Long-term sea surface temperature measurements from the Leigh Marine Laboratory, northern New Zealand

Overview

Daily sea surface temperature (SST) measurements have been taken at <2 m depth at Goat Island, northeastern New Zealand, adjacent to the University of Auckland’s Leigh Marine Laboratory since 1967. The location is an open rocky coast in the outer part of the Hauraki Gulf that is exposed to wind and swells from the northeast direction.

The measurements were originally taken manually at 9am each day from the rocky shore (36 16.125 S; 174 47.996 E) using a bucket and thermometer. Since 2011, measurements have been taken by means of an electronic data logger (HOBO Water Temp Pro v2) attached ~1m below the surface to a mooring located approximately 200m offshore from the original sampling site (36 16.010 S; 174 48.070 E) on a sandy bottom ~12 m depth. The daily data set is mostly complete but there are some gaps, with the largest gap of 159 days occurring between the cessation of manual measurements and start of automated measurements (Cook et al. 2022). To allow analysis of long-term trends in the data set, these gaps have been infilled using a number of approaches (Shears et al In review; Shears and Bowen 2017; Cook et al. 2022).

This data collection includes the following three files that are explained in more detail below:

1. LeighSST_Manual_1967-2011.csv
2. LeighSST_Automated_2011-present_updated_29-01-2024.csv [updated periodically]
3. LeighSST_Infilled_1967-2023_updated_29-01-2024.csv

1. Manual daily SST measurements from 1967-2011 [LeighSST_Manual_1967-2011.csv]

This file contains the original daily measurements taken manually at 9 am from the rocky shore from 1st January 1967 to 30th April 2011. Daily measurements involved collecting a seawater from the shore, using a bucket on a rope lowered to ~2 m depth, and then measuring the temperature (±0.1^oC) with a calibrated mercury thermometer. When the ocean was too rough to safely access the shore measurements were taken from the nearby beach. The dataset is also available at http://hdl.handle.net/2292/20612

2. Automated SST measurements from 2011 to present [LeighSST_Automated_2011-present_updated_29-01-2024.csv]

This data set includes either hourly or half-hourly measurements of sea temperature since 7th October 2011 from the temperature logger located 1m below the surface at coordinates: 36 16.010 S; 174 48.070 E. There are two gaps in 2013 and 2014 when the mooring was lost and a period from 15/2/2023 to 1/3/2023 when the mooring sunk during Cyclone Gabrielle and the logger was on the seafloor at ~12 m depth.

The logger is collected and downloaded every 2-3 months and this file will be updated periodically with the new data.

Data from 2011 to 2014 is also available at http://hdl.handle.net/2292/25315

3. Daily infilled SST data set from 1967-2023 [LeighSST_Infilled_1967-2023_updated_29-01-2024.csv]

This data set provides a continuous daily record of SST at 9am at Leigh from 1967 to 2023. This includes the original manual measurements (1967-2011), daily 9 am values extracted from the logger data (2011-2023; rounded to 1dp for consistency with long-term data), and gaps in the time series infilled using a variety of methods. The infilled data set of Cook et al. (2022) was used to account for gaps in the daily data up until October 2011. This involved linear interpolation to fill short gaps (≤10 days) in the record and estimates from satellite-derived SST (European Space Agency Climate Change Initiative) to fill the large gap (159 days) between 1/5/2011 and 6/10/2011. Two gaps since 2011 (6/3/2013 – 13/6/2013 and 26/2/2014 – 20/5/2014) due to mooring loss were infilled using 9 am values from a nearby temperature logger (~600 m to the west; 36°15.96′S; 174°47.80′E; as in Shears and Bowen 2017).

This data set has been analyzed in Shears et al (In review).

References

• Cook F, Smith RO, Roughan M, Cullen NJ, Shears NT, Bowen M. 2022. Marine heatwaves in shallow coastal ecosystems are coupled with the atmosphere: insights from half a century of daily in situ temperature records. Frontiers in Climate. 4:207.
• Shears NT, Bowen MM. 2017. Half a century of coastal temperature records reveal complex warming trends in western boundary currents. Scientific Reports. 7:1–9.
• Shears NT, Bowen MM, Thoral F. In review. Long-term warming and record-breaking marine heatwaves in the Hauraki Gulf, northern New Zealand. New Zealand Journal of Marine and Freshwater Research