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We present the first coordinated study using two lidars at two separate locations to characterize a 1 h mesoscale gravity wave event in the mesopause region. The simultaneous observations were made with the Student Training and Atmospheric Research (STAR) Na Doppler lidar at Boulder, CO, and the Utah State University Na Doppler lidar and temperature mapper at Logan, UT, on 27 November 2013. The high precision possessed by the STAR lidar enabled these waves to be detected in vertical wind. The mean wave amplitudes are ~0.44 m/s in vertical wind and ~1% in relative temperature at altitudes of 82–107 km. Those in the zonal and meridional winds are 6.1 and 5.2 m/s averaged from 84 to 99 km. The horizontal and vertical wavelengths inferred from the mapper and lidars are ~219 ± 4 and 16.0 ± 0.3 km, respectively. The intrinsic period is ~1.3 h for the airglow layer, Doppler shifted by a mean wind of ~17 m/s. The wave packet propagates from Logan to Boulder with an azimuth angle of ~135° clockwise from north and an elevation angle of ~ 3° from the horizon. The observed phase difference between the two locations can be explained by the traveling time of the 1 h wave from Logan to Boulder, which is about ~2.4 h. The wave polarization relations are examined through the simultaneous quantifications of the three wind components and temperature. This study has developed a systematic methodology for fully characterizing mesoscale gravity waves, inspecting their intrinsic properties and validating the derivation of horizontal wave structures by applying multiple instruments from coordinated stations.

Abstract. Atmospheric temperatures and winds in the mesosphere and lower thermosphere have been measured simultaneously using the Aura satellite and a meteor radar at Bear Lake Observatory (42 • N, 111 • W), respectively. The data presented in this study is from the interval March 2008 to July 2011.The mean winds observed in the summer-time over Bear Lake Observatory show the meridional winds to be equatorward at meteor heights during April-August and to reach monthly-mean velocities of −12 m s −1 . The mean winds are closely related to temperatures in this region of the atmosphere and in the summer the coldest mesospheric temperatures occur about the same time as the strongest equatorward meridional winds. The zonal winds are eastward through most of the year and in the summer strong eastward zonal wind shears of up to ∼4.5 m s −1 km −1 are present. However, westward winds are observed at the upper heights in winter and sometimes during the equinoxes. Considerable inter-annual variability is observed in the mean winds and temperatures.Comparisons of the observed winds with URAP and HWM-07 reveal some large differences. Our radar zonal wind observations are generally more eastward than predicted by the URAP model zonal winds. Considering the radar meridional winds, in comparison to HWM-07 our observations reveal equatorward flow at all meteor heights in the summer whereas HWM-07 suggests that only weakly equatorward, or even poleward flows occur at the lower heights. However, the zonal winds observed by the radar and modelled by HWM-07 are generally similar in structure and strength.Signatures of the 16-and 5-day planetary waves are clearly evident in both the radar-wind data and Aura-temperature data. Short-lived wave events can reach large amplitudes of up to ∼15 m s −1 and 8 K and 20 m s −1 and 10 K for the 16-and 5-day waves, respectively. A clear seasonal and shortterm variability are observed in the 16-and 5-day planetary wave amplitudes. The 16-day wave reaches largest amplitude in winter and is also present in summer, but with smaller amplitudes. The 5-day wave reaches largest amplitude in winter and in late summer. An inter-annual variability in the amplitude of the planetary waves is evident in the four years of observations. Some 41 episodes of large-amplitude wave occurrence are identified. Temperature and wind amplitudes for these episodes, A T and A W , that passed the Student T-test were found to be related by, A T = 0.34 A W and A T = 0.62 A W for the 16-and 5-day wave, respectively.

this document, VOS rate and VOS tariff are used interchangeably to refer to the amount (number) that is being paid by the utility for solar generation by self-generating customers. The term VOS mechanism is used to refer to the policy or program in the broader sense. 2 Few studies, to date, have included cost components in the calculation of the VOS rate. The analysis conducted for this report is based on the most commonly discussed value components and does not include the costs of solar to the electricity system. 3 The goal of this report is not to estimate the VOS rate or "number" for any value component in any particular location. Research by NREL, Clean Power Research (CPR), Electric Power Research Institute (EPRI), Rocky Mountain Institute (RMI), and Interstate Renewable Energy Council (IREC) lays the foundation for performing VOS rate calculations; summaries of some existing VOS rate calculation research are presented in the Appendix A. vi This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications. for only the net excess generation that is fed back to the utility (that is, to subtract out any generation that is consumed on-site). The stakeholders in a VOS rate program have various interests and concerns, some shared and some individual. The utilities, regulators, and electricity customers all have an interest in the provision of reliable electric service that meets electricity demands into the future. Solar generation, being a local supply of power with no fuel cost, offers some future reliability benefit. Utilities will benefit from a VOS program that is straightforward to manage, a characteristic that can be considered during VOS program design. Utilities also may want to recover the costs of providing fixed-cost services (such as transmission and distribution) to their customers. A "buyall, sell-all" VOS program design separates the utility's compensation for solar generation from the customer's purchase of retail electricity, which can allow for full recovery of utility fixed costs. Policymakers have an interest in ensuring that the utility receives payment for the services that it provides and that cross-subsidies between solar and non-solar customers are minimized. They also may want to address increasing customer demand for distributed solar and to capture the associated environmental benefits. The DGPV owner is interested in having a long-term agreement to receive payment for solar generation that (at least) covers the cost of solar investment. The PV system generation purchaser/owner can benefit from the hedge that fixedcost solar electricity can provide from future increases in retail rates. By being alert to the existing market for solar, and adding interim support mechanisms to the VOS rate, if necessary, policy makers can support continued solar develop and address customer interests. x

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