We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Precipitation characteristics of the Eurasian Arctic drainage system.
- Authors
Mark C. Serreze; Andrew J. Etringer
- Abstract
This study examines characteristics of precipitation over the major watersheds of the Eurasian Arctic drainage system over the period 196092. In addition to the Ob, Yenisey and Lena (the three largest drainage systems), we examine the combined KolymaIndigirka in eastern Eurasia. Each basin exhibits approximately symmetric mean annual cycles of monthly total precipitation and daily event size, with winter minima and July maxima. These are strikingly similar to the annual cycles of total column water vapour (precipitable water), which fundamentally reflects the control on saturation vapour pressure by temperature. Effective precipitation mechanisms exist in all seasons. However, because of the long distance from strong moisture sources (continentality), precipitation tends to follow the seasonality in column water vapour. An effective contrast is presented for the Iceland sector. Here, the annual cycle of precipitation is tied not to the seasonality in column water vapour, but to the stronger precipitation-generating mechanisms in winter. Hence, the annual cycles of precipitation and column water vapour in this region oppose each other. Mean winter precipitation over the Eurasian watersheds is primarily driven by a modest convergence of water vapour. Whereas precipitation peaks in summer, the mean flux convergence exhibits a general minimum (negative in the Ob). Summer precipitation is hence primarily associated with surface evaporation. A strong role of convection is supported from consideration of static stability, the fairly weak spatial organization of precipitation totals and results from prior studies. On daily time scales, the largest basin-averaged precipitation events, for both summer and winter, are allied with synoptic-scale forcing. This is seen in relationships with cyclone frequency, and patterns of 500 hPa height, vertical motion and the 700 hPa vapour flux. The relative frequency of four 500 hPa synoptic types captures the basic time series structures of precipitation. Copyright © 2003 Royal Meteorological Society
- Subjects
METEOROLOGICAL precipitation; WATERSHEDS; DRAINAGE; PRECIPITABLE water
- Publication
International Journal of Climatology, 2003, Vol 23, Issue 11, p1267
- ISSN
0899-8418
- Publication type
Article
- DOI
10.1002/joc.941