Large-Scale Estimates of CH4 Flux in Arctic Ecosystems: Field Testing of a Fast Response CH4 Analyzer for Remote Locations

北极生态系统是大气CH4的来源，然而，在小空间尺度上，其通量变化极大。因此，为了确定CH4外排的大小，需要整合斑块尺度变异性的大尺度测量。激光技术的最新进展导致了用于景观尺度通量测量的灵敏，快速响应的CH4传感器的发展。然而，许多这些仪器在操作过程中需要复杂的支持系统和大量的功率，这限制了它们在远程现场研究中的使用。最近开发了一种快速响应的开放路径CH4传感器，该传感器不需要大量的外部电源进行操作。虽然这种传感器在远程通量研究中似乎是实用的，但尚不清楚它是否足够敏感，可以解决北极生态系统特征的小CH4通量，或者是否足够坚固，可以承受恶劣的北极环境。因此，该传感器将在1994年野外季节在各种北极生态系统的便携式涡流相关塔上进行两周的测试。如果现场测试成功，该传感器可用于未来在偏远北极生态系统中基于塔架和/或飞机的涡流相关通量研究。该奖项是在SGER（探索性研究小额赠款）倡议下获得的。该项目是北极系统科学，陆地/大气/冰相互作用通量项目的一部分。

Arctic ecosystems are sources of CH4 to the atmosphere, however, fluxes are extremely variable over small spatial scales. Therefore, large-scale measurements which integrate patch-scale variability are needed to determine the magnitude of CH4 efflux. Recent advances in laser technology have resulted in the development of sensitive, rapid response CH4 sensors for landscape-scale flux measurements. However, many of these instruments require elaborate support systems and large amounts of power during operation, which inhibit their use in remote field studies. A fast response open path CH4 sensor was recently developed that does not require a large amount of extraneous supplies for operation. Although this sensor appears to be practical for use in remote flux studies, it is unknown whether it is sensitive enough to resolve the small CH4 fluxes characteristic of arctic ecosystems, or robustenough to withstand the harsh arctic environment. Therefore, the sensor will be tested on a portable eddy correlation tower in a variety of arctic ecosystems for two weeks during the 1994 field season. If the field test is successful, the sensor may then be implemented for future tower and/or aircraft-based eddy correlation flux studies in remote arctic ecosystems. This award is made under the SGER (Small Grants for Exploratory Research) initiative. The project is part of the Arctic System Science,Land/Atmosphere/Ice Interactions Flux project.