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Introduction
The OAPA meteorological station records the main atmospheric variables in real time at the historical site of the Palermo Astronomical Observatory "G.S. Vaiana". Data are acquired through a Campbell Scientific CR1000 datalogger and made available for scientific and public consultation.
Operational status
| Acquisition status | Active |
|---|---|
| Data frequency | 1 sample per minute, obtained by combining 5 measurements acquired at 12-second intervals |
| Update | Real-time |
| Records in archive | 7.089.037 |
Published data are subject to consistency checks and may be updated or corrected following maintenance and scientific validation activities.
Data quality and treatment of non-conforming values
The site offers two read-only view modes, selectable on the data pages: raw data and filtered data (quality control).
- Raw data: the values recorded by the datalogger, exactly as stored in the database, with no correction applied.
- Filtered data (quality control): applies, in read-only mode, a set of quality checks: values marked as non-conforming are never deleted from the database, but are excluded from averages, min/max and charts in this view.
- Negative solar irradiance (caused by a night-time instrumental effect) is reported as zero in filtered mode; raw mode shows the actual recorded value.
- Rainfall marked as spurious (e.g. caused by strong wind gusts) is treated as zero in sums when in filtered mode; raw mode shows the actual recorded value.
- In some historical periods a variable may appear unavailable in filtered mode: this does not mean the measurement is missing, but that the recorded value is marked as non-conforming for that period.
- The site never modifies the database: neither view mode writes, alters or deletes data.
Measured variables
| Variable | Description | Unit | Notes |
|---|---|---|---|
| Air temperature | Air temperature measured by the station. | °C | Mean, minimum and maximum values. |
| Relative humidity | Percentage of moisture in the air. | % | Mean, minimum and maximum values. |
| Atmospheric pressure | Air pressure at the measurement site. | hPa | Mean value. |
| Wind speed | Wind intensity recorded by the station. | m/s | Mean value and maximum gust. |
| Wind direction | Prevailing wind direction. | ° | Vector representation. |
| Solar radiation | Incident solar energy measured by the station. | W/m² | Mean value. |
| Precipitation | Cumulative rainfall over the observation period. | mm | Period total. |
Instrumentation and site
| Data logger | Campbell Scientific CR1000 |
|---|---|
| Organisation | Palermo Astronomical Observatory (OAPa) — INAF |
| Measurement site | Palazzo Reale, Palermo |
| Coordinates | 38.1115° N, 13.3532° E |
| Elevation | 75 m a.s.l. |
| Electronic series start | 14 December 2012 |
| Resolution | 1 sample per minute, obtained by combining 5 measurements acquired at 12-second intervals |
| Update | Real-time |