Global Marine Observation Data Table - Columns in the MO table

Table Description:

The Marine table contains marine meteorological values measured during the hour ending at the stated date and time.

Marine reports are defined by position (latitude and longitude) and by time.

Duplicates can exist at a specified position and time, e.g. when ships are alongside for bunkering, so the identifier of the ship or buoy is part of the primary key of the entity.

Identifier is either call-sign or buoy-id, depending upon report type.

Please note that unlike for the other MIDAS Tables, the data in the Marine Observations table is not found by SRC-ID (i.e. station site) but by identifier (i.e. instrument). If you know the SRC-ID of the station of interest, you can find associated instruments via the BADC MIDAS Station Search facility.

Most marine observations do not include cloud layers, ice reports or precipitation.

The MIDAS Marine Observations table is partitioned by longitude_band_code and by ob_time. longitude_band_code is a single character in the range A - J, each covering a set of longitude values as follows:

longitude band code	longitude values covered	Approx. geographical area covered
A	-180 : -130	Mid-Pacific Ocean
B	-130 : -80	Eastern Pacific Ocean, Gulf of Mexico, Western Caribbean Sea and Hudson Bay
C	-80 : -50	Western Atlantic Ocean including Scotia Sea, Cape Horn area, Caribbean Sea, Sargasso Sea, Labrador Sea and Baffin Sea
D	-50 : -30	Mid-Atlantic Ocean
E	-30 : -20	Mid-Atlantic Ocean
F	-20 : 10	Western Atlantic Ocean including UK Coastal Waters, The Channel and North Sea, Greenland Sea, Bay of Biscay, Eastern Mediterranean Sea, Gulf of Guinea, Cape of Good Hope, Arctic Ocean
G	10 : 30	Arctic Ocean, Gulf of Bothnia, Baltic Sea, Western Mediterranean Sea, Cape Town
H	30 : 100	Indian Ocean, Arctic Ocean, Gulf of Aden, Red Sea, Persian Gulf, Bay of Bengal, Southern Ocean, Barents Sea, Black Sea, Arabian Sea
I	100 : 140	Arctic Ocean, Laptev Sea, Yellow Sea, South China Sea, Java Sea, Timor Sea, Philippine Sea, Sea of Japan, East Siberian Sea, Arafuro Sea, Eastern Indian Ocean
J	140 : 180	Arctic Ocean, Sea of Okhotsk, Bering Sea, Coral Sea, Tasman Sea

Columns in the MO table (133 parameters):

PK	Attribute	Description / Units / Precision
*	ob_time	Date and time of observation
*	latitude	0.1 deg
*	longitude	0.1 deg
*	id
*	id_type	Identifier type
*	version_flag	Observation version number - Use the row with '1', as this has been quality checked by the Met Office
	met_domain_name	Message type
*	longitude_band_code	There are 10 longitude bands that are clearly defined but not equally spaced around the globe: A -179.9999 : -130.0 B -129.9999 : -80.0 C -79.9999 : -50.0 D -49.9999 : -30.0 E -29.9999 : -20.0 F -19.9999 : 9.9000 G 9.9001 : 29.9000 H 29.9001 : 99.9000 I 99.9001 : 139.9000 J 139.9001 : 180.0
	ob_rcpt_code	Code for reception method
	rec_st_ind	State indicator for the record**
	country_format_num	Country format number
	src_opr_type	Source operation type code
	wind_direction	Wind direction from which the wind blows, measured in Degrees (true). The entry for an east wind is 090, that for a south wind is 180 and so on clockwise. Note that zero values in both wind speec and wind direction fields indicate that there was no wind blowing at the time of observation. More
	wind_speed	Wind speed in Knots
	prst_wx_id	Present weather code
	past_wx_id_1	Past weather code #1 - This is a number between 0-9 which details what the weather has been like in the last 6 hours for observations at 00, 06, 12, 1800 UTC, the last 3 hours for observations at 03, 09, 15, 2100 UTC and the previous hour at any other times. The past weather is only recorded when a manual observation is done at the station. definition
	past_wx_id_2	Past weather code #2 - Same principle as above but is used to cover two codes or just one code occurring throughout the appropriate period. If more than 2 codes apply for the period then the 2 highest are used. So for example if it rained for a whole hour at the 1000 UTC ob then the code would be 66. If there was rain and drizzle during the period it would be 65 and if cloud was covering more than half the sky during the period it would be 22. The past weather is always coded as two digits which are separated into id_1 and id_2 in MIDAS. definition
	cld_ttl_amt_id	Total cloud amount code - definition
	low_cld_type_id	Low cloud type code - definition
	med_cld_type_id	Medium cloud type code - definition
	hi_cld_type_id	High cloud type code - definition
	cld_base_amt_id	Cloud base amount code - definition
	cld_base_ht	Cloud base height decametres
	msl_pressure	Mean sea level air pressure Unit=1 hpa to the nearest 0.1 hpa Precision aneroid barometers are now in general use for measuring pressure and a correction for altitude is applied to obtain the value at mean sea level (MSL).
	visibility	Visibility decametres
	air_temperature	Air temperature Unit=1 deg C to the nearest 0.1 deg C
	dewpoint	Dewpoint temperature - is the temperature to which the air must be cooled to produce saturation with respect to water at its existing atmospheric pressure and humidity - more... Unit=1 deg C to the nearest 0.1 deg C
	wetb_temp	Wet bulb temperature - is the lowest temperature that can be obtained by evaporating water into the air. It measures the humidity of the air - more... Unit=1 deg C to the nearest 0.1 deg C
	sea_temperature	Sea Surface temperature (0.1 deg. C)
	pres_tdcy_id	Pressure tendency characteristic code
	pres_tdcy_amt	Amount of pressure change (0.1 hPa)
	wind_wave_per	Wind wave period - Wind Wave Period is the time (in seconds) that it takes successive wind wave crests or troughs to pass a fixed point. Precision is 0.1 sec.
	wind_wave_ht	Wind wave height - is the vertical distance (meters) between any wind wave crest and the succeeding wind wave trough (independent of swell waves). Precision is 0.1 metre.
	swell_dir_1	First Swell direction - The direction from which the first swell waves at the firstswell wave period (SWPD) are coming. The units are true degrees, to the nearest 10, from true North, increasing clockwise, with North as 0 (zero) degrees and East as 90 degrees. 0 means Calm, No Waves; 999 means Confused, Direction indeterminate.
	swell_period_1	First Swell wave period (0.1 sec) - Swell Period is the time (in seconds) that it takes successive swell wave crests or troughs pass a fixed point.
	swell_height_1	First Swell height (0.1 metre) - Swell height is the vertical distance (meters) between any swell crest and the succeeding swell wave trough.
	swell_dir_2	Second Swell direction - The direction from which the second swell waves at the second swell wave period (SWPD) are coming. The units are true degrees, to the nearest 10, from true North, increasing clockwise, with North as 0 (zero) degrees and East as 90 degrees. 0 means Calm, No Waves; 999 means Confused, Direction indeterminate.
	swell_period_2	Second Swell wave period (0.1 sec)
	swell_height_2	Second Swell height (0.1metre)
	msr_wave_dir	Wave direction (deg true)
	msr_wave_per	Measured mean wave period (0.1 sec)
	msr_wave_height	Measured wave height (0.1 metre)
	ship_direction	ship direction code - the ship direction in the last 3 hours. 0 - Ship stopped 1 - NE 2 - E 3 - SE 4 - S 5 - SW 6 - W 7 - NW 8 - N
	ship_distance	ship distance in nautical miles
	location_q	QC code - location**
	wind_direction_q	QC code - wind direction**
	wind_speed_q	QC code - wind speed**
	prst_wx_id_q	QC code - present weather code**
	past_wx_id_1_q	QC code - past weather code #1**
	past_wx_id_2_q	QC code - past weather code #2**
	cld_ttl_amt_id_q	QC code - cloud total amount**
	low_cld_type_id_q	QC code - low cloud type code**
	med_cld_type_id_q	QC code - medium cloud type code**
	hi_cld_type_id_q	QC code - high cloud type code**
	cld_base_amt_id_q	QC code - cloud base amount**
	cld_base_ht_q	QC code - cloud base height**
	visibility_q	QC code - visibility**
	msl_pressure_q	QC code - MSL pressure**
	air_temperature_q	QC code - Air temperature**
	dewpoint_q	QC code - dewpoint**
	wetb_temp_q	QC code - wetbulb temperature**
	sea_temperature_q	QC code - sea temperature**
	wind_wave_per_q	QC code - wind wave period**
	wind_wave_ht_q	QC code - wind wave height**
	swell_dir_1_q	QC code - swell direction #1**
	swell_period_1_q	QC code - swell period #1**
	swell_height_1_q	QC code - swell height #1**
	swell_dir_2_q	QC code - swell direction #2**
	swell_period_2_q	QC code - swell direction #2**
	swell_height_2_q	QC code - swell height #2**
	msr_wave_per_q	QC code - wave period**
	msr_wave_height_q	QC code - measured half metre wave height**
	location_j	Descriptor - location**
	wind_direction_j	Descriptor - wind direction**
	wind_speed_j	Descriptor - wind speed**
	prst_wx_id_j	Descriptor - present weather**
	past_wx_id_j	Descriptor - past weather**
	cld_amt_id_j	Descriptor - Cloud amount**
	cld_type_j	Descriptor - Cloud type**
	cld_ht_j	Descriptor - Cloud height**
	visibility_j	Descriptor - visibility**
	msl_pressure_j	Descriptor - MSL pressure**
	air_temperature_j	Descriptor - Air temperature**
	dewpoint_j	Descriptor - Dewpoint**
	wetb_temp_j	Descriptor - Wetbulb temperature**
	sea_temperature_j	Descriptor - Sea temperature**
	wind_wave_j	Descriptor - Wind wave**
	swell_j	Descriptor - Swell wave**
	msr_wave_j	Descriptor - Measured wave**
	meto_stmp_time
	midas_stmp_etime
	cld_amt_id_1	Layer cloud amount code #1
	cloud_type_id_1	Cloud type code #1
	cld_base_ht_id_1	Cloud base height code #1 (decametres)
	cld_amt_id_2	Layer cloud amount code #2
	cloud_type_id_2	Cloud type code #2
	cld_base_ht_id_2	Cloud base height code #2 (decametres)
	cld_amt_id_3	Layer cloud amount code #3
	cloud_type_id_3	Cloud type code #3
	cld_base_ht_id_3	Cloud base height code #3 (decametres)
	cld_amt_id_4	Layer cloud amount code #4
	cloud_type_id_4	Cloud type code #4
	cld_base_ht_id_4	Cloud base height code #4 (decametres)
	vert_vsby	Vertical visibility
	prcp_ob_hr_cnt	Precipitation hour count
	prcp_amt	Precipitation amount (mm)
	cld_amt_id_1_q	QC code - layer cloud amount #1, cloud type code #1 and cloud base ht code #1**
	cloud_type_id_1_q	QC code - layer cloud amount #1, cloud type code #1 and cloud base ht code #1**
	cld_base_ht_id_1_q	QC code - layer cloud amount #1, cloud type code #1 and cloud base ht code #1**
	cld_amt_id_2_q	QC code - layer cloud amount #2, cloud type code #2 and cloud base ht code #2**
	cloud_type_id_2_q	QC code - layer cloud amount #1, cloud type code #1 and cloud base ht code #2**
	cld_base_ht_id_2_q	QC code - layer cloud amount #1, cloud type code #1 and cloud base ht code #2**
	cld_amt_id_3_q	QC code - layer cloud amount #3, cloud type code #3 and cloud base ht code #3**
	cloud_type_id_3_q	QC code - layer cloud amount #3, cloud type code #3 and cloud base ht code #3**
	cld_base_ht_id_3_q	QC code - layer cloud amount #3, cloud type code #3 and cloud base ht code #3**
	cld_amt_id_4_q	QC code - layer cloud amount #4, cloud type code #4 and cloud base ht code #4**
	cloud_type_id_4_q	QC code - layer cloud amount #4, cloud type code #4 and cloud base ht code #4**
	cld_base_ht_id_4_q	QC code - layer cloud amount #4, cloud type code #4 and cloud base ht code #4**
	vert_vsby_q	QC code - vertical visibility**
	ice_format_id	Ice Formation ID Pre 1979: kind of ice 1979 and beyond: concentration/arrangement of sea ice - code 0639
	ice_age_id	Ice Age ID Pre 1979: effect of ice on navigation 1979 and beyond: stage of ice development - code 3739
	land_ice_type_id	Land-Ice Type ID Pre 1979: bearing of principal ice edge 1979 and beyond: ice of land origin - code 0439
	ice_edge_id	Ice edge ID Pre 1979: distance of ice edge from reporting ship; 1979 and beyond: bearing of principal ice edge - code 0739
	ice_cond_trnd	Ice Condition Trend Pre 1979: Orientation of ice edge; 1979 and beyond: Ice situation and trend over preceding 3 hours - code 5239
	ice_accr_type	Ice accretion type - code 1751
	ice_accr_thkn	Ice accretion thickness
	ice_accr_rate	Ice accretion rate - code 3551
	q10deg_sq_num	To be defined
	rltv_hum	Calculated relative humidity**
	rltv_hum_j	Descriptor - relative humidity**
	mar_max_gust_speed	Max gust speed in knots
	mar_max_gust_per	Period of maximum gust relative to current time, in minutes e.g. -60 is last hour
	mar_max_gust_speed_q	QC code - max gust speed**

** Details available to registered users only.

More information about the Met Office MIDAS data is available in the documentation provided by the Met Office.

How to start filtering the rows of data out:

1. As the data arrive at the Met Office it undergoes quality control to check that the data are correct and consistent with the surrounding data points. Whether the process has occured or not is indicated by the version flag (1 is the one to use as indicated in the table above).

2. To show the progress of the data through the quality control the various variables will have an associated _q value (e.g. air_temperature_q). This _q value will have different values for each record (see details in table above).

3. While the Met Office MIDAS system overwrites the existing entry in their database the BADC's MIDAS entries do not as the BADC takes snapshots of the the MIDAS database from time to time leading to duplicate entries occuring in our archive. If duplicate records are found, check the associated meto_stmp_time to determine which record is the most recent one - this is the one to use and the other(s) can be ignored.