Daily air and water temperatures, monthly mean wave heights, and monthly tidal extremes from central Oregon to southern California

Latitudinal variation in intertidal conditionsTemperature Logger Data AnalysisTo characterize the temperature regime at each site (see Sites dataset), we used existing temperature loggers deployed by the PISCO and MARINe research programs during 2016-2018. Most sites (n = 25) had at least one logger deployed during the study but several sites (n=8) did not, so we used the nearest site with a logger, with a maximum distance of 44.8 km away from a site. Temperature loggers (HOBO TidBit v2 by Onset) were deployed at fixed locations inside steel mesh cages, set to record every 15 mins, and swapped every ~6-12 months. Once loggers were collected, we assigned the tidal levels for each site and time stamp using Xtide software (https://flaterco.com/xtide/files.html) and the nearest harmonic tidal station (see Environmental Stations). We included logger temperatures for 2016 – 2018 since not all sites had loggers deployed continuously in 2018 alone. We graphed the temperature and the tide heights for each logger, and used this to visually estimate the shore level of the logger to the nearest 0.5 ft (air temperatures have clearly higher variance than water temperatures). We assigned any tide height higher than the logger height as “water” and any tide height lower than the logger height as “air”. We calculated the daily average mean and maximum air and water temperatures at each site, then graphed the monthly means with latitude to visualize latitudinal trends. We also calculated the average daily mean and maximum water temperature from 2016-2018. On wavy days, temperatures assigned as air temperatures probably intermittently submerged. However, we are more interested in air temperature stress than average air temperature, so our focal air temperature metric was maximum daily air temperature, which likely occurred during the lowest tides when waves were not washing over the loggers.Tidal Extremes, Tidal Amplitude, and Significant Wave HeightTo broadly characterize tidal levels and wave exposure trends that may influence the latitudinal and vertical ranges of our focal species, we queried daily environmental data during 2018 from offshore NOAA offshore oceanographic buoys for waves (https://www.ndbc.noaa.gov/obs.shtml) and onshore tidal stations for tides (https://tidesandcurrents.noaa.gov/stations.html?type=Water+Level+Reports) closest to each of our sites (see Environmental Stations). We calculated and graphed the average daily and then monthly mean significant wave height (i.e., highest ⅓ of waves) from each oceanographic buoy and the highest and lowest monthly tidal extremes for each onshore tidal station.

潮间带环境的纬度梯度变化——温度记录仪数据分析

为表征各采样点的温度格局（采样点数据集（Sites dataset）详见对应部分），我们使用了PISCO与MARINe研究项目于2016-2018年间布设的现有温度记录仪。多数采样点（n=25）在本研究期间至少布设了一台温度记录仪，但另有8个采样点未布设相关设备，因此我们采用了距离目标采样点最近的布设记录仪的采样点数据，两点间最大直线距离为44.8公里。

所用温度记录仪为Onset公司生产的HOBO TidBit v2，被安装于钢制网笼内的固定位置，设置为每15分钟记录一次数据，约每6至12个月更换一次。

完成记录仪回收后，我们使用Xtide软件（https://flaterco.com/xtide/files.html）及距离最近的谐波潮汐站，为各采样点的每个时间戳分配对应潮汐水位信息，相关谐波潮汐站信息详见环境监测站（Environmental Stations）。由于并非所有采样点在2018年全年都持续布设记录仪，我们纳入了2016至2018年的全部记录仪温度数据。

我们为每台记录仪绘制了温度与潮高的变化曲线，并以此将记录仪所在岸线高度目测估算至最近的0.5英尺（空气温度的波动幅度明显高于海水温度）。我们将潮高高于记录仪安装高度的时段归类为「浸水时段」，潮高低于记录仪安装高度的时段归类为「曝露于空气的时段」。

我们计算了各采样点每日的平均气温、最高气温、平均海水温度与最高海水温度，随后绘制了月均温度与纬度的关系图，以可视化呈现纬度梯度趋势。我们还计算了2016至2018年间的日均平均与最高海水温度。

在多浪天气中，被归类为空气温度的时段可能会间歇性被海水淹没。不过本研究更关注空气温度胁迫而非平均气温，因此我们选取的核心气温指标为每日最高气温——该温度通常出现在最低潮且海浪未冲刷记录仪的时段。

潮汐极值、潮汐振幅与有效波高

为全面表征可能影响目标物种纬度与垂直分布范围的潮汐水位与波浪暴露趋势，我们从距各采样点最近的NOAA离岸海洋浮标（https://www.ndbc.noaa.gov/obs.shtml）获取2018年的海浪环境数据，从最近的沿岸潮汐站获取2018年的潮汐数据，相关站点信息详见环境监测站（Environmental Stations），其中沿岸潮汐站数据来源于https://tidesandcurrents.noaa.gov/stations.html?type=Water+Level+Reports。

我们计算并绘制了各海洋浮标的日均、月均有效波高（即排名前三分之一的海浪高度），以及各沿岸潮汐站的月均最高与最低潮汐极值。