FIRE Cirrus II IFO UND Citation PMS 2D-C Probe Ice Water Content Analysis File Format The following documentation describes the file format for ice water content and other parameters derived from data taken by the University of North Dakota Citation aircraft PMS 2D-C probe during the FIRE Cirrus IFO - II. These files were generated using software provided by Dr. Andy Heymsfield of NCAR; questions concerning the derivation of the computed variables should be directed to him. A total of nine (9) files have been generated, one for each flight except 11/28/91, when the 2D probe was inoperative. The file structure contains 17 records of ASCII header information, followed by ASCII data values. The values were computed for 5-second intervals during times when the 2D probe was detecting particles. The file layout is given by the following FORTRAN code, which indicates the formats used to write the data files: Header Information: ** Aircraft Name, Date, Flight Number, Flight Start and End Times WRITE (2,1000) AIRCRAFT,IDATE,IFLT,IBOP,IEOP 1000 FORMAT (A8,A12,3I10) ** Probe Resolution 2D-C, 2D-P (not used) WRITE (2,1010) A1,CRES,A2,PRES 1010 FORMAT (1X,A30,F6.0,10X,A2,F6.0) ** Header Text WRITE (2,1020) ALPHA 1020 FORMAT (A60) ** Area Ratio Bin Endpoints WRITE (2,1030) (ARENDS(J),J=1,11) 1030 FORMAT (1X,11F5.2) ** Header Text, Number of Size Bins, Header Text WRITE (2,1050) A1,NCHAN(I),ALPHA 1050 FORMAT (A13,I2,A60) ** End Points of the Size Bins WRITE (2,1060) (CHENDS(J,I),J=1,NCHAN(I)+1) 1060 FORMAT (10X,20F7.0) ** Concentration Averaging Time WRITE (2,1080) A1,NSEC,ALPHA 1080 FORMAT (A29,I10,A60) ** Header Text WRITE (2,9002) 9002 FORMAT (' C-PROBE CHANNEL MIDPOINTS (MICRONS):') ** 2D-C Size Bin Midpoints WRITE (2,9003) (CHMID(I,1),I=1,NCHAN(1)) 9003 FORMAT (19F7.1) ** Header Text WRITE (2,9004) 9004 FORMAT (' P-PROBE CHANNEL MIDPOINTS (MICRONS):') ** 2D-P Size Bin Midpoints (not used) WRITE (2,9005) (CHMID(I,2),I=1,NCHAN(2)) 9005 FORMAT (19F7.1) ** Header Text, Crossover Size (not used) WRITE (2,9001) XOVER,NC2 9001 FORMAT (' WHEN COMPOSITE SIZE SPECTRUM GENERATED, C-TO-P-PROBE', & ' CROSSOVER OCCURS AT',F8.1,' MICRONS. THERE ARE',I3, & ' CHANNELS.') ** Minimum Threshold for Accepted Area Ratio WRITE (2,9006) MINAR 9006 FORMAT (' PARTICLES BELOW AREA RATIO BIN',I3,' ARE REJECTED.') ** Program or User-Defined Habits WRITE (2,9007) NAMHAB(ISHAB) 9007 FORMAT (' HABITS DETERMINED BY: ',A8) ** Header Text WRITE (2,9008) 9008 FORMAT (' HABITS: SM SPATIAL, SM COLUMN, LG SPATIAL, LG COLUMN,', & ' SPATIAL W/ EXTENSIONS, BULLET ROSETTE, PLATE') ** Date of Run, Version Number WRITE (2,2010) ITODA,JVERS 2010 FORMAT (1X,2A8,5X,A11) ** Column Labels WRITE(2,1010) 1010 FORMAT (//5X,'TIMES',7X,'PS TEMP ALT USTAR DBARM DMAX', & 6X,'W1',6X,'W2',6X,'W3',6X,'W4 WTOTAL',5X,'DT8 DT12', & 6X,'M1',6X,'M2 DPTC'/ & 7X,'RH',5X,'IWC XM1 XM2 XM3 PRECIP DBZ VBAR', & ' C-TOTAL LE 200 200-500 500-800 GT 800 CE8', & ' CE12',6X,'M3',6X,'M4'/ & 9X,' TIMP RHORH SI SW', & 5X,'LAMBDA NZERO RSQ') Data WRITE(2,1000) IT1,IT2,PS,TEMP,ALT,USTAR,DBARM,DMAX,(W(I),I=1,4), & WTOT,DT8,DT12,(TMASS(I),I=1,2),DPTC,RH, & RIWC,(XM(I),I=1,3),R,DBZ,VBAR,TTCONC, & (CBIN(I),I=1,4),CE8,CE12,(TMASS(I),I=3,4), & TIMP,RHORH,SI,SW,LAMBDA,NZERO,RSQ,ICP(KK) 1000 FORMAT (2I7,F6.0,F7.1,F7.0,1PE8.1,0PF6.3,F6.3,9(1PE8.1),0PF6.1/ & 6X,F4.0,0PF7.4,F7.4,F7.4,F7.4,1PE8.1,0PF6.1,F6.1,5(1PE8.1), & 0PF8.2,F8.2,2(1PE8.1)/10X,0PF6.2,3(1PE9.1),2(1PE11.3), & 0PF8.4,1X,A2) The following table describes the output variables and their units: VARIABLE DESCRIPTION UNITS ---------------------------------------------------------------------- IT1,IT2 MEASUREMENT TIME INTERVAL HH/MM/SS PS STATIC PRESSURE mb TEMP AMBIENT TEMPERATURE degrees C ALT PRESSURE ALTITUDE m USTAR VERTICAL VELOCITY NEEDED TO KEEP THE cm/s RELATIVE HUMIDITY CONSTANT DBARM MEDIAN PARTICLE MASS WEIGHTED DIAMETER cm DMAX MAXIMUM PARTICLE DIAMETER cm W1 DIFFUSIONAL GROWTH RATE IN CHANNEL 1 g/sec W2 DIFFUSIONAL GROWTH RATE IN CHANNEL 2 g/sec W3 DIFFUSIONAL GROWTH RATE IN CHANNEL 3 g/sec W4 DIFFUSIONAL GROWTH RATE IN CHANNEL 4 g/sec WTOT TOTAL DIFFUSTIONAL GROWTH RATE g/sec DT8 DEPLETION TIME (8 micron droplets) sec DT12 DEPLETION TIME (12 micron droplets) sec TMASS1 IWC IN CHANNEL 1 g/m^3 TMASS2 IWC IN CHANNEL 2 g/m^3 DPTC DEW POINT TEMPERATURE (EG&G) degrees C RH RELATIVE HUMIDITY (EG&G) % RIWC ICE WATER CONTENT g/m^3 XM1 ICE WATER CONTENT BASED ON SNOW HABIT g/m^3 XM2 ICE WATER CONTENT BASED ON SMALL SNOW HABIT g/m^3 XM3 ICE WATER CONTENT BASED ON LARGE SNOW HABIT g/m^3 R PRECIPITATION RATE mm/hr DBZ RADAR REFLECTIVITY FACTOR decibels VBAR MEAN REFLECTIVITY WEIGHTED WITH THE cm/s TERMINAL VELOCITY TTCONC TOTAL PARTICLE CONCENTRATION #/L CBIN1 PARTICLE CONCENTRATION WITHIN THE RANGE LE 200 #/L CBIN2 PARTICLE CONCENTRATION WITHIN THE RANGE 200-500 #/L CBIN3 PARTICLE CONCENTRATION WITHIN THE RANGE 500-800 #/L CBIN4 PARTICLE CONCENTRATION WITHIN THE RANGE GT 800 #/L CE8 COLLECTION EFFICIENCY (8 micron droplets) none CE12 COLLECTION EFFICIENCY (12 micron droplets) none TMASS3 IWC IN CHANNEL 3 g/m^3 TMASS4 IWC IN CHANNEL 4 g/m^3 TIMP # OF CRYSTAL-CRYSTAL COLUMNS sec^(1-) RHORH WATER VAPOR DENSITY g/cm^3 SI SUPERSATURATION WITH RESPECT TO ICE % SW SUPERSATURATION WITH RESPECT TO WATER % LAMBDA COEFFICIENTS USED TO FIT THE EQUATION #/cm^3 NZERO N=N0*EXP(-LAMBDA*D) #/L/mm RSQ COEFFICIENT OF THE FIT none ICP PROBE TYPE (C OR P) none