A climatology of 1000-500 hPa thickness


Data Source: The NCAR/NCEP Renalaysis data for the period 1948-2004.


Long-term mean thickness (all months)

Java animation of the annual cycle of thickness.

Mean winter thickness
Mean Spring thickness
Mean Summer thickness
Mean Fall thickness

All time minimum thickness

All time maximum thickness


Meteorological Hell!                 A chart showing how many times each grid point exhibits the highest thickness in the N.H.
Meteorological North pole!       A chart showing how many times each grid point exhibits the lowest thickness in the N.H


Continentality:  Mean         July  - January  Thickness
                           Mean Summer  - Winter   Thickness


Occurrences of thickness < 498 dam   Units are: number per year
Occurrences of thickness < 540 dam   Units are: number per year
Occurrences of thickness > 576 dam   Units are: number per year


Composite thickness associated with extreme values of NAO and PNA indices
(Winter season only)
Here, extreme value is defined as an index value that is more than 1 standard deviation away from its
mean.


Mean thickness and anomaly for extreme positive winter NAO

Mean thickness and anomaly for extreme negative winter NAO

Mean thickness and anomaly for extreme positive winter PNA

Mean thickness and anomaly for extreme negative winter PNA


Thickness trend over the years 1952-2001


Trend in the mean thickness: Units (m/yr) (all seasons combined)

Winter thickness trend
Spring thickness trend
Summer thickness trend
Fall thickness trend

Trend in the continentality: Units (m/yr)

Trend in the area covered by the 498 (and lower) dam thickness values