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Global Attributes:	Title: Mixing layer height from Doppler lidar vertical wind Institution: Research Center Juelich, Institute for Energy and Climate research (IEK-8) Contact_person: Ulrich Loehnert (Loehnert@meteo.uni-koeln.de) Source: HALO Photonics Doppler lidar (production number 17) History: Data processed with mlh_to_nc, f_mlh, and write_mlh_nc by University of Cologne Conventions: CF-1.6 where applicable Processing_date: 17.11.2014 16:27 (UTC) Author: Jan Schween (jschween@uni-koeln.de) Comments: Mixing layer height (zmlaw) from vertical wind speeds found in HD(CP)2 data base. Retrieval is based on standard deviation of vertical wind (w_sdev) and threshold w_sdev_ts. Also provided is uncertainty as lower and upper bound when increasing / decreasing threshold by 25% (zmlaw_uncty). Vertical wind is only available if backscattering targets like aerosol particles and cloud droplets are present with sufficient quantity. Therefore, vertical range of accurate Doppler velocity observations are limited to sensitivity of sensor. Status of retrieval is documented in variable zmlaw_flag: If there is no w_sdev data or all w_sdev values are below w_sdev_ts no zmlaw is returned (zmlaw_flag=0 or 1, respectively). If there is a region directly above the ground with w_sdev >= w_sdev_ts and at least one point with w_sdev < w_sdev_ts the height of this point is returned (zmlaw_flag=2). In clear sky cases, when all w_sdev values are higher than threshold, last height with finite w_sdev was set to zmlaw (zmlaw_flag=3). When clouds were present, zmlaw is forced to just below cloud if std values were higher than threshold throughout the height between ground and cloud base (zmlaw_flag=4). For details of retrieval see Schween et al. 2014, doi:10.5194/amtd-7-4275-2014. License: 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 Observation Data Product Standard.

Variables:	lon: 32 bit Real lon standard_name: longitude long_name: longitude units: degrees_east
	lat: 32 bit Real lat standard_name: latitude long_name: latitude units: degrees_north
	zsl: 32 bit Real zsl standard_name: altitude long_name: altitude above mean sea level units: m
	w_sdev_ts: 32 bit Real w_sdev_ts long_name: threshold for standard deviation of vertical wind speed to determine zmlaw units: m s-1 comment: Common value is 0.4m/s based on the Lenschow (1981) profile and an assumed convective velocity scale of 1.5m/s.
	time_step: 32 bit Real time_step long_name: time step units: s
	time_interval: 32 bit Real time_interval long_name: length of time interval for determination of w_sdev units: s
	beta_cloud_ts: 32 bit Real beta_cloud_ts long_name: threshold for cloudbase from beta_mean units: m-1 sr-1
	time: Array of 32 bit Integers [time = 0..288] time: standard_name: time long_name: time units: seconds since 1970-01-01 00:00:00 UTC comments: Center time of interval from which w_sdev was determined. bounds: time_bnds
	time_bnds: Array of 32 bit Integers [time = 0..288][bounds = 0..1] time: bounds: comments: Start and end time of averaging interval for w_sdev.
	height: Array of 32 bit Reals [height = 0..114] height: standard_name: height long_name: height above instrument units: m comment: Height of center of range gates above instrument.
	zmlaw: Array of 32 bit Reals [time = 0..288] time: standard_name: atmosphere_boundary_layer_thickness long_name: mixing layer height from vertical wind units: m ancillary_variables: zmlaw_flag zmlaw_uncty comments: Lowest height where w_sdev is below w_sdev_ts (Schween et al. 2014). _FillValue: -99999.0 missing_value: NaN
	zmlaw_uncty: Array of 32 bit Reals [time = 0..288][bounds = 0..1] time: bounds: units: m comments: Uncertainty of zmlaw as lower and upper bound when threshold is by 25% larger or smaller, respectively.
	zmlaw_flag: Array of 8 bit Bytes [time = 0..288] time: _Unsigned: false long_name: status of zmlaw retrieval flag_values: 0b, 1b, 2b, 3b, 4b flag_meanings: no_w_sdev no_w_sdev_gt_w_sdev_ts w_sdev_lt_w_sdev_ts no_w_sdev_lt_w_sdev_ts cloud_base comment: Meanings in clear text: 0: no valid w_sdev 1: all w_sdev below threshold 2: transition from w_sdev above threshold to below at zmlaw 3: no value below threshold => zmlaw is end of sensitive range 4: zmlaw is cloud base. Be aware that values are comma- and meanings space-separated !
	w_sdev: Grid time: height: long_name: standard deviation of w units: m s-1 missing_value: NaN _FillValue: -99999.0 comment: Standard deviation of vertical wind determined from interval of length time_interval around times indicated in variable time. It is corrected for noise according to the technique described in Lenschow et al. (2000).
	w: Grid time: height: standard_name: upward_air_velocity long_name: mean of w units: m s-1 missing_value: NaN _FillValue: -99999.0 comment: Average of w in interval of length time_interval around times indicated in variable time.
	w_skew: Grid time: height: long_name: skewness of w units: 1 missing_value: NaN _FillValue: -99999.0
	beta: Grid time: height: standard_name: volume_attenuated_backwards_scattering_function_in_air long_name: mean of backscatter coefficient units: m-1 sr-1 missing_value: NaN _FillValue: -99999.0 comment: Average of beta in interval of length time_interval around times indicated in variable time.
	T_corr: Grid time: height: long_name: Correlation length in w time series units: s missing_value: NaN _FillValue: -99999.0

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DDS:

Dataset {
    Float32 lon;
    Float32 lat;
    Float32 zsl;
    Float32 w_sdev_ts;
    Float32 time_step;
    Float32 time_interval;
    Float32 beta_cloud_ts;
    Int32 time[time = 289];
    Int32 time_bnds[time = 289][bounds = 2];
    Float32 height[height = 115];
    Float32 zmlaw[time = 289];
    Float32 zmlaw_uncty[time = 289][bounds = 2];
    Byte zmlaw_flag[time = 289];
    Grid {
     ARRAY:
        Float32 w_sdev[time = 289][height = 115];
     MAPS:
        Int32 time[time = 289];
        Float32 height[height = 115];
    } w_sdev;
    Grid {
     ARRAY:
        Float32 w[time = 289][height = 115];
     MAPS:
        Int32 time[time = 289];
        Float32 height[height = 115];
    } w;
    Grid {
     ARRAY:
        Float32 w_skew[time = 289][height = 115];
     MAPS:
        Int32 time[time = 289];
        Float32 height[height = 115];
    } w_skew;
    Grid {
     ARRAY:
        Float32 beta[time = 289][height = 115];
     MAPS:
        Int32 time[time = 289];
        Float32 height[height = 115];
    } beta;
    Grid {
     ARRAY:
        Float32 T_corr[time = 289][height = 115];
     MAPS:
        Int32 time[time = 289];
        Float32 height[height = 115];
    } T_corr;
} ftpthredds/samd/data/dlidST/00/zmlaw/l2/sups/joy/2013/sups_joy_dlidST00_l2_zmlaw_v00_20130617000000.nc;

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