1) College of Atmospheric Sciences, Key Laboratory of Arid Climatic Change and Reducing Disaster of Gansu Province, Lanzhou University, China
arid and semiarid areas, boundary layer height, climatic variations, heat flux, volumetric soil water, dynamic factor
Browse "Advance Publication" version.
Date of correction: 20170517
Reason for correction: Typography Error
Details: Japanese Abstract
Based on the ERA-20C, climatic variations of the boundary layer height (BLH) over arid and semiarid areas in East Asia and North Africa that span 1900-2010 were analyzed. In East Asia, the BLH exhibited a descending trend from arid region centers to the periphery. Over the past 111 years, the BLH has had a rising trend of 14.0 m decade−1. in the representative region (EA1) of the eastern areas with the 111-year average of 725 m and a decreasing trend of −1.6 m decade−1. in the representative region (EA2) of the western areas with the 111-year average of 792 m. From the mid-1960s to 1970s, EA1's BLH had a sharp rise that caused the average to increase by 93 m after the 1980s. In North Africa, the BLH exhibited a high spatial distribution in the western and southern areas and a relatively low spatial distribution in the eastern and northern areas. Over the past 111 years, the BLH has had a rising trend of 9.7 m decade−1. in the representative region (NA1) of the southwestern region with the 111-year average of 915 m and a decreasing trend of −6.3 m decade−1. in the representative region (NA2) of other regions with the 111-year average of 882 m. In the 1940s and the 1970s, NA1's BLH had two obvious increases that caused the average to increase by 51 m and 22 m, respectively, while NA2's BLH had two obvious declines that caused the average to decrease by 48 m and 7 m, respectively. On the spatial distribution, the BLH, sensible heat flux, latent heat flux, and volumetric soil water had a good corresponding relationship. On the temporal change, the BLH in East Asia had a stronger correlation with thermodynamic factors, whereas the BLH in North Africa had a stronger correlation with dynamic factors. Besides, the upper-level stratification also has some influence on the BLH's change.
Edited and published by : Meteorological Society of Japan Produced and listed by : Meteorological Society of Japan