Background

This R Markdown documents the preparation of the observed tide data recorded along the Florida Panhandle. The available record from 4 stations were downloaded from NOAA Tides and Currents (https://tidesandcurrents.noaa.gov/stations.html#Florida):

The text files were brought into Excel for cleaning. Date-Time gaps were filled in with empty cells in order to create a continuous time-series. Cells with error flags (i.e., 99, 999, 9999, as appropriate) were replaced with empty cells so as not to interfere with later analyses. The final cleaned Excel files were then brought into R for further analysis.

This analysis uses the following libraries:

library(dplyr)
library(knitr)
library(plotrix)
## [1] "This RMarkdown and the included analyses were built using R version 4.0.4 (2021-02-15)"

All Available Hourly Data

Below is a visualization of the available hourly tide data from the 4 stations. Note there are several small gaps within the various stations in addition to 1 large gap at the Panama City Beach station. Mean sea level for the various stations is ~0.10-0.15 m above the baseline for the NAVD88 vertical datum.

Below is a summary of the available tide data from each station. Though most high tides are no more than ~0.47 m NAVD88 (95th percentile), maximum observed tides - corresponding to storm surges - approach or exceed 2 m NAVD88.

Tidal Data - Hourly, 1998 to 2019
Pensacola #8729840 Panama City Beach #8729210 Panama City #8729108 Apalachicola #8728690
Mean 0.158 0.128 0.094 0.098
SE 0.000 0.001 0.000 0.001
N 185723.000 140760.000 185943.000 190511.000
Median 0.161 0.132 0.101 0.117
Min -0.650 -0.746 -0.812 -0.786
Max 1.966 1.946 1.834 2.565
95th Percentile 0.476 0.470 0.421 0.437


Nesting Season Only - Hourly Data

Below are visualizations of tide height only during the nesting season (May through October). Mean sea level during this time is slightly elevated relative to the full-year average - ~0.16-0.22 m above baseline for the NAVD88 vertical datum.

Below is a summary of the available tide data from each station. The 95th percentile high tide is slightly elevated (~0.50 m) relative to the full-year level. Note that the maximum observed tide heights occurred during the nesting season.

Nesting Season Tidal Data - Hourly, 1998 to 2019
Pensacola #8729840 Panama City Beach #8729210 Panama City #8729108 Apalachicola #8728690
Mean 0.225 0.198 0.161 0.158
SE 0.001 0.001 0.001 0.001
N 93194.000 69523.000 95697.000 96060.000
Median 0.223 0.195 0.161 0.179
Min -0.419 -0.462 -0.526 -0.711
Max 1.966 1.946 1.834 2.565
95th Percentile 0.510 0.501 0.450 0.461


Calculate average daily tidal minimum, maximum, and range by station within the nesting season

The tidal range is small in the northern Gulf of Mexico - ranging from 0.376 m to 0.518 m by station. Coupled with the low wave activity reported by the 3 offshore buoys, beaches in the study area are typically dissipative with broad, flat profiles.

Pensacola #8729840 Panama City Beach #8729210 Panama City #8729108 Apalachicola #8728690
mean High Tide (m NAVD88) 0.411 0.412 0.358 0.376
mean Low Tide (m NAVD88) 0.035 -0.008 -0.046 -0.142
mean Range (m NAVD88) 0.376 0.420 0.404 0.518


Intra-Annual Distributions

Below is the monthly and weekly high tide heights at each station derived from the hourly data. Note the general increasing trend throughout the nesting season. The highest daily tides correspond with typical hatchling emergence.