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Level 2b Cloudnet product:Liquid water content (scaled adiabatic method) on Météo France model gridData Home | Overview of Cloudnet products | Product list | Quicklooks | Conditions of useSummary
Dataset contentsSample NetCDF file: 20031001_chilbolton_lwc-adiabatic-meteo-france-grid.nc The following is a description of the variables in this product, produced automatically from the metadata in the sample file (using the nc2html unix utility): Dataset title: Liquid water content at Chilbolton, averaged to the Meteo-France ARPEGE grid.This dataset contains liquid water content derived using radar/lidar cloud boundaries and liquid water path from dual-wavelength microwave radiometers, averaged on to the grid of a forecast model. It also contains the liquid water content and liquid water path from that model, so may be used to calculate statistics quantifying the model performance.
Software version:1.1 Dimensions and coordinate variablestimeHours UTC
Type:single-precision floating-point vector Height above ground
Type:single-precision floating-point array (No coordinate variable) Variableshorizontal_resolutionHorizontal resolution of model
Type:single-precision floating-point scalar Height of radar above mean sea level
Type:single-precision floating-point scalar Time since initialization of forecast For each profile in the file this variable contains the time elapsed since the initialization time of the forecast from which it was taken. Note that the profiles in this file may be taken from more than one forecast. Units:hoursType:single-precision floating-point vector Rain rate threshold Measurements above a surface rain rate of greater than this value were excluded due to the possibility of strong attenuation leading to an underestimate of cloud fraction. Units:mm hr-1Type:single-precision floating-point scalar Height above ground
Type:single-precision floating-point array Observed mean liquid water content, 1 hour sampling This variable is the observed mean liquid water content estimated for pixels where the "categorization" data has diagnosed that liquid water is present, averaged onto the model grid with height, and 1 hour in time. The model temperature and pressure were used to estimate the theoretical adiabatic liquid water content gradient for each cloud base and the adiabatic liquid water content was scaled so that its integral matches the liquid water path obtained from a coincident microwave radiometer measurement. If the liquid layer is detected by the lidar only, there is the potential for cloud top height to be underestimated and if the integrated liquid water content is less than that measured by the microwave radiometer, the cloud top is extended until both agree. When microwave radiometer data were not available, liquid water content was not retrieved although the adiabatic value is still included in the lwc_adiabatic and lwc_adv_adiabatic variables. Rain present below the liquid is associated with an uncertain measurement of liquid water path and cloud boundaries so these profiles are not included. Units:kg m-3Type:single-precision floating-point array Observed mean liquid water content, 23.4 km. This variable is the same as the observed mean liquid water content, lwc, except that model winds were used to estimate the time taken to advect the model's horizontal resolution of 23.4 km (max 1 hour, min 10 minutes). Units:kg m-3Type:single-precision floating-point array Observed mean adiabatic liquid water content, 1 hour sampling This variable is the liquid water content that would be present if the cloud conformed to adiabatic conditions, for periods where liquid water path was available from coincident dual-wavelength microwave radiometer data. Units:kg m-3Type:single-precision floating-point array Observed mean adiabatic liquid water content, 23.4 km. This variable is the same as the adiabatic mean liquid water content, lwc_adiabatic, except that model winds were used to estimate the time taken to advect the model's horizontal resolution of 23.4 km (max 1 hour, min 10 minutes). Units:kg m-3Type:single-precision floating-point array Observed mean adiabatic liquid water content, 1 hour sampling This variable is the liquid water content that would be present if the cloud conformed to adiabatic conditions, including data where no liquid water path information was available. Units:kg m-3Type:single-precision floating-point array Observed mean adiabatic_inc_nolwp liquid water content, 23.4 km. This variable is the same as the adiabatic mean liquid water content, lwc_adiabatic_inc_nolwp, except that model winds were used to estimate the time taken to advect the model's horizontal resolution of 23.4 km (max 1 hour, min 10 minutes). Units:kg m-3Type:single-precision floating-point array Observed mean liquid water content (tophat distribution), 1 hour sampling This variable is the liquid water content assuming a tophat distribution. I.e. the profile of liquid water content in each layer is constant. Units:kg m-3Type:single-precision floating-point array Observed mean liquid water content (tophat distribution), 23.4 km. This variable is the same as lwc_th, except that model winds were used to estimate the time taken to advect the model's horizontal resolution of 23.4 km (max 1 hour, min 10 minutes). Units:kg m-3Type:single-precision floating-point array Std. of observed liquid water content, 1 hour sampling This variable is the standard deviation of the liquid water content estimated for pixels where the "categorization" data has diagnosed that liquid water is present, averaged onto the model grid with height, and 1 hour in time. The model temperature and pressure were used to estimate the theoretical adiabatic liquid water content gradient for each cloud base and the adiabatic liquid water content was scaled so that its integral matches the liquid water path obtained from a coincident microwave radiometer measurement. If the liquid layer is detected by the lidar only, there is the potential for cloud top height to be underestimated and if the integrated liquid water content is less than that measured by the microwave radiometer, the cloud top is extended until both agree. When microwave radiometer data were not available, liquid water content was not retrieved although the adiabatic value is still included in the lwc_adiabatic and lwc_adv_adiabatic variables. Rain present below the liquid is associated with an uncertain measurement of liquid water path and cloud boundaries so these profiles are not included. Units:kg m-3Type:single-precision floating-point array Std. of observed liquid water content, 23.4 km. This variable is the same as the standard deviation of the observed liquid water content, lwc_std, except that model winds were used to estimate the time taken to advect the model's horizontal resolution of 23.4 km (max 1 hour, min 10 minutes). Units:kg m-3Type:single-precision floating-point array Std. of observed adiabatic liquid water content, 1 hour sampling This variable is the standard deviation of the liquid water content that would be present if the cloud conformed to adiabatic conditions, for periods where liquid water path was available from coincident dual-wavelength microwave radiometer data. Units:kg m-3Type:single-precision floating-point array Std. of observed adiabatic liquid water content, 23.4 km. This variable is the same as the standard deviation of the adiabatic liquid water content, lwc_adiabatic_std, except that model winds were used to estimate the time taken to advect the model's horizontal resolution of 23.4 km (max 1 hour, min 10 minutes). Units:kg m-3Type:single-precision floating-point array Std. of observed adiabatic liquid water content, 1 hour sampling This variable is the standard deviation of the liquid water content that would be present if the cloud conformed to adiabatic conditions, including data where no liquid water path information was available. Units:kg m-3Type:single-precision floating-point array Std. of log10(observed adiabatic_inc_nolwp liquid water content), 23.4 km. This variable is the same as the standard deviation of the adiabatic log10(liquid water content), lwc_adiabatic_inc_nolwp_std_log, except that model winds were used to estimate the time taken to advect the model's horizontal resolution of 23.4 km (max 1 hour, min 10 minutes). Units:kg m-3Type:single-precision floating-point array Std. of observed liquid water content (tophat distribution), 1 hour sampling This variable is the standard deviation of the liquid water content assuming a tophat distribution. I.e. the profile of liquid water content in each layer is constant. Units:kg m-3Type:single-precision floating-point array Std. of observed liquid water content (tophat distribution), 23.4 km. This variable is the same as lwc_th_std, except that model winds were used to estimate the time taken to advect the model's horizontal resolution of 23.4 km (max 1 hour, min 10 minutes). Units:kg m-3Type:single-precision floating-point array Std. of log10(observed liquid water content), 1 hour sampling This variable is the standard deviation of the log10(liquid water content) estimated for pixels where the "categorization" data has diagnosed that liquid water is present, averaged onto the model grid with height, and 1 hour in time. The model temperature and pressure were used to estimate the theoretical adiabatic liquid water content gradient for each cloud base and the adiabatic liquid water content was scaled so that its integral matches the liquid water path obtained from a coincident microwave radiometer measurement. If the liquid layer is detected by the lidar only, there is the potential for cloud top height to be underestimated and if the integrated liquid water content is less than that measured by the microwave radiometer, the cloud top is extended until both agree. When microwave radiometer data were not available, liquid water content was not retrieved although the adiabatic value is still included in the lwc_adiabatic and lwc_adv_adiabatic variables. Rain present below the liquid is associated with an uncertain measurement of liquid water path and cloud boundaries so these profiles are not included. Units:kg m-3Type:single-precision floating-point array Std. of log10(observed liquid water content), 23.4 km. This variable is the same as the standard deviation of the log10(observed liquid water content), lwc_std_log, except that model winds were used to estimate the time taken to advect the model's horizontal resolution of 23.4 km (max 1 hour, min 10 minutes). Units:kg m-3Type:single-precision floating-point array Std. of log10(observed adiabatic liquid water content), 1 hour sampling This variable is the standard deviation of the log10(liquid water content) that would be present if the cloud conformed to adiabatic conditions, for periods where liquid water path was available from coincident dual-wavelength microwave radiometer data. Units:kg m-3Type:single-precision floating-point array Std. of log10(observed adiabatic liquid water content), 23.4 km. This variable is the same as the standard deviation of the adiabatic log10(liquid water content), lwc_adiabatic_std_log, except that model winds were used to estimate the time taken to advect the model's horizontal resolution of 23.4 km (max 1 hour, min 10 minutes). Units:kg m-3Type:single-precision floating-point array Std. of log10(observed adiabatic liquid water content), 1 hour sampling This variable is the standard deviation of the log10(liquid water content) that would be present if the cloud conformed to adiabatic conditions, including data where no liquid water path information was available. Units:kg m-3Type:single-precision floating-point array Std. of log10(observed liquid water content) (tophat distribution), 1 hour sampling This variable is the standard deviation of the log10(liquid water content) assuming a tophat distribution. I.e. the profile of liquid water content in each layer is constant. Units:kg m-3Type:single-precision floating-point array Std. of log (observed liquid water content) (tophat distribution), 23.4 km. This variable is the same as lwc_th_std_log, except that model winds were used to estimate the time taken to advect the model's horizontal resolution of 23.4 km (max 1 hour, min 10 minutes). Units:kg m-3Type:single-precision floating-point array Observed mean liquid water path, 1 hour sampling This variable is the observed [mean, min, max, std] of liquid water path retrieved from dual-wavelength microwave radiometers, averaged 1 hour in time. Rain present below liquid layers is associated with an uncertain measurement of liquid water path and cloud boundaries so these profiles are not included. Units:kg m-2Type:single-precision floating-point array Observed mean liquid water path, 23.4 km. This variable is the same as the observed liquid water path, lwp, except that model winds were used to estimate the time taken to advect the model's horizontal resolution of 23.4 km (max 1 hour, min 10 minutes). The mean wind, mean_wind_speed_adv, was calculated from the mean of model winds in the grid boxes in the profile that contain liquid water. Units:kg m-2Type:single-precision floating-point array Observed mean liquid water path, 23.4 km. This variable is the same as the observed liquid water path, lwp, except that model winds were used to estimate the time taken to advect the model's horizontal resolution of 23.4 km (max 1 hour, min 10 minutes). The mean wind, mean_wind_speed_adv_3km, was calculated from the mean of the magnitude of the model winds from 0 to 3 km in the vertical. Units:kg m-2Type:single-precision floating-point array Mean model winds where liquid water path is present in profile This variable is the mean model wind used to estimate the time taken to advect the model's horizontal resolution of 23.4 km. It was calulated from the mean of the magnitude of the model winds in the grid boxes that contain liquid water. Units:m s-1Type:single-precision floating-point vector Mean model wind direction where liquid water path is present in profile This variable is the mean of the model wind direction in the grid boxes that contain liquid water. Units:degreesType:single-precision floating-point vector Mean model winds from 0 to 3 km This variable is the mean model wind used to estimate the time taken to advect the model's horizontal resolution of 23.4 km. It was calulated from the mean of the model winds from 0 to 3 km in the vertical. Units:m s-1Type:single-precision floating-point vector Mean model wind direction from 0 to 3 km This variable is the mean of the model wind direction from 0 to 3 km in the vertical. Units:degreesType:single-precision floating-point vector Model liquid water content
Type:single-precision floating-point array Model liquid water path
Type:single-precision floating-point vector These pages are maintained by . |