Hawaii Ocean Time-series (HOT)
in the School of Ocean and Earth Science and Technology at the University of Hawai'i at Manoa
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Profiling Reflectance Radiometer (PRR)

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 PRR
FTP View Data
To assist in the interpretation of the data, it can be displayed using the Hawaii Ocean Time-series Data Organization & Graphical System (HOT-DOGS©).

Sampling Procedure

Vertical profiles of upwelling radiance and downwelling irradiance were made using a Biospherical PRR-600 Profiling Reflectance Radiometer. Surface irradiance was collected using a sister instrument (PRR-610). These instruments measures downwelling irradiance (Ed) and upwelling radiance (Lu) as well as surface irradiance (Es) from a deck unit on 7 wavelength channels (Table below). The radiance channels comply with the SeaWIFS satellite optical parameters. The instrument is lowered by hand and depending on the subsurface currents, is deployed to a depth between 125 and 175 meters.


Channel Downwelling
(Ed) 		Upwelling
(Lu) 		Surface
(Es)
1 412 412 412
2 443 443 443
3 490 490 490
4 510 510 510
5 555 555 555
6 665 665 665
7 PAR 683 PAR

Results

Figure 58 shows a time-series of the 1% light level and KPAR during the 25 years we've been collecting in-situ PAR data. Both vary seasonally. Data for HOT cruises 90-214 were collected using a Biospherical PRR-600, while cruises 215 (Sep 09) onward used a Satlantic HyperPro. The average 1% light-level at Station ALOHA is 105.6 m while the average KPAR between 100 & 150m is 0.0439 m-1.

This study is a collaborative effort between the College of Oceanic and Atmospheric Sciences of Oregon State University and the Laboratory for Microbial Oceanography of the University of Hawai'i at Manoa.