A Weather Station is Only as Good as its Installation and Operation
Weather stations are designed to operate outdoors in harsh conditions. Having an appropriately functioning meteorological station starts with selecting the appropriate equipment. Yet even the best stations require maintenance, particularly in extreme climates with tropical rains and humidity, extreme variations between wet and dry seasons, extreme heat or cold. Instruments collect dust, or are attacked or chewed by animals, or shielded by soiling. Power supplies fail. Communications modules may require adjustment from time to time, or network coverage may shift in remote areas. All of the variations that occur in the field may cause instruments to become unreliable, not perform as expected, or fail.
A good-quality, reliable weather station starts with the right equipment, and good-quality installation.
Many times, equipment manufactured for installation in moderate climates, or far from the equator where the sun can be presumed to be always south or north of the station, are not suitable for installation in many African countries where climates may be extreme or near the equator.
Initial installations may have errors or omissions that make it more likely to encounter reliability problems later on, or to unknowingly read biased data. These may include a lack of proper lightning protection, incorrect mounting or orientation of sensors, particularly for sensors such as solar radiation near the equator.
Figure 1 Pyranometer mounted with factory-supplied mounting kit was too close to the tower near the equator and experienced shading half the year. Pyranometer was also not level.
Figure 2 Failed o-ring on a temperature sensor mounted in region with aggressive variation between wet and dry seasons
Figure 3 Humidity, dust, and insects entered datalogger box as a result of failure in the seal, designed for use in more moderate climates.
Figure 4 A monkey in a tower by cables with disintegrating isolation sheaths
Ways to Improve the Quality of Reliability of Data from Hydrometeorological Stations
Many times, when purchasing hydrometeorological equipment, buyers budget for the cost of purchase but do not consider the total cost of ownership over the life of the equipment. As a result, the budget for purchase is made available but often not the budget for successful operation and upkeep.
Many industries have moved towards a “total cost of ownership” budgeting philosophy where the cost of owning an asset, such as a meteorological station, is considered over its lifetime of useful operation. In this view, the initial purchase cost is often only a fraction of the total cost of ownership, while the cost of ensuring the station operates properly over its lifetime is considered from the very beginning. By taking this into account, buyers can help assure that the resources are available to obtain the necessary performance from the hydrometeorological station over its useful lifetime – and to make sure that it serves its useful lifetime, instead of failing early due to lack of maintenance or parts. Such a “total cost of ownership” analysis allows buyers to see the real cost of owning an hydrometeorological station, and therefore be able to effectively compare available alternatives for the purchase, rent or service of a station.
Almost all stations today have communication facilities to report data. The good operation of these stations requires continuous monitoring and evaluation of data to detect potential errors or deviations, analyze the source and take appropriate corrective action. Successful operation of hydrometeorological stations requires continuous monitoring and continuous upkeep by specialized staff. That data monitored is usually not just the hydrometeorological parameters recorded by the station, but also the diagnostic parameters, such as battery voltage, charging intervals, temperature within the datalogger units, etc. Many hydrometeorological departments lack the resources needed for such continuous monitoring and as a result, the integrity of the data provided by their meteorological stations may suffer.
Many buyers and owners of assets are relying increasingly on long‑term service agreements for the operation and maintenance of their assets. Such models have long been prevalent in other fields, such as power generation, where it is common for a long-term service agreement to exist with the main contractor to operate and maintain an asset. Such agreements usually include providing all the necessary monitoring, diagnostics, maintenance, calibration and spare parts and can hold the operator responsible for the performance of the asset under certain conditions.
As a further extension of the principle of long-term service agreements, many public utilities now are being purchased purely on a service model, where private entities finance, own, and operate assets and provide a service to the buyer, whether that service is power, water, telecommunications, transport, or data. Meteorological services may evolve in much the same way with public meteorological departments entering into long-term agreements for the supply, installation, operation and provision of meteorological data. This removes the burden of operating remote equipment and helps ensure higher availability and quality of data by providing a responsible entity. It also helps define the total cost of ownership of the meteorological stations.
Whether by continuous monitoring of data, long-term service agreements, or provision of hydrometeorological data as a service, these models all help define and control the total cost of ownership of hydrometeorological measurements and information. They help owners obtain higher quality data and focus their resources on providing services to the public through such data.