ASCII Code Manual for Quality Controlled Surface Meteorological Data

Shawn R. Smith and David Legler

Coupled Ocean Atmosphere Response Experiment (COARE)
Surface Meteorological Data Processing Center (DPC)
Center for Ocean-Atmospheric Prediction Studies
Florida State University

03 Aug 1995

Report COAREMET 95-11

Version 1.0

1. Introduction

The COARE American Standard Code for Information Interchange (ASCII) manual for quality controlled surface meteorological data outlines the codes used within the DPC surface meteorological data sets released to the COARE community. The code is a synthesis of the COADS documentation (Slutz et al. 1985), standard World Meteorological Organization (WMO) synoptic code, and new codes derived at Florida State University (FSU). In many places numeric codes were used to keep the data set compact.

The COARE ASCII data file includes up to 24 possible variables. In some cases, multiple measurements of the same variable are available (e.g. sea temperature measured from a thermosalinograph and a bucket temperature) and are differentiated using sequentially numbered variable names (TS, TS2, TS3, TS4, etc). As described in section 2, variables include not only meteorological data (temperature, pressure, etc.), but also a number of supporting variables (time of observation, platform position and movement, etc.). A variable containing quality control (QC) flags is included to indicate the QC applied to the data values. Multiple variable attributes provide information on data units, instruments used, instrument height, etc. in an attempt to provide an even mix between raw data and metadata. Eleven global attributes contain general information for all data within the ASCII file.

When the data that arrive at the Surface Meteorology DPC, the only change to the data is a simple conversion to a standard set of units. The original units are noted in a variable attribute. Any data arriving without an accurate time stamp or information on whether the time is local or GMT were discarded only after all attempts to obtain correct time information were exhausted. The data also must have position information, i.e. data lacking latitude and longitude values were discarded only after all attempts to correctly position the data failed. Furthermore, if data arrived with no units attached, only after every effort to determine their units was exhausted, were the data discarded. Data collected without a record of time, position, or units are useless to the research community. However, all original data contributions are archived in the event additional information is discovered later that would allow the inclusion of discarded data.

The ASCII file structure, an example is found in Appendix 1, begins with the file name followed by the eleven global attributes. The second part of the header is a table giving the values for the variable attributes. The final section of the file is the data in a column format with the variable names at the top of each data column. A sample FORTRAN code to read the ASCII file in Appendix 1 is presented in Appendix 2 and can be modified for any COARE ASCII file.

Section 2 outlines the data variables and attributes and describes all numeric codes that are employed. Section 3 covers the global attributes. Throughout the manual, variables will be indicated by bold type and attributes will be italicized.

2.Variables

Up to 24 variables with a maximum of 8 associated attributes may appear in a surface meteorology file for COARE, Table 1. All data files will contain the time, latitude, longitude, and quality control flag variables. The quality control flags are single alphabetic characters that represent either problems or notable features in the data. The quality control flags for multiple variables are combined in a single string and stored in the flag variable. The flag variable as a result is a character string that has a length equal to the number of variables that underwent quality control. (A list of the flags, their definitions, and an example of their usage is found in section 2x). For each variable, Table 1 shows whether or not that attribute is associated with a particular variable.

Table 1: Variable attribute list. 

Variable     long_name     units       convers_  type      inst  ht  FORTRAN      qcindex   
                                       units                         _format                
ctc          cruise        code (see                                 A9                     
             track code    text)                                                            
time         time          min.                  Table 2             I12          *         
                           since                                                            
                           1-1-1980                                                         
                           00:00                                                            
lat          latitude      degrees N   Table 3                       F9.2         *         
lon          longitude     degrees E   Table 3                       F9.2         *         
PL_HD        platform      degrees -                *         F9.1         *         
             heading       clockwise                                                        
                           from N                                                           
PL_SPD       platform      m s-1       Table 5             *         F9.1         *         
             speed                                                                          
DIR          earth         degrees -   Table 4             *     *   F9.1         *         
             relative      clockwise                                                        
             wind          from N                                                           
             direction                                                                      
SPD          earth         m s-1       Table 5             *     *   F9.1         *         
             relative                                                                       
             wind speed                                                                     
P            atmospheric   mb          Table 6   Table 7   *     *   F9.1         *         
             pressure                                                                       
T            air           degrees C   Table 8             *     *   F9.2         *         
             temperature                                                                    
TW           wet-bulb      degrees C   Table 8             *     *   F9.2         *TD       
             temperature                                                                    
TD           dewpoint      degrees C   Table 8             *     *   F9.2         *TD       
             temperature                                                                    
TS           sea           degrees C   Table 8   Table 9   *     *   F9.2         *         
             temperature                                                                    
RH           relative      percent                         *     *   F9.1         *         
             humidity                                                                       
Q            specific      g kg-1                          *     *   F9.1         *         
             humidity                                                                       
PRECIP       precipitatio  mm          Table 10            *     *   F9.1         *         
             n                                                                              
WX           present       code                                      I6                     
             weather       (Table 11)                                                       
TCA          total cloud   code        Table 13                      I6                     
             amount        (Table 12)                                                       
LMCA         low/middle    code        Table 13                      I6                     
             cloud amount  (Table 12)                                                       
ZCL          cloud height  code                                      I6                     
                           (Table 14)                                                       
LCT          low cloud     code                                      I6                     
             type          (Table 15)                                                       
MCT          middle        code                                      I6                     
             cloud type    (Table 16)                                                       
HCT          high cloud    code                                      I6                     
             type          (Table 17)
flag quality code A* control (Table 18) flags

The definition of the attributes are:

  1. Cruise track code (RESEARCH VESSEL DATA ONLY)
    The cruise track code stores up to a 9 character string that marks each recording time as being either a TOGA/COARE cruise, a WOCE cruise, another dedicated cruise (other), or a cruise with an 'unknown' designation. The COARE cruise track code will only include the leg number for a specific ship using the code T/CLEG###. As an example, if a data record was collected on the second leg of the Moana Wave COARE cruise, then the cruise track code would be T/CLEG002.

  2. Time
    The time is a double precision variable with units equal to minutes since 1-1-1980 00:00. The time is quality controlled for non-sequential and unrealistic values. The type is encoded according to Table 2.

    Table 2: Time types

    Code Definitions

    1. Unknown time type

    2. Mean time
      (Data represent a mean observed/recorded over some period of time. Notes on the position of the recorded time stamp within the mean (e.g. beginning, end, or middle of mean) and the length of the averaging period will be provided in the data quality reports).

    3. Instantaneous time
      (Data are recorded as instantaneous values at the time indicated)

      A FORTRAN subroutine to convert from minutes since 1-1-1980 00:00 to year, month, day, hour, and minute values is provided in Appendix 3.

  3. Latitude

  4. Longitude

    Platform position is in units of degrees; positive degrees for north latitude, negative degrees for south latitude, and positive 0-359 degrees east longitude. The units of the original values of latitude and longitude are found in Table 3.

    Table 3: Units of original latitude and longitude.

    Code Definitions

    1. Degrees and tenths
    2. Whole degrees
    3. Non-random tenths
    4. Interpolated
    5. Degrees and minutes
    6. High resolution data (e.g., degrees to seconds, or degrees and hundredths)
    7. Other (refer to supplemental data)

    The latitude and longitude is quality controlled for data validity, unrealistic platform movement, and whether an oceanographic platform moves over land.

  5. Platform heading
    The heading is recorded in units of degrees (recorded clockwiserelative to true north) and represents the direction that the bow of the ship is pointing. Valid headings range from 000.0 to 359.0 degrees. A convers_units attribute stores the type of compass that recorded the original data using the codes found below in Table 4.

  6. Platform speed
    The platform speed is recorded in units of meter per second after a conversion from the original units (encoded using Table 5).

  7. Earth-relative wind direction
    The earth-relative wind direction is stored with units of degrees and is encoded using:

    going clockwise from true north. All wind directions are reported in the standard meteorological convention; the direction the wind is blowing from. Table 4 lists the possible compass types used to record the original data.

    Table 4: Compass direction conversion units.

    Code Definitions

    1. 36-point compass
    2. 32-point compass
    3. 16 of 36-point compass
    4. 16 of 32-point compass
    5. 8-point compass
    6. 360-point compass
    7. High resolution data (e.g., tenths of degrees)
    8. 16 point compass

  8. Earth-relative wind speed
    The earth-relative wind speed is recorded in units of meters per second, and Table 5 lists the codes for the original units of the wind speed data.

    Table 5: Wind speed conversion units.

    Code Definitions

    1. Meters per second, estimated
    2. Meters per second, unknown
    3. Meters per second, measured
    4. Knots, estimated
    5. Knots, unknown
    6. Knots, measured
    7. Beaufort force (based on documentation)
    8. High resolution measurement (e.g., hundredths of a meter per second)

  9. Atmospheric pressure
    Pressure is recorded in units of millibars. The units of the original data are listed in Table 6 and Table 7 outlines the codes for the pressure type.

    Table 6: Atmospheric pressure conversion units.

    Code Definitions

    1. Millibars
    2. Bars
    3. Millimeters of mercury
    4. Inches of mercury
    5. Pascals

    Table 7: Atmospheric pressure type.

    Code Definitions

    1. Unknown type
    2. Sea level
    3. Station level

  10. Air temperature

  11. Dewpoint temperature

  12. Wet bulb temperature

    All atmospheric temperatures are recorded in units of degrees Celsius after a conversion from the original units (see Table 8).

    Table 8: Temperature conversion units.

    Code Definitions

    1. Degrees Celsius and tenths
    2. Half degrees Celsius
    3. Whole degrees Celsius
    4. Degrees Fahrenheit and tenths
    5. Half degrees Fahrenheit
    6. Whole degrees Fahrenheit
    7. High resolution data (e.g., hundredths of a degree Celsius or Fahrenheit)
    8. Other (notes will be found in data quality reports)

  13. Sea temperature
    The sea temperature is recorded in units of degrees Celsius with the original units encoded according to Table 8. NOTE: The sensor depth is recorded in meters and is a positive for all non-missing values (the attribute name is changed from ht to avoid confusion). The specific instrument type used to measure the sea temperature is stored in inst while the general instrument type is recorded using the codes in Table 9.

    Table 9: General instrument types used to record sea temperature.

    Code Definitions

    1. Unknown or non-bucket
    2. Condenser inlet (intake)
    3. Trailing thermistor
    4. Hull contact sensor
    5. Through hull sensor
    6. Radiation thermometer
    7. Bait tanks thermometer
    8. Others
    9. Bucket
    10. Implied bucket (an HSST SID or any match)
    11. Thermometer
    12. Other electronic sensor

  14. Relative humidity

  15. Specific humidity

    Though the relative humidity, recorded in units of percent, is the more common moisture measurement; the specific humidity, always recorded in grams per kilogram, is preferred and supplied whenever it is present in the original data.

  16. Precipitation
    The precipitation is recorded in units of millimeters and Table 10 lists the original precipitation units.

    Table 10: Precipitation conversion units.

    Code Definitions

    1. Inches
    2. Tenths of an inch
    3. Hundredths of an inch
    4. Centimeters
    5. Millimeters
    6. High resolution (>0.1 millimeter)

    An alternative measure of precipitation, the rain rate (RRATE) may be used in some files. The rain rate units are amount of rain per unit time. All other attributes are the same as in PRECIP.

  17. Present weather
    Table 11: Present weather codes are the same as those from COADS data (Slutz et al. 1985).

    Code Definitions

    Codes 00 to 49 indicate no precipitation at the site (e.g., ship, buoy, etc.) at time of observation:

    1. Cloud development not observed
    2. Clouds generally dissolving or becoming less developed
    3. State of the sky unchanged
    4. Clouds generally forming or developing
    5. Visibility reduced by smoke
    6. Haze
    7. Widespread dust in suspension in the air, not raised by wind at or near the station at time of observation
    8. Dust or sand raised by wind at or near the station at time of observation, but no well-developed dust whirls or sand whirls and no dust storm or sandstorm seen
    9. Well developed dust whirls or sand whirls seen at or near the station during the preceding hour or at time of observation, but no dust storm or sandstorm
    10. Dust storm or sandstorm within sight at time of observation, or at the station during the preceding hour
    11. Light fog (visibility 1,100 yards or more); synonymous with European term "mist"
    12. Patches of shallow fog or ice fog at the station, not deeper than about 10 meters
    13. More or less continuous shallow fog or ice fog at the station, not deeper than about 10 meters
    14. Lightning visible, no thunder heard
    15. Precipitation within sight, not reaching the surface of the sea
    16. Precipitation within sight, reaching the surface of the sea, but more than 5 kilometers from the station
    17. Precipitation within sight, reaching the surface of the sea, near to, but not at the station
    18. Thunderstorm, but no precipitation at time of observation
    19. Squalls at or within sight of the station during the preceding hour or at time of observation
    20. Funnel cloud or waterspout at or within sight of the station during the preceding hour or at time of observation

    Codes 20 to 29 refer to phenomena that occurred at the station during the preceding hour but not at time of observation:

    1. Drizzle (not freezing) or snow grains
    2. Rain (not freezing)
    3. Snow
    4. Rain and snow or ice pellets, type (a)
    5. Freezing drizzle or freezing rain
    6. Shower of rain
    7. Shower of snow, or of rain and snow
    8. Shower of hail (ice pellets, type (b), snow pellets), or of rain and hail
    9. Fog or ice fog
    10. Rhunderstorm (with or without precipitation)

    Codes 30 to 99 refer to phenomena occurring at the ship at time of observation:

    1. Slight or moderate dust storm or sandstorm has decreased during the preceding hour
    2. Slight or moderate dust storm or sandstorm with no appreciable change during the preceding hour
    3. Slight or moderate dust storm or sandstorm has begun or has increased during the preceding hour
    4. Severe dust storm or sandstorm has decreased during the preceding hour
    5. Severe dust storm or sandstorm with no appreciable change during the preceding hour
    6. Severe dust storm or sandstorm has begun or has increased during the preceding hour
    7. Slight or moderate drifting snow generally low (below eye level, less than 6 feet)
    8. Heavy drifting snow generally low (below eye level, less than 6 feet)
    9. Slight or moderate blowing snow generally high (above eye level, 6 feet or more)
    10. Heavy blowing snow generally high (above eye level, 6 feet or more)
    11. Fog or ice fog at a distance at time of observation, but not at the station during the preceding hour, the fog or ice fog extending to a level above that of the observer
    12. Fog or ice fog in patches
    13. Fog or ice fog (sky visible) has become thinner during the preceding hour
    14. Fog or ice fog (sky invisible) has become thinner during the preceding hour
    15. Fog or ice fog (sky visible) with no appreciable change during the preceding hour
    16. Fog or ice fog (sky invisible) with no appreciable change during the preceding hour
    17. Fog or ice fog (sky visible) has begun or has become thicker during the preceding hour
    18. Fog or ice fog (sky invisible) has begun or has become thicker during the preceding hour
    19. Fog, depositing rime, sky visible
    20. Fog, depositing rime, sky invisible

    Codes 50 to 99 indicate precipitation at the station at time of observation:

    1. Drizzle, not freezing, intermittent, slight at time of observation
    2. Drizzle, not freezing, continuous, slight at time of observation
    3. Drizzle, not freezing, intermittent, moderate at time of observation
    4. Drizzle, not freezing, continuous, moderate at time of observation
    5. Drizzle, not freezing, intermittent, heavy (dense) at time of observation
    6. Drizzle, not freezing, continuous, heavy (dense) at time of observation
    7. Drizzle, freezing, slight
    8. Drizzle, freezing, moderate or heavy (dense)
    9. Drizzle and rain, slight
    10. Drizzle and rain, moderate or heavy
    11. Rain, not freezing, intermittent, slight at time of observation
    12. Rain, not freezing, continuous, slight at time of observation
    13. Rain, not freezing, intermittent, moderate at time of observation
    14. Rain, not freezing, continuous, moderate at time of observation
    15. Rain, not freezing, intermittent, heavy at time of observation
    16. Rain, not freezing, continuous, heavy at time of observation
    17. Rain, freezing, slight
    18. Rain, freezing, moderate or heavy
    19. Rain or drizzle and snow, slight
    20. Rain or drizzle and snow, moderate or heavy
    21. Intermittent fall of snowflakes, slight at time of observation
    22. Continuous fall of snowflakes, slight at time of observation
    23. Intermittent fall of snowflakes, moderate at time of observation
    24. Continuous fall of snowflakes, moderate at time of observation
    25. Intermittent fall of snowflakes, heavy at time of observation
    26. Continuous fall of snowflakes, heavy at time of observation
    27. Ice prisms (with or without fog)
    28. Snow grains (with or without fog)
    29. Isolated star-like snow crystals (with or without fog)
    30. Ice pellets, type (a) (sleet, U.S. definition)
    31. Rain shower, slight
    32. Rain shower, moderate or heavy
    33. Rain shower, violent
    34. Shower of rain and snow mixed, slight
    35. Shower of rain and snow mixed, moderate or heavy
    36. Snow shower, slight
    37. Snow shower, moderate or heavy
    38. Slight showers of snow pellets or ice pellets, type (b), with or without rain or rain and snow mixed
    39. Moderate or heavy showers of snow pellets or ice pellets, type (b), with or without rain or rain and snow mixed
    40. Slight showers of hail, with or without rain or rain and snow mixed, not associated with thunder
    41. Moderate or heavy showers of hail, with or without rain or rain and snow, mixed, not associated with thunder
    42. Slight rain at time of observation, thunderstorm during preceding hour but not at time of observation
    43. Moderate or heavy rain at time of observation, thunderstorm during preceding hour but not at time of observation
    44. Slight snow, or rain and snow mixed, or hail, at time of observation with thunderstorm during the preceding hour but not at time of observation
    45. Moderate or heavy snow, or rain and snow mixed, or hail, at time of observation with thunderstorm during the preceding hour but not at time of observation
    46. Thunderstorm, slight or moderate, without hail, but with rain and/or snow at time of observation
    47. Thunderstorm, slight or moderate, with hail at time of observation
    48. Thunderstorm, heavy, without hail but with rain and/or snow at time of observation
    49. Thunderstorm combined with dust storm or sandstorm at time of observation
    50. Thunderstorm, heavy, with hail at time of observation

  18. Total cloud amount

  19. Low/middle cloud amount

    The codes for the total and low/middle cloud amounts (Table 14) are from the COADS data (Slutz et al. 1985). For the total cloud amount, codes 0 to 9 show the fraction, in oktas, of the celestial dome covered by all clouds. For the low/middle cloud amount the codes show the fraction, in oktas, of the celestial dome covered by all the low clouds and, if no low clouds are present, the fraction covered by all the middle clouds.

    Table 12: Cloud amount codes.

    Code Definitions

    1. Clear
    2. 1 okta or less, but not zero
    3. 2 oktas
    4. 3 oktas
    5. 4 oktas
    6. 5 oktas
    7. 6 oktas
    8. 7 oktas or more, but not 8 oktas
    9. 8 oktas
    10. Sky obscured or cloud amount cannot be estimated

    If the data arriving at the DPC use tenths to describe cloud cover, the convention in Table 15 will be used to convert from tenths to oktas and the original data units will be noted using the codes in Table 16.

    Table 13: Relationship between tenths and oktas

    tenthsoktas
    00
    11
    2,32
    43
    54
    65
    7,86
    97
    108

    Table 14: Cloud amount conversion units

    Code Definitions

    1. Oktas
    2. Tenths

  20. Cloud height
    Cloud height is recorded using the standard 0-10 synoptic code. Table 17 shows the height ranges and codes for measurements in feet or meters.

    Table 15: Cloud height codes, adapted from Table 9 of the COADS data documentation (Slutz et al. 1985)

    Approximate height of lowest cloud base

    CodeFeetMeters
    00-1490-49
    1150-29950-99
    2300-599100-199
    3600-999200-299
    41000-1999300-599
    52000-3499600-999
    63500-49991000-1499
    75000-64991500-1999
    86500-79992000-2499
    9>=8000 or no clouds>=2500 or no clouds

    10 indicates that the cloud height cannot be estimated because of darkness or for other reasons.

  21. Low cloud type
    Table 16: Low cloud type codes extracted from the COADS data documentation (Slutz et al. 1985). The codes show observed characteristics of clouds of the types stratocumulus, stratus, cumulus, cumulonimbus, and their variations.

    Code Definitions

    1. No stratocumulus, stratus, cumulus, or cumulonimbus.

    2. Cumulus with little vertical extent and seemingly flattened, or ragged cumulus other than of bad weather, or both.

    3. Cumulus of moderate or strong vertical extent, generally with protuberances in the form of domes or towers, either accompanied or not by other cumulus or by stratocumulus, all having their base at the same level.
    4. Cumulonimbus the summits of which, at least partially, lack sharp outlines but are neither clearly fibrous (cirriform) nor in the form of an anvil; cumulus, stratocumulus, or stratus may also be present.
    5. Stratocumulus formed by the spreading out of cumulus; cumulus may also be present
    6. Stratocumulus not resulting from the spreading out of cumulus
    7. Stratus in a more or less continuous sheet or layer, or in ragged shreds, or both, but no stratus fractus of bad weather.
    8. Stratus fractus of bad weather (generally existing during precipitation and a short time before and after) or cumulus fractus of bad weather, or both (pannus), usually below altostratus or nimbostratus.
    9. Cumulus and stratocumulus other than that formed from the spreading out of cumulus; the base of the cumulus is at a different level from that of the stratocumulus.
    10. Cumulonimbus, the upper part of which is clearly fibrous (cirriform), often in the form of an anvil; either accompanied or not by cumulonimbus without anvil or fibrous upper part, by cumulus, stratocumulus, stratus, or pannus.
    11. Low clouds not visible, owing to darkness, fog, blowing dust or sand, or other similar phenomena

  22. Middle cloud type
    Table 17: Middle cloud type codes extracted from the COADS data documentation (Slutz et al. 1985). The codes show observed characteristics of clouds of the types altocumulus, altostratus, and nimbostratus.

    Code Definitions

    1. No altocumulus, altostratus, or nimbostratus.
    2. Altostratus, the greater part of which is semi-transparent; through this part the sun or moon may be weakly visible, as through ground glass
    3. Altostratus, the greater part of which is sufficiently dense to hide the sun or moon, or nimbostratus
    4. Altocumulus, the greater part of which is semi-transparent; the various elements of the cloud change only slowly and are all at a single level
    5. Patches (often in the form of almonds or fishes) of altocumulus, the greater part of which is semi-transparent; the clouds occur at one or more levels and the elements are continually changing in appearance
    6. Semi-transparent altocumulus in bands, or altocumulus in one or more fairly continuous layers (semi-transparent or opaque), progressively invading the sky; these altocumulus clouds generally thicken as a whole
    7. Altocumulus resulting from the spreading out of cumulus (or cumulonimbus)
    8. Altocumulus in two or more layers, usually opaque in places, and not progressively invading the sky; or opaque layer of altocumulus, not progressively invading the sky; or altocumulus together with altostratus or nimbostratus
    9. Altocumulus with sproutings in the form of small towers or battlements; or altocumulus having the appearance of cumuliform tufts
    10. Altocumulus of a chaotic sky, generally at several levels
    11. Middle clouds not visible, owing to darkness, fog, blowing dust or sand, or other similar phenomena, or more often because of the presence of a continuous layer of lower clouds

  23. High cloud type
    Table 18: High cloud type codes extracted from the COADS data documentation (Slutz et al. 1985). The codes show observed characteristics of clouds of the types cirrus, cirrocumulus and cirrostratus.

    Code Definitions

    1. No cirrus, cirrocumulus or cirrostratus
    2. Cirrus in the form of filaments, strands, or hooks, not progressively invading the sky
    3. Dense cirrus, in patches or entangled sheaves, which usually do not increase and sometimes seem to be the remains of the upper part of a cumulonimbus, or cirrus with sproutings in the form of small turrets or battlements, or cirrus having the appearance of cumuliform tufts
    4. Dense cirrus, often in the form of an anvil, being the remains of the upper parts of cumulonimbus
    5. Cirrus in the form of hooks or of filaments, or both, progressively invading the sky; they generally become denser as a whole
    6. Cirrus (often in bands converging towards one point or two opposite points of the horizon) and cirrostratus, or cirrostratus alone; in either case, they are progressively invading the sky, and generally growing denser as a whole, but the continuous veil does not reach 45 degrees above the horizon
    7. Cirrus (often in bands converging towards one point or two opposite points of the horizon) and cirrostratus, or cirrostratus alone; in either case, they are progressively invading the sky, and generally growing denser as a whole; the continuous veil extends more than 45 degrees above the horizon, without the sky being totally covered
    8. Veil of cirrostratus covering the celestial dome
    9. Cirrostratus not progressively invading the sky and not completely covering the celestial dome
    10. Cirrocumulus alone, or cirrocumulus accompanied by cirrus or cirrostratus, or both, but cirrocumulus is predominant
    11. High clouds not visible, owing to darkness, fog, blowing dust or sand, or other similar phenomena, or more often because of the presence of a continuous layer of lower clouds

  24. Quality control flag
    The quality control flags (Table 19) are single alphabetic characters for each data value. Only those variables with a qcindex have flag values (the qcindex is an integer pointer to the flag for a selected variable), i.e. not all meteorological variables are quality controlled.

    Table 19: Definitions of COARE quality control flags

    Flag Definitions

    1. Original data had unknown units. The units shown were determined using a climatology or some other method
    2. Original data were out of the range bounds outlined (Table 20)
    3. Time data are not sequential or date/time not valid
    4. Data failed T>=Tw>=Td test. In the free atmosphere, the value of the temperature is always greater than or equal to the wet-bulb temperature, which in turn is always greater than or equal to the dew point temperature
    5. Data failed resultant wind recomputation check. When the data set includes the platform's speed and direction along with the platform relative wind speed and direction, a program recomputes the earth relative wind speed and direction and compares the computed values to the reported earth relative wind speed and direction. A failed test occurs when the wind direction difference is > 10° or the wind speed difference is >5 m/s
    6. Platform velocity unrealistic. Determined by platform position and speed data
    7. Data are greater than 4 standard deviations from the COADS climatological means (da Silva et al. 1994). The test is only applied to pressure, temperature, sea temperature, relative humidity, and wind speed data.
    8. Discontinuity found in data
    9. Interesting feature found in data. More specific information on the feature is contained in the data reports. Examples include: hurricanes passing station, sharp sea water temperature gradients, strong convective events, etc
    10. Data are of poor quality by visual inspection, DO NOT USE
    11. Data suspect/use with caution - this flag applies when the data look to have obvious errors, but no specific reason for the error can be determined.
    12. Oceanographic platform passes over land or fixed platform moves dramatically
    13. Known instrument malfunction
    14. Position of platform or its movement are uncertain. Data should be used with caution
    15. Spike in the data. Usually one or two sequential data values (sometimes up to 4 values) that are drastically out of the current data trend. Spikes occur for many reasons including power surges, typos, data logging problems, lightning strikes, etc
    16. Data passed evaluation

    Table 20: Range Bounds used in determining the use of flag B 

    	Variable               Lower Bound      Upper Bound      Units         Other                 
	time                   1-1-1980         12-31-1999                                           
	latitude               90               90               degrees                             
	longitude              0                359              degrees                             
	platform heading       0                359              degrees                             
	platform speed         0                15               m/s           research vessels      
		 	       0                0                m/s           stationary buoys      
			       0                2                m/s           drifters              
	plat. wind direction   0                360              degrees                             
	plat. wind speed       0                40               m/s                                 
	wind direction         0                360              degrees                             
	wind speed             0                40               m/s                                 
	pressure               950              1050             mb            Sea level             
	air temperature        10               40               [[ring]]                            
															 Celsius                             
	wet bulb temperature   10               40               [[ring]]                            
															 Celsius                             
	dew point temperature  10               40               [[ring]]                            
															 Celsius                             
	sea temperature        0                35               [[ring]]                            
															 Celsius                             
	relative humidity      0                100              percent       radiation

    As an example of the usage of the flag variable, assume that a COARE ASCII file contains only time, latitude, longitude, atmospheric pressure, and air temperature data along with a flag variable. Based on Table 1, all five variables will be quality controlled and each will have a unique qcindex. If the values for the first record of all five variables pass all quality control checks, then the first record of the flag variable will contain "ZZZZZ"; i.e. the flag variable contains QC flags for each QC variable, in this example 5 flags. However, if the second record contains a non-sequential time, but good latitude and longitude values, a pressure value of 1090 mb, and a temperature that is 6 standard deviations from the climatology, then the second record of flag will contain "CZZBG". The qcindex allows access to the flags for any variable. For example, the flag for the second record for atmospheric pressure (qcindex=4) is a "B" indicating the pressure value is out of bounds.

3. Global Attributes

The global attributes in the COARE DPC ASCII files include parameters that apply to all the variables in the file or to the file in general. Again a mix of data and metadata are included.

  1. title
    A descriptive title highlighting the platform name, location, and special instrument characteristics. Often used to title plots of the data from the ASCII file. Ex: "Midas observations - R/V Wecoma - T/CLEG001 Cruise"

  2. site
    This attribute will contain either the alphanumeric R/V or land station name or a buoy location.

  3. elev
    Stores the geographic elevation of the site in meters above sea level. This value is zero for ships and buoys.

  4. ID
    Either the ship/platform identification, call sign, or WMO number.

  5. platform
    Instrument system that recorded the data. For example: IMET, ISS, ATLAS, unspecified tower, bridge report, hand held instruments, etc.

  6. facility
    The institution or country that either collected the data or are the primary holder of the data. For example: NOAA, PMEL, WHOI, University of Washington, Chile, etc.

  7. fsu_version
    The current version number or the data in the file.

  8. missing_value
    A missing value flag that is used for all variables. Typically set to -9999.

  9. startdate
    The first date of the data in the file. Coded as DD MMM YYYY where DD Day number (01 to 31), MMM Month (JAN,FEB,MAR,APR,MAY,JUN,JUL,AUG,SEP,OCT,NOV,DEC), YYYY Four digit year (ex: 1992)

  10. enddate
    The last date of the data in the file. Coded the same as startdate.

  11. Release_Date
    Date that QC data set was released by COARE DPC.

4. References

da Silva, A. M., C. C. Young, and S. Levitus, 1994: Atlas of Surface Marine Data, Volume 1: Algorithms and Procedures. NOAA Atlas Series. In preparation.

Slutz, R.J., S.J. Lubker, J.D. Hiscox, S.D. Woodruff, R.L. Jenne, D.H. Joseph, P.M. Steurer, and J.D. Elms, COADS (Comprehensive Ocean-Atmosphere Data Set) Release 1, pp. 300, CIRES University of Colorado, 1985.

Appendix 1

Example COARE-Met ASCII Data File 

CCVG.931007011v100.nc

title        :Vidal Gormaz: WOCE PR_14_/04
site         :Vidal Gormaz
elev         :0
ID           :CCVG
platform     :Standard instrument shelter on open bridge
facility     :Chilean Navy
fsu_version  :100
missing_value:-9999
startdate    :7 OCT 1993
enddate      :17 OCT 1993
EXPOCODE     :20VG
Release_Date :22 JUN 1995

Variable(qcindex) long_name                     units                      convers_units type      ht  inst                                              FORTRAN_format
ctc     (       )cruise track code                                                                                                                      A9             
time    (      1)time                          minutes from 1-1-1980 00:00                  2                                                           I12            
lat     (      2)latitude                      degrees                                 0                                                                F9.2           
lon     (      3)longitude                     degrees east                            0                                                                F9.2           
PL_HD   (      4)platform heading              degrees                                 5              Magellan 5000D GPS                                F9.0           
PL_SPD  (      5)platform speed                meters/second                           5              Magellan 5000D GPS                                F9.1           
DIR     (      6)earth relative wind direction degrees true                            0        15.24 calculated from F420G Electric Speed Indicator    F9.0           
SPD     (      7)earth relative wind speed     meters/second                           5        15.24 calculated from F420G Electric Speed Indicator    F9.0           
P       (      8)atmospheric pressure          millibars                               0    2    9.50 Lufft model 8103 quartz barograph                 F9.1           
T       (      9)air temperature               Celsius                                 0         9.00 Nurnberg thermometer                              F9.1           
TS      (     10)sea temperature               Celsius                                 0    1 -999.90 thermocouple                                      F9.1           
TD      (     11)dewpoint temperature          Celsius                                 2         9.00 NOAA/NWS ship synoptic code table                 F9.1           
TW      (     12)wet bulb temperature          Celsius                                 0         9.00 Nurnberg thermometer                              F9.1           
WX      (       )present weather                                                                                                                        I6             
TCA     (       )total cloud amount                                                    1                                                                I6             
LMCA    (       )low/middle cloud amount                                               1                                                                I6             
ZCL     (       )cloud base height                                                                                                                      I6             
LCT     (       )low cloud type                                                                                                                         I6             
MCT     (       )middle cloud type                                                                                                                      I6             
HCT     (       )high cloud type                                                                                                                        I6             
flag    (       )quality control flags                                                                                                                  A12            

      ctc        time      lat      lon    PL_HD   PL_SPD      DIR      SPD        P        T       TS       TD       TW    WX   TCA  LMCA   ZCL   LCT   MCT   HCT        flag
PR_14_/04     7240680   -37.90   285.90     229.      0.8     180.       7.   1015.8     12.5     13.3     10.0     11.5     3     1     0     9     0    10    10ZZZZZEKZZZZZ
PR_14_/04     7241040   -38.00   285.30     270.      5.1     190.      10.   1018.0     13.0     13.3     11.0     12.0     3     8     8     1     4    10    10ZZZZZEEZZZZZ
PR_14_/04     7241400   -37.90   285.20     269.      5.7     190.       7.   1019.8     14.0     13.3     12.0     13.0     2     8     8     4     3    10    10ZZZZZEKZZZZZ
PR_14_/04     7241760   -37.90   284.40     238.      1.0     190.      10.   1021.0     13.5     13.3      9.0     11.0     2     8     8     5     3    10    10ZZZZZEKZZZZZ
PR_14_/04     7242120   -38.00   283.40     270.      5.7     190.       8.   1020.0     12.0     13.3      8.0     10.0     2     4     4     5     1    10    10ZZZZZEEZZZZZ
PR_14_/04     7242480   -38.00   282.50     269.      5.7     190.       7.   1022.5     14.0     14.0      9.0     11.0     3     7     7     5     2     0     0ZZZZZEEZZZZZ
PR_14_/04     7242840   -38.00   281.60     260.      5.7     190.       5.   1022.0     16.5     12.8      9.0     12.5     2     8     8     5     1    10    10ZZZZZEEZZZZZ
PR_14_/04     7243200   -38.00   280.40     271.      5.7     180.       6.   1022.0     12.5     13.3      7.0     10.0     2     5     5     5     3    10    10ZZZZZKKZZZZZ
PR_14_/04     7243560   -38.00   279.40     269.      5.7     190.       3.   1022.5     13.0     13.4      7.0     10.0     3     3     3     4     4     0     0ZZZZZEEZZZZZ
PR_14_/04     7243920   -37.90   278.40     270.      5.7     270.       5.   1023.0     13.0     13.9     10.0     11.5     3     8     8     4     4     8     0ZZZZZEEZZZZZ
PR_14_/04     7244280   -38.00   277.80     270.      0.5     210.       2.   1023.5     14.5     14.0     10.0     12.0     3     6     6     5     2     0     0ZZZZZEKZZZZZ
PR_14_/04     7244640   -38.10   277.80     180.      5.7     190.       3.   1023.0     16.5     14.0     10.0     13.0     1     1     1     4     2     0     0ZZZZZKEZZZZZ
PR_14_/04     7245000   -40.00   277.80     180.      5.7     290.       4.   1024.0     12.0     13.3     10.0     11.0     1     1     1     4     2     0     0ZZZZZEKZZZZZ
PR_14_/04     7245360   -40.60   277.80     180.      5.7     320.       7.   1022.0     12.0     12.2      9.0     10.5     0     0     0     9     0     0     0ZZZZZEKZZZZZ
PR_14_/04     7245720   -41.70   277.80     185.      5.7     300.       8.   1020.5     14.0     11.7     13.0     13.5     3     5     5     5     3     0     0ZZZZZEKZZZZZ
PR_14_/04     7246080   -42.50   277.80     182.      6.2     330.      12.   1016.5     12.0     11.7     10.0     11.0     2     7     7     6     4     0     6ZZZZZEKZZZZZ
PR_14_/04     7246440   -43.30   277.80     180.      6.2     320.      12.   1014.2     10.5     10.6     10.0     10.0    80     6     6     3     4    10    10ZZZZZEKZZZZZ
PR_14_/04     7246800   -44.10   277.80     180.      5.1     270.       8.   1014.6     10.0     10.6      8.0      9.0     2     5     5     4     8    10    10ZZZZZEKZZZZZ
PR_14_/04     7247160   -44.80   277.70     190.      5.1     260.      12.   1015.0     11.5     10.6      9.0      9.5     3     8     8     2     1     0     0ZZZZZKKZZZZZ
PR_14_/04     7247520   -45.50   277.70     190.      4.6     310.       9.   1016.0      9.0      9.0      8.0      7.5     3     7     7     2     1     0     0ZZZZZEKZZZDD
PR_14_/04     7247880   -46.20   277.80     210.      5.1     310.       9.   1015.0      9.0      9.0      7.0      8.0     1     0     0    10     0     0     0ZZZZZEKZZZZZ
PR_14_/04     7248240   -46.90   277.80     235.      4.1     320.      11.   1011.5      9.0      8.9      8.0      7.5     3     9     8     2     7    10    10ZZZZZEKZZZDD
PR_14_/04     7248600   -47.50   277.80     145.      4.6     310.      10.   1007.0      9.0      9.0      5.0      7.0     3     8     8     5     4    10    10ZZZZZEKZZZZZ
PR_14_/04     7248960   -48.00   278.10      95.      6.2     300.      10.   1002.0      9.0      8.9      5.0      7.0     3     8     8     4     8    10    10ZZZZZEKZZZZZ
PR_14_/04     7249320   -48.00   279.30      35.      6.2     360.      11.    999.0      9.0      8.9      8.0      8.5     3     9     8     4    10    10    10ZZZZZEEZZZZZ
PR_14_/04     7249680   -47.90   280.50      60.      5.0     350.      12.    995.0     10.5      9.0      9.0     10.0    14     8     8     4     7    10    10ZZZZZEEZZZZZ
PR_14_/04     7250040   -47.80   280.70     340.      1.0     350.      20.    992.5     10.5      8.9      9.0     10.0    14     8     8     4     8    10    10ZZZZZEKZZZZZ
PR_14_/04     7250400   -47.70   280.70     335.      1.0     300.      15.    994.5      9.5      8.9      6.0      8.0 -9999     8     8     4     8    10    10ZZZZZEKZZZZZ
PR_14_/04     7250760   -48.00   280.80     330.      0.0     330.       6.    998.0      8.5      7.8      7.0      7.5    25     8     8     3     8    10    10ZZZZZEKZZZZZ
PR_14_/04     7251120   -47.90   281.90      90.      5.1     150.      11.    993.0      6.0      7.6      0.0      6.0    25     8     8     3     8    10    10ZZZZZEKZZZZZ
PR_14_/04     7251480   -48.00   283.00       0.      1.0     350.      14.    989.0     11.0      9.4      9.0     11.0    25     8     8     3     8    10    10ZZZZZKKZZZZZ
PR_14_/04     7251840   -47.90   283.90     345.      3.8     320.      18.    995.0      7.5     10.6      7.0      7.0     1     7     7     4     8    10    10ZZZZZKEZZZZZ
PR_14_/04     7252200   -46.90   283.80       8.      5.1     240.       7.    998.5      9.0      9.0      5.0      7.0     1     2     2     4     6     0    10ZZZZZEKZZZZZ
PR_14_/04     7252560   -45.80   284.00       3.      5.1     160.       7.    996.2      8.4     10.6      1.0      6.5     3     8     8     4     7    10    10ZZZZZEKZZZZZ
PR_14_/04     7252920   -44.90   284.10      12.      5.1     120.       3.    992.8      9.5     10.0      4.0      7.0     3     7     7     4     4    10    10ZZZZZEEZZZZZ
PR_14_/04     7253280   -43.90   284.30      15.      5.7     350.       6.    998.5     11.0      9.8      9.0     10.0     3     8     8     4     4    10    10ZZZZZEKZZZZZ
PR_14_/04     7253640   -42.90   284.60      12.      5.7     180.       7.   1000.0     10.5     11.7      7.0      9.0     3     8     8     4     4    10    10ZZZZZEKZZZZZ
PR_14_/04     7254000   -41.60   285.00      20.      5.9     240.       9.   1006.5     10.5     10.0      9.0     10.0    25     8     8     3     6    10    10ZZZZZEKZZZZZ
PR_14_/04     7254360   -40.90   285.10      12.      6.2     250.       7.   1011.0     11.5     12.8     10.0     11.0    25     5     5     3     6    10    10ZZZZZEKZZZZZ
PR_14_/04     7254720   -39.90   285.50      16.      6.2     280.       9.   1012.0     12.0     12.8      7.0      9.5     3     5     5     5     4    10    10ZZZZZEEZZZZZ
PR_14_/04     7255080   -38.70   285.80      12.      5.7     330.      10.   1013.0     11.5     12.8     11.0     11.0    23     5     5     4     4    10    10ZZZZZEEZZZZZ
PR_14_/04     7255440   -37.60   286.10      15.      5.7       0.       9.   1014.2     10.0     12.8      2.0      9.0     3     7     7     4     1    10    10ZZZZZEEZZZZZ
PR_14_/04     7255800   -36.70   286.70      50.      5.7     340.       9.   1016.0     13.5     12.2     12.0     13.0     1     7     7     5     1     3     2ZZZZZEEZZZZZ



Appendix 2


[Does not, will not exist]


Appendix 3



The following FORTRAN subroutine can be used to convert the time values from
the COARE ASCII files to two-digit year, month, day, hour, and minute values.
The routine processes individual time values (timestamp), but could be easily
modified to handle an entire time array.  The code can be acquired
electronically from:



	ftp coaremet.fsu.edu

	login anonymous

	cd pub/coare/src

	get invtime.f



and any problems that occur while using the code can be addressed to
coaremet@coaps.fsu.edu.


      subroutine invtime(timestamp,yr,mon,day,hr,min)
c      
c This subroutine will convert a minutes timestamp to a year/month
c date. Based on the function convtime by Shawn Smith (COAPS).
c
c Written the spring of 1995, several iterations.
c James N. Stricherz (stricherz@coaps.fsu.edu)
c
c This code returns correct results for the range of 01 Jan 1980 0000GMT
c thru 31 Dec 1999 2359GMT. I know it does, because I tried each minute
c of that range.
c
      integer year(1980:2000), month(13), leap_mon(13), min_day,
     +        min_hr, yr, mon, day, hr, min,timestamp,itime,tmon,ttime,
     +        thour
     
      data year /0, 527040, 1052640, 1578240, 2103840, 2630880, 3156480,
     +             3682080, 4207680, 4734720, 5260320, 5785920, 6311520,
     +             6838560, 7364160, 7889760, 8415360, 8942400, 9468000,
     +             9993600,10519200/    
      data month /0,  44640,  84960, 129600, 172800, 217440, 260640,
     +       305280, 349920, 393120, 437760, 480960,525600/
      data leap_mon /0,  44640,  86400, 131040, 174240, 218880, 262080,
     +          306720, 351360, 394560, 439200, 482400,527040/
      data min_day, min_hr /1440, 60/
*
*     ok, lets inverse the effects of the years -- subtract off the
*     number of minutes per year until it goes negative. iyr 
*     then gives the year that the time (in minutes) occurs...
*
      if (timestamp.ge.year(2000)) then
         yr=-9999
         return
      endif
      iyr=1979
      itime=timestamp
 10   iyr=iyr+1
      ttime=itime-year(iyr)
      if (ttime.le.0) then
         if (iyr.eq.1980) iyr=iyr+1
         iyr=iyr-1
         itime=itime-year(iyr)
      else
         goto 10
      endif
*
*     assign the return variable
*
      yr=iyr
*
*     ok, the remaining time is less than one full year, so convert
*     by the same method as above into months:
*
      imon=0
*
*     that darn leap month!
*
      if (mod(iyr,4).ne.0) then
*
*     increment the month, and subtract off the minutes from the
*     remaining time for a non-leap year
*
 20      imon=imon+1
         tmon=itime-month(imon)
         if (tmon.gt.0) then
            goto 20
         else if (tmon.lt.0) then
            imon=imon-1
            itime=itime-month(imon)
         else
            if (imon.gt.12) then
               imon=imon-12
               yr=yr+1
            endif
            mon=imon
            day=1
            hr=0
            min=0
            return
         endif
      else
*     
*     same thing, same code, but for a leap year
*
 30      imon=imon+1
         tmon=itime-leap_mon(imon)
         if (tmon.gt.0) then
            goto 30
         elseif (tmon.lt.0) then
            imon=imon-1
            itime=itime-month(imon)
         else
            if (imon.gt.12) then
               imon=imon-12
               yr=yr+1
            endif
            mon=imon
            day=1
            hr=0
            min=0
            return
         endif         
      endif
*
*     assign the return variable
*
      mon=imon
*
*     any remaining minutes will belong to day/hour/minutes
*     ok, let's get those pesky days!
*
      iday=0
 40   iday=iday+1
      ttime=itime-min_day
      if (ttime.ge.0) then
         itime=ttime
         goto 40
      endif
*
*     assign the return variable
*
      if (mod(iyr,4).eq.0.and.mon.gt.2) then
         day=iday-1
      else 
         day=iday
      endif
*
*     pick off the hours of the days...remember, hours can be 0, so
*     we start at -1
*
      ihour=-1
 50   ihour=ihour+1
      thour=itime-min_hr
      if (thour.ge.0) then
         itime=thour
         goto 50
      endif
*
*     assign the return variables
*
      hr=ihour
*
*     the remainder at this point is the minutes, so return them directly!
*
      min=itime
      return
      end





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