ESTIMATION OF THE IMPACT OF LAND-SURFACE FORCINGS ON TEMPERATURE TRENDS IN ARGENTINA

MARIO N. NUÑEZ; HECTOR CIAPPESONI; ALFREDO ROLLA; EUGENIA KALNAY; MING CAI

Foz do Iguacu, PR, Brazil

Congreso; 8th International Conference on Southern Hemisphere Meteorology and Oceanography; 2006

American Meteorological Society

We have carried out a comparison of trends in the NCEP/NCAR reanalysis anomalies and observation anomalies for Argentina. Although it is not possible to definitively attribute the differences between the observation and the NN-Reanalysis temperature trends solely to land use, including urbanization, agriculture and irrigation, the results obtained are not incompatible with such an interpretation. To the extent that both urbanization and irrigated agriculture contribute to an increase in the heat storage capacity of the surface, they should contribute to an increase in the minimum temperature, a decrease in the maximum temperature, and a reduction in the diurnal temperature range shown in our estimates over most of the Argentina territory. Also it is not possible to definitively attribute to the precipitation changes, our results suggest that increase in precipitation at least in part would tend to decrease the maximum temperature and increase the minimum temperature, because precipitation contribute to an increase in the heat storage capacity of the surface. More studies are necessary, including a comparison of changes in population, urbanization, increase of areas for agriculture, and plausible changes in high latitudes regional circulation, to attribute the recently observed changes in temperature and precipitation over Argentina, to changes in land surface use.