     4.0     4.2

  84782  -18.1   -70.3    458  ALL  MSLP    495     0    0    1.8     9.4     9.6

  85041  -11.0   -68.8    235  ALL  MSLP    335     0    0    1.9     6.2     6.5

  85141  -14.5   -67.6    204  ALL  MSLP    337     0    0    2.0     4.2     4.7

  85365  -22.0   -63.7    645  ALL  MSLP    328     1    0    2.9     3.9     4.9

  85394  -22.8   -64.3    381  ALL  MSLP    245     1    0    2.8     3.6     4.6

  85406  -18.4   -70.3     55  ALL  MSLP    721     0    0    1.8     6.3     6.6

  85418  -20.5   -70.2     48  ALL  MSLP    715     0    0    1.4     5.0     5.2

  85442  -23.4   -70.4    140  ALL  MSLP    724     0    0    1.5     3.7     4.0

  87222  -28.6   -65.8    454  ALL  MSLP    715     0    0    2.5    -3.5     4.2

 

 WMO REGION 4        

 

 STN NO.   LAT    LONG  HT(M) TIME  ELEM   NOBS   NGE  PGE     SD    BIAS     RMS

 

  71048   61.6  -125.8    610  ALL  MSLP    698     1    0    2.9     4.7     5.5

  71506   67.0  -136.2    720  ALL  MSLP    724     0    0    2.8    -3.1     4.2

  72375   35.1   -11.2   2139  ALL  MSLP    698    17    2    5.4    -1.0     5.5

  72376   35.2  -111.8   2192  ALL  MSLP    692     0    0    3.7     4.0     5.5

  72462   37.4  -105.9   2299  ALL  MSLP    712     5    1    4.4     6.2     7.6

  72475   38.4  -113.0   1536  ALL  MSLP    688     0    0    3.5     3.7     5.1

  72486   39.3  -114.8   1909  ALL  MSLP    692     1    0    3.8     3.5     5.2

  72487   37.6  -114.5   1335  ALL  MSLP    675     0    0    3.1     3.8     4.9

  72570   40.5  -107.5   1915  ALL  MSLP    630     2    0    3.7     6.3     7.3

  72578   42.9  -112.6   1365  ALL  MSLP    700     1    0    4.0     4.2     5.8

  76118   30.4  -109.7   1040  ALL  MSLP    177     2    1    2.4   -11.1    11.3

  76220   29.0  -107.8   1870  ALL  MSLP    309    45   15    2.7     9.4     9.8

  76243   28.7  -100.5    250  ALL  MSLP    496     0    0    2.0     3.4     4.0

  76323   26.9  -105.7   1744  ALL  MSLP    379    13    3    3.4     8.3     9.0

  76539   22.1  -101.0   1870  ALL  MSLP    446     0    0    2.4    -3.6     4.3

  76687   19.5   -96.9   1389  ALL  MSLP    622     0    0    1.6     4.2     4.5

  76743   18.0   -92.9     10  ALL  MSLP    433     0    0    1.3     5.8     5.9

  76762   17.5   -99.5   1865  ALL  MSLP    372     0    0    1.6    -4.3     4.6

  76843   16.8   -93.1    528  ALL  MSLP    526     1    0    1.2     5.7     5.9

  76855   15.6   -96.5     43  ALL  MSLP    303     0    0    1.8    -4.0     4.4

  76903   14.9   -92.3    182  ALL  MSLP    548     0    0    1.4     5.8     6.0

 

 WMO REGION 5        

 

 STN NO.   LAT    LONG  HT(M) TIME  ELEM   NOBS   NGE  PGE     SD    BIAS     RMS

 

  48632    4.5   101.4   1545  ALL  MSLP    263     0    0    1.5     3.9     4.2

  92010   -6.1   145.4   1587  ALL  MSLP    255     0    0    1.1     8.3     8.4

  94997  -53.1    73.7     13  ALL  MSLP    359     0    0    2.6    -3.0     4.0

  96947   -8.0   112.7    526  ALL  MSLP    220     0    0    1.2     3.1     3.4

 

 STN NO.   LAT    LONG  HT(M) TIME  ELEM   NOBS   NGE  PGE     SD    BIAS     RMS

 

  97008    3.6   125.5     38  ALL  MSLP    466     0    0     .7     3.1     3.2

  97378  -10.7   123.1      1  ALL  MSLP    266   211   79    1.2   -14.2    14.2

 

 WMO REGION 6        

 

 STN NO.   LAT    LONG  HT(M) TIME  ELEM   NOBS   NGE  PGE     SD    BIAS     RMS

 

  06253   56.4     2.1     34  ALL  MSLP    516     0    0    1.1    -4.0     4.2

  15292   45.4    22.3    242  ALL  MSLP    731     0    0    1.4     3.3     3.6

  40296   31.0    35.5   -350  ALL  MSLP    676     1    0    1.2     3.6     3.8

 

 WMO REGION ANTARCTICA

 

 STN NO.   LAT    LONG  HT(M) TIME  ELEM   NOBS   NGE  PGE     SD    BIAS     RMS

 

  89512  -70.8    11.8    102  ALL  MSLP    716     7    1    2.5    -3.8     4.6

  89514  -70.8    11.7    117  ALL  MSLP    375     6    2    2.4    -3.5     4.2