Mediterranean SST report (Summer 2019)

Abstract

Third issue of Mediterranean SST report (Summer 2019) from Mediterranean Center for Environmental Studies (CEAM) Meteorology and Pollutant Dynamics department to periodically review and update sea surface temperature climatology and trend in the Mediterranean basin.

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Mediterranean SST report
Summer 2019
Issue #3
09-2019
Mediterranean SST report is an inia-
ve of the Mediterranean Center for
Environmental Studies (CEAM) Meteor-
ology and Pollutant Dynamics group to
periodically update sea surface temper-
ature climatology and trend in the Med-
iterranean basin as indicators of global
change. This newsleer will be issued
on a seasonal basis to disseminate the
state of the art about Mediterranean
SST and as informaon for stakeholders
and media interested in climate change.
This newsleer is parally funded
by research project VERSUS
(CGL2015-67466-R), from the
Spanish R&D&I naonal plan.
SST daily updated informaon
can be found at our webportal
SST-CEAMed at:
hp://www.ceam.es/SST.
Me d i terran e a n SST r eport wi l l be i s sued in a season a l basis (4 mes a year) . I f you a re i n t e rest e d in rec e i v ing
up c o m ing issue s please c ontac t F r ancis c o P astor at p a co@cea m.e s . Pl e a s e , fe el free to di strib u t e to any o n e
wh o m ight b e inte r e sted.
All graphics and analysis are based on daily SST data from GHRSST Level 4 AVHRR_OI Global Blended Sea Surface
Temperature Analysis (GDS version 2) from NOAA Naonal Centers for Environmental Informaon available at PO-
DAAC site (hps://podaac.jpl.nasa.gov/dataset/AVHRR_OI-NCEI-L4-GLOB-v2.0).

Trend summary (1982-2019)
Gl obal tr end 1.2˚ C
Gl obal da ily tr end 9.05·10-5˚ C/day
June 0.2 ˚C
Mon thly an omalie s July 0.2 ˚C
August 0.3 ˚C
SUMMARY
Global mean Mediterranean SST started summer period below climac mean values but rapidly
climbed to above mean values, with the highest posive anomaly on July, lasng for July and Au-
gust. Deseasonalized SST show similar posive anomalies for June and July that was slightly
higher in August.
For the whole data series (January 1982–August 2019), the previously seen warming trend per-
sists. From the me series of daily averaged Mediterranean deseasonalized sea surface tempera-
ture a global increase of almost 1.2˚ C was found.
Mediterranean SST report - Summer 2019
Da t a s ource : GHR S S T L e vel 4 AVH RR_ OI Glo bal Ble n d ed Sea Surfa c e T e mpera t u r e Analy s i s (GDS ver sio n 2) fro m N C E I
av a i lable a t PODA A C site hps: / / podaa c . j pl.na s a . gov/ d a t aset/ AVHR R _ OI -N C EI-L4-GLOB -v2.0
Gl obal SST long ter m trend ha s been updated for
the January 1982-Aug ust 2019 period . Tempo ral
me an S ST d eseaso n alized series (trend comp o-
nen t withou t season al eec t) yield a global i n -
cr ease of a b out 1.2˚ C f or the st u dy perio d,
sh o wn in gure 1 .
Fi gure 2 show s yearly SST ser ies, comput e d from
daily data . Black line sho ws the 1 9 82 -2019 a nnu-
al mean for Medit e rranea n S ST, the red line cor-
re sponds to yea r 2018 and gr een line to 2 019.
At the very beginni n g of June SST v alues wer e
sl ightly be low the climac mean but in the sec-
on d half of the month a remarkable increa se
wa s recorde d with peak valu es at the end of
Ju n e and start of July. For th e rest of July and
ful l August SST valu es remai ned clea rly above
cl imac values.
Figure 1. Time evoluon for deseasonalized mean Mediterranean SST
Figure 2. Yearly me series for mean Mediterranean SST
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Global trends and anomalies for deseasonalized SST

Global SST anomalies
As seen in prev ious reports , a consiste nt war ming trend has been measu r ed for SST daily anomal y
fro m 1 982 to 2019 (se e  gure 3). Most of the posi ve SST anoma lies (rel ave to 1982 -2011 refer ence
per iod) occur aer 2 000 w ith a pea k o n 201 6.
Fo r both, daily and monthly SST anomal i es, posi-
v e trend is also fo und for the analyze d period .
In bot h ca ses, most of the posi ve anomal ies
have been r ecorde d a  er 2000 for both global
an d deseasonaliz ed SST.
Mediterranean SST report - Summer 2019
Da t a s ource : GHR S S T L e vel 4 AVH RR_ OI Glo bal Ble n d ed Sea Surfa c e T e mpera t u r e Analy s i s (GDS ver sio n 2) fro m N C E I
av a i lable a t PODA A C site hps: / / podaa c . j pl.na s a . gov/ d a t aset/ AVHR R _ OI -N C EI-L4-GLOB -v2.0
Figure 3. Mean SST daily anomaly
Figure 4. Mean SST monthly anomaly
SST monthly analysis June 2019
Ju n e S ST spaal distr ibuon show s a t ransion structure towa rds the summe r p aern. North to south
gr adient is not so clear as in previo us months but a west to east posi ve gradient i s c learly seen. The
highest SST valu e s are found to the East of t he L evann e sea, just oshor e I s rael, Leban on, Syria and
Tu rkey.
Re gardin g monthly S S T anomaly, a light p o sive an o maly is presen t across m ost of the Med iterran ean
basin. The mo st no ceable posi ve an o maly areas are located to the nort h of the basin, mainl y in
Fr ench coast, nort hern Adria c and Aegean seas. Speci a l me non has to be done fo r the very hig h
an o maly i n the Bl ack Sea. As per global SST ano m aly va lues, J u ne 2019 holds t he eig hth posi on in t he
historical series (1982 -2019) while the SS T trend componen t stan d s for t he fourteenth value.
June SST 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2009
SST anomaly 0 0.3 1.1 -0.1 0.5 0.7 0.5 1.5 1.4 0.6 0.8
SST trend anomaly 0.2 0.5 0.7 0.3 0.6 0.8 0.6 0.6 0.7 0.3 0.3
Minimum values in blue/maximum values in red
Figure 5. Mean monthly SST (le) and mean monthly SST anomaly (right) on June 2019
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SST monthly analysis July 2019
A cle ar summe r paern could be observ ed durin g July for the SST eld. A s et of clearl y dier enated
ar eas with a light west to east gradi ent can be seen, with the hig hest valu es to the east of the Levan -
n e ba sin. Anot her remar kable fea ture are the relavely co ld waters to th e east of the Aege an sea
an d clos e t o t h e Gibralt ar strait . Regardin g S ST monthly anoma l y, strong p o sive val u es are in the ar-
ea bet ween southe rn France, Cor sica and the Balear ic Islands. Ju l y 2019 SST monthly an omaly is in
the 5th p osion of the me series (19 82 -2018) while dese asonali zed S ST occu pies the s ixteen th posi-
o n .
Mediterranean SST report - Summer 2019
Da t a s ource : GHR S S T L e vel 4 AVH RR_ OI Glo bal Ble n d ed Sea Surfa c e T e mpera t u r e Analy s i s (GDS ver sio n 2) fro m N C E I
av a i lable a t PODA A C site hps: / / podaa c . j pl.na s a . gov/ d a t aset/ AVHR R _ OI -N C EI-L4-GLOB -v2.0
July SST 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2009
SST anomaly 0.4 0.5 1.1 0.3 0 1.3 0.4 0.8 0.8 1.1 0.6
SST trend anomaly 0.3 0.5 0.7 0.4 0.6 0.9 0.6 0.6 0.8 0.2 0.3
Figure 6. Mean monthly SST (le) and mean monthly SST anomaly (right) on July 2019
Minimum values in blue/maximum values in red
SST monthly analysis August 2019
As in t h e previous month, Aug ust shows the typ ical summe r SST spaal distri buon with a light Wes t
to East posiv e grad i ent. Lowe s t values are presen t i n East ern Aegean Sea and two small areas in the
Ly on Gulf and i n t he vicin ity of Gibr altar Strait. Highe st SST value s appear in the Levan  ne basin , spe-
ci ally in its easter nmost area. A general light posive anoma ly i s prese nt i n most of the M editerrane-
an basi n w ith the mos t signi c ave anom a lies os hore south e rn Franc e. SST mont h l y anomal y f or Au-
gu st 2019 stands for the 6th hig hest va lue of t h e me series (1982 -2019) ; in th e case of the d e seaso n -
al ized SS T, Augu st month ly anom aly is in the 20th pos ion.
August SST 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2009
SST anomaly 0.1 0.3 1.3 0.4 0.2 1.3 -0.1 0.6 1.2 0.6 0.5
SST trend anomaly 0.3 0.5 0.7 0.4 0.7 0.9 0.6 0.6 0.8 0.2 0.4
Figure 7. Mean monthly SST (le) and mean monthly SST anomaly (right) on August 2019
Minimum values in blue/maximum values in red
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Mediterranean SST community
University of Liège (Belgium)
GeoHydrodynamics and Environment Research group
GH E R (hp:// labos. ulg.ac. be/gher ) is a resear ch group of the Univers ity of Liè g e (Belgiu m), devo t ed
to m arine a nd enviro n mental studies through modelling, data a ssimi laon and data analys is tech-
niq ues. The G H ER has developed DINE OF (Data In t erpola ng Empiri cal Ortho gonal Funco n s), a meth -
od to recon struct missi ng informa on in satellite datas ets, due for exam p le to the prese nce of cloud s
in the a tmosphe re. An EOF basis is used in an i t erave way, all owing to extract the main p aerns of
va riabil ity of the data and accu rately ll the gaps. DINEO F has been successful l y applied to vari ables
li ke Sea Surface Tempera t ure (SST) , ocean colo u r and salin i ty, and also in co mbinaon s of dieren t
va riable s, like SST and win d. The develo p ment of DINEOF throu gh the years has been made possi ble
wi th funding f rom the Belgian Scie nce Pol-
icy (hp: //www.b elspo.b e/ ) an d ESA
(hp://www.esa.in t / ).
A daily D INEOF recons trucon of the
We stern Med iterran ean SST is perf o rmed
in n ear-real  me (hp://ww w.dine o f.net/
DIN EOF/) tha t runs autom acall y since
20 0 9. Th e reco n struco n is done da ily
ov er the latest 6 month s of data, and the
la st 10 days are displayed (see Figur e 1 for an SST map example ). While this product aims mainl y at
pro viding an example about the use of DINEOF, i t also allows to monit or t he S ST m esosca le d y namics
of the Med i terran ean Sea in near -rea l me. Fig ure 2 shows SST me seri es durin g t h e two heat wave s
a ecng Europe in summer 2019, which cause d an anomalous SST of alm ost 2°C wit h respec t to the
pre vious 9 year s averag e.
• A. Alv era -Azcára te, A. Ba rth, G. P arard, J M . Becke rs. Anal ysis of SMOS sea surf a ce sali n ity data u sing
DIN EOF. R emote S ensing o f Environment . 180 (2016) 1 37 -145. 2016
• A. Alv era-Azcár ate, A. Barth, JM Bec kers, RH
We isberg. Mu lvari a te reconst rucon of
mi ssing data in sea sur f ace temp e rature ,
ch lorophy ll and win d satellite elds . Journal
of Ge ophysical Researc h. 112: C03008 ,
2007. doi: 10.1029/2006JC003660
• A. Alver a -A zcárat e , A . Barth , M. Rixen, J M
Be ckers. Recon struco n o f incompl ete
oc eanogra phic datasets usi ng Empirica l Or-
tho gonal Func ons to the Adri ac Sea Sur-
face Temper ature. Ocean Model ling, 9: 325-
346, 2005
Mediterranean SST report - Summer 2019
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Figure 1: SST from the VIIRS sensor in the western Mediterranean Sea on 11 September
2019 (le) and DINEOF reconstrucon (right).
Figure 2: SST from Sennel 3 on 26/07/2019 (top le), DINEOF reconstrucon (top right) and average SST me series on the Western Mediterranean
from 27 June to 30 July 2019 compared to the 2010-2018 basin average (boom). See hp://www.dineof.net/DINEOF/dineof_July2019.html

Mediterranean SST report - Summer 2019
Mediterr a nean S S T report is an inia ve of the M editerr anean Center for E n vironm ental
St u dies (CEAM) Meteo rology and Polluta nt Dynami cs depart ment a s part o f the resea rch
pro ject VERSU S CGL2015 -67466-R (MICI NN/FEDE R), f unded by the Spanis h R&D&I naon-
al p lan of Span ish Mini stry of Sci ence, In n o vaon and Un iversi  es and Eur opean Re gional
Developme nt Fund.
Mor e inf o rmaon about Medite rranean sea surface tem perature (dai ly upd ates) at our
SS T CEAMe d web p ortal www .ceam. e s/SST
Ci t aon: Medit errane an Sea Surfa ce Tempera ture repo r t (Summe r 2 019). M eteorol ogy
an d Pollu t ant Dyn amics Area. F undació n CEAM. 2019.
Dat a sou rce: N aonal Cen t ers f or En vironme ntal Informa on. 2016. GHRS ST Le v el 4
AV HRR_OI Global Blended Sea Surface Temper ature Analy sis (GDS versio n 2) from NCEI.
Ve r. 2.0. PO.DA AC, CA, USA. Dat aset acce s sed 2019 -03-31 at hp://d x.doi.o rg/10. 5067/
GH AAO-4BC02 .
Al l the maps and gra phs in this do cument have been creat e d by the CEAM Meteoro logy
an d P ollutan t Dynami cs d epartment f r om t h e NCEI dat a and graphs. This report i s l i-
ce nsed unde r an Arib uon-NonCom mercial -N o Deriva ves 4.0 I nterna onal (CC BY -NC-
ND 4 .0) Cr eave Co mmons license (h ps://c reave commons .org/li censes/ by -nc-nd/4.0/
le galcod e ).
Contact informaon
Web portal www.ceam.es/SST
Twier @CEAM_Meteo
Mail paco@ceam.es
Th e C EAM F o u ndao n is su p p orted b y Gene r a l itat V a lencia n a
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