Dataset: Summary metrics of light and temperature at multiple sites and depths on the fore reef of Moorea, French Polynesia from 2005 to 2019

The researchers derived seven environmental variables related to sea water temperature and light regimes at each site and depth:

1) the mean of the maximum daily sea water temperature from June to November ('Max Daily Temp (Jun-Nov)'),

2) the mean of the maximum daily sea water temperature from December to May ('Max Daily Temp (Dec-May)'),

3) the mean of the minimum daily sea water temperature from December to May ('Min Daily Temp'),

4) the mean of the daily sea water temperature variance from December to May ('Temp Variance [Mean]'),

5) the maximum of the daily sea water temperature variance from December to May ('Temp Variance [Max]'),

6) the mean photosynthetically active radiation (PAR) from December to February ('Mean Light'), and

7) the minimum PAR from December to February ('Min Light').

The sea water temperature regimes at 10 m and 20 m were quantified based on the in situ time series (2005 – 2019) collected at 2 min intervals as part of the MCR-LTER program (http://mcrlter.msi.ucsb.edu/data/variable/) using Seabird Electronics SBE39 and SBE56 temperature recorders (0.002 °C accuracy, 0.0001 °C resolution, < 10 s response time) mounted onto plates directly affixed to the reef surface. Sea water temperatures for 5 m depth, where there were no loggers, were derived for each site based on SST and the diurnal and semi-diurnal variance observed at 2-min intervals in the backreef at 2 m and the forereef at 10 m. Daily average sea water temperatures at 5 m were interpolated onto a 2-min grid and realistic variability superimposed based on the time series of semi-diurnal and diurnal variability observed at 2 m and 10 m at each site focusing on variations between 1 hr and the local inertial period of 40 hrs.

PAR was derived for each site and depth based on satellite estimates of surface PAR and the diffuse attenuation coefficient for PAR (K_d(PAR)) available from the European Space Agency GlobColour datasets over the period April 2016 to April 2020 (http://www.globcolour.info/). Daily PAR and K_d(PAR) values were obtained around Mo'orea at a 1/24° resolution (approximately 6 x 6 km), with site specific values based on the average of the nearest 4 pixels (approximately 12 x 12 km). Depth specific PAR values (PAR_z) were then determined at 5, 10, and 20 m water depths at each site based on the site-specific PAR and K_d(PAR): PAR_z(Z) = PAR.e⁻ᴷᵈ⁽ᴾᴬᴿ⁾.²

A climatology was calculated for the time series of temperature and light at each site and depth, which closely resembled bimodal normal distributions corresponding to summer and winter seasons.