No abstract

Bora is a strong, temporally and spatially variable downslope wind that blows along the Eastern Adriatic Coast and many other dynamically similar places around the world. Bora mean velocity rarely exceeds 20 m/s, while its strong gusts create significant problems for engineering structures, traffic and agriculture. Previous meteorological and geophysical studies laid foundations on Bora large-and mesoscale motions, but further research is necessary to fully understand and resolve Bora turbulence in a form usable for engineers. In this study, unique high-frequency measurements, carried out simultaneously in three heights on a meteorological tower in the hinterland of the city of Split, Croatia, are analyzed for a single summertime Bora episode. Time histories and vertical profiles are studied for turbulence intensity, Reynolds shear stress and turbulence length scales in comparison with values recommended in major international wind engineering standards. Turbulence intensity and Reynolds shear stress proved to be not that sensitive to meandering of the mean wind velocity, as the observed values remain within the same range during the time record. This trend applies on mean wind velocities larger than 5 m/s, as for smaller velocities the spread of values increases considerably. Turbulence length scales are observed to increase with increasing mean wind velocity and vice versa. With increasing height from the ground, turbulence intensity and absolute Reynolds shear stress decrease, turbulence length scales increase, all in agreement with the atmospheric physics. However, while turbulence intensity, Reynolds shear stress and longitudinal turbulence length scales generally agree well with the values recommended in international standards for the respective terrain type,

Main text As part of the ongoing key comparison BIPM.QM-K1, a comparison has been performed between the ozone national standard of Croatia maintained by the Croatian Meteorological and Hydrological Service (DHMZ) and the common reference standard of the key comparison, maintained by the Bureau International des Poids et Mesures (BIPM). The instruments have been compared over a nominal ozone amount fraction range of 0 nmol mol-1 to 500 nmol mol-1. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

As part of the on-going key comparison BIPM.QM-K1, a comparison has been performed between the ozone national standard of Croatia maintained by the Meteorological and Hydrological Service (DHMZ) and the common reference standard of the key comparison, maintained by the Bureau International des Poids et Mesures (BIPM), via a transfer standard maintained by the National Institute of Standards and Technology (NIST). The instruments have been compared over a nominal ozone amount-of-substance fraction range of 0 nmol/mol to 500 nmol/mol. KEY WORDS FOR SEARCH Ozone, Standard Reference Photometer, BIPM, DHMZ, CIPM MRA, KCDB Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).