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Montornes A.,University of Barcelona | Montornes A.,Aws Truepower | Codina B.,University of Barcelona | Zack J.W.,MESO Inc.
Atmospheric Chemistry and Physics | Year: 2015

Although ozone is an atmospheric gas with high spatial and temporal variability, mesoscale numerical weather prediction (NWP) models simplify the specification of ozone concentrations used in their shortwave schemes by using a few ozone profiles. In this paper, a two-part study is presented: (i) an evaluation of the quality of the ozone profiles provided for use with the shortwave schemes in the Advanced Research version of the Weather Research and Forecasting (WRF-ARW) model and (ii) an assessment of the impact of deficiencies in those profiles on the performance of model simulations of direct solar radiation. The first part compares simplified data sets used to specify the total ozone column in six schemes (i.e., Goddard, New Goddard, RRTMG, CAM, GFDL and Fu-Liou-Gu) with the Multi-Sensor Reanalysis data set during the period 1979-2008 examining the latitudinal, longitudinal and seasonal limitations in the ozone profile specifications of each parameterization. The results indicate that the maximum deviations are over the poles and show prominent longitudinal patterns in the departures due to the lack of representation of the patterns associated with the Brewer-Dobson circulation and the quasi-stationary features forced by the land-sea distribution, respectively. In the second part, the bias in the simulated direct solar radiation due to these deviations from the simplified spatial and temporal representation of the ozone distribution is analyzed for the New Goddard and CAM schemes using the Beer-Lambert-Bouguer law and for the GFDL using empirical equations. For radiative applications those simplifications introduce spatial and temporal biases with near-zero departures over the tropics throughout the year and increasing poleward with a maximum in the high middle latitudes during the winter of each hemisphere. © Author(s) 2015. Source

Montornes A.,University of Barcelona | Codina B.,University of Barcelona | Zack J.W.,MESO Inc. | Sola Y.,University of Barcelona
Atmospheric Chemistry and Physics | Year: 2016

Solar eclipses are predictable astronomical events that abruptly reduce the incoming solar radiation into the Earth's atmosphere, which frequently results in non-negligible changes in meteorological fields. The meteorological impacts of these events have been analyzed in many studies since the late 1960s. The recent growth in the solar energy industry has greatly increased the interest in providing more detail in the modeling of solar radiation variations in numerical weather prediction (NWP) models for the use in solar resource assessment and forecasting applications. The significant impact of the recent partial and total solar eclipses that occurred in the USA (23 October 2014) and Europe (20 March 2015) on solar power generation have provided additional motivation and interest for including these astronomical events in the current solar parameterizations. Although some studies added solar eclipse episodes within NWP codes in the 1990s and 2000s, they used eclipse parameterizations designed for a particular case study. In contrast to these earlier implementations, this paper documents a new package for the Weather Research and Forecasting-Advanced Research WRF (WRF-ARW) model that can simulate any partial, total or hybrid solar eclipse for the period 1950 to 2050 and is also extensible to a longer period. The algorithm analytically computes the trajectory of the Moon's shadow and the degree of obscuration of the solar disk at each grid point of the domain based on Bessel's method and the Five Millennium Catalog of Solar Eclipses provided by NASA, with a negligible computational time. Then, the incoming radiation is modified accordingly at each grid point of the domain. This contribution is divided in three parts. First, the implementation of Bessel's method is validated for solar eclipses in the period 1950-2050, by comparing the shadow trajectory with values provided by NASA. Latitude and longitude are determined with a bias lower than 5 × 10-3 degrees (i.e., ∼ 550 m at the Equator) and are slightly overestimated and underestimated, respectively. The second part includes a validation of the simulated global horizontal irradiance (GHI) for four total solar eclipses with measurements from the Baseline Surface Radiation Network (BSRN). The results show an improvement in mean absolute error (MAE) from 77 to 90 % under cloudless skies. Lower agreement between modeled and measured GHI is observed under cloudy conditions because the effect of clouds is not included in the simulations for a better analysis of the eclipse outcomes. Finally, an introductory discussion of eclipse-induced perturbations in the surface meteorological fields (e.g., temperature, wind speed) is provided by comparing the WRF-eclipse outcomes with control simulations. © 2016 Author(s). Source

Montornes A.,University of Barcelona | Codina B.,University of Barcelona | Zack J.W.,MESO Inc.
Tethys | Year: 2015

parameterizations. Differences in these approximations bring about to distinct results for the radiative fluxes, even under the same atmospheric conditions. 5 Since the transfer of solar and terrestrial radiation represents the primordial physical process that shapes the atmospheric circulation, those deviations must have and impact on the numerical weather prediction (NWP) model performance. In this paper, an analysis of the role of the shortwave 10 schemes on the Weather Research and Forecasting (WRFARW) model is presented. The study compares the effect of four parameterizations (Dudhia, New Goddard, CAM and RRTMG) in two cases: i) cloudless and ii) cloudy sky situations for a domain defined over Catalonia (northeast of the 15 Iberian Peninsula). We analyze the direct and the indirect feedback between the dynamical aspects and the physical parameterizations driven by changes on the radiative transfer equation computation. The cumulative effect of those variations are studied through three simulation windows: current 20 day (0-23 h), day-ahead (24-47 h) and two days ahead (48-71 h). These analyses are focused on several NWP model fields. From the most directly related to the shortwave schemes such as the global horizontal irradiance or the heating rate profile, 25 to apparently secondary outcomes such as the wind speed or the cloud composition among others. The observed differences between model runs using different solar parameterizations increase with the simulation horizon, being more important in the cloudy scenario than in the cloudless sky. © 2015, Associacio Catalana de Meteorologia . All rights reserved.. Source

Perez R.,University at Albany | Lorenz E.,University of Oldenburg | Pelland S.,Natural Resources Canada | Beauharnois M.,University at Albany | And 13 more authors.
Solar Energy | Year: 2013

This article combines and discusses three independent validations of global horizontal irradiance (GHI) multi-day forecast models that were conducted in the US, Canada and Europe. All forecast models are based directly or indirectly on numerical weather prediction (NWP). Two models are common to the three validation efforts - the ECMWF global model and the GFS-driven WRF mesoscale model - and allow general observations: (1) the GFS-based WRF- model forecasts do not perform as well as global forecast-based approaches such as ECMWF and (2) the simple averaging of models' output tends to perform better than individual models. © 2013 Elsevier Ltd. Source

Meso Inc. and Mano Nanotechnologies Inc. | Date: 2013-08-08

Disclosed herein is a drifting airborne probe that includes a body having an aerodynamic shape that is biologically inspired by a wind dispersible natural seed. The probe includes a total mass of less than 10 grams, a power source operably connected to the body; at least one sensor operably connected to the body for collecting data from the environment and about the environment, a transmitter for transmitting the data operably connected to the body and no active propulsion system. Disclosed herein is also a method for collecting and transmitting data about an environment that includes providing a plurality of these drifting airborne probes. Moreover, a system that utilizes a plurality of these drifting airborne probes is also provided.

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