Local data format document for the GRENE Asia Monsoon project

Case: Surface meteorological observation data of Thai Meteorological Department

Note: The content of this page is just tentative.

Basic structure

Data are stored in a text file in ASCII code. (UTF8 code is allowed in comment lines and in some metadata lines.)

One file contains observations of one meteorological element at one location in one year.

One file contains, at first a set of data lines as the body, and then a set of metadata lines as the trailer.

Data lines

Lines beginning with ASCII characters other than "#".

Handled as space-separated columns. (Consecutive multiple spaces are equivalent to a single space.)

One line corresponds to one time point or one fixed-length time interval.

• Column 1: year
• Column 2: month
• Column 3: day
• Column 4: hour
• Column 5: time coordinate.
  • For daily data, day-of-year (1 for 1 Jan., 366 for 31 Dec. in leap year).
  • For hourly (also 3-hourly etc.) data, day-of-year with fractions. (0.0 for hour 00 1 Jan., 366.0 for hour 24 31 Dec. in leap year).
• Column 6: observed value.
• Column 7 and beyond: time-specific flags if they exist, null otherwise.

Example

1979  1  1  7    0.29167  1013.25

Comment lines

Lines beginning with a "#" followed by a space or another "#".

Containing any information relevant to human readers. Ignored by machine processing.

Example

# This is a comment line.

Metadata lines

Lines beginning with a "#" followed without spaces by a keyword and then a ":".

A keyword consists of upper and lower case alphabets, numerals and "_". (Space, invisible characters, "#" and ":" are explicitly excluded. Other ASCII characters may be allowed when appropriate.) Distinction between upper and lower cases is ignored. It is recommended to compose keywords in lower-case letters only.

Syntax of the content following ":" is specific to the keyword. The default is a plain English text which may contain spaces and punctuation marks.

Example

#element_name: air pressure at sea level
#unit: hPa
#source_provider: Thai Meteorological Department
#received_date: 2010-03-29
#converted_date: 2012-08-09

Metadata keywords and their meanings

A tentative version, documented in Japanese