Associations of diurnal temperature range change with the leading climate variability modes during the Northern Hemisphere wintertime and their implication on the detection of regional climate trends

作者：Wu Qigang^*

来源：Journal of Geophysical Research, 2010, 115: D19101.

DOI：10.1029/2010JD014026

This study examines associations of diurnal temperature range (DTR) changes in observations at the global, hemispheric, subcontinental, and grid box scales with five leading climate variability modes, including the Arctic Oscillation (AO), hemispheric Pacific-North America (PNA)-like mode, Pacific Decadal Oscillation, El Nino Southern Oscillation (ENSO), and Antarctic Oscillation (AAO) during the Northern Hemisphere winter season (Jan-Mar). Winter DTR variability in most subcontinental regions is significantly related to variations in either the AO, or hemispheric PNA-like mode, or ENSO index in the Northern Hemisphere. In the Southern Hemisphere, the DTR variability appears closely coupled with variations in the ENSO and AAO. From 1951 to 2000, variations in the circulation patterns account for a significant fraction of the DTR increase at all scales although the strength of these associations varies geographically. After removing the linearly congruent component of leading climate variability modes from the total wintertime DTR trends in the observations, statistically significant residual trends in DTR are still found at the global, hemispheric, and most subcontinental regions. Ensemble mean multimodel averaged DTR trends to major anthropogenic and natural forcing are significantly smaller than not only observed total DTR trends but also residual trends at these large scales. The implication of changes in the leading climate variability modes on the detection of regional DTR trends is discussed. We find that the detection of the regional response to combined anthropogenic and natural forcing is robust to the exclusion of trends related to changes of the five modes considered here.

• 出版日期2010-10-1
• 单位南京大学