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lidar systems; the first one is devoted to stratospheric studies ( Clemesha and Rodrigues 1971 ) and the second one, an elastic backscatter lidar system, is devoted to tropospheric aerosol profiling for air pollution applications ( Landulfo et al. 2004 ). The synergy of ancillary meteorological measurements and simultaneous investigations of the optical properties of the suspended aerosols (by sun photometers or spectrophotometers) can provide additional information for reducing the lidar data
lidar systems; the first one is devoted to stratospheric studies ( Clemesha and Rodrigues 1971 ) and the second one, an elastic backscatter lidar system, is devoted to tropospheric aerosol profiling for air pollution applications ( Landulfo et al. 2004 ). The synergy of ancillary meteorological measurements and simultaneous investigations of the optical properties of the suspended aerosols (by sun photometers or spectrophotometers) can provide additional information for reducing the lidar data
sensing measurements can allow only the retrieval of optical and microphysical aerosol properties. Thus, it becomes evident that a complete characterization of aerosols needs the use of different and complementary instruments. Data from ground-based lidar and sun photometer, and particle counters on board an instrumented ultralight aircraft, have been used by Di Iorio et al. (2003) to characterize aerosol properties at the island of Lampedusa, during the Photochemical Activity and Ultraviolet
sensing measurements can allow only the retrieval of optical and microphysical aerosol properties. Thus, it becomes evident that a complete characterization of aerosols needs the use of different and complementary instruments. Data from ground-based lidar and sun photometer, and particle counters on board an instrumented ultralight aircraft, have been used by Di Iorio et al. (2003) to characterize aerosol properties at the island of Lampedusa, during the Photochemical Activity and Ultraviolet
(the transition layer between PBL and the free troposphere) are not well understood and thus are not well parameterized in atmospheric models. Observations of fluxes covering the entire PBL and the entrainment zone are rare. With respect to aerosols, vertical transport is even more complicated because the ascent of particles is often combined with water uptake because of a relative humidity increase with height in the PBL. The particle mass concentration and optical and microphysical properties
(the transition layer between PBL and the free troposphere) are not well understood and thus are not well parameterized in atmospheric models. Observations of fluxes covering the entire PBL and the entrainment zone are rare. With respect to aerosols, vertical transport is even more complicated because the ascent of particles is often combined with water uptake because of a relative humidity increase with height in the PBL. The particle mass concentration and optical and microphysical properties
and clouds is necessary mainly for obtaining better radiative forcing estimatesāone of the major uncertainties in understanding the influence of aerosols and precursor gases on weather, climate change, and underlying processesāand for refining models for improving satellite data retrieval algorithms. In view of the importance of aerosols in tropical atmospheric processes ( Hansen et al. 2000 ), the availability of data describing their main properties is rather poor, in particular with respect to
and clouds is necessary mainly for obtaining better radiative forcing estimatesāone of the major uncertainties in understanding the influence of aerosols and precursor gases on weather, climate change, and underlying processesāand for refining models for improving satellite data retrieval algorithms. In view of the importance of aerosols in tropical atmospheric processes ( Hansen et al. 2000 ), the availability of data describing their main properties is rather poor, in particular with respect to
; that is, it is a āmonostaticā lidar. The laser operates at a wavelength of 9.4 Ī¼ m. Using the MOPA configuration, amplitude modulation is applied to the CW beam to chop out pulses. The pulse width produced by the modulation is adjustable. We typically operate with a pulse width of 400 ns (60 m) when staring at zenith and 1 Ī¼ s (150 m) when scanning. Each pulsed beam passes through a CO 2 optical amplifier to increase the pulse energy to 1 mJ. In Fig. 1 , the black and green beam paths are CW
; that is, it is a āmonostaticā lidar. The laser operates at a wavelength of 9.4 Ī¼ m. Using the MOPA configuration, amplitude modulation is applied to the CW beam to chop out pulses. The pulse width produced by the modulation is adjustable. We typically operate with a pulse width of 400 ns (60 m) when staring at zenith and 1 Ī¼ s (150 m) when scanning. Each pulsed beam passes through a CO 2 optical amplifier to increase the pulse energy to 1 mJ. In Fig. 1 , the black and green beam paths are CW
comprises total power radiometers utilizing direct detection receivers within two bands. Band A contains seven channels from 22.335 to 31.4 GHz and band B contains seven channels from 51 to 58 GHz. The channels of band A are not only suited for determining LWP but also contain limited information about the vertical profile of humidity through the pressure broadening of the optically thin 22.235-GHz H 2 O line. The channels of band B, on the other hand, contain information on the vertical profile of
comprises total power radiometers utilizing direct detection receivers within two bands. Band A contains seven channels from 22.335 to 31.4 GHz and band B contains seven channels from 51 to 58 GHz. The channels of band A are not only suited for determining LWP but also contain limited information about the vertical profile of humidity through the pressure broadening of the optically thin 22.235-GHz H 2 O line. The channels of band B, on the other hand, contain information on the vertical profile of
of the density current (dc) depth to the inversion depth ( H ), as shown here: and The potential temperature jump across the inversion is denoted by Ī“Īø . This theory provides an approach for verifying the bore properties observed by the DIAL and Doppler systems. It can be difficult to distinguish bores from density currents and solitons. The passage of either a density current or a bore is typically identifiable by an abrupt pressure jump hydrostatically related to the mean cooling
of the density current (dc) depth to the inversion depth ( H ), as shown here: and The potential temperature jump across the inversion is denoted by Ī“Īø . This theory provides an approach for verifying the bore properties observed by the DIAL and Doppler systems. It can be difficult to distinguish bores from density currents and solitons. The passage of either a density current or a bore is typically identifiable by an abrupt pressure jump hydrostatically related to the mean cooling
forecasting. In this study, we are focusing on the determination of initial fields for mesoscale atmospheric modeling. Here, mathematical problems are indeed still an issue, as pointed out (e.g., in Rosatti et al. 2005 ; Steppeler et al. 2006 ). Furthermore, mesoscale forecasts are highly sensitive to the quality of model physics including land surface exchange ( Cheng and Cotton 2004 ; Trier et al. 2004 ; Holt et al. 2006 ), boundary layer properties ( Bright and Mullen 2002 ; Berg and Zhong 2005
forecasting. In this study, we are focusing on the determination of initial fields for mesoscale atmospheric modeling. Here, mathematical problems are indeed still an issue, as pointed out (e.g., in Rosatti et al. 2005 ; Steppeler et al. 2006 ). Furthermore, mesoscale forecasts are highly sensitive to the quality of model physics including land surface exchange ( Cheng and Cotton 2004 ; Trier et al. 2004 ; Holt et al. 2006 ), boundary layer properties ( Bright and Mullen 2002 ; Berg and Zhong 2005
the lamp itself. The procedure is divided into two parts. The first part is to determine the system calibration constant. The second is to measure the transmission and detection efficiency. The system calibration constant is derived from the convolution of the Raman band with the filter bandpass function along each optical path to the detector. The result is scaled by the transmission and detection efficiency measured by using a calibrated irradiance lamp applied directly to the system. The
the lamp itself. The procedure is divided into two parts. The first part is to determine the system calibration constant. The second is to measure the transmission and detection efficiency. The system calibration constant is derived from the convolution of the Raman band with the filter bandpass function along each optical path to the detector. The result is scaled by the transmission and detection efficiency measured by using a calibrated irradiance lamp applied directly to the system. The
of the lower atmosphere is the boundary layer radar (BLR). The term BLR is generally applied to a class of pulsed Doppler radar that transmits radio waves vertically, or nearly vertically, and receives Bragg backscattered signals from refractive index fluctuations of the optically clear atmosphere. The operating frequency of this type of radar is typically near 1 GHz. Therefore, the Bragg scale is such that BLRs are sensitive to turbulent structures that have spatial scales near 15 cm. Enhanced
of the lower atmosphere is the boundary layer radar (BLR). The term BLR is generally applied to a class of pulsed Doppler radar that transmits radio waves vertically, or nearly vertically, and receives Bragg backscattered signals from refractive index fluctuations of the optically clear atmosphere. The operating frequency of this type of radar is typically near 1 GHz. Therefore, the Bragg scale is such that BLRs are sensitive to turbulent structures that have spatial scales near 15 cm. Enhanced
