A comparison of ABL heights inferred routinely from lidar and radiosondes at noontime
- 120 Downloads
The height of the atmospheric boundary layer (ABL) obtained with lidar and radiosondes is compared for a data set of 43 noon (12.00 GMT) cases in 1984. The data were selected to represent the synoptic circulation types appropriately. Lidar vertical profiles at 1064 nm were used to obtain three estimates for the ABL height (hlid), based on the first gradient in the back-scatter profile, namely, at the beginning, middle and top of the gradient. The boundary-layer height obtained with the radiosondes (hs) was determined with the dry-parcel-intersection method in unstable conditions. As a first guess for near-neutral and stable conditions, the height of the first significant level in the potential temperature profile was taken.
Overall, the boundary-layer thickness estimates agree surprisingly well (regression linehlidb=hs:cc.=0.93 and the standard error=121 m). However, in 10% of the cases, the lidar estimate was significantly lower (difference>400 m) than the routinely inferredhs. These outliers are discussed separately.
For stable conditions, an estimate of ABL height (hN) is also made based on the friction velocity and the Brunt-Väisälä frequency. The agreement betweenhNandhlidbis good.
rapid growth of the boundary layer arround the measurement time;
the presence of a deep entrainment layer leading to a large zone in which quantities are not well mixed;
a large systematic error of 100–200 m in the estimate of boundary-layer height obtained from the radiosonde due to the way that profiles are recorded, as a series of significant points.
KeywordsLidar Vertical Profile Atmospheric Boundary Layer Potential Temperature Friction Velocity
Unable to display preview. Download preview PDF.
- Annema, K. H., Monna, W. A. A. and Muller, S. H.: 1984, ‘A Comparative Investigation of Three Commercial Radiosonde Systems’, in:Instruments and Observing Methods Report No. 15: WMO Technical Conference on Instruments and Cost-Effective Meteorological Observations (TECEMO), Noordwijkerhout, The Netherlands, pp. 24–27.Google Scholar
- Beljaars, A. C. M. and Holtslag, A. A. M.: 1990, ‘Description of a Software Library for the Calculation of Surface Fluxes’,Environmental Software 5, 60–68.Google Scholar
- Boers, R., Eloranta, E. W. and Coulter, R. L.: 1984, ‘Lidar Observations of Mixed-Layer Dynamics: Tests of Parameterized Entrainment Models of Mixed-Layer Growth Rate’,J. Climate Appl. Meteorol. 23, 247–266.Google Scholar
- Coulter, R. L.: 1979, ‘A Comparison of Three Methods for Measuring Mixing-Layer Height’,J. Appl. Meteorol. 18, 1495–1499.Google Scholar
- Dop, H. van, de Haan, B. J. and Engeldal, C.: 1982, ‘The KNMI Mesoscale Air Pollution Model’, Scientific Report 82-6, Royal Netherlands Meteorological Institute, De Bilt.Google Scholar
- Driedonks, A. G. M.: 1981, ‘Dynamics of the Well-Mixed Atmospheric Boundary Layer’, Scientific Report 81-2, Royal Netherlands Meteorological Institute, De Bilt.Google Scholar
- Gryning, S. E., Holtslag, A. M. M., Irwin, J. S. and Sivertsen, B.: 1987, ‘Applied Dispersion Modelling Based on Meteorological Scaling Parameters’,Atmos. Environ. 21, 79–89.Google Scholar
- Hess, P. and Brezowsky, H.: 1977, “Katalog der Grosswetterlagen Europa's. 3., verbesserte und ergänzte Auflage’, Berichte des Deutchen Wetterdienstes, p. 113.Google Scholar
- Holtslag, A. A. M. and Nieuwstadt, F. T. M.: 1986, ‘Scaling the Atmospheric Boundary Layer’,Boundary-Layer Meteorol. 36, 201–209.Google Scholar
- Holtslag, A. A. M. and van Ulden, A. P.: 1983 ‘A Simple Scheme for Daytime Estimates of the Surface Fluxes from Routine Weather Data’,J. Climate Appl. Meteorol. 22, 517–529.Google Scholar
- Holzworth, G. C.: 1964, ‘Estimates of Mean Maximum Mixing Depths in the Contiguous United States’,Monthly Weather Review 92, 235–242.Google Scholar
- Kitaigorodskii, S. A. and Joffre, S. M.: 1988, ‘In Search of a Simple Scaling for the Height of the Stratified Atmospheric Boundary Layer’,Tellus 40A, 419–433.Google Scholar
- Monna, W. A. A. and Annema, K. H.: 1988, ‘A Comparative Investigation of the Vaisala Microcora and Digicora Ground Systems’, in:Instruments and Observing Methods Report No. 33: WMO Technical Conference on Instruments and Cost-Effective Meteorological Observations (TECEMO), Noordwijkerhout, The Netherlands, 24–27 September 1984.Google Scholar
- Nieuwstadt, F. T. M.: 1981, ‘The Nocturnal Boundary Layer’, Theory and Experiments. Scientific Report 81-1. Royal Netherlands Meteorological Institute, De Bilt.Google Scholar
- Salemink, H. W. M. and van Maanen, E. A.: 1985, Toepassingen van de LIDAR-meettechniek in atmosferisch onderzoek. RIVM rapport: 228201006 (in Dutch).Google Scholar
- Stull, R. B.: 1988,An Introduction to Boundary Layer Meteorology, Deventer: Kluwer Academic Publishers.Google Scholar
- Tennekes, H.: 1973, ‘A Model for the Dynamics of the Inversion above a Convective Boundary Layer’,J. Atm. Sci. 30, 558–567.Google Scholar
- Wieringa, J.: 1986, ‘Roughness-Dependent Geographical Interpolation of Surface Wind Speed Averages’,Quart. J. Royal Meteorol. Soc. 112, 867–889.Google Scholar
- WMO, 1988, International Codes, Volume I (Annex II to WMO Technical Regulations), WMO No. 306, WMO Geneva, Switzerland.Google Scholar
- Wyngaard, J. C.: 1984, ‘Toward Convective Boundary Layer Parameterization: A Scalar Transport Module’.J. Atm. Sci. 41, 1959–1969.Google Scholar