MICROCLIMATIC OBSERVATIONS AT ENIWETOK 1. INTRODUCTION For a one-year period, from August, 1957, to August, 1958, the authors to- : } gether with their other field colleagues conducted a study of microclimatic conditions at Eniwetok Atoll in the Marshall Islands. the study was to determine to what extent a deep, The primary purpose of large atoll lying far at sea in a trade wind zone creates its own weather and climate. Stated differently, how and to what degree do the weather and climate of Entwetok differ from the Weather and climate that would obtain if there were only open ocean where Eniwetok lies? This report on our study does not attempt to answer the fundamental question raised above. hata report, Instead, 1t merely presents our observational findings. It is a designed to make available to meteorologists and others data that re hope will be useful to them in many different kinds of inquiries. We are including in this report not only the data themselves, together with }of ormation concerning the observational sites and procedures used, but also a fodicum of information concerning the nature of the atoll and of broad-scale ‘leather conditions in the Eniwetok area, This additional information is provided G make our results most seful to as many different investigators as possible, moluding those unfamiliar with Eniwetok and with the Marshall Islands Atoll area. Since the observational plan of this study is described in detail in Section all that will be done here is to indicate its nature in very broad terms, ring two different two-week periods, one during August, 1957, and the other pring January-February, 1958, weather observations were made at seven different gtes in the atoll. T, These sites were on the islets of FRED, BRUCE, KEITH, and YVONNE; and also in the lagoon at MACK!. For convenience, fferred to, American code names are (See Figure 1.) used for most islets ELMER, At FRED and reef's Both code names and native names appear in Figure 1. ere were hourly observations, made by the USAF, / KEITH, observations were 3-hourly. Air Weather Service. At BRUCE Elsewhere, observations were made daily.