AIDJEX Bulletin #40 - Polar Science Center - University of Washington

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TABLE 1 DIFFERENCES IN DAILY TEMPERATURE (NWS "BARROW" DATA MINUS BUOY DATA) Internal Temperature, OC External Temperature, OC Kinimum Maximum Mean Minimum Maximum Mean Buoy 2663 March-May Me an 0.79 -0.52 0.30 1.92 0.05 0.99 Standard Deviation 2.39 2.58 2.21 1.86 1.76 1.29 June- July Me an -3.07 -3.20 -3.18 1.20 -0.37 0.65 Standard Deviation 1.57 2.37 1.75 0.73 3.16 0.90 , Buoy 1871 March-May Me an 1.87 0.22 0.81 -- -- -- Standard Deviation 5.50 2.33 2.03 -- -- -- June-July Me an -2.42 -2.71 -2.45 -- -- -- Standard Devi at ion 1.25 2.42 1.50 -- -- -- CONCLUSIONS The results of this test provide a basis for designing pressure and temperature sensors for ADRAMS buoys. They apply directly to the equipment and weather conditions actually tested, and may be instructive for other applications. Insulation of the buoy hull effectively reduced temperature variations in the buoy electronics and thus improves temperature compensation of the pressure sensor. This feature has since become standard for ADRAMS. The barometers were free from drift during the field experiment. Temperature compensation errors were not detectable. The clock correction 76
algorithm removed large initial errors, but introduced 0.15 mb random errors and significant loss of data in an unnecessary attempt to correct for diurnal clock variations. Wind caused systematic pressure errors, but they would not be significant for most applications. With appropriate corrections, the barometric pressure is good to better than 0.1 mb, an error due largely to the sampling resolution. The external temperature sensors must be protected better than they were during the test. The suitability of daily average external and internal temperature measurements should be considered. If better instantaneous air temperatures are needed, smaller sensors or some other treatment of radiation effects will be required. In conclusion, it is possible to obtain uniformly good measurements of barometric pressure and temperature without resorting to field calibrations. A summary of specific pressure accuracy requirements is given in Appendix B. ACKNOWLEDGMENT NASA operated the data collection system and provided the data from the field experiment at no charge. The Naval Arctic Research Laboratory provided field support for the test with the cooperation of the Arctic Project Office of the Outer Continental Shelf Environmental Assessment Program. The work was performed under the auspices of the Polar Research Center, University of Washington, for the NOAA Data Buoy Office on contract no. 01-7-038-947. APPENDIX A The Digiquartz sensors are relatively insensitive to pressure (full-scale excursions in pressure produce only a 10% change in output), which puts a greater burden on counting accuracy. A sensor with one atmosphere full-scale range will have a change in output of only one part in lo5 for 0.1 mb pressure change. Accordingly, the time base will contribute 0.1 mb error for each part in lo5 variation from the assumed clock rate. While this clock accuracy is achieved easily with aodern laboratory equipment, it cannot be taken for granted over a temperature range of 8OoC and a time scale of one year. 77
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DATA BUOYS AIDJEX BULLETIN No. 40 J
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NOTE TO FRIENDS, AND BYSTANDERS . .
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SUMMARY OF TECHNICAL DEVELOPMENTS I
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milestones, kept the vendor working
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The scene during deployment of HF-N
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The initial AIDJEX scientific plan
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poizr-orbiting satellite, which is
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t@ the spacecraft during each orbit
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BUOY NAHE COMMUN. COMMANDS FIXES TA
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L( 0 I 2 3 4 3 Radial error, kilome
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The buoy will be subjected to tempe
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nics occupy about 12 feet of the 17
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Ill -- - KEY AIUJEX WIN WW AEBa 0 4
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event that a melt pond should form
Page 30 and 31: chute supplied by Paranetics Inc. i
Page 32 and 33: 6'" IqORGANIC LITHIUM BP.TTEI?Y IMP
Page 34 and 35: OM (AD RAMS) UREMEN~ \ AIRDROP N m
Page 36 and 37: provides a grid from which geostrop
Page 38 and 39: words; a four-bit air temperature w
Page 40 and 41: PERFORMANCE OF MET/OCEAN BUOYS IN A
Page 42 and 43: Sensor samples were taken every thr
Page 44 and 45: strengths are known, were used with
Page 46 and 47: the ice (causing reduced shear). An
Page 48 and 49: (McPhee, Mangum, and Martin) , TABL
Page 50 and 51: 70°N 75'N n 3 P 17OOW (D Y 170°W
Page 52 and 53: 12OOW * U Station 25. Xeasurements
Page 54 and 55: (McPhee , Mangum, and Martin) 2701
Page 56 and 57: (McPhee, Mangum, and Martin) a 0 a
Page 58 and 59: "i BUOY 4 I 43 360- 309- 257 206 15
Page 60 and 61: a30gl 251 I 60 511 r 43 BUOY 4 I
Page 62 and 63: n 4, (McPhee, Mangum, and Martin) 8
Page 64 and 65: (McPhee, Mangum, and Martin) 33 W c
Page 66 and 67: . '-,..I.. . B A R R O W W I N D S
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Page 70 and 71: I 25 23 t h--:!li[ NCI PiHCEl4l 22
Page 72 and 73: .5 .4 .3 0 A R 2 R 0 W J - 0 B U -
Page 74 and 75: 9 1.5 1.0 c 8 w .5 R 930 $ 565 1000
Page 76 and 77: Clock corrections were applied rout
Page 78 and 79: Q) u o z z i 4- 4- Z + + z f n 9 Ef
Page 82 and 83: Laboratory calibration of the ADRAM
Page 84 and 85: 3.20- - 1 t W o? 2 3.051 ...:-.;..
Page 86 and 87: POSITION MEASUREMENTS OF AIDJEX MAN
Page 88 and 89: some redundancy. Four points were u
Page 90 and 91: 75.5 75.: - E75.1 LLI % y75.c - 1 1
Page 92 and 93: The translocation principle removes
Page 94 and 95: POSITION ACCURACY To evaluate the q
Page 96 and 97: TABLE 1 STAND-ALONE ACCURACY 68th P
Page 98 and 99: Az i mu t h s When both receivers a
Page 100 and 101: DATA PROCESSING Following the field
Page 102 and 103: model ice motion in the statistical
Page 104 and 105: FREC 1 INCY / DOPPLER / FREQUENCY /
Page 106 and 107: 35 30 25 v) > 0 2 20 LL 0 r= E m 15
Page 108 and 109: An example of a large-scale buoy ar
Page 110 and 111: observations are needed in remote a
Page 112 and 113: useful for determining how various
Page 114 and 115: as well as velocity fields, we must
Page 116 and 117: Since small changes in the yield su
Page 118 and 119: The transformation of the system of
Page 120 and 121: e able to judge how well such a mod
Page 122 and 123: then the flow rule becomes Q = +A -
Page 124 and 125: [-B' -F Finally, we eliminate Carte
Page 126 and 127: differential equation. 2. Discontin
Page 128 and 129: Substituting (36) and (37) into (34
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arbitrarily assign the values of 1
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The special case when advection can
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TABLE 1 STRETCHING, STRESS, ASP CHA
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ate of deformation, we have normali
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CHARACTERISTIC EQUATIONS The ordina
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One way to circumvent the problems
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The equations governing solutions a
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It is readily seen that when body f
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which may be substituted into equat
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a the stress derivative dCldS remai
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Although we have not studied in thi
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Courant, R., and D. Hilbert. 1962.
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A RESEARCH PLAN TO TEST THE AIDJEX
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the barges managed to reach their d
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APPROACH A baseline simulation 0-f
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SENSITIVITY OF ICE RESPONSE TO DIFF
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Since free drift of ice is computed
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and what is observed becomes less i
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stresses appear to be relatively un
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ehavior is directly related to accu
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TABLE 1 COMPARISON OF ESTIMATED ERR
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a) Base line b) 24-hour prediction
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\ / a) Base line b) 24- hour predi
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a) Base line b) 24- hour predi ct i
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\ / a) Base line b) 24-hour predict
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.. a) Base line b) 24- hour predict
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J2 a) Base line b) 24-hour predicti
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) 24-hour prediction c) 36-hour pre
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8 Figure 17. AIDJEX surface pressur
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APPENDIX 1 AIDJEX DATA FILES 1. Pos
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9A. Surface-1 eve1 ai r pressure (d
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19. Surface pressure (Val i dated)
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APPENDIX 2 AIDJEX DATA TRANSFERRED
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I -7-71327GEO A Cards (continued) 7
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B Cards (continued) 201
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AIDJEX Bulletin #40 - Polar Science Center - University of Washington

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