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Observational Network and Drought Monitoring
Published in Saeid Eslamian, Faezeh Eslamian, Handbook of Drought and Water Scarcity, 2017
Meteorological observations are made with carefully calibrated and harmonized instruments such as barometer, thermometers, wind vane, anemometer, and raingauge at predetermined timings. Some observations like visibility, cloud amount, and cloud type are estimated by the observer. The number and type of instruments/sensors may vary from observatory to observatory. Human-operated observatory takes observations daily every 3 h starting from 00 GMT. These data are kept locally and communicated to a central location—the weather office, where these data are analyzed to issue weather forecast and warnings. Past data and current data are used to compute anomalies and the number of derived parameters. Agrometeorological observatories take observations on parameters like wind, temperature, humidity, evaporation, sunshine, soil temperature, and soil moisture. Observatories located at airports may take observations even at a shorter duration. Observatories at sea and the coast take observations on sea surface conditions also. There could be automatic instruments recording the observations and communicating to a computer and a computer network to send the entire data set to a designated location as soon as it is recorded. Some of these data flow across the globe.
Clock synchronisation: the establishment of Coordinated Universal Time (UTC) through the work of Louis Essen
Published in The International Journal for the History of Engineering & Technology, 2023
Time synchronisation between the ground station clocks was extended to the reference clocks at the USNO, Washington D.C., and the Royal Greenwich Observatory, Herstmonceux, East Sussex, by means of local, ground-wave radio transmissions. A comparison of reception times showed that, on 27 August 1962, UK time (UTC) was ahead of US time by 2,234 microseconds.64 This small difference was resolved by mutual agreement. Sutcliffe described the discussions as: A great compromise – there were no politics – we agreed and it was adjusted with nobody noticing. No, it didn’t go before any government committees – the whole lot would have been out of sync again before anyone came to a decision.65 As a result of this experiment, time signals in the US were advanced by 1 millisecond and time signals in the UK were retarded by 1 millisecond – thus bringing the two time scales into closer alignment. As other countries began to use atomic standards they adopted the same time and an international synchronised time service was established.66
Short-term variability of total column ozone from the Dobson spectrophotometer measurements at Belsk, Poland, in the period 23 March 1963–31 December 2019
Published in Tellus B: Chemical and Physical Meteorology, 2021
J. W. Krzyścin, B. Rajewska-Więch, J. Borkowski
TCO observations have been carried out at Belsk (the Central Geophysical Observatory of the Institute of Geophysics Belsk, Polish Academy of Sciences) since March 1963 using the Dobson spectrophotometer No. 84. The TCO retrieval follows the technique of the differential optical absorption spectroscopy applied to a wavelength pair with strong and weak ozone absorption in the UV range. The following pairs are used: A (305.5 and 325.0 nm), C (311.5 and 332.4 nm), and D (317.5 and 339.9 nm). Different combinations of double wavelengths pairs (AD, CD) and observation settings, direct sun (DS), zenith blue (ZB), and zenith cloudy (ZC), have been applied to achieve the highest possible accuracy of the TCO observation under given atmospheric conditions (Degórska et al., 1978).
New Zealand gravity reference stations 2020: history and development of the gravity network
Published in New Zealand Journal of Geology and Geophysics, 2022
Vaughan Stagpoole, Fabio Caratori Tontini, Yoichi Fukuda, Derek Woodward
In 2015 absolute gravity observations were undertaken at three South Island and five North Island locations using a Micro-g LaCoste FG-5 gravity meter from AuScope/RSES of the Australian National University (No. 237) and operated by Geoscience Australia (Stagpoole et al. 2015). The survey included Godley Head and Mt John absolute gravity sites, the IGSN71 sites in Dunedin (EQTT) and WELLINGTON-A (F6EE) and several new sites in the North Island including a purpose-built mark (WARG) near the Very Long Baseline Interferometry (VLBI) facility of the Warkworth radio astronomy observatory (Figure 4).