netcdf hope_lac_cln00_l4_cllw_1_7297064759646302936 { dimensions: time = UNLIMITED ; // (2880 currently) height = 491 ; nv = 2 ; variables: double time(time) ; time:standard_name = "time" ; time:long_name = "time of profile" ; time:units = "seconds since 1970-01-01 00:00:00" ; time:bounds = "time_bnds" ; double time_bnds(time, nv) ; float zag(height) ; zag:standard_name = "height" ; zag:long_name = "height above ground" ; zag:units = "m" ; zag:bounds = "zag_bnds" ; float zag_bnds(height, nv) ; float zsl ; zsl:standard_name = "altitude" ; zsl:long_name = "Altitude above mean sea level" ; zsl:units = "m" ; float lon ; lon:standard_name = "longitude" ; lon:units = "degree_east" ; float lat ; lat:standard_name = "latitude" ; lat:units = "degree_north" ; float cllw(time, height) ; cllw:standard_name = "mass_concentration_of_cloud_liquid_water_in_air" ; cllw:long_name = "adiabatically scaled liquid water content" ; cllw:units = "kg m-3" ; cllw:_FillValue = -999.f ; cllw:comment = "This variable was calculated for the profiles where the \"categorization\" data has diagnosed that liquid water is present \n", "and liquid water path is available from a coincident microwave radiometer. The model temperature and pressure were used to estimate the \n", "theoretical adiabatic liquid water content gradient for each cloud base and the adiabatic liquid water content is then scaled so that its \n", "integral matches the radiometer measurement so that the liquid water content now follows a quasi-adiabatic profile. If the liquid layer is \n", "detected by the lidar only, there is the potential for cloud top height to be underestimated and so if the adiabatic integrated liquid water \n", "content is less than that measured by the microwave radiometer, the cloud top is extended until the adiabatic integrated liquid water content \n", "agrees with the value measured by the microwave radiometer. \n", "Missing values indicate that either 1) a liquid water layer was diagnosed but no microwave radiometer data was available, \n", "2) a liquid water layer was diagnosed but the microwave radiometer data was unreliable; this may be because a melting layer was present in the profile, \n", "or because the retrieved lwp was unphysical (values of zero are not uncommon for thin supercooled liquid layers), or \n", "3) that rain is present in the profile and therefore, the vertical extent of liquid layers is difficult to ascertain. \n", "The error variable is determined as follows: \n", "lwc_error=10*log[ (X+dX)/X ] with X being the measured value and dX being the absolute uncertainty." ; float cllw_error(time, height) ; cllw_error:long_name = "error of adiabatically scaled liquid water content" ; cllw_error:units = "dB" ; cllw_error:_FillValue = -999.f ; cllw_error:comment = "This variable is an estimate of the random error in liquid water content due to the uncertainty in the microwave radiometer \n", "liquid water path retrieval and the uncertainty in cloud base and/or cloud top height. This is associated with the resolution of the grid used, 31 m, \n", "which can affect both cloud base and cloud top. If the liquid layer is detected by the lidar only, there is the potential for cloud top height to be underestimated. \n", "Similarly, there is the possibility that the lidar may not detect the second cloud base when multiple layers are present and the cloud base will be \n", "overestimated. It is assumed that the error contribution arising from using the model temperature and pressure at cloud base is negligible.\n", "The error variable is determined as follows:\n", "lwc_error=10*log[ (X+dX)/X ] with X being themeasured value and dX being the absolute uncertainty." ; short cllw_retrieval_status(time, height) ; cllw_retrieval_status:long_name = "cloud liquid water content retrieval status" ; cllw_retrieval_status:units = "1" ; cllw_retrieval_status:definition = "0: No liquid water\n", "1: Reliable retrieval\n", "2: Adiabatic retrieval: cloud top adjusted\n", "3: Adiabatic retrieval: new cloud pixel\n", "4: Unreliable lwp: no retrieval\n", "5: Unreliable lwp/cloud boundaries: no retrieval\n", "6: Rain present: no retrieval\n", "128: Missing Value" ; cllw_retrieval_status:long_definition = "Use unsigned int8 as reference!\n", "0: No liquid water detected\n", "1: Reliable retrieval \n", "2: Adiabatic retrieval where cloud top has been adjusted to match liquid water path from microwave radiometer because layer is not detected by radar\n", "3: Adiabatic retrieval: new cloud pixels where cloud top has been adjusted to match liquid water path from microwave radiometer because layer is not detected by radar\n", "4: No retrieval: either no liquid water path is available or liquid water path is uncertain\n", "5: No retrieval: liquid water layer detected only by the lidar and liquid water path is unavailable or uncertain: cloud top may be higher than diagnosed cloud top since lidar signal has been attenuated\n", "6: Rain present: cloud extent is difficult to ascertain and liquid water path also uncertain\n", "128: Missing Value. Probably no measurement performed" ; cllw_retrieval_status:_FillValue = 128s ; cllw_retrieval_status:comment = "Use unsigned int8 as reference!\n", "This variable describes whether a retrieval was performed for each pixel, and its associated quality, in the form of 6 different classes.\n", "The classes are defined in the definition and long_definition attributes. The most reliable retrieval is that when both radar and lidar detect the liquid layer, and \n", "microwave radiometer data is present, indicated by the value 1. The next most reliable is when microwave radiometer data is used to adjust the cloud depth when \n", "the radar does not detect the liquid layer, indicated by the value 2, with a value of 3 indicating the cloud pixels that have been added at cloud top to avoid the \n", "profile becoming superadiabatic. A value of 4 indicates that microwave radiometer data were not available or not reliable (melting level present or unphysical values) \n", "but the liquid layers were well defined. If cloud top was not well defined then this is indicated by a value of 5. \n", "The full retrieval of liquid water content, which requires reliable liquid water path from the microwave radiometer, was only performed for classes 1-3. \n", "No attempt is made to retrieve liquid water content when rain is present; this is indicated by the value 6.\n", "bit 7 (2^7=128) is not Cloudnet standard. It was added for HDCP2." ; cllw_retrieval_status:_Unsigned = "True" ; float cllw_th(time, height) ; cllw_th:long_name = "liquid water content (tophat distribution)" ; cllw_th:units = "kg m-3" ; cllw_th:_FillValue = -999.f ; cllw_th:comment = "This variable is the liquid water content assuming a tophat distribution. I.e. the profile of liquid water content in each layer is constant." ; float clwvi(time) ; clwvi:standard_name = "atmosphere_mass_content_of_cloud_liquid_water" ; clwvi:long_name = "liquid water path" ; clwvi:units = "kg m-2" ; clwvi:_FillValue = -999.f ; clwvi:comment = "This variable is the vertically integrated liquid water directly over the site.\n", "The temporal correlation of errors in liquid water path means that it is not really meaningful to distinguish bias from random error,\n", "so only an error variable is provided." ; float clwvi_error(time) ; clwvi_error:long_name = "error of liquid water path" ; clwvi_error:units = "kg m-2" ; clwvi_error:_FillValue = -999.f ; clwvi_error:comment = "This variable is the vertically integrated liquid water directly over the site.\n", "The temporal correlation of errors in liquid water path means that it is not really meaningful to distinguish bias from random error,\n", "so only an error variable is provided." ; // global attributes: :cloudnet_Conventions = "CF-1.0" ; :cloudnet_title = "Liquid water content from Krauthausen" ; :cloudnet_location = "Krauthausen" ; :cloudnet_day = 1. ; :cloudnet_month = 4. ; :cloudnet_year = 2013. ; :cloudnet_history = "19 Feb 2015 10:02:41 - Generated from categorization data by Patric Seifert <
>\n", "Radar history: Original data has been averaged to 30 seconds.\n", "Lidar history: Lidar backscatter derived from raw values in arbitrary units: calibrated by user Ewan O\'Connor <
> on 26-Jul-2013.\n", "Model history: v1.49 created by Thorsten Reinhardt and Sonja Eikenberg 2012-01-20.\n", "Gauge history: unknown\n", "Microwave radiometer history: Created from HATPRO data with MWR-PRO V03 Retrieval with offset correction" ; :cloudnet_source = "CloudNet categorization product (software version 0.10.2) comprising:\n", "35.5 GHz Cloud radar MIRA\n", "Radar type: Monostatic, pulsed, magnetron\n", "Peak Power 30 kW\n", "Antenna Type: Cassegrain 1.2 m\n", "Antenna Beam Width: 0.5 deg;\n", "CHX090111;\n", "COSMO-EU;\n", "Rain gauge;\n", "MWR-PRO V03 Retrieval with offset correction applied to HATPRO raw data." ; :cloudnet_institution = "Data processed at the Department of Meteorology, University of Reading." ; :cloudnet_comment = "This dataset contains liquid water content calculated by using radar and lidar to identify the liquid cloud base and top in each profile, \n", "using the model temperature and pressure to calculate the adiabatic liquid water content in each cloud layer, and then using dual-wavelength \n", "microwave radiometers to scale the liquid water content values to yield the correct liquid water path. While this simple partitioning with \n", "height is somewhat uncertain, liquid water clouds are frequently thin, occupying only a few vertical model levels, so this dataset is adequate \n", "for testing liquid water content in models. Also available for comparison is the adiabatic liquid water content (i.e. unscaled by the microwave radiometer liquid water path)." ; :title = "Cloudnet liquid water content dataset" ; :Institution = "Leibniz Institut for Tropospheric Research (TROPOS), Leipzig, Germany" ; :Contact_person = "Patric Seifert (
" ; :Comments = "This dataset is based on data processed with cloudnet. Cloudnet is member of ACTRIS and data is available \n", "for numerous sites in addition to those of HD(CP)2. See http://actris.nilu.no/ for details. There is a distinct \n", "data policy agreement between HD(CP)2 and ACTRIS to manage the sharing of datasets between both projects. The nc conventions of \n", "the original cloudnet-nc-files were slightly modified to fit HD(CP)2 file conventions. In addition, not all \n", "variables of the original cloudnet-nc-files are contained in the HD(CP)2 files. The original comments and global arguments \n", "of cloudnet present in the nc files were renamed to *cloudnet_ARGUMENT_NAME*." ; :Licence = "For non-commercial use only. This data is subject to the HD(CP)2 data policy to be found at hdcp2.zmaw.de and in the HD(CP)2 \n", " Observation Data Product Standard.\n", "In addition the data is subject to the Data Protocol Agreement between ACTRIS and HD(CP)2 for the common use of Cloudnet products: \n", "1. Both ACTRIS and HD(CP)2 scientific steering committees (SSCs) agree, that all Cloudnet products are substantial for multiple \n", " applications in atmospheric science related to cloud-processes and should thus be made easily and freely available to atmospheric scientists world-wide.\n", "2. The original and citable Cloudnet data from all ACTRIS and HD(CP)2 atmospheric observatories (AO or termed supersites) are\n", "available through the Cloudnet web site (http://www.cloud-net.org) or the ACTRIS data centre (http://actris.nilu.no/). Currently, \n", "Cloudnet data is created locally on the respective AO server and then transferred to the Cloudnet server in Reading, UK.\n", "3. An exception to 2.) are the Cloudnet data from the atmospheric observatories LACROS (Leipzig), JOYCE (Juelich) and RAO (Lindenberg) \n", "during the course of HD(CP)2. Currently HD(CP)2 is developing an Observation Data Product Standard for its atmospheric column, respectively \n", "full-domain data needed for the HD(CP)2 numerical model evaluation and improvement. The main motivation for this is to provide easy access \n", "to data from the HD(CP)2 domain in unified formats from one server. HD(CP)2 data will be made available via the ICDC data center (icdc.zmaw.de) in Hamburg.\n", "4. Cloudnet data created at the 3 AOs mentioned above shall be additionally stored in HD(CP)2 compliant file format under the following conditions only.\n", " o HD(CP)2-compliant files acknowledge the Cloudnet data origin explicitly in the header in an adequate way.\n", " o If Cloudnet data is locally reprocessed and sent to the Cloudnet server, the HD(CP)2 compliant Cloudnet files are also simultaneously recreated \n", " and linked with ICDC.\n", " o Download statistics of data containing Cloudnet products are created through ICDC once HD(CP)2-compliant Cloudnet files become available. \n", "These statistics will be regularly made available to the ACTRIS and HD(CP)2 SSCs to document the use of Cloudnet data.\n", "5. If the above conditions are met during the first phase of HD(CP)2, the HD(CP)2-compliant Cloudnet files may be produced for other AOs in the \n", "HD(CP)2 domain. This is subject to the agreement of both ACTRIS and HD(CP)2 SSCs.\n", "6. In the future, ACTRIS and HD(CP)2 agree on an effort towards a unified Cloudnet data portal of all European AOs, strongly linked to the \n", "activities already on-going with the US partners from ARM/DOE." ; :Dependencies = "external" ; :Station_name = "LACROS field site" ; }