Examples of the Mean Three-Dimensional Wind Circulation Over the Tropical North Pacific Ocean
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DEPART” OF COMMERCE WEATHER BUREAU SINCLAIR WEEKS, Secretary F. W. REICHELDEFWEB, Chief MONTHLY WEATHER REVIEW JAMES E. CASKEY, JR., Editor Volume 84 Closed May 15, :1956 Number 3 MARCH 1956 Issued June 15, 1956 EXAMPLES OF THE MEAN THREE-DIMENSIONAL WIND CIRCULATION OVER THE TROPICAL NORTH PACIFIC OCEAN GORDON A. DEAN Institute of Geophysics, University of California 1 [Manuscript received February 13, 1956; revised March 29, 19561 ABSTRACT Two extreme climatological contrasts in the1954 mean monthly wind circulation overthe tropical North Pacific; Ocean are presented in the form of cross sections and horizontalanalyses. The wind field is shown on cross sections near 165O E. from 5O to 35O N. latitude. The horizontal variations of the wind are shown at 10,000-foot intervals throughout the troposphere and lower stratosphere. Twenty-seven figures are presented. 1. INTRODUCTION 2. THE TWO MEAN WIND FLOW PATTERNS Until recently, the lack of upper air datain the Tropics The first mean wind flow pattern illustrated (figs. 8-17) has prevented climatologists from preparing maps depict- is derived from winds prevailing during the month of ing mean high-level circulation patterns over most of the February 1954. This was a “high index” period and the tropical North Pacific Ocean. In an attempt to correct horizontal analyses are believed to be typical at each level the lack, as far as this ispossible with recent RAWIN data, of the mean wind circulation over the tropical North one phase of the work conducted in tropical meteorology Pacific Ocean area during high zonal index in temperate at the Oahu Research Center has been the drawing of latitudes.Daily analyses show that, the synoptic flow detailed analyses of mean monthly winds for various pattern in the middle and high troposphere through the btmospheric levels over the Marshall Islands (Korshover month was essentially zonal and strong in speed. [l]). Although limited data have confined Korshover’s The second mean wind flow pattern illustrated (figs. work to the atomic weapons testing periods consisting of 18-27) is based on winds observed during the period GREENHOUSE (spring 1951), IVY (fall 1952), and CASTLE April 16 through May 15, 1954. For this interval of time (spring 1954), study of the analyses has suggested that the mean horizontal analyses are believed to be typical at two, signifhntly different, mean wind flow patterns each level studied of the mean wind circulation during a regularly occur over the Marshall Islands. Consequently, “low index” period. That the mean wind analyses are it is the purpose of this paper to describe these patterns representative of high and low index situations can be more fully by extending the three-dimensional analysis of checkedby the striking similarity of the climatological the mean wind flow patterns to the entire tropical North maps to the daily synoptic maps for the same periods as Pacific Ocean area. analyzed by the weather personnel on OPERATION CASTLE. In other words, the daily departure of the synoptic field of 1 The research workin this paper has been made possibleby support of the aeophyslcs motion, from the mean, for both periods was very small. Raaeareh Directorate of the Air ForceCambridge Research Center under Contract NO.AFl9(W)-Ms. The meager evidence from years before 1954 (almost 87 Unauthenticated | Downloaded 09/27/21 03:30 AM UTC 88 MONTHLY WEATHER REVIEW MABCE 1956 FIGURE1.-Upper-air observing network in the Central Pacific during spring 1954. 'I'mm l.--PaciJic upper-wind stations. types of wind finding equipment.and times of observation Type of Type of wind Time of observs- Station No. Stationname Station No. Stationname finding T~~~~~~~-equip- tion (QMT) merit**rEE5 merit** " " Block 91 Block 47 I1 . 066 ............1 Midway .................................. R 03.09.15. 21 208 ............ Seoul...................................... R 03.09.15. 21 115............ Iwo Jlma.................................. R 03.09.15. 21 635............ Nagoya ................................... R 03.09.15. 21 131............ Marcus................................... El 03,09,15, 21 646 ............ Tateno .................................... R 03. 15 4YV .......... Victor ..................................... R 03 09 15 21 778 ............ Shionomisaki ............................. R 03.09.15. 21 165............ Lihue..................................... R 03: 06-P: 15,21-P 80s ............ Itazuke ................................... R 03.09.15. 21 218 ............ Guam..................................... R 03,09,15, 21 827 ............ Kagoshima ................................ R 03.09.15. 21 245............ Wake ..................................... It 03,09,15, 21 898 ............ Shimizu ................................... P 03.09.15. 21 W'........... Eniwetok ................................. R 03,09, 15, 21 931 ............ Okinawa .................................. R 03.09.15. 21 254 ............ Rongerik .................................. R 03,09,15, 21 375 ............ Johnston .................................. R 03 09.15 21 Block 94 285 ............ Hilo ....................................... R 03: 09-P: 15,Z1-P 334 ............ Truk...................................... R 07,l5-P 014 ............ Madang ................................... 04,10,16, 22 348' ........... Ponape ................................... R 03,09,15, 21 ............ .................................... 356*_________._Kussie .................................... R 03.09,15,21 085 i Rabaul PI04,10,16, 22 366 *........... Kwajalein ................................. R 03,09,15, 21 Block 97 376*"-"""-- Majuro ................................... R 03,09,15, 21 408 ............ Palau ..................................... R 03,l 5-P 014 ............ Menado ................................... P2305,11, 413 ............ Yap ....................................... R 03,l 5-P 146............ Kendari ................................... P2305,11, 530............ Nauru .................................... DL M 06 180............ Makasser ................................. P2305,11, 533 ............ Ocean..................................... CL 06, 12,18 404 ............ Moritai ................................... P 05,11, 23 610 ............ Tarawa ................................... P 15,11,17,x): 23 502............ Jefman .................................... P2302,08, 6'23 ............ Beru ...................................... CL x), 06.18 5@3 ............ Biak ...................................... P2203,08, 487 ............ Fanning .................................. CL 10,06, 18 690 ............ Hollandia ................................. P2202,08, 4w)............ Christmas ................................. CL M, 06, 18 I 724 ............ Ambon ................................... P'2305,11, 700 ............ Canton ................................... R 13,09,15,21 705 ............ Gardner ................................... CL M .06.18 Block 98 10............ Hull ...................................... CL I 00;06;18 223 ............ Laoag- .................................... P 03. 15 327 ............ Clark Field............................... R 03.09.15. 21 Block 46 618 ............ Puerto Princes8 ........................... P 03.15. 21 ___630 ........... Guy0 ..................................... P 03.21 1 645............ Cebu ...................................... P 03; 15 697............ Taipeh .................................... 03,09, 15, 21 754 ............ Davao .................................... P 03. 15 734 ...._.......Makung .................................. 830 ............ Jolo ....................................... P 03.09 752 ............ ................................. 836............. Zamboanga ............................... P 03.15. 21 Hengchun 1 1 I :%% 1 *Ocarsionally 3-hourly observations are included in addition to the required &hourly observations. **R=Rawinmnde . P=Pilot balloon . C~=Low-levelcloud direction . Unauthenticated | Downloaded 09/27/21 03:30 AM UTC &iABCH 1958 MONTHLY WEATHER REVIEW 89 TABLE2.-Number of wind observations at each wind analysis level Level (ft.) Level (ft.) station Station 1 2,OOO I 10,WO [m,WO I 30,WO I 40,OOO I 60,OOO I 60,MM I 65,- I 2.OW(lo,WO~20.000~30,WO~4o,WO/W,WO~Bo,aa~a,~~7o,~~~ FEBRUARY 1-28,1964 APRIL I6"AY 16,1954 Block 91 Block 91 _. - - __ __ 4YV ""_" 80 79 60 17 4YV .._..__103 95 a4 64 46 32 21 OBB ""_"" 108 110 106 88 64 41 24 20 17 066 "....." 118 111 106 102 86 50 n 22 17 116 ""_"" 90 69 63 41 28 18 10 9 10 115._..__.__ 94 104 104 104 104 96 62 67 60 40 131_________ 106 106 107 91 71 38 18 8 131 _..______116 114 111 103 99 86 66 59 60 35 166 ___..____97 74 64 47 34 23 10 10 165 ._._...__115 78 67 63 Bo 33 19 17 16 218 """"~ 111 111 108 I06 106 89 45 49 39 218 ..______.114 114 114 110 105 98 63 58 63 35 241, ."""" 108 110 107 98 79 44 17 13 245 ____.____116 117 116 116 111 95 66 51 43 16 250 ___._____123 123 I22 123 123 122 94 92 86 250 ____..___146 144 142 140 140 137 109 93 91 81 Zh4 _________ 82 87 85 85 85 79 56 61 51 275." ...... 117 117 117 117 114 72 39 30 27 26 276 _________ 112 110 109 108 100 89 68 49 45 285 .___..__.110 83 71 60 63 36 24 285 """"_ 90 70 61 48 37 27 334 __...__..67 64 32 22 20 18 13 14 12 a74 ""."" 54 47 30 27 26 22 16 15 16 348." ...... 130 130 130 130 129 129 108 97 94 89 348.... _____ 106 106 108 108 108 107 69 69 71 356 .__......126 129 128 129 129 113 84 76 74 72 w """_" 101 108 107 109 109 107 76 66 63 366 ""..... 139 139 139 137 136 109 68 61 48