Great Barrier Reef sea surface temperature: longitudinal anomaly 1998-2024, 2050, 2080

The summer mean longitudinal Sea Surface Temperature anomaly represents the temperature difference of any single 5km pixel with the temperature summer mean across a latitudinal transect. We define refugia as areas where the SST is more than 1°C cooler than the surrounding waters during the warm season (January to March), using hourly SST data from our regional model. We calculate hourly SST anomalies at each location by removing the longitudinal averages along a transect from the coast to the open ocean. We first average SST values at each latitude at each hour along a longitudinal transect—from the coast to 200 km past the edge of the continental shelf (defined by the 200-m isobath). Next, we compare the SST at each grid point along the transect with this average to calculate an anomaly value. The SST anomaly is thus calculated as T' = T - Tbar. Here, T is the SST at each grid point, and Tbar is the SST averaged over the longitudinal transect. Summer is defined from 01-January to 31-March. The date of the product is referred to as the middle of the summer days, 15-February.夏季平均纵向海表温度距平（Summer Mean Longitudinal Sea Surface Temperature Anomaly）指任意单个5公里分辨率像元的温度，与该纬向断面上的夏季平均温度之间的差值。我们将海洋避难所定义为暖季（1月至3月）海表温度较周边水域低1℃以上的区域，所用数据为区域模式输出的逐小时海表温度（Sea Surface Temperature, SST）资料。我们通过移除海岸至开阔洋面纬向断面上的纵向平均温度，计算各位置的逐小时海表温度距平。具体步骤如下：首先，对沿海岸至大陆架边缘（以200米等深线为界定标准）外200公里的纬向断面上，各纬度逐小时的海表温度求取平均；随后，将断面上各网格点的海表温度与该平均值进行对比，以计算距平值。海表温度距平的计算公式为 T' = T - T̄，其中T为单个网格点的海表温度，T̄为该纬向断面上的平均海表温度。本研究中的夏季定义为1月1日至3月31日。该数据集产品的参考日期设定为夏季中旬，即2月15日。