장기 기온 경향의 연직분포에 관한 재분석자료들 간의 불일치 (Discrepancies in the Vertical Profiles of Long-term Temperature Trends among Reanalyses)

서지정보

· 발행기관 : 건국대학교 기후연구소
· 수록지 정보 : 기후연구 / 9권 / 1호 / 15 ~ 31페이지
· 저자명 : 윤재승, 정일웅, 신상희, 임창묵

초록

Agreement in the vertical profiles of the temperature trends from radiosonde observation(HadAT) and four kinds of reanalysis dataset (ERA40, ERA-I, NCEP-DOE, and 20CR) are examinedfor the period of 1979-2000. There are noticeable spread among reanalysis and observation datasets inthe temperature trend depending on region and vertical level. East Asia shows large discrepancy amongdatasets, while Europe shows relatively good agreement. Generally, biases in temperature trends are largerin the upper troposphere (above 300 hPa) than in the lower and middle troposphere. Comprehensivecomparison of the long-term temperature trends among reanalyses is made for horizontal distributionswith height, latitude-pressure cross-sectional distributions, zonally-averaged meridional distributions withheight, and area-averaged vertical profiles in both DJF and JJA. Consequently, we find that the degreeof agreement among reanalyses significantly varies with vertical level, region, and season. The highestdiscrepancy is found over southern high-latitudes and in the upper troposphere over southern tropics. Inthe tropical upper troposphere above 200 hPa, observation (HadAT) shows cooling trend increases withheight, but three reanalyses show warming trends except NCEP-DOE reanalysis in which cooling trend isoverestimated. In conclusion, discrepancies in the vertical profiles of long-term temperature trends amongfour kinds of reanalysis datasets are quite large, and then a scrupulous approach should be needed whenreanalysis dataset is used for climate change study.

영어초록

Agreement in the vertical profiles of the temperature trends from radiosonde observation(HadAT) and four kinds of reanalysis dataset (ERA40, ERA-I, NCEP-DOE, and 20CR) are examinedfor the period of 1979-2000. There are noticeable spread among reanalysis and observation datasets inthe temperature trend depending on region and vertical level. East Asia shows large discrepancy amongdatasets, while Europe shows relatively good agreement. Generally, biases in temperature trends are largerin the upper troposphere (above 300 hPa) than in the lower and middle troposphere. Comprehensivecomparison of the long-term temperature trends among reanalyses is made for horizontal distributionswith height, latitude-pressure cross-sectional distributions, zonally-averaged meridional distributions withheight, and area-averaged vertical profiles in both DJF and JJA. Consequently, we find that the degreeof agreement among reanalyses significantly varies with vertical level, region, and season. The highestdiscrepancy is found over southern high-latitudes and in the upper troposphere over southern tropics. Inthe tropical upper troposphere above 200 hPa, observation (HadAT) shows cooling trend increases withheight, but three reanalyses show warming trends except NCEP-DOE reanalysis in which cooling trend isoverestimated. In conclusion, discrepancies in the vertical profiles of long-term temperature trends amongfour kinds of reanalysis datasets are quite large, and then a scrupulous approach should be needed whenreanalysis dataset is used for climate change study.

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