Variability in atmospheric circulation and moisture flux over the Arctic

• Published in: Philosophical Transactions of the Royal Society of London. Series A: Physical and Engineering Sciences
• Format: Article in Journal/Newspaper
• Language: English
• Published: The Royal Society 1995
• Subjects: Arctic; North Atlantic
• Online Access: http://dx.doi.org/10.1098/rsta.1995.0065; https://royalsocietypublishing.org/doi/pdf/10.1098/rsta.1995.0065

Mean characteristics and variability in the spatio-temporal distribution of Arctic water vapour and vapour fluxes are examined using several different rawinsondederived databases. Precipitable water averaged over the polar cap, 70-90° N, peaks in July at 14.0 mm. Large poleward fluxes near the prime meridian reflect transport associated with north Atlantic cyclones and, for most months, a local maximum in available water vapour. The mean vapour flux convergence averaged for the polar cap peaks in September. There is a mean annual excess of precipitation minus evaporation ( P — E ) of 163 mm, with a 78 mm range between extreme years. High P — E is favoured by a meridional circulation accompanied by a more dominant North Atlantic cyclone track. No trend in annual P — E is apparent over the 1974-1991 period.