The file annualmonthlymeans18952022withheader.csv ( download) has records of several monthly environmental measurements, from 1895 through 2022, for the SERC climatological region (Maryland Division 4 - upper southern). The data were provided by the NOAA National Centers for Environmental information, Climate at a Glance. While these measurements are not associated with dendrometer use, they give you an opportunity to search for trends and relationships that may correlate with the patterns you find in the dendrometer data file, or perhaps just to explore the long-term changes in these factors.
The header rows in the file give some background and the website origin of the data.
The data columns in this file are:
| Year | |
| Month | 1-12; 1=January |
| Decyr | The year, with the decimal part representing the mid-month date as a fraction of the year |
| Pmm | Monthly precipitation, in mm |
| PDSI | Palmer Drought Stress Index (see below) |
| Tmean | Mean monthly temperature (°C) |
| Tmin | Minimum monthly temperature (°C) |
| Tmax | Maximum monthly temperature (°C) |
The Palmer Drought Stress Index (PDSI) estimates the difference between precipitation over recent months and the plant demand for water. It scales from very wet (+3) to very dry (-3).
You could use the data from 2010 through 2022 to look for relationships between the dendrometer gap readings and the climate factors in this table. If you do that, are the relationships the same for each of the four trees or do different trees behave differently? What other factors might apply?
Or you might explore long-term trends such as temperature, precipitation, or soil moisture balance. What do they look like? Are there any correlations?