Geoscience Reference
In-Depth Information
Figure 6.1.
Monthly precipitation for the central Arctic Ocean based on data from
the Russian North Pole manned camps with daily bias adjustments. Raw precipitation
totals are shown along with the adjustments for winds and neglect of trace amounts.
Adjusted precipitation is represented by the total length of the bars (from Yang,
1999
,
by permission of AGU).
monthly station data sets (e.g., Groisman et al.,
1991
; Mekis and Hogg,
1999
; Yang,
1999
) were employed for land areas and for the Arctic Ocean. These records, which
are of highly variable length, were gridded and then adjusted for gauge undercatch
using the same coefficients employed by Legates and Willmott (
1990
). The fields
were then blended with precipitation forecasts from the NCEP/NCAR reanalysis
for which systematic biases were removed using statistical distributions from the
bias-adjusted gridded stations records. The techniques represent an outgrowth of
those described by Serreze et al. (
2003b
). Over open (ice-free) ocean, use was made
of updated and improved satellite-derived records from the Global Precipitation
Climatology Project (Huffman et al.,
1997
). Precipitation values over central
Greenland rely on interpolation from coastal sites and should be viewed with due
caution - results for this region based on snow accumulation and modeling will be
examined separately.
For a large part of the Arctic, winter is quite dry. January precipitation totals over
much of eastern Eurasia, northern Alaska, northern Canada and the central Arctic
Ocean are between 10 and 20 mm. These are regions far removed from Atlantic
and Pacific moisture sources and for which winter cyclone activity is infrequent.
Winter month precipitation totals are much higher in the Atlantic sector of the
Arctic. This arises from frequent cyclone activity along the North Atlantic cyclone
track, especially in the vicinity of the Icelandic Low, and associated moisture flux
