1、Lessons Learned Entry: 0530Lesson Info:a71 Lesson Number: 0530a71 Lesson Date: 1994-10-07a71 Submitting Organization: LARCa71 Submitted by: Bernard LewisSubject: Flux Measurements Providing Information on the Source/Sink Distribution of O3 and CH4 over Regions of Alaska Description of Driving Event:
2、 In situ airborne measurements of the turbulent flux and mean values of O3, CO and CH4 were obtained in the boundary layer over selected wetland systems in Alaska. These measurements were obtained in July-August 1988 as part of the NASA Global Tropospheric Experiment Programs Arctic Boundary Layer E
3、xpedition. The flux measurements obtained from this study provide information on the source/sink distribution of O3 and CH4 over the Yukon-Kuskokwim Delta (YKD) and Alaskan North Slope (ANS) regions of Alaska. The source/sink distribution over the YKD is qualitatively correlated with surface vegetat
4、ion type, identified from multispectral scanner imagery. Direct measurements of the spiral variation in the CH4 source strength were obtained over the YKD. The CH4 source strength over the YKD ranged from 2.5 to 85 MG M-2 D-1 during a flux survey flight which spanned a considerable portion of the YK
5、D, a spatially averaged, seasonally adjusted source strength of 51 MG M-2 D-1 was established for the YKD. Indirect CH4 flux estimates obtained over tundra were estimated to be 44 TG/A based on:1. the spatially averaged source strength obtained over the YKD2. current estimates of the global coverage
6、 of tundra3. assuming a similarity between other tundra areas and that of the YKD.Lesson(s) Learned: Airborne CO flux measurements over the Yukon-Kuskokwim Delta (YKD) indicate low negative flux values over the coastal areas, while some positive fluxes were observed in the inland, sparsely forested
7、regions. Analyses indicate the possibility of in situ photochemical destruction/production of CO. Tundra surfaces are estimated to be responsible for approximately 32% of the total deposition loss of O3 poleward of 60 degrees north. Data from the airborne O3 flux measurements made during Provided by
8、 IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-this study indicate similar values of RC for the Alaskan North Slope (ANS) and YKD.Recommendation(s): In situ airborne measurements of the turbulent flux and mean values for O3, CO, and CH4 were obtained in the bo
9、undary layer over the YKD and ANS regions in Alaska. The flux measurements provided information on the source/sink distribution of O3 and CH4 over these selected areas.Evidence of Recurrence Control Effectiveness: N/ADocuments Related to Lesson: N/AMission Directorate(s): N/AAdditional Key Phrase(s): a71 Research & DevelopmentAdditional Info: Approval Info: a71 Approval Date: 1997-04-02a71 Approval Name: Elijah C. Kenta71 Approval Organization: 421a71 Approval Phone Number: 757-864-3345Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
