Synoptic situations associated to floods in the river mouths

Purposes: Classify synoptic situations associated to various types of floods Assess the changes of synoptical conditions favorable for inundations in a changing climate. Types of floods: Storm surges Water-flow Ice-jam Areas: Baltic sea Black sea Azov sea Caspian sea Barents sea

Method: Synoptic frontal analysis is applied DATA Data from GIS-Meteo system is used (since 1997). Time resolution – 3 hours includes: SLP, geopotential at all pressure levels ( hPa) Precipitation Cloudiness temperature at 2m and pressure levels Data of radiolocation Wind speed and direction

Нагонные наводнения Storm surges Caused by Wind foricing

Neva. February GMT H500 Surface map L L Large depression located to the north-west of St-Petersburg

Wind at 10 m GMT Strong continuous wind forcing, wind oriented along the river channel

Pregolya Surface map H500 Additional factor -precipitation

Norvegian cyclone

Mouth of Don river. April GMT L L Surface map Black sea area

GMT Wind at 10 m

Mouth of Kuban’ GMT Surface map H500

Kalmykiya GMT H500 Surface map Caspian sea area

North Dvina GMT H500 Surface map White sea area

Water flow Caused by Abundant precipitation Snow and glacier’s melting

Novorossiysk 7-9 December 2002 Surface map L L H L Black sea area Common predictor – intensive frontal zone

Mzymta October 1997 Surface map L

Tuapse

Dgubga

Pregolya 7-10 August 2005 Surface map L Baltic sea area

Terek June 2002 Surface map H

Ice-jam

Pechora June 2008 Surface map L Н Н Frontal zone expanded in north-south direction, positive temperature in river source and negative temperature – in the river mouth

Pechora June 1998 Surface map L L

Mouth of Kuban’ ч Black sea area

Initial idea – classify the synoptical situations associated with floods, Assess the changes of probability of these situations in a changing climate. Not possible as the large variability of situations resulting in the same type of flood exists. Classification of synoptical situations for all floods Identification of potential predictors – meteorological factors characteristics of all cases of specific flood type Ice-jam –large zonal frontal zone expanding in north-south direction, temperature jumps, precipitations fall conditions, wind direction in the mouth of river etc Storm surges trajectories of depressions, wind speed and wind direction, duration of forcing Water flow – the main factor abundant precipitation No unified scheme of synoptic situation, but the intensive frontal zone is always presented Temperature gradient – approximation of frontal zone probability of gradient exceeding some threshold for modern and future climate Difificult to estimate the influence of climate changes, too many influencing factors which are not adequately represented in climate models Possible to estimate the influence of climate changes, several factors should be included – current work Estimated in climate model

Model - MPI-ECHAM5 (Max Planck Institute for Meteorology, Hamburg, Germany) Predictor - Probability of intensive frontal zone Number of cases Year 549 (7,5%)638 (8,7%)461 (6,3%) grad T> 16 o C/1000 km 862 (11,8%)945 (12,9%)754 (10,3%) grad T> 14 o C/1000 km Winter 340 (18,9%)424 (23,6%)261 (14,5%) grad T> 18 o C/1000 km 490 (27,2%)571 (31,7%)423 (23,3%) grad T > 16 o C/1000 km Summer 29 (1,6%)51 (2,8%)96 (5,3%) grad T> 12 o C/1000 km 136 (7,4%)158 (8,6%)252 (13,7%) grad T>10 o C/1000 km

Mean Rms Dispersion Minimum Maximum Number of cases with intensive frontal zone Winter Number of cases years

Mean Rms Dispersion Minimum 001 Maximum Number of cases with intensive frontal zone Summer Number of cases years