Atmospheric and seeing forecast: WRF model validation with in situ measurements at ORM★

Giordano, Christophe; Vernin, J.; Ramió, H. Vázquez; Muñoz–Tuñón, C.; Varela, A. M.; Trinquet, H.

doi:10.1093/mnras/stt117

Cited by 63 publications

(50 citation statements)

References 18 publications

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“…In most recent years other studies concerning the OT forecast on the whole atmosphere have been published using other mesoscale models (Trinquet & Vernin (2007); Cherubini et al (2008); Cherubini et al (2011); Giordano et al (2013); Liu et al (2015)) or using GCMs (Ye (2011); Osborn & Sarazin (2018)). Methods employed include the TKE prognostic equation approach and empirical approaches based on description of the C 2 N as a function of the temperature and wind speed.…”

Section: Introductionmentioning

confidence: 99%

Filtering techniques to enhance optical turbulence forecast performances at short time-scales

Masciadri

Martelloni

Turchi

2019

Monthly Notices of the Royal Astronomical Society

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The efficiency of the management of top-class ground-based astronomical facilities supported by Adaptive Optics (AO) relies on our ability to forecast the optical turbulence (OT) and a set of relevant atmospheric parameters. Indeed, in spite of the fact that the AO is able to achieve, at present, excellent levels of wavefront corrections (a Strehl Ratio up to 90% in H band), its performances strongly depend on the atmospheric conditions. Knowing in advance the atmospheric turbulence conditions allows an optimization of the AO use. It has already been proven that it is possible to provide reliable forecasts of the optical turbulence (C 2 N profiles and integrated astroclimatic parameters such as seeing, isoplanantic angle, wavefront coherence time, ...) for the next night. In this paper we prove that it is possible to improve the forecast performances on shorter time scales (order of one or two hours) with consistent gains (order of 2 to 8) employing filtering techniques that make use of real-time measurements. This has permitted us to achieve forecasts accuracies never obtained before and reach a fundamental milestone for the astronomical applications. The time scale of one or two hours is the most critical one for an efficient management of the ground-based telescopes supported by AO. We implemented this method in the operational forecast system of the Large Binocular Telescope, named ALTA Center that is, at our knowledge, the first operational system providing forecasts of turbulence and atmospheric parameters at short time scales to support science operations.

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Section: Introductionmentioning

confidence: 99%

Filtering techniques to enhance optical turbulence forecast performances at short time-scales

Masciadri

Martelloni

Turchi

2019

Monthly Notices of the Royal Astronomical Society

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“…In Giordano et al 2013 13 we showed that the WRF model is able to predict the weather and the optical turbulence with a rather good precision. Considering the characteristic scale of the optical turbulence, we thought that the finest resolution of 1 x 1km was not enough to reach the best precision, and we wanted to increase the accuracy of our forecast to really improve the flexible scheduling, and to create the best possible map of site quality.…”

Section: Discussionmentioning

confidence: 82%

“…Then Masciadri et al 1999 4, 5 and 2001 6 used Meso-Nh model to reconstruct the profile of the C 2 N . This model has been used and validate above different site (see Masciadri et al 2004 12 Giordano et al 2013, 13 and 2014 14 used the WRF model (see Klemp et al 2007 15 ) coupled with the Trinquet-Vernin (TV) model (Trinquet & Vernin 2007 16 ) to forecast the optical conditions and to define a map of astronomical quality at La Palma, Canary Islands, and especially above the Observatorio del Roque de los Muchachos (ORM). These studies lead us to say that the WRF/TV model is able to forecast meteorological and optical parameters such as the pressure, the temperature, the wind velocity, the seeing ε 0 , the isoplanatic angle θ 0 , and the coherence time τ 0 .…”

Section: Introductionmentioning

confidence: 99%

Seeing and ground meteorology forecast for site quality and observatory operations

et al. 2014

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The quality of astronomical observations is strongly related to the quality properties of the atmosphere. This parameter is important for the determination of the observation modes, and for observation program, the socalled flexible scheduling. We propose to present the implementation of the WRF model in order to routinely and automatically forecast the optical conditions. The purpose of our study is to predict 24 hours ahead the optical conditions above an observatory to optimize the observation time, not only the meteorological conditions at ground level, but also the vertical distribution of the optical turbulence and the wind speed, i.e the so-called astronomical seeing. The seeing is computed using the Trinquet-Vernin model coupled with the vertical profiles of the wind shear and the potential temperature predicted by the WRF model. We made a comparison between the WRF output and the in situ measurements made with the DIMM and an automatic weather station above the Observatorio del Roque de los Muchachos, Canary Island. Here we show that the increase of resolution in both the terrain model and 3D grid yields better forecast when compared with in situ optical and meteorological observations.

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“…One consists in the short time forecast which predicts the cloud coverage level up to a few days, while the other is based on the statistical analysis of longer term trends. Example of short time forecasts of observing conditions (including wind and turbulence) are in Masciadri et al (2002), Sarazin (2005), Giordano et al (2013), Cavaz-⋆ E-mail:stefano.cavazzani@unipd.it zani et al (2015), and Osborn et al (2018). On the other hand, the availability of longer term data from satellites permits a statistical approach and the search for periodic trends.…”

Section: Introductionmentioning

confidence: 99%

Detection of a 14-d atmospheric perturbation peak at Paranal associated with lunar cycles

Cavazzani

Ortolani

Scafetta

et al. 2019

Monthly Notices of the Royal Astronomical Society: Letters

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In this paper we investigate the correlation between the atmospheric perturbations at Paranal Observatory and the Chilean coast tides, which are mostly modulated by the 14-day syzygy solar-lunar tidal cycle. To this aim, we downloaded 15 years (2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017) of cloud coverage data from the AQUA satellite, in a matrix that includes also Armazones, the site of the European Extremely Large Telescope. By applying the Fast Fourier Transform to these data we detected a periodicity peak of about 14 days. We studied the tide cycle at Chanaral De Las Animas, on the ocean coast, for the year 2017, and we correlated it with the atmospheric perturbations at Paranal and the lunar phases. We found a significant correlation (96%) between the phenomena of short duration and intensity (1-3 days) and the tidal cycle at Chanaral. We then show that an atmospheric perturbation occurs at Paranal in concomitance with the low tide, which anticipates the full (or the new) moon by 3-4 days. This result allows to improve current weather forecasting models for astronomical observatories by introducing a lunar variable.

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Atmospheric and seeing forecast: WRF model validation with in situ measurements at ORM★

Cited by 63 publications

References 18 publications

Filtering techniques to enhance optical turbulence forecast performances at short time-scales

Filtering techniques to enhance optical turbulence forecast performances at short time-scales

Seeing and ground meteorology forecast for site quality and observatory operations

Detection of a 14-d atmospheric perturbation peak at Paranal associated with lunar cycles

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