MIRAI MR08-05 Irradiance/Radiance

Last Modified: 2012-10-26
: MR08-05
: Processed (DMO)-QCed
: JAMSTEC
: Radiance, Irradiance, Fluorescence, PAR, Relative irradiance, Extinction coefficient
:
OCEANS > OCEAN OPTICS > EXTINCTION COEFFICIENTS
OCEANS > OCEAN OPTICS > IRRADIANCE
OCEANS > OCEAN OPTICS > PHOTOSYNTHETICALLY ACTIVE RADIATION

For Using Data

Makio Honda (JAMSTEC)
See Terms and Conditions about constrain of use.
See Terms and Conditions about data citation.
Optical measurement data during MR08-05 cruise were obtained by the following methods. See Data List for available data at each station. Observation and devices for this method are outlined below. For further information, please see Cruise Report.
The Optical measurement system consists of two instruments of the SeaWiFS Profiling Multichannel Radiometer (SPMR) and the SeaWiFS Multichannel Surface Reference (SMSR), as well as deck unit, winch and PC.
These instruments measure downwelling irradiance (Ed), upwelling radiance (Lu) and irradiance above the water surfaces (Es) continuously. (Photosynthetic organisms are able to use only the specific spectral range of solar radiation in the process of photosynthesis.) Upwelling radiance (Lu) is used to provide normalized water leaving radiance for SeaWiFS calibration and validation and the empirical development of radiative transfer algorithms for the exploration of ocean color satellite data. Details for these instruments are outlined below.

About SPMR
The SPMR measures vertical profiles of downwelling irradiance (Ed) and upwelling radiance (Lu) in 13-channel spectral bands, as well as instrument tilt, fluorometry, conductivity and an external temperature sensor.
It is deployed in a freefall mode through the water column.

1) Measurement method : Freefall
2) Observation depth : 0-100m (1.00 m/s)
3) Tilt : less than 3 degrees
4) Ed and Lu sensor : 13 channels
5) Other sensors : Tilt meter, fluorometer, conductivity and external temperature probe

About SMSR
The SMSR measures irradiance above the water surfaces (Es) in 13-channel spectral bands, which also has tilt meter and an internal temperature sensor. The SMSR is used for the derivation of the penetration of visible and ultra-violet light in the ocean, and for the determination of the vertical distribution of apparent optical properties for comparison with in-situ pigment measurements.

1) Measurement method : As a reference sensor which mounted on the anti-rolling system's deck and never shadowed by any ship structure.
2) Es sensor : 13 channels
3) Other sensors : Tilt meter

Observed data was analyzed by software and extinction rate and photosynthetically available radiation (PAR) were computed.
1) Manufacture : Satlantic Inc.
2) Instrument name : SeaWiFS Profiling Multichannel Radiometer
3) Field of view : Cosine response (Irradiance), 10degree in water(Radiance)
4) Collector area : 86.0mm2 (Irradiance)
5) Entrance aperture : 9.5mm diameter
6) Irradiance detector type : Custom 17mm2 and 33mm2 silicone photodiodes
7) Radiance detector type : Custom 13mm2 and 33mm2 silicone photodiodes
8) Spectral bandwidth : 10nm
9) Bandwidth range : 370-705nm
10) Filter type : Custom low fluorescence interference
11) Winch : Brook Ocean Technology Limited.
Device control and processing soft : Satlantic PROSOFT 6 (Satlantic Co. Ltd.)
Two types of data files are produced : BIN file and PAR file.
: MR08-05
: Processed (DMO)-QCed
: JAMSTEC
: Radiance, Irradiance, Fluorescence, PAR, Relative irradiance, Extinction coefficient
:
OCEANS > OCEAN OPTICS > EXTINCTION COEFFICIENTS
OCEANS > OCEAN OPTICS > IRRADIANCE
OCEANS > OCEAN OPTICS > PHOTOSYNTHETICALLY ACTIVE RADIATION

Observation Map

Imagery reproduced from ...

Data List

  File names
MR08-05_freefall.zip
: MR08-05
: Processed (DMO)-QCed
: JAMSTEC

Optical Measurement Data Sheet Format

Format information describes column no., column heading mnemonic and comments of optical measurement data sheet in MR08-05.
Optical measurement data are produced two types of data files: BIN file and PAR file.(see below.)
BIN file : Digital data of upwelling, downwelling radiance, irradiance above the water surfaces and fluorescence for every 1m from near surface to approximately 100m for respective wave lengths during freefall deployment.
PAR file : In situ PAR, surface PAR, relative irradiance and extinction coefficient each 1m from near surface to approximately 100m during freefall deployment.

Format Description for BIN file
Each data file contains six lines header (meta data) followed by data lines for each cast.
Missing value is presented by -999.

Header part of BIN file
Line No.Column Heading MnemonicComments
1CRUISEIDCruise ID
2STATIONIDStation name
3STARTDATEObservation start date (UTC: yyyymmdd)
4STARTTIMEObservation start time (UTC: hhmm)
5LATITUDEObservation start position Latitude degree
6LONGITUDEObservation start position Longitude degree

Data part of BIN file
Column No.Column Heading MnemonicComments
1PressureDepth (dbar)
2TimeHour (UTC: hh)
3TimeMinute (UTC: mm.mm)
4Lu380.3Upwelling radiance (µW/cm2/nm/sr)
5Lu399.8Upwelling radiance (µW/cm2/nm/sr)
6Lu412.4Upwelling radiance (µW/cm2/nm/sr)
7Lu442.8Upwelling radiance (µW/cm2/nm/sr)
8Lu455.8Upwelling radiance (µW/cm2/nm/sr)
9Lu489.6Upwelling radiance (µW/cm2/nm/sr)
10Lu519.3Upwelling radiance (µW/cm2/nm/sr)
11Lu554.5Upwelling radiance (µW/cm2/nm/sr)
12Lu564.6Upwelling radiance (µW/cm2/nm/sr)
13Lu619.2Upwelling radiance (µW/cm2/nm/sr)
14Lu665.6Upwelling radiance (µW/cm2/nm/sr)
15Lu682.6Upwelling radiance (µW/cm2/nm/sr)
16Lu704.5Upwelling radiance (µW/cm2/nm/sr)
17LuDARKCounts
18Ed380.0Downwelling irradiance (µW/cm2/nm)
19Ed399.7Downwelling irradiance (µW/cm2/nm)
20Ed412.4Downwelling irradiance (µW/cm2/nm)
21Ed442.9Downwelling irradiance (µW/cm2/nm)
22Ed455.2Downwelling irradiance (µW/cm2/nm)
23Ed489.4Downwelling irradiance (µW/cm2/nm)
24Ed519.8Downwelling irradiance (µW/cm2/nm)
25Ed554.9Downwelling irradiance (µW/cm2/nm)
26Ed565.1Downwelling irradiance (µW/cm2/nm)
27Ed619.3Downwelling irradiance (µW/cm2/nm)
28Ed665.5Downwelling irradiance (µW/cm2/nm)
29Ed682.8Downwelling irradiance (µW/cm2/nm)
30Ed705.2Downwelling irradiance (µW/cm2/nm)
31EdDARKCounts
32Es379.5Irradiance above the water surfaces (µW/cm2/nm)
33Es399.6Irradiance above the water surfaces (µW/cm2/nm)
34Es412.2Irradiance above the water surfaces (µW/cm2/nm)
35Es442.8Irradiance above the water surfaces (µW/cm2/nm)
36Es456.1Irradiance above the water surfaces (µW/cm2/nm)
37Es490.9Irradiance above the water surfaces (µW/cm2/nm)
38Es519.0Irradiance above the water surfaces (µW/cm2/nm)
39Es554.3Irradiance above the water surfaces (µW/cm2/nm)
40Es564.5Irradiance above the water surfaces (µW/cm2/nm)
41Es619.5Irradiance above the water surfaces (µW/cm2/nm)
42Es665.6Irradiance above the water surfaces (µW/cm2/nm)
43Es683.0Irradiance above the water surfaces (µW/cm2/nm)
44Es705.9Irradiance above the water surfaces (µW/cm2/nm)
45EsDARKCounts
46Fluor1Fluorescence (µg/L)
47VELFree fall velocity (m/s)

Format Description for PAR file
Each data file contains eight lines header (meta data) followed by data lines for each cast.
Missing value is presented by -999.
Header part of PAR file
Line No.Column Heading MnemonicComments
1CRUISEIDCruise ID
2STATIONIDStation name
3STARTDATEObservation start date (UTC: yyyymmdd)
4STARTTIMEObservation start time (UTC: hhmm)
5LATITUDEObservation start position Latitude degree
6LONGITUDEObservation start position Longitude degree
7K_PAR(0_)Surface extinction coefficience
8avg Par_REF(0+)Average Surface PAR

Data part of PAR file
Column No.Column Heading MnemonicComments
1PressureDepth (dbar)
2Par_REF(0+)Surface PAR (quanta/cm2/sec)
3Par_PROEach depth of
4LightRelative irradiance (%)
5K_PARExtinction coefficience (/m)


: MR08-05
: Processed (DMO)-QCed
: JAMSTEC
Flags of data quality control are as follows.

Related Information

Update History

2012-10-26
An observation data was registerd.