World Weather/Climate Extremes Website

World: Highest Sea Level Air Pressure Above 750 meters

Record Value 1084.8hPa (adjusted using WMO formula)
Date of Record 19/12/2001
Length of Record 1963-present
Instrumentation Russian-made mercury barometer, special brand is SPA-A(B)
Geospatial Location Tosontengel Mongolia [48°44’N, 98°16’E, elevation: 1724.6 meters (5658.1 ft)]

References

2011-2012 Special WMO CCl Ad-hoc Evaluation Committee consisting of Purevjav Gomboluudev (Institute of Meteorology and Hydrology, Mongolia) Rob Allen (UK Met Office Hadley Centre), Manola Brunet, University Rovira i Virgili, Tarragona Spain, WMO CCl president of OPACE 2), Randy Cerveny (Arizona State University, Tempe AZ), Gil Compo, Research Scientist, CIRES, University of Colorado, Fatima Driouech (Direction de la Météorologie Nationale Casablanca, co-president of WMO CCl OPACE 2), Phil Jones, Director, Climate Research Unit, University of East Anglia , Tom Peterson, NOAA’s National Climatic Data Center, president of the WMO CCl) José Luis Stella (Departamento Climatología Servicio Meteorológico Nacional, Argentina.

Discussion

on 19 December, 2001 in Tosontsengel Mongolia, at 2 am local time on the 19th, (18/1800 UTC) the station pressure rose to 845.9 hPa. Using the supplied station pressure of 845.9 hPa, a geopotential height of 1725.8 m, and an ambient air temperature of -42ºC, the WMO method for reduction to sea level pressure produces an adjusted sea level pressure value of 1084.8 mb. The formula used is given in WMO Techn. Note No. 61, page 22, eq. 2)

Although this station exceeds the standard WMO threshold limit for reduction to sea level (i.e., 750 m), the Rapporteurs for Climate Extremes (Cerveny and Stella) have accepted this record with the caveat of a special category only for evaluations above 750m. Another sea level pressure category continues to exist for elevations below 750 meters.

Because sea-level pressure adjustment requires the use of a hypothetical lapse rate between the level at which the pressure is recorded and sea-level (for the WMO model, set at the standard atmosphere lapse rate of 6.5 K km-1), it is the judgment of the WMO evaluation committee and the Rapporteurs that high elevation observations' adjusted sea level pressures be considered on a case-by-case basis.

Tosontsengel, Mongolia

Closeup Satellite Image of Tosontsengel, Mongolia

Tosontsengel, Mongolia

Regional Satellite Image of Tosontsengel, Mongolia