Satellite observations of the meso- and submesoscale

eddies in the Baltic and Black Seas

Svetlana Karimovafeba@list.ru

M.Sc. in oceanography – Lomonosov Moscow State University

Ph.D. student – Space Research Institute of RAS (IKI)

Department of the Earth investigations from space

Space Radar Laboratory

Research topics

Mesoscale and submesoscale eddies of the Black and Baltic Seas as seen by satellite radiometer and synthetic aperture radar (SAR) data:

Ways of eddies visualization in satellite images Generic types Spatial and temporal parameters Areas of distribution Seasonal and interannual dynamics Influence on vertical water structure and

bioproductivity

2INTRODUCTION

Motivations• Mesoscale eddies:

– horizontal water transport– upwelling/downwelling– contamination dilute and water self-

cleaning– seawaters bioproductivity

• Submesoscale eddies:– reasons and mechanisms of generation– lifetime– depth– contribution to water transport and mixing

3INTRODUCTION

Areas of interest4INTRODUCTION

Baltic Sea

Black Sea

Baltic Sea

Black Sea

Satellite radiometer data

•MODIS Aqua, spatial resolution 1 km, time coverage 04.2006-12.2009, total number of images 1100 Water-leaving radiance 551 nm (WLR) Chlorophyll-а concentration (Chl-a) Sea surface temperature (SST)

•AVHRR NOAA/MetOp-2, SST, spatial resolution 1 км, time coverage 09.2004-12.2009, total number of images 4400

5MESOSCALE EDDIES: GENERAL INFORMATION

Image examples (20.06.2006) 6MESOSCALE EDDIES

MODIS WLR

MODIS SST

AVHRR SST

MODIS Chl-a

The Black Sea mesoscale eddies• The Rim Current meanders and rings• Quasistationary anticyclonic eddies• Near-shore anticyclonic eddies (NAEs)• Mushroom-like currents (eddy dipoles)• Eddies of the Anatolian Coast• Shear eddy chains

7MESOSCALE EDDIES: GENERAL INFORMATION

Mushroom-like currents 8

2008

interannual variability

Mushroom-like currents:

9

Winter

Spring

Summer Autumn

10

Seasonal variability

Mushroom-like currents’ scale

Mushroom cap width (km)

Number

11MESOSCALE EDDIES: GENERAL INFORMATION

Eddy-induced chl-a transport12MESOSCALE EDDIES: INFLUENCE ON WATER STRUCTURE

MODIS WLR MODIS WLR 20.05.200920.05.2009

Eddy-induced chl-a productionAVHRR SST 5.08.

2008MODIS Chl-a 8.08.2008

13MESOSCALE EDDIES: INFLUENCE ON WATER STRUCTURE

Mushroom-like current

Cruise11-17.08.2004

MODIS Aqua Chl-a

14.08.2004

14MESOSCALE EDDIES: INFLUENCE ON WATER STRUCTURE

SeaWiFS Chl-a

Density section 1814-1825

15MESOSCALE EDDIES: INFLUENCE ON WATER STRUCTURE

Synthetic Aperture Radar (SAR) imagesEnvisat ASAR and ERS-2 SAR. Spatial

resolution 12.5 or 75 m depending on image mode

Black Sea:• Since 1998• 2006-2008: 390 images (Russian part of the sea)• 2009: 315 imagesTotal: 875 images

Baltic Sea:• 2009: 336 images

16SUBMESOSCALE EDDIES

Spiral lines of natural films (“black eddies”). The Baltic

Sea

Envisat ASAR WSM, 25.04.2009, 09:09 GMT

17SUBMESOSCALE EDDIES

Spiral lines of natural films (“black eddies”).The Baltic Sea

ERS-2 SAR IMM, 21.06.2009, 09:47 GMT

©ESA 200918

Wave/current interaction

(“white” eddies)Envisat ASAR:

a) 26.01.2010 07:58 GMTb) 18.02.2010 07:37 GMTc) 05.11.2009 07:37 GMT

19SUBMESOSCALE EDDIES

Eddies visualized by ice tracers. The Kattegat Strait

Envisat ASAR WSM 26.01.2010, 09:36 GMT

©ESA 201020

Number of the eddies discovered in SAR images of the Black Sea

Generally: 845 eddies in 875 images (1 eddy per image) 845 eddies in 186 images (4,5 eddies per image)

In 2009: 553 eddies in 311 images (1,8 eddies per image) 553 eddies in 100 images (5,5 eddies per image)

“Black” and “white”

“Black”

“White”

Number

Relation of the “black” and “white” eddies detected in SAR images

21SUBMESOSCALE EDDIES

The Black Sea eddy size

“Black” eddies size

Diameter (km)

Number

Number

“White” eddies size

Diameter (km)

Baltic

Black

“Black” 3-5 6-7“White” 5-6 4-5

Size comparing

22

“Black” eddies in the

Baltic Sea

LEGEND:• Winter• Spring• Summer• Autumn

23

“Black” eddies in the Black SeaLegend:• Winter• Spring• Summer• Autumn

24SUBMESOSCALE EDDIES DISTRIBUTION

(а) Envisat ASAR 23.07.2008; (b) ASAR&MERIS; (c) Envisat MERIS 24.07.2008(а) Envisat ASAR 01.08.2008; (b) ASAR&MERIS; (c) Envisat MERIS 31.07.2008

25SAR AND RADIOMETER DATA COMPARISON

(a) Envisat ASAR 17.07.2009;(b) Landsat ETM+ 17.07.2009 (bands 3, 2, 1)

26SAR AND RADIOMETER DATA COMPARISON

Frontal

eddies

Envisat ASAR 08.04.2009 08:07 GMT

WLR Chl-a SST

27SAR AND RADIOMETER DATA COMPARISON

Space Research Institute, Moscow

28EDDIES IN THE BALTIC AND BLACK SEAS