DYNAMO 2011-12 Indonesia Merauke Radiosonde L3.2 Data

1.0 General Description

This data set includes 364 high vertical resolution soundings from Merauke, Indonesia (WMO 97980) collected during the DYNAMO field campaign for 2011-12. Soundings were typically released twice daily at 00 and 12 UTC from 30 September 2011 to 31 March 2012. The station utilized Meisei RS-06G radiosondes. These soundings were provided by JAMSTEC. This L3.2 version of the data set was released 20 May 2014. It includes the L3.0 corrections (application of PDF matching and correction for the relative humidity discontinuity at the 0C level), the L3.1 correction for reducing the temperature discontinuity at around 300 hPa and the additional L3.2 corrections of setting suspicious zero surface winds to missing and a correction for reducing erroneous heating/cooling data in daytime/nighttime soundings. These adjustments were applied by JAMSTEC.

1.1 Data Set Contact

Scot Loehrer

2.0 Detailed Data Description

2.1 Detailed Format Description

All upper air soundings were converted to National Center for Atmospheric Research/Earth Observing Laboratory (NCAR/EOL) Sounding Composite Format (ESC). ESC is a version of the National Center for Atmospheric Research (NCAR) CLASS format and is an ASCII format consisting of 15 header records for each sounding followed by the data records with associated QC information.

Header Records

The header records (15 total records) contain data type, project ID, site ID, site location, release time, sonde type, and meteorological and wind data processors. The first five header lines contain information identifying the sounding, and have a rigidly defined form. The following 7 header lines are used for auxiliary information and comments about the sounding, and may vary from dataset to dataset. The last 3 header records contain header information for the data columns. Line 13 holds the field names, line 14 the field units, and line 15 contains dashes ('-' characters) delineating the extent of the field.

The five standard header lines are as follows:

LineLabel (padded to 35 char)Contents
1Data Type:Description of type and resolution of data.
2Project ID:Id of weather project.
3Release Site Type/Site ID:Description of the release site.
4Release Location (lon,lat,alt):Position of release site in the format described below.
5UTC Release Time (y,m,d,h,m,s):Time of release, in the format: yyyy, mm, dd, hh:mm:ss

The release location is given as: lon (deg min), lat (deg min), lon (dec. deg), lat (dec. deg), alt (m)

Longitude in deg min is in the format: ddd mm.mm'W where ddd is the number of degrees from True North (with leading zeros if necessary), mm.mm is the decimal number of minutes, and W represents W or E for west or east longitude, respectively. Latitude has the same format as longitude, except there are only two digits for degrees and N or S for north/south latitude. The decimal equivalent of longitude and latitude and station elevation follow.

The seven non-standard header lines may contain any label and contents. The labels are padded to 35 characters to match the standard header lines. Records for this dataset include the following non-standard header lines.

LineLabel (padded to 35 char)Contents
6Sonde Id/Sonde Type:7113343/Meisei RS-06G
12Nominal Release Time (y,m,d,h,m,s):Nominal time of release, in the format: yyyy, mm, dd, hh:mm:ss

Data Records

The data records each contain time from release, pressure, temperature, dew point, relative humidity, U and V wind components, wind speed and direction, ascent rate, balloon position data, altitude, and quality control flags (see the QC code description). Each data line contains 21 fields, separated by spaces, with a total width of 130 characters. The data are right-justified within the fields. All fields have one decimal place of precision, with the exception of latitude and longitude, which have three decimal places of precision. The contents and sizes of the 21 fields that appear in each data record are as follows:

Field No.WidthFormatParameterUnitsMissing Value
35F5.1Dry-bulb TemperatureDegrees C999.0
45F5.1Dew Point TemperatureDegrees C999.0
55F5.1Relative HumidityPercent999.0
66F6.1U Wind ComponentMeters / Second9999.0
76F6.1V Wind ComponentMeters / Second9999.0
85F5.1Wind SpeedMeters / Second999.0
95F5.1Wind DirectionDegrees999.0
105F5.1Ascent RateMeters / Second999.0
135F5.1Elevation AngleDegrees999.0
145F5.1Azimuth AngleDegrees999.0
164F4.1QC for PressureCode (see below)99.0
174F4.1QC for TemperatureCode (see below)99.0
184F4.1QC for HumidityCode (see below)99.0
194F4.1QC for U Wind ComponentCode (see below)99.0
204F4.1QC for V Wind ComponentCode (see below)99.0
214F4.1QC for Ascension RateCode (see below)99.0

Fields 16 through 21 contain the Quality Control information derived at the NCAR Earth Observing Laboratory (NCAR/EOL). Any QC information from the original sounding is replaced by the following EOL codes:

99.0Unchecked (QC information is "missing.") ("UNCHECKED")
1.0Checked, datum seems physically reasonable. ("GOOD")
2.0Checked, datum seems questionable on physical basis. ("MAYBE")
3.0Checked, datum seems to be in error. ("BAD")
4.0Checked, datum is interpolated. ("ESTIMATED")
9.0Checked, datum was missing in original file. ("MISSING")

Sample Data

The following is a sample record of DYNAMO Indonesia Merauke High Resolution Radiosonde sounding data in ESC format. The data portion is much longer than 80 characters and, therefore, wraps around to a second line. See section 2.1 for an exact format specification.

Data Type:                         BMKG Radiosonde/Ascending
Project ID:                        DYNAMO
Release Site Type/Site ID:         Merauke, Indonesia/97980
Release Location (lon,lat,alt):    140 24.85'E, 08 31.12'S, 140.414, -8.519, 3.0
UTC Release Time (y,m,d,h,m,s):    2012, 03, 03, 11:13:31
Sonde Id/Sonde Type:               7113343/Meisei RS-06G
Nominal Release Time (y,m,d,h,m,s):2012, 03, 03, 11:13:31
 Time  Press  Temp  Dewpt  RH    Ucmp   Vcmp   spd   dir   Wcmp     Lon     Lat   Ele   Azi    Alt    Qp   Qt   Qrh  Qu   Qv   QdZ
  sec    mb     C     C     %     m/s    m/s   m/s   deg   m/s      deg     deg   deg   deg     m    code code code code code code
------ ------ ----- ----- ----- ------ ------ ----- ----- ----- -------- ------- ----- ----- ------- ---- ---- ---- ---- ---- ----
   0.0 1005.1  27.3  24.9  87.0    0.0    0.0   0.0   0.0 999.0  140.414  -8.518 999.0 999.0     3.0  3.0  3.0  3.0  1.0  1.0  9.0
   1.0 1005.0  26.3  24.7  90.9   -0.9   -1.2   1.6  37.2   0.5  140.414  -8.518 999.0 999.0     3.5  3.0  3.0  3.0  1.0  1.0 99.0
   2.0 1004.4  26.3  24.7  91.1   -1.4   -0.3   1.4  78.2   5.3 9999.000 999.000 999.0 999.0     8.8  2.0  1.0  1.0  1.0  1.0 99.0
   3.0 1004.0  26.2  24.7  91.5   -1.1    0.3   1.1 106.1   3.6  140.414  -8.519 999.0 999.0    12.4  1.0  1.0  1.0  1.0  1.0 99.0
   4.0 1003.4  26.1  24.7  91.8   -0.3   -0.1   0.4  67.6   5.1  140.414  -8.519 999.0 999.0    17.5  1.0  1.0  1.0  1.0  1.0 99.0
   5.0 1003.0  26.1  24.7  92.0    0.0   -0.3   0.3 358.5   4.4  140.414  -8.519 999.0 999.0    21.9  1.0  1.0  1.0  1.0  1.0 99.0
   6.0 1002.2  26.1  24.7  92.1   -0.7    0.3   0.8 111.6   7.1  140.414  -8.519 999.0 999.0    29.0  1.0  1.0  1.0  1.0  1.0 99.0
   7.0 1001.6  26.2  24.7  91.2   -1.5    0.5   1.6 109.9   5.2  140.414  -8.519 999.0 999.0    34.2  1.0  1.0  1.0  1.0  1.0 99.0
   8.0 1001.0  26.3  24.7  90.7   -1.6    0.8   1.8 116.6   5.1 9999.000 999.000 999.0 999.0    39.3  3.0  3.0  3.0  1.0  1.0 99.0
   9.0 1001.0  26.5  24.8  90.6   -1.9    1.5   2.4 128.4   0.2  140.414  -8.519 999.0 999.0    39.5  3.0  3.0  3.0  1.0  1.0 99.0
  10.0 1000.8  26.6  24.9  90.3   -1.9    2.0   2.8 137.3   1.7  140.414  -8.518 999.0 999.0    41.2  1.0  1.0  1.0  1.0  1.0 99.0
  11.0 1000.7  26.6  24.8  90.1   -1.6    2.4   2.9 146.3   0.6  140.414  -8.519 999.0 999.0    41.8  1.0  1.0  1.0  1.0  1.0 99.0
  12.0 1000.5  26.6  24.8  89.8   -1.5    2.9   3.2 151.9   1.9  140.414  -8.519 999.0 999.0    43.7  1.0  1.0  1.0  1.0  1.0 99.0
  13.0 1000.2  26.6  24.7  89.5   -1.9    3.4   3.9 151.0   2.4 9999.000 999.000 999.0 999.0    46.1  1.0  1.0  1.0  1.0  1.0 99.0
  14.0 1000.0  26.6  24.7  89.1   -1.7    4.0   4.3 156.7   1.9  140.414  -8.518 999.0 999.0    48.0  1.0  1.0  1.0  1.0  1.0 99.0

2.2 Data Remarks

Version 1 of the Merauke L3.2 data set was released 20 May 2014 by Kunio Yoneyama of JAMSTEC.

For L3.0 data, corrections of humidity have been applied with two methods. One is a CDF matching based on the intercomparison of Vaisala RS92 and Meisei onboard the Mirai, and the second is a correction for the RH discontinuity at the 0C level following a method provided by Sugidachi and Fujiwara (2013). These corrections are indicated as "CDF Matching" and "RH Discontinuity at 0C (Sugidachi & Fujiwara 2013)", respectively, in the header line 7-8. Details can be found in Ciesielski et al. (2014).

For the L3.1 data, in addition to the corrections applied to produce Level 3.0 data, temperature discontinuity at around 300hPa is corrected. Meisei radiosonde receiving system has a software which reduces the influence of solar radiation reflected from the sensor package, which is originally set to act from 300hPa level. Actually, it forces the reduction of temperature at and above 300hPa. In particular, this feature is found not only for daytime sounding but also for nighttime sounding, indicating too much reduction. This is because the software reduces the temperature regardless with actual condition and launch time, while the soundings over the Indonesian Maritime Continent are typically conducted in the local morning and evening time, when the errors caused by solar radiation are expected to be small. Therefore, by assuming that temperature lapse rate is close to the mean value between just below/above layers, the difference of lapse rate from the mean is calculated, and the temperature difference deduced from the lapse rate difference is added to the observed values (typical value is about 0.2C). When this correction is applied, "Ta discontinuity at 300hPa" is indicated in the header line 9.

For this L3.2 data, in addition to the corrections applied to produce L3.0 and L3.1 data, two additional corrections have been applied. At some Indonesian sounding sites, the operators enter the wind data of 0m/s, 0deg as the initial value regardless with actual wind condition. Thus, if the wind data of first point, which is manually recorded by the operator, is 0m/s, 0deg, and any of the first three data, which are the value measured by a Radiosonde, exceeds 0.5m/s, we judge the surface wind data is suspicious, and have replaced them with 999m/s and 999deg, indicating missing values. Another correction scheme is meant for reduction of erroneous heating/cooling data in daytime/nighttime soundings. Since the observation was carried out on land, there are possible that large heating/cooling may happen near the ground surface. However, we found wrong cases. For example, while we confirmed a good agreement between T/RH values measured using a calibrated handy sensor and that of radiosonde, only surface meteorological data measured independently shows quite different value. On the one hand, radiosonde sensor is exposed under the sun prior to launch at some sites, which might cause sensor arm heating. This may also be partly due to the launch site infrastructure condition, where the site is surrounded by buildings. Therefore, near surface (surface ~ 40m) T/RH values are replaced with the data obtained from linear extrapolation using above layer data following Yoneyama et al. (2002). These corrections are indicated in the header as "Missing Surface Wind" and "Surface Heating/Cooling (Yoneyama et al. 2002)", respectively.

2.3 Station List

Merauke 97980 Indonesia 140.414 -8.519 3.0

3.0 Quality Control Processing

This dataset underwent an automated QC process. The dataset underwent internal consistency checks which included two types of checks, gross limit checks on all parameters and rate-of-change checks on temperature, pressure and ascension rate. Some further information on the QC processing conducted by NCAR/EOL can be found in Loehrer et al. (1996) and Loehrer et al. (1998).

3.1 Gross Limit Checks

These checks were conducted on each sounding and data were automatically flagged as appropriate. Only the data point under examination was flagged. NCAR/EOL conducted the following gross limit checks on the DYNAMO 2011-12 Indonesia Merauke sounding dataset. In the table P = pressure, T = temperature, RH = relative humidity, U = U wind component, V = V wind component, B = bad, and Q = questionable.

ParameterGross Limit CheckParameter(s) FlaggedFlag Applied
Pressure < 0 mb or > 1050 mb PB
Altitude < 0 m or > 40000 m P, T, RHQ
Temperature < -90 °C or > 45 °C TT
Dew Point < -99.9 °C or > 33 °C
> Temperature
Relative Humidity < 0% or > 100% RHB
Wind Speed < 0 m/s or > 100 m/s
> 150 m/s
U, V
U, V
U Wind Component < 0 m/s or > 100 m/s
> 150 m/s
V Wind Component < 0 m/s or > 100 m/s
> 150 m/s
Wind Direction < 0° or > 360° U, VB
Ascent Rate < -10 m/s or > 10 m/s P, T, RHQ

3.2 Vertical Consistency Checks

These checks were conducted on each sounding and data were automatically flagged as appropriate. These checks were started at the lowest level of the sounding and compared neighboring 2-sec data points (except at pressures less than 100 mb where 30-sec average values were used). In the case of checks ensuring that the values increased/decreased as expected, only the data point under examination was flagged. However, for the other checks, all of the data points used in the examination were flagged. All items within the table are as previously defined.

ParameterVertical Consitency CheckParameter(s) FlaggedFlag Applied
Time decreasing / equal NoneNone
Altitude decreasing / equal P, T, RHQ
Pressure increasing / equal
> 1 mb/s or < -1 mb/s
> 2 mb/s or < -2 mb/s
P, T, RH
P, T, RH
P, T, RH
Temperature < -15 °C/km
< -30 °C/km
> 50 °C/km (not applied at p < 250 mb)
>100 °C/km (not applied at p < 2 50 mb)
P, T, RH
P, T, RH
P, T, RH
P, T, RH
Ascent Rate change of > 3 m/s or & lt; -3 m/s
change of > 5 m/s or < -5 m/s

3.3 Visual Quality Checks

Each sounding was visually examined for data quality issues. Any issues found were flagged in the data file and/or noted in Section 3.4.

3.4 Data Quality Issues

3.4.1 Incorrect Release Time

The sounding release time provided in many of the raw data files was incorrect and thus much pre-release data were labeled as post-release. These release times were not automatically determined, but rather manually by the operator and is typically before the actual release time. For this L2 version of the Merauke data set the first record in the file is the independent surface data point. The data from the radiosonde were not included in the file until the point where the radiosonde pressure remained consistently below the independent surface pressure.

3.4.2 Falling Radiosonde Data

Many raw data files included data from the falling radiosonde after balloon burst. These falling records at the end of the soundings have been removed from this L2 data set.

3.4.3 Noisy Temperature Data

Many of the soundings exhibit noise in the temperature data for varying portions of the sounding. The noise varies from minor to quite substantial. The initial thought from JAMSTEC is that this may be due to the sensor boom not being set properly at release. The issue is being examined. A couple of examples of this issue can be found in the soundings at:


3.4.4 Low Radiosonde Pressure Data

There are some soundings where the first radiosonde pressure is substantially lower than the independent surface value:

201111092308 (7mb)
201112032323 (5mb)
201112062315 (5mb)
201201081142 (13mb)
201201101119 (22mb)
201201151131 (5mb)
201201221127 (6mb)
201201252341 (8mb)
201203021145 (8mb)
201203252318 (78mb)

3.4.5 Near Surface Wind Data

The winds in the lowest 5-10 mb are somewhat erratic and there are sometimes spikes in the wind speed.

3.4.6 Soundings with very unstable ascent rates

Many 2012 soundings from Merauke have very unstable ascent rates. These soundings have many periods of descent (or very slow ascent) mixed with periods of (very) fast ascent rates. The temperature and dew point data during these periods are questionable or bad. This seems to be a problem with the pressure data. In this state these soundings should be used with care.

201201122333 - all above 75mb
201201142320- below 500mb
201202261132 - above 300mb
201203042321 - mostly above 70mb
3.4.7 Other issues

201111131114 - RH above ~144mb stays in mid 90% range
201111192338 - winds a constant 1.5m/s at 270 degrees for entire flight
201111231140 - limited RH data
201112061137 - possibly impacted by balloon icing, a couple of periods of descent beginning around 0C level. Above ~470 mb the ascent rate is < 2.5m/s.
201112072332 - limited RH data
201112121116 - limited RH data
201201181110 - limited RH data
201201232336 - period of descent around 0C level
201202042347 - limited RH data
201202111119 - limited RH data

3.4.8 Possible Dry Bias Above 0C Level

According to JAMSTEC their University colleagues have noticed an artificial error for the RH data above the 0C level. It seems that Meisei adopted a correction scheme for a wet bias found in their data, but the scheme has a discontinuity at OC by 3%. As a result there is a discontinuous gap at 0C and it now makes it dry above this point. The University colleagues are developing a correction scheme and JAMSTEC will determine its validity for the DYNAMO Meisei data. This was corrected in this L3.0 version of the data.

4.0 References

Ciesielski, P. E., H. Yu, R. H. Johnson, K. Yoneyama, M. Katsumata, C. N. Long, J. Wang, S. M. Loehrer, K. Young, S. F. Williams, W. Brown, J. Braun, T. Van Hove, 2014: Quality-controlled upper-air sounding dataset for DYNAMO/CINDY/AMIE: Development and corrections. J. Atmos. Oceanic Technol., 31, 741-764.

Loehrer, S. M., T. A. Edmands, and J. A. Moore, 1996: TOGA COARE upper-air sounding data archive: development and quality control procedures. Bull. Amer. Meteor. Soc., 77, 2651-2671.

Loehrer, S. M., S. F. Williams, and J. A. Moore, 1998: Results from UCAR/JOSS quality control of atmospheric soundings from field projects. Preprints, Tenth Symposium on Meteorological Observations and Instrumentation, Phoenix, AZ, Amer. Meteor. Soc., 1-6.

Sugidachi, T., and M. Fujiwara, 2013: Corection of the stepwise change observed at 0C in Meisei RS2-91, RS-01G, and RS-06G radiosonde relative humidity profiles. J. Meteor. Soc. Japan, 91, 323-336.

Yoneyama, K., M. Hanyu, S. Sueyoshi, F. Yoshiura, and M. Katsumata 2002: Radiosonde observation from the ship in the tropical region. JAMSTECR, 45, 31-39. Available from "http://www.godac.jamstec.go.jp/catalog/data/doc_catalog/media/shiken45_04.pdf"