Net precipitation over the Baltic Sea during present and future climate conditions

Climate Research

Anna Rutgersson¹  Jouni Räisänen¹  Anders Omstedt¹ 

关键词: Water cycle;    Baltic Sea;    Precipitation;    Evaporation;    Climate;   

DOI  :  10.3354/cr022027

来源: Inter-Research Science Publishing

【 摘 要 】

ABSTRACT: By using a process-oriented ocean model forced with data from a gridded synoptic database, net precipitation values (precipitation minus evaporation) over the Baltic Sea are obtained. For a range of realistic meteorological forcing the averageannual value obtained from an 18 yr (1981-1998) simulation ranges between 1100 and 2500 m³ s^-1. The monthly variations are significant with the highest values occurring in early summer and even negative values in late autumn. Ice isan important factor, and the net precipitation is close to zero in the southern basins with no ice. Calculated net precipitation for a 98 yr period (1901-1998) using river runoff and maximum ice extent indicates that the investigated 18 yr period waswetter than the almost 100 yr climate mean. A realistic climate estimate of net precipitation during the 20th century is estimated to be 1500 ± 1000 m³ s^-1. The evaluation of 2 present day regional climate simulations indicated highprecipitation, low evaporation, and thus excessive net precipitation compared to the climate estimate from this investigation. When simulating the effect of increased greenhouse gases, the change in net precipitation was positive but small due to thecompensating effects of increased precipitation and increased evaporation associated with increased temperature and reduced ice.

【 授权许可】

Unknown