GAMIL2.0 is the newly released version of the Grid-point Atmospheric Model of IAP LASG(GAMIL),in which the major modifications from GAMIL1.0 include an updated deep convection scheme and the incorporation of a two-mom...GAMIL2.0 is the newly released version of the Grid-point Atmospheric Model of IAP LASG(GAMIL),in which the major modifications from GAMIL1.0 include an updated deep convection scheme and the incorporation of a two-moment bulk stratiform cloud microphysics scheme.This study evaluates the performances of both versions on Madden Julian Oscillation(MJO) simulations.The results show that GAMIL2.0 obtains an enhanced MJO eastward and northward propagation,which is weak in GAMIL1.0,and it reproduces a more reasonable MJO major structure coupling upper level wind,lower level wind,and outgoing long wave radiation.The contributions of each scheme and factor to the improvement of GAMIL2.0 simulations need further study.展开更多
Spring is the critical period for atmospheric circulation transition from winter to summer. The spring water cycle is very im- portant to agriculture in planting crop and the initial growth of crop. Note that there wa...Spring is the critical period for atmospheric circulation transition from winter to summer. The spring water cycle is very im- portant to agriculture in planting crop and the initial growth of crop. Note that there was a significant abrupt decadal change in the water budget increase during early spring over eastern China in the late 1970s. Studied here are the decadal variations of water budgets over the key regions and the associated change of water cycle over East Asia and atmospheric circulation over Asia-West Pacific region in early spring, using the observed （OBS） precipitation, the ECMWF （ERA） and NCEP/NCAR rea- nalysis （NRA）, and the Mantua＇s Pacific decadal oscillation index （PDOI）. The water budget increments from March to April exhibited a sharp decrease over the key region around Huaihe River basin （HHR） （111°-120°E; 31°-36°N） after year 1978. Before 1977 the water vapor flux through south boundary of the HHR region increased greatly during March to April by 1.52 mm d^-1 in ERA and 1.88 mm d^-1 in NRA. Concurrently the moisture convergence and precipitation over the region also in- creased greatly. The increment for the moisture convergence was 1.11 mmd^-1 in ERA and 1.22 mm d^-1 in NRA, and for the precipitation was 1.05 mm d^-1 in observation and 1.05 mm d^-1 in ERA. April was the time that the water budgets over HHR increased most rapidly before 1977. But after 1978 the water budgets decreased conversely from Mach to April. The water vapor flux increment through the south boundary was -0.03 mmd^-1 in ERA and 0.01 mm d^-1 in NRA, the moisture conver- gence increment was -0.91 mm d^-1 in ERA and -0.53 mm d^-1 in NRA, and precipitation increment was -0.08 mm d^-1 in ob- servation and -0.15 mm d^-1 in ERA. Further investigation has shown that the large-scale atmospheric circulation in the early spring has correspondingly changed significantly after the late 1970s. During March to April, the weakening of the trough over East Asia became significantly slower, and the strengthening of the ridge over the west China became significantly faster in the middle troposphere after the late 1970s. At the same time, in the lower troposphere, the strengthening and northward extending of the west pan of the subtropical high and the weakening of the trough over the southwest part of the Aleutian low in the early spring became slower, and the weakening of the main part of Asian high became slower, but the strengthening of its west part became faster. This significant decadal change of circulation caused a sharp decrease in the northward extending speed of wa- ter vapor transport, and in the water budgets increasing speed over the southeastern China during early spring after the late 1970s.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sci-ences (Grant No. XDA05110304)the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No. KZCX2-YW-Q11-04)+2 种基金the National High Technology Research and Development Program of China (863 Program, Grant No. 2010AA012304)the National Basic Research Program of China (973 Program,Grant No. 2010CB951904)the National Natural Science Foundation of China (Grant Nos. 41023002 and 41005053)
文摘GAMIL2.0 is the newly released version of the Grid-point Atmospheric Model of IAP LASG(GAMIL),in which the major modifications from GAMIL1.0 include an updated deep convection scheme and the incorporation of a two-moment bulk stratiform cloud microphysics scheme.This study evaluates the performances of both versions on Madden Julian Oscillation(MJO) simulations.The results show that GAMIL2.0 obtains an enhanced MJO eastward and northward propagation,which is weak in GAMIL1.0,and it reproduces a more reasonable MJO major structure coupling upper level wind,lower level wind,and outgoing long wave radiation.The contributions of each scheme and factor to the improvement of GAMIL2.0 simulations need further study.
基金supported by Key Project for Integration and Ap-plicaion of Key Meteorological Technology (Grant No.CMAGJ2012Z08)Public Welfare Scientific Research Project (Meteorology) Foundation (Grant No.GYHY201106010)National Natural Science Foundation of China (Grant Nos.40821092,40810059005 and 41105097)
文摘Spring is the critical period for atmospheric circulation transition from winter to summer. The spring water cycle is very im- portant to agriculture in planting crop and the initial growth of crop. Note that there was a significant abrupt decadal change in the water budget increase during early spring over eastern China in the late 1970s. Studied here are the decadal variations of water budgets over the key regions and the associated change of water cycle over East Asia and atmospheric circulation over Asia-West Pacific region in early spring, using the observed （OBS） precipitation, the ECMWF （ERA） and NCEP/NCAR rea- nalysis （NRA）, and the Mantua＇s Pacific decadal oscillation index （PDOI）. The water budget increments from March to April exhibited a sharp decrease over the key region around Huaihe River basin （HHR） （111°-120°E; 31°-36°N） after year 1978. Before 1977 the water vapor flux through south boundary of the HHR region increased greatly during March to April by 1.52 mm d^-1 in ERA and 1.88 mm d^-1 in NRA. Concurrently the moisture convergence and precipitation over the region also in- creased greatly. The increment for the moisture convergence was 1.11 mmd^-1 in ERA and 1.22 mm d^-1 in NRA, and for the precipitation was 1.05 mm d^-1 in observation and 1.05 mm d^-1 in ERA. April was the time that the water budgets over HHR increased most rapidly before 1977. But after 1978 the water budgets decreased conversely from Mach to April. The water vapor flux increment through the south boundary was -0.03 mmd^-1 in ERA and 0.01 mm d^-1 in NRA, the moisture conver- gence increment was -0.91 mm d^-1 in ERA and -0.53 mm d^-1 in NRA, and precipitation increment was -0.08 mm d^-1 in ob- servation and -0.15 mm d^-1 in ERA. Further investigation has shown that the large-scale atmospheric circulation in the early spring has correspondingly changed significantly after the late 1970s. During March to April, the weakening of the trough over East Asia became significantly slower, and the strengthening of the ridge over the west China became significantly faster in the middle troposphere after the late 1970s. At the same time, in the lower troposphere, the strengthening and northward extending of the west pan of the subtropical high and the weakening of the trough over the southwest part of the Aleutian low in the early spring became slower, and the weakening of the main part of Asian high became slower, but the strengthening of its west part became faster. This significant decadal change of circulation caused a sharp decrease in the northward extending speed of wa- ter vapor transport, and in the water budgets increasing speed over the southeastern China during early spring after the late 1970s.
