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| Titel |
Observing crosswind over urban terrain using scintillometer and Doppler lidar |
| VerfasserIn |
D. van Dinther, C. R. Wood, O. K. Hartogensis, A. Nordbo, E. J. O'Connor |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1867-1381
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 8, no. 4 ; Nr. 8, no. 4 (2015-04-24), S.1901-1911 |
| Datensatznummer |
250116307
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| Publikation (Nr.) |
 copernicus.org/amt-8-1901-2015.pdf |
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| Zusammenfassung |
| In this study, the crosswind (wind component perpendicular to a path,
U⊥) is measured by a scintillometer and estimated with Doppler
lidar above the urban environment of Helsinki, Finland, for 15 days. The
scintillometer allows acquisition of a path-averaged value of U⊥ (U⊥), while the lidar allows acquisition of path-resolved
U⊥ (U⊥ (x), where x is the position along the path). The
goal of this study is to evaluate the performance of scintillometer
U⊥ estimates for conditions under which U⊥ (x) is
variable. Two methods are applied to estimate U⊥ from the
scintillometer signal: the cumulative-spectrum method (relies on
scintillation spectra) and the look-up-table method (relies on time-lagged
correlation functions). The values of U⊥ of both methods
compare well with the lidar estimates, with root-mean-square deviations of
0.71 and 0.73 m s−1. This indicates that, given the data treatment
applied in this study, both measurement technologies are able to obtain
estimates of U⊥ in the complex urban environment. The
detailed investigation of four cases indicates that the cumulative-spectrum
method is less susceptible to a variable U⊥ (x) than the look-up-table
method. However, the look-up-table method can be adjusted to improve its
capabilities for estimating U⊥ under conditions under for
which U⊥ (x) is variable. |
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