Diurnally Asymmetric Trends of Temperature, Humidity, and Precipitation in Taiwan
Journal
Journal of Climate
Journal Volume
22
Journal Issue
21
Pages
5635-5649
Date Issued
2009
Author(s)
Abstract
In this work, 45 years (1961-2005) of hourly meteorological data in Taiwan, including temperature, humidity, and precipitation, have been analyzed with emphasis on their diurnal asymmetries. A long-term decreasing trend for relative humidity (RH) is found, and the trend is significantly greater in the nighttime than in the daytime, apparently resulting from a greater warming at night. The warming at night in three large urban centers is large enough to impact the average temperature trend in Taiwan significantly between 1910 and 2005. There is a decrease in the diurnal temperature range (DTR) that is largest in major urban areas, and it becomes smaller but does not disappear in smaller cities and offshore islands. The nighttime reduction in RH is likely the main cause of a significant reduction of fog events over Taiwan. The smaller but consistent reductions in DTR and RH in the three off-coast islands suggests that, in addition to local land use changes, a regional-scale process such as the indirect effect of anthropogenic aerosols may also contribute to these trends. A reduction in light precipitation (<4mmh-1) and an increase in heavy precipitation (>10 mm h-1) are found over Taiwan and the offshore islands. The changes in precipitation are similar to the changes of other areas in Asia, but they are different from those of the United States, Europe, and the tropical oceans. The latter do not show any reduction in light precipitation. © 2009 American Meteorological Society.
Other Subjects
Anthropogenic aerosols; Average temperature; Diurnal asymmetry; Diurnal temperature ranges; Fog events; Heavy precipitation; Indirect effects; Land-use change; Meteorological data; Relative humidities; Tropical ocean; Urban areas; Urban centers; Aerosols; Land use; Landforms; Moisture; Oceanography; Atmospheric humidity; air temperature; asymmetry; diurnal variation; precipitation (climatology); relative humidity; trend analysis; urban atmosphere; Taiwan
Type
journal article