English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

We describe the challenges associated with the interpretation of extinctioncoefficient measurements by the Stratospheric Aerosol and Gas Experiment(SAGE II) in the presence of clouds. In particular, we have found thattropospheric aerosol analyses are highly dependent on a robust method foridentifying when clouds affect the measured extinction coefficient. Herein,we describe an improved cloud identification method that appears to capturecloud/aerosol events more effectively than early methods. In addition, wesummarize additional challenges to observing the Asian Tropopause AerosolLayer (ATAL) using SAGE IIobservations. Using this new approach, we perform analyses of the uppertroposphere, focusing on periods in which the UTLS (upper troposphere/lowerstratosphere) is relatively free ofvolcanic material (1989–1990 and after 1996). Of particular interest is theAsian monsoon anticyclone where CALIPSO (Cloud-Aerosol Lidar Pathfinder Satellite Observations) has observed anaerosol enhancement. This enhancement, called the ATAL, has a similar morphology to observed enhancements inlong-lived trace gas species like CO. Since the CALIPSO record begins in2006, the question of how long this aerosol feature has been presentrequires a new look at the long-lived SAGE II data sets despite significanthurdles to its use in the subtropical upper troposphere. We find that thereis no evidence of ATAL in the SAGE II data prior to 1998. After 1998, it isclear that aerosol in the upper troposphere in the ATAL region issubstantially enhanced relative to the period before that time. In addition,the data generally supports the presence of the ATAL beginning in 1999and continuing through the end of the mission, though some years (e.g., 2003)are complicated by the presence of episodic enhancements most likely ofvolcanic origin

Improved SAGE II cloud/aerosol categorization and observations of the Asian tropopause aerosol layer: 1989–2005