19
ORIGINAL PAPER ROCADA: a gridded daily climatic dataset over Romania (1961–2013) for nine meteorological variables Alexandru Dumitrescu 1 Marius-Victor Birsan 1 Received: 14 June 2014 / Accepted: 9 April 2015 Ó Springer Science+Business Media Dordrecht 2015 Abstract Daily records of nine meteorological variables covering the interval 1961–2013 were used in order to create a state-of-the-art homogenized climatic dataset over Romania at a spatial resolution of 0.1°. All meteorological stations with full data records, as well as stations with up to 30 % missing data, were used for the following variables: air pressure (150 stations); minimum, maximum, and average air temperature (150 stations); soil temperature (127 stations); precipitation (188 stations); sunshine hours (135 stations); cloud cover (104 stations); relative humidity (150 stations). For each parameter, the data series were first homogenized with the software MASH (Multiple Analysis of Series for Homogenization); then, the data series were gridded by means of the software MISH (Meteorological Inter- polation based on Surface Homogenized Data). The datasets are freely available on request on the PANGAEA data portal (doi.pangaea.de/10.1594/PANGAEA.833627). Keywords ROCADA Á Climatic dataset Á Gridded data Á Homogenization Á Spatial interpolation Á MASH Á MISH Á Romania 1 Introduction The realization and availability of high-quality climatic data are essential for the realistic assessment of the impacts of climate variability and change on a region. The creation of gridded datasets by means of interpolation techniques using the local data values (i.e., Electronic supplementary material The online version of this article (doi:10.1007/s11069-015-1757-z) contains supplementary material, which is available to authorized users. & Marius-Victor Birsan [email protected]; [email protected] Alexandru Dumitrescu [email protected]; [email protected] 1 Department of Climatology, Meteo Romania (National Meteorological Administration), Sos. Bucuresti-Ploiesti 97, 013686 Bucharest, Romania 123 Nat Hazards DOI 10.1007/s11069-015-1757-z

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  • ORI GIN AL PA PER

    ROCADA: a gridded daily climatic datasetover Romania (19612013) for nine meteorologicalvariables

    Alexandru Dumitrescu1 Marius-Victor Birsan1

    Received: 14 June 2014 / Accepted: 9 April 2015 Springer Science+Business Media Dordrecht 2015

    Abstract Daily records of nine meteorological variables covering the interval 19612013were used in order to create a state-of-the-art homogenized climatic dataset over Romania at a

    spatial resolution of 0.1. All meteorological stations with full data records, as well as stationswith up to 30 % missing data, were used for the following variables: air pressure (150

    stations); minimum, maximum, and average air temperature (150 stations); soil temperature

    (127 stations); precipitation (188 stations); sunshine hours (135 stations); cloud cover (104

    stations); relative humidity (150 stations). For each parameter, the data series were first

    homogenized with the software MASH (Multiple Analysis of Series for Homogenization);

    then, the data series were gridded by means of the software MISH (Meteorological Inter-

    polation based on Surface Homogenized Data). The datasets are freely available on request on

    the PANGAEA data portal (doi.pangaea.de/10.1594/PANGAEA.833627).

    Keywords ROCADA Climatic dataset Gridded data Homogenization Spatial interpolation MASH MISH Romania

    1 Introduction

    The realization and availability of high-quality climatic data are essential for the realistic

    assessment of the impacts of climate variability and change on a region. The creation of

    gridded datasets by means of interpolation techniques using the local data values (i.e.,

    Electronic supplementary material The online version of this article (doi:10.1007/s11069-015-1757-z)contains supplementary material, which is available to authorized users.

    & Marius-Victor [email protected]; [email protected]

    Alexandru [email protected]; [email protected]

    1 Department of Climatology, Meteo Romania (National Meteorological Administration), Sos.Bucuresti-Ploiesti 97, 013686 Bucharest, Romania

    123

    Nat HazardsDOI 10.1007/s11069-015-1757-z

  • weather stations records) allows the estimation of the climatological characteristics for

    locations or areas where measurements are not available (Sluiter 2012). Gridded data are

    essential for evaluating the performance of regional climate models, and they serve as

    input data for spatially distributed agrometeorological and hydrological models (e.g.,

    Tveito et al. 2006; Birsan 2013).

    Within the framework of the project CARPATCLIM (Climate of the Carpathian Re-

    gion), funded by the EU Joint Research Centre, the national meteorological services from

    nine countries (Romania, Hungary, Ukraine, Slovakia, Serbia, Poland, Czech Republic,

    Croatia and Austria) joined efforts in order to build a daily gridded climatology of the

    Carpathian Mountains region, with Romania covering over one-third of the area. The

    project represented a good opportunity to update the data inventory (together with their

    gaps, quality and homogeneity), and its scientific usefulness has already been proved by

    several studies (e.g., Lakatos et al. 2013; Spinoni et al. 2014; Birsan et al. 2014a; Cheval

    et al. 2014a).

    Here, we present the realization and evaluation of a daily gridded climatic dataset over

    Romania (ROCADAROmanian ClimAtic DAtaset), for nine meteorological variables,

    and spanning over the period 19612013. We applied the same homogenization and

    gridding software package used in the CARPATCLIM project, due to its tested perfor-

    mance, reliability and speed. A comparison with the E-OBS (Haylock et al. 2008) and

    APHRODITE (Yatagai et al. 2012) datasets and with raw time series from some inde-

    pendent weather stations (i.e., stations that were not involved in the creation of any of the

    two gridded datasets) is also presented.

    Several recent studies have dealt with the climatic changes over Romania, regarding not

    only the increase in precipitation and air temperature extremes (e.g., Ionita et al. 2012;

    Busuioc et al. 2014; Rimbu et al. 2014; Stefanescu et al. 2014), but also the terrestrial

    stilling (Birsan et al. 2013), seasonal or annual changes in relative humidity, cloud cover,

    number of sunshine hours (Dumitrescu et al. 2014; Marin et al. 2014), the snow pack

    decrease (Birsan and Dumitrescu 2014a; Micu 2009), as well as changes in streamflow

    regime (Birsan et al. 2012, 2014; Birsan 2015; Ionita et al. 2014; Ionita 2015),

    evapotranspiration (Croitoru et al. 2013) or drought (Cheval et al. 2014b). These studies

    demonstrate the importance of making available a quality-controlled, daily climatic dataset

    covering the entire Romania and extending over a long period of time.

    2 Location and data

    Covering an area of 238 391 km2, Romania is the largest country in southeastern Europe.

    The terrain is fairly equally distributed between mountainous (Carpathians), hilly and

    lowland territories. Elevation varies from sea level to 2544 m.a.s.l. It has a continental

    temperate climate with various influences: oceanic in the central and western parts, con-

    tinental in the east and Mediterranean in the south. The agricultural land covers 62 % of

    Romania, while forested areas occupy about one-third of the country (e.g., Balteanu et al.

    2010).

    The construction of the gridded dataset was realized using daily time series with full

    data record over 19612013, as well as some additional data series with at least 70 % data

    completeness (for a better spatial coverage), for nine meteorological variables, namely air

    pressure (mb): 150 stations; minimum, maximum and average air temperature (C): 150stations; soil temperature (C): 127 stations; precipitation (mm): 188 stations and rain

    Nat Hazards

    123

  • gauges; number of sunshine hours (h): 135 stations; cloud cover (scale 110): 104 stations;

    relative humidity (%): 150 stations.

    All time series were extracted from the climatic database of the Romanian National

    Meteorological Administration (Meteo Romania). The related weather stations are located

    at elevations ranging from 1 to 2506 m.a.s.l. and have a good coverage both spatially and

    with respect to elevation (Fig. 1). The stations characteristics and their data record com-

    pleteness for each parameter are listed in Table 1.

    3 Methods

    For each parameter, the station data series were homogenized with the software MASH

    v3.03 (Multiple Analysis of Series for Homogenization), formulated and developed by

    Szentimrey (1999). MASH is a relative homogenization method that makes no a priori

    assumption regarding the data homogeneity, and it uses an exhaustive searching scheme to

    detect the most probable break and shift points in the data series from each weather station.

    Within MASH, data completion and quality control are performed automatically. The

    distribution of the examined meteorological element is taken into account for using an

    additive model (e.g., for temperature) or a multiplicative one (e.g., for precipitation), while

    corrections are applied to the inhomogeneous series until no break is found. The ho-

    mogenization of daily data uses the parameterization results obtained from monthly data

    homogenization (Szentimrey 2008, 2011).

    In a study comparing several widely used homogenization methods, Costa and Soares

    (2009) found the MASH method to be one of the most comprehensive procedures for

    homogenization. The quality of the homogenized data series is evaluated by the joint

    Fig. 1 Spatial distribution of meteorological station involved in this work

    Nat Hazards

    123

  • Table

    1L

    ist

    of

    the

    stat

    ion

    sin

    vo

    lved

    inth

    ean

    aly

    sis,

    incl

    ud

    ing

    thei

    rst

    atio

    nco

    de,

    loca

    tio

    n,

    elev

    atio

    nan

    dco

    mp

    lete

    nes

    so

    fth

    ed

    ata

    reco

    rdfo

    ral

    lp

    aram

    eter

    s

    Nr

    Sta

    tio

    nn

    ame

    IDP

    PC

    CA

    PR

    HS

    HT

    ST

    AL

    ON

    (E

    )L

    AT

    (N

    )E

    levat

    ion

    [m.a

    .s.l

    .]

    1A

    dam

    clis

    i4

    08

    80

    00

    16

    0.4

    12

    00

    27

    .96

    71

    34

    4.0

    88

    62

    15

    7.1

    2A

    dju

    d6

    06

    70

    51

    10

    0.5

    11

    64

    12

    7.1

    71

    81

    46

    .10

    50

    21

    03

    .3

    3A

    lex

    and

    ria

    35

    95

    21

    00

    00

    01

    02

    5.3

    54

    37

    43

    .97

    82

    97

    4.0

    4A

    rad

    60

    81

    21

    00

    00

    01

    02

    1.3

    55

    22

    46

    .13

    38

    51

    15

    .6

    5A

    rdu

    sat

    73

    93

    22

    7

    2

    3.3

    66

    67

    47

    .65

    00

    01

    60

    .5

    6A

    ries

    eni

    62

    82

    46

    5

    2

    2.7

    66

    67

    46

    .46

    66

    78

    63

    .9

    7A

    vra

    mIa

    ncu

    -Var

    furi

    62

    22

    50

    2

    2

    2.8

    33

    33

    46

    .36

    66

    79

    23

    .2

    8A

    vra

    men

    i8

    05

    65

    72

    9

    28

    .72

    92

    92

    92

    92

    6.9

    50

    00

    48

    .08

    33

    32

    34

    .3

    9B

    acau

    63

    56

    58

    02

    00

    00

    02

    6.9

    14

    07

    46

    .53

    21

    51

    85

    .3

    10

    Bai

    a-M

    are

    740330

    01

    00

    10

    023.4

    9324

    47.6

    6121

    196.8

    11

    Bai

    lest

    i4

    01

    32

    10

    00

    00

    00

    23

    .33

    26

    24

    4.0

    29

    51

    56

    .2

    12

    Bai

    soar

    a6

    34

    32

    20

    30

    00

    0

    23

    .31

    18

    24

    6.5

    35

    77

    13

    19.3

    13

    Ban

    loc

    52

    31

    08

    01

    00

    00

    02

    1.1

    37

    97

    45

    .38

    30

    58

    0.1

    14

    Bar

    aolt

    60

    55

    37

    0

    00

    16

    02

    5.5

    97

    40

    46

    .08

    10

    45

    06

    .9

    15

    Bas

    esti

    72

    83

    10

    8

    2

    3.1

    66

    67

    47

    .46

    66

    71

    89

    .6

    16

    Bec

    het

    34

    73

    57

    00

    00

    06

    02

    3.9

    45

    69

    43

    .79

    00

    63

    9.3

    17

    Ber

    zeas

    ca4

    39

    15

    72

    8

    28

    .22

    8

    2

    82

    1.9

    50

    00

    44

    .65

    00

    08

    4.7

    18

    Bac

    les

    42

    83

    07

    11

    51

    .82

    26

    22

    3.1

    14

    58

    44

    .47

    67

    23

    13

    .2

    19

    Bar

    lad

    61

    47

    40

    00

    00

    01

    02

    7.6

    45

    58

    46

    .23

    13

    61

    60

    .4

    20

    Bis

    trit

    a7

    08

    43

    00

    00

    01

    00

    24

    .51

    54

    54

    7.1

    49

    42

    37

    1.1

    21

    Bla

    j6

    11

    35

    50

    13

    0.2

    01

    60

    23

    .93

    67

    74

    6.1

    78

    82

    27

    5.8

    22

    Bo

    ita

    53

    84

    16

    01

    20

    .41

    65

    02

    4.2

    73

    18

    45

    .65

    31

    84

    84

    .8

    23

    Bo

    iuM

    are

    72

    43

    35

    8

    2

    3.5

    83

    33

    47

    .40

    00

    04

    26

    .6

    24

    Bo

    rod

    65

    92

    36

    19

    1

    8.9

    19

    19

    19

    19

    22

    .59

    16

    14

    6.9

    93

    92

    33

    4.7

    25

    Bo

    tiza

    74

    04

    09

    8

    2

    4.1

    50

    00

    47

    .66

    66

    75

    06

    .4

    Nat Hazards

    123

  • Table

    1co

    nti

    nued

    Nr

    Sta

    tio

    nn

    ame

    IDP

    PC

    CA

    PR

    HS

    HT

    ST

    AL

    ON

    (E

    )L

    AT

    (N

    )E

    levat

    ion

    [m.a

    .s.l

    .]

    26

    Bo

    tosa

    ni

    74

    16

    40

    00

    00

    00

    02

    6.6

    47

    04

    47

    .73

    60

    51

    22

    .1

    27

    Bo

    zov

    ici

    45

    52

    00

    6

    5.7

    61

    11

    06

    22

    .00

    77

    44

    4.9

    18

    65

    25

    0.1

    28

    Bra

    ila

    51

    27

    55

    25

    2

    62

    62

    72

    52

    62

    7.9

    21

    19

    45

    .20

    69

    91

    2.1

    29

    Bra

    sov

    54

    25

    32

    00

    00

    00

    02

    5.5

    27

    72

    45

    .69

    61

    35

    38

    .4

    30

    Bu

    cure

    sti

    Afu

    mat

    i4

    30

    61

    31

    31

    71

    4.7

    15

    13

    14

    15

    26

    .21

    42

    94

    4.5

    00

    39

    81

    .5

    31

    Bu

    cure

    sti

    Ban

    easa

    43

    06

    08

    02

    00

    02

    02

    6.0

    79

    76

    44

    .51

    08

    29

    0.9

    32

    Bu

    cure

    sti

    Fil

    aret

    42

    56

    06

    02

    0.2

    0

    00

    26

    .09

    53

    24

    4.4

    12

    36

    85

    .9

    33

    Bu

    zau

    50

    96

    49

    00

    00

    30

    02

    6.8

    53

    00

    45

    .13

    29

    19

    0.0

    34

    Bu

    zias

    53

    91

    36

    3

    2

    1.6

    00

    00

    45

    .65

    00

    01

    24

    .5

    35

    Cac

    ica

    738554

    8

    25.9

    0000

    47.6

    3333

    477.1

    36

    Cal

    afat

    359257

    05

    00

    00

    022.9

    4757

    43.9

    8525

    61.5

    37

    Cal

    aras

    i4

    12

    72

    10

    30

    00

    00

    27

    .33

    98

    64

    4.2

    06

    43

    17

    .1

    38

    Car

    acal

    40

    64

    21

    06

    00

    10

    02

    4.3

    58

    81

    44

    .10

    04

    41

    10

    .2

    39

    Car

    anse

    bes

    52

    52

    15

    00

    00

    00

    02

    2.2

    26

    84

    45

    .41

    75

    62

    14

    .4

    40

    Cea

    hla

    uT

    oac

    a6

    56

    55

    56

    65

    .56

    6

    62

    5.9

    51

    51

    46

    .97

    77

    61

    82

    3.1

    41

    Cea

    hla

    u-S

    at7

    02

    55

    62

    8

    27

    .82

    82

    82

    92

    82

    5.9

    33

    33

    47

    .03

    33

    37

    09

    .9

    42

    Ch

    isin

    euC

    ris

    63

    21

    30

    17

    11

    73

    12

    1.5

    43

    00

    46

    .51

    89

    49

    2.9

    43

    Cam

    pen

    i(B

    istr

    a)6

    22

    30

    34

    5

    .15

    17

    5

    23

    .04

    19

    54

    6.3

    64

    10

    59

    5.6

    44

    Cam

    pin

    a5

    17

    54

    50

    19

    0.4

    11

    21

    02

    5.7

    53

    95

    45

    .14

    44

    84

    77

    .5

    45

    Cam

    pu

    lun

    g5

    17

    50

    70

    30

    03

    40

    25

    .03

    81

    44

    5.2

    75

    15

    68

    4.7

    46

    Clu

    j-N

    apoca

    647334

    00

    00

    01

    023.5

    7299

    46.7

    7799

    404.2

    47

    Cam

    pu

    lun

    gM

    old

    ov

    enes

    c7

    32

    53

    42

    5

    24

    .52

    5

    28

    25

    25

    .56

    66

    74

    7.5

    33

    33

    64

    1.4

    48

    Co

    jocn

    a6

    45

    35

    09

    23

    .83

    33

    34

    6.7

    50

    00

    33

    5.2

    49

    Co

    nst

    anta

    41

    38

    38

    00

    00

    16

    16

    02

    8.6

    46

    38

    44

    .21

    40

    91

    7.8

    50

    Co

    rug

    ea4

    44

    82

    00

    1

    .64

    50

    12

    8.3

    43

    58

    44

    .73

    47

    02

    21

    .3

    Nat Hazards

    123

  • Table

    1co

    nti

    nued

    Nr

    Sta

    tio

    nn

    ame

    IDP

    PC

    CA

    PR

    HS

    HT

    ST

    AL

    ON

    (E

    )L

    AT

    (N

    )E

    levat

    ion

    [m.a

    .s.l

    .]

    51

    Co

    tnar

    i7

    22

    65

    70

    00

    00

    20

    26

    .92

    74

    14

    7.3

    58

    67

    27

    4.7

    52

    Cra

    iov

    a4

    14

    35

    20

    00

    00

    00

    23

    .86

    84

    64

    4.3

    10

    60

    18

    5.9

    53

    Cru

    cea

    (Co

    nst

    anta

    )4

    32

    81

    47

    28

    .23

    33

    34

    4.5

    33

    33

    91

    .8

    54

    Cu

    ntu

    51

    82

    31

    0

    0.4

    0

    0

    22

    .50

    30

    54

    5.3

    00

    81

    14

    65.4

    55

    Cu

    rtea

    de

    Arg

    es5

    09

    44

    10

    00

    00

    00

    24

    .67

    12

    84

    5.1

    79

    17

    45

    3.2

    56

    Dal

    ga

    42

    57

    02

    26

    2

    6.3

    27

    27

    28

    27

    27

    .03

    33

    34

    4.4

    16

    67

    45

    .0

    57

    Ded

    ule

    sti

    50

    04

    32

    07

    00

    9

    02

    4.5

    71

    79

    45

    .01

    62

    95

    51

    .2

    58

    Dej

    70

    93

    52

    07

    00

    00

    02

    3.9

    00

    50

    47

    .12

    82

    62

    36

    .6

    59

    Dev

    a5

    53

    25

    40

    00

    01

    00

    22

    .90

    04

    64

    5.8

    65

    04

    24

    1.0

    60

    Do

    bra

    (Alb

    a)5

    46

    33

    97

    23

    .65

    00

    04

    5.7

    66

    67

    50

    7.3

    61

    Do

    roh

    oi

    75

    66

    25

    28

    2

    8.6

    29

    29

    29

    29

    26

    .41

    66

    74

    7.9

    33

    33

    22

    3.5

    62

    Dro

    bet

    a-T

    urn

    uS

    ever

    in438238

    00

    00

    00

    022.6

    2765

    44.6

    2673

    60.1

    63

    Dra

    gas

    ani

    44

    44

    17

    03

    00

    00

    02

    4.2

    38

    71

    44

    .66

    57

    62

    63

    .5

    64

    Du

    mb

    rav

    eni

    61

    44

    36

    04

    0.1

    09

    20

    24

    .59

    31

    84

    6.2

    28

    25

    32

    0.0

    65

    Du

    mit

    ra7

    13

    42

    88

    24

    .46

    66

    74

    7.2

    16

    67

    35

    5.0

    66

    Fag

    aras

    55

    14

    59

    01

    20

    .20

    00

    02

    4.9

    36

    72

    45

    .83

    63

    64

    29

    .3

    67

    Fal

    tice

    ni

    72

    86

    20

    1

    29

    .83

    02

    9

    29

    26

    .33

    33

    34

    7.4

    66

    67

    26

    2.2

    68

    Fau

    rei

    50

    57

    19

    25

    2

    4.5

    25

    25

    25

    25

    27

    .31

    66

    74

    5.0

    83

    33

    38

    .7

    69

    Fet

    esti

    42

    27

    51

    8

    99

    17

    99

    27

    .84

    04

    84

    4.3

    91

    78

    52

    .7

    70

    Fo

    csan

    i5

    41

    71

    23

    0

    29

    .83

    0

    30

    30

    27

    .20

    12

    94

    5.6

    87

    88

    49

    .1

    71

    Fo

    roti

    c5

    14

    13

    58

    21

    .58

    33

    34

    5.2

    33

    33

    13

    8.1

    72

    Fu

    nd

    ata

    52

    85

    18

    00

    00

    5

    02

    5.2

    73

    27

    45

    .43

    19

    11

    33

    0.7

    73

    Fu

    nd

    ule

    a4

    28

    63

    20

    16

    00

    00

    02

    6.5

    25

    05

    44

    .45

    32

    36

    5.0

    74

    Gal

    ati

    53

    08

    01

    00

    00

    01

    02

    8.0

    33

    93

    45

    .47

    33

    06

    7.1

    75

    Gar

    nic

    44

    51

    48

    10

    21

    .80

    00

    04

    4.7

    50

    00

    48

    7.6

    Nat Hazards

    123

  • Table

    1co

    nti

    nued

    Nr

    Sta

    tio

    nn

    ame

    IDP

    PC

    CA

    PR

    HS

    HT

    ST

    AL

    ON

    (E

    )L

    AT

    (N

    )E

    levat

    ion

    [m.a

    .s.l

    .]

    76

    Giu

    rgiu

    35

    25

    57

    00

    00

    61

    02

    5.9

    34

    22

    43

    .87

    54

    72

    3.2

    77

    Go

    rgo

    va

    51

    19

    12

    0

    00

    02

    02

    9.1

    58

    27

    45

    .17

    71

    10

    .6

    78

    Gri

    vit

    a4

    45

    71

    80

    00

    03

    00

    27

    .29

    59

    94

    4.7

    40

    96

    43

    .8

    79

    Gu

    rah

    on

    t6

    17

    22

    09

    9

    .71

    01

    71

    11

    02

    2.3

    34

    90

    46

    .27

    95

    11

    62

    .2

    80

    Hau

    zest

    i5

    43

    20

    95

    22

    .15

    00

    04

    5.7

    16

    67

    29

    9.7

    81

    Har

    sov

    a4

    41

    75

    70

    0

    .71

    32

    12

    7.9

    65

    08

    44

    .69

    20

    03

    2.0

    82

    Ho

    lod

    64

    62

    07

    13

    14

    13

    .11

    31

    71

    41

    32

    2.1

    13

    87

    46

    .78

    89

    01

    55

    .8

    83

    Hu

    edin

    65

    13

    05

    3

    4.4

    51

    29

    42

    3.0

    34

    12

    46

    .85

    76

    55

    57

    .7

    84

    Hu

    si6

    41

    80

    32

    8

    27

    .82

    82

    82

    82

    82

    8.0

    50

    00

    46

    .68

    33

    31

    35

    .0

    85

    Iasi

    71

    07

    36

    00

    00

    00

    02

    7.6

    30

    08

    47

    .17

    10

    69

    5.0

    86

    Ieze

    r7

    37

    43

    90

    50

    09

    0

    24

    .65

    07

    34

    7.6

    02

    83

    17

    90.3

    87

    Igh

    iu6

    09

    33

    17

    23

    .51

    66

    74

    6.1

    50

    00

    28

    6.0

    88

    Into

    rsu

    raB

    uza

    ulu

    i5

    41

    60

    10

    00

    02

    02

    02

    6.0

    58

    30

    45

    .66

    85

    56

    97

    .8

    89

    Jid

    vei

    61

    44

    06

    1

    2

    4.1

    00

    00

    46

    .23

    33

    32

    63

    .9

    90

    Jose

    ni

    64

    25

    40

    45

    3.8

    47

    44

    25

    .51

    41

    74

    6.7

    06

    08

    75

    1.6

    91

    Juri

    lovca

    44

    68

    53

    0

    0.4

    00

    40

    28

    .87

    79

    34

    4.7

    66

    41

    31

    .9

    92

    Lac

    auti

    55

    16

    21

    00

    00

    0

    02

    6.3

    77

    08

    45

    .82

    40

    11

    77

    4.2

    93

    Lu

    go

    j5

    41

    15

    40

    50

    01

    10

    02

    1.9

    34

    63

    45

    .68

    67

    31

    21

    .4

    94

    Mai

    can

    esti

    53

    07

    29

    28

    2

    7.8

    28

    2

    82

    82

    7.4

    83

    33

    45

    .50

    00

    01

    5.5

    95

    Man

    gal

    ia3

    49

    83

    50

    15

    00

    46

    02

    8.5

    88

    98

    43

    .81

    64

    72

    .1

    96

    Mar

    aus

    63

    52

    00

    6

    2

    2.0

    00

    00

    46

    .58

    33

    32

    11

    .6

    97

    Mar

    cule

    sti

    42

    57

    30

    30

    2

    9.9

    30

    30

    30

    30

    27

    .50

    00

    04

    4.4

    16

    67

    34

    .9

    98

    Med

    gid

    ia4

    15

    81

    60

    00

    09

    00

    28

    .25

    28

    84

    4.2

    43

    56

    71

    .5

    99

    Mie

    rcure

    aC

    iuc

    62

    25

    44

    02

    00

    00

    02

    5.7

    74

    17

    46

    .37

    15

    86

    68

    .1

    100

    Mie

    rsig

    653150

    4

    21.8

    3333

    46.8

    8333

    120.8

    Nat Hazards

    123

  • Table

    1co

    nti

    nued

    Nr

    Sta

    tio

    nn

    ame

    IDP

    PC

    CA

    PR

    HS

    HT

    ST

    AL

    ON

    (E

    )L

    AT

    (N

    )E

    levat

    ion

    [m.a

    .s.l

    .]

    10

    1M

    oin

    esti

    62

    76

    29

    6

    2

    6.4

    83

    33

    46

    .45

    00

    05

    67

    .6

    10

    2M

    old

    ova

    Vec

    he

    44

    41

    27

    61

    95

    .56

    12

    96

    21

    .63

    46

    14

    4.7

    22

    85

    78

    .9

    10

    3N

    egre

    sti

    (Vas

    lui)

    65

    07

    27

    91

    29

    .49

    99

    92

    7.4

    43

    70

    46

    .83

    83

    31

    23

    .1

    10

    4O

    cna

    Su

    gat

    ag7

    47

    35

    62

    32

    .92

    21

    2

    23

    .94

    21

    44

    7.7

    77

    37

    50

    4.2

    10

    5O

    clan

    d6

    10

    52

    69

    25

    .43

    33

    34

    6.1

    66

    67

    54

    9.3

    10

    6O

    do

    rhei

    ul

    Sec

    uie

    sc6

    18

    51

    81

    1

    .62

    14

    62

    25

    .29

    33

    44

    6.2

    97

    09

    49

    7.2

    10

    7O

    hab

    a-M

    atn

    ic5

    28

    20

    57

    22

    .08

    33

    34

    5.4

    66

    67

    22

    2.6

    10

    8O

    nce

    sti

    62

    87

    16

    27

    2

    6.7

    27

    2

    72

    72

    7.2

    66

    67

    46

    .46

    66

    72

    02

    .0

    10

    9O

    radea

    70

    31

    56

    00

    00

    00

    02

    1.8

    97

    55

    47

    .03

    60

    21

    32

    .5

    11

    0O

    ravit

    a5

    02

    14

    10

    00

    03

    10

    21

    .71

    18

    44

    5.0

    38

    96

    25

    7.5

    11

    1P

    acli

    sa5

    34

    25

    32

    3

    22

    .72

    3

    23

    23

    22

    .88

    33

    34

    5.5

    66

    67

    38

    2.1

    11

    2P

    ades

    (Apa

    Nea

    gra

    )5

    01

    25

    20

    80

    02

    29

    02

    2.8

    61

    05

    44

    .99

    71

    42

    60

    .4

    11

    3P

    alti

    nis

    53

    93

    57

    01

    00

    .41

    10

    0

    23

    .93

    40

    04

    5.6

    57

    51

    14

    29.6

    11

    4P

    anci

    u5

    55

    70

    59

    27

    .08

    33

    34

    5.9

    16

    67

    26

    9.2

    11

    5P

    arin

    cea

    62

    97

    07

    7

    2

    7.1

    16

    67

    46

    .48

    33

    32

    82

    .6

    11

    6P

    aran

    g5

    23

    32

    80

    70

    .10

    21

    0

    23

    .46

    46

    24

    5.3

    87

    69

    14

    74.7

    11

    7P

    atar

    lag

    ele

    51

    96

    22

    0

    0.4

    01

    92

    02

    6.3

    70

    80

    45

    .32

    49

    62

    85

    .6

    11

    8P

    etro

    san

    i5

    25

    32

    30

    10

    01

    00

    02

    3.3

    78

    25

    45

    .40

    66

    16

    06

    .2

    11

    9P

    iatr

    aN

    eam

    t6

    56

    62

    10

    00

    .10

    32

    02

    6.3

    90

    90

    46

    .93

    40

    23

    59

    .8

    12

    0P

    ietr

    oas

    ele

    50

    26

    08

    25

    2

    5.4

    25

    25

    27

    25

    26

    .57

    72

    04

    5.0

    97

    35

    25

    2.9

    12

    1P

    ites

    ti4

    52

    45

    20

    00

    00

    00

    24

    .86

    74

    64

    4.8

    49

    29

    32

    3.3

    12

    2P

    loie

    sti

    45

    76

    00

    00

    00

    00

    02

    5.9

    88

    99

    44

    .95

    60

    91

    79

    .1

    12

    3P

    oia

    na

    Sta

    mp

    ei7

    19

    50

    74

    4

    .14

    48

    42

    5.1

    36

    04

    47

    .32

    49

    29

    11

    .8

    12

    4P

    olo

    vra

    gi

    51

    13

    49

    01

    00

    .10

    06

    02

    3.8

    10

    15

    45

    .16

    58

    75

    32

    .4

    12

    5P

    otl

    og

    i4

    35

    53

    57

    25

    .58

    33

    34

    4.5

    83

    33

    13

    7.8

    Nat Hazards

    123

  • Table

    1co

    nti

    nued

    Nr

    Sta

    tio

    nn

    ame

    IDP

    PC

    CA

    PR

    HS

    HT

    ST

    AL

    ON

    (E

    )L

    AT

    (N

    )E

    levat

    ion

    [m.a

    .s.l

    .]

    12

    6P

    red

    eal

    53

    05

    35

    00

    00

    12

    02

    5.5

    85

    10

    45

    .50

    64

    61

    08

    3.5

    12

    7R

    adau

    ti7

    51

    55

    50

    18

    00

    11

    02

    5.8

    91

    85

    47

    .83

    80

    13

    86

    .3

    12

    8R

    agla

    -Cet

    ate

    70

    44

    37

    8

    2

    4.6

    16

    67

    47

    .06

    66

    74

    67

    .1

    12

    9R

    arau

    72

    75

    27

    25

    2

    4.6

    25

    25

    25

    .56

    82

    14

    7.4

    50

    19

    15

    45.6

    13

    0R

    amn

    icu

    Sar

    at5

    23

    70

    30

    80

    00

    20

    27

    .04

    01

    64

    5.3

    90

    75

    14

    0.5

    13

    1R

    amn

    icu

    Val

    cea

    50

    64

    22

    00

    00

    02

    02

    4.3

    80

    98

    45

    .08

    91

    92

    30

    .9

    13

    2R

    om

    an6

    55

    65

    00

    18

    00

    01

    02

    6.9

    13

    39

    46

    .96

    94

    62

    18

    .9

    13

    3R

    osi

    ori

    de

    Ved

    e4

    07

    50

    00

    20

    00

    10

    24

    .98

    00

    34

    4.1

    07

    74

    10

    3.1

    13

    4R

    us

    71

    63

    35

    10

    23

    .58

    33

    34

    7.2

    66

    67

    28

    9.8

    13

    5R

    usc

    aM

    onta

    na

    (Co

    vas

    na)

    53

    42

    28

    4

    2

    2.4

    66

    67

    45

    .56

    66

    73

    79

    .3

    13

    6S

    acu

    ieni

    72

    22

    05

    02

    00

    .10

    02

    02

    2.0

    95

    80

    47

    .34

    44

    71

    13

    .6

    13

    7S

    arm

    asu

    64

    54

    10

    19

    1

    8.9

    19

    19

    19

    19

    24

    .16

    14

    04

    6.7

    47

    94

    37

    3.3

    13

    8S

    atu

    Mar

    e7

    48

    25

    30

    30

    .30

    00

    02

    2.8

    88

    78

    47

    .72

    17

    71

    20

    .2

    13

    9S

    ebes

    (Alb

    a)5

    57

    33

    40

    40

    05

    00

    23

    .54

    30

    94

    5.9

    64

    53

    25

    4.9

    14

    0S

    emen

    ic5

    07

    15

    80

    70

    00

    0

    22

    .05

    71

    24

    5.1

    81

    73

    14

    27.0

    14

    1S

    fan

    tuG

    heo

    rghe

    (Del

    ta)

    45

    49

    36

    0

    00

    10

    0

    29

    .60

    05

    24

    4.8

    96

    87

    0.7

    14

    2S

    fan

    tuG

    heo

    rghe

    (Mu

    nte

    )5

    52

    54

    82

    8

    28

    .22

    82

    92

    92

    82

    5.8

    03

    71

    45

    .87

    19

    25

    25

    .6

    14

    3S

    ibiu

    54

    84

    09

    00

    0.1

    00

    00

    24

    .09

    29

    44

    5.7

    89

    70

    44

    4.2

    14

    4S

    igh

    etu

    lM

    arm

    atie

    i7

    58

    35

    50

    0

    .10

    01

    02

    3.9

    05

    88

    47

    .93

    95

    72

    73

    .2

    14

    5S

    inai

    a(1

    50

    0)

    52

    35

    30

    00

    00

    02

    5.5

    15

    71

    45

    .35

    52

    61

    48

    5.5

    14

    6S

    ann

    ico

    lau

    Mar

    e6

    04

    03

    70

    80

    00

    00

    20

    .60

    31

    64

    6.0

    71

    63

    80

    .3

    14

    7S

    olo

    nt

    63

    36

    33

    5

    2

    6.5

    50

    00

    46

    .55

    00

    03

    91

    .5

    14

    8S

    ov

    eja

    60

    06

    40

    7

    2

    6.6

    66

    67

    46

    .00

    00

    05

    25

    .8

    14

    9S

    per

    mez

    eu7

    18

    41

    07

    24

    .16

    66

    74

    7.3

    00

    00

    32

    8.9

    15

    0S

    tei

    63

    22

    29

    02

    00

    .41

    01

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    Nat Hazards

    123

  • Table

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    51.9

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    61

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    7.5

    89

    14

    82

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    27

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    46

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    97

    62

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    .6

    16

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    ecu

    ci5

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    60

    60

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    16

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    16

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    arg

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    iesc

    60

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    Nat Hazards

    123

  • Table

    1co

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    nn

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    Nat Hazards

    123

  • comparative mathematical examination of the original and the homogenized series systems

    (Costa and Soares 2009). The good performance of MASH was also demonstrated in a

    recent study dealing with benchmarking of homogenization algorithms (Venema et al.

    2012), within the COST (European Cooperation in Science and Technology) Action

    Fig. 2 Multiannual means (19612013) for each parameter. The bottom right map shows the locations ofthe six independent stations used in the quantitative analysis

    Nat Hazards

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  • ES0601: Advances in homogenization methods of climate series: an integrated approach

    (HOME).

    The gridding was based on the software MISH (Meteorological Interpolation based on

    the Surface Homogenized Data Basis), version 1.03, developed by Szentimrey and Bihari

    (2004, 2005). The main advantage of MISH over most geostatistical methodswhere the

    predictors refer to a single realization in timeconsists in statistically estimating trend

    differences and covariances using long-term climatological time series. Therefore, when

    these parameters are known, they provide much more information than when using only

    the predictors of a single realization. The MISH method (Szentimrey and Bihari 2007) is

    especially developed to incorporate information from time series in the interpolation

    procedure and is capable to include ancillary data. The software consists of two parts: (1)

    the modeling part and (2) the interpolation one. The modeling system for statistical climate

    parameters is based on the long homogenized data series and supplementary model vari-

    ables. As in MASH, the interpolation system contains an additive (e.g., for temperature) or

    multiplicative (e.g., for precipitation) model and an interpolation formula that can be used

    depending on the climate elements. The interpolation system is applied to the results of the

    modeling system. The interpolation error or representativity is also modeled (Tveito et al.

    2006).

    4 Results and discussion

    It is worth mentioning that, beyond their advanced theoretical background, both MASH

    (homogenization) and MISH (interpolation) programs performed admirably in terms of

    reliability, speed and user requirements. After applying the two programs to each of the

    nine meteorological variables, the output data were converted to NetCDF (network

    Common Data Form) format, a CSV (comma-separated values) version of the dataset

    being also available. The dataset managed to capture well the orographical effects for all

    parameters, as Fig. 2 shows.

    A quantitative analysis of the ROCADA dataset has been carried out by comparing the

    precipitation and temperature data from six independent stations (Table 2)by inde-

    pendent stations we refer to stations that were not involved in the construction of the

    gridded datasets; their location is shown in Fig. 2bottom left (for soil temperature, only

    four out of six stations had available data). The time series from these stations were

    compared with the time series extracted from the corresponding grid cells, from ROCADA,

    E-OBS and APHRODITE datasets.

    Table 2 Meteorological stations used for comparing the raw data records with the time series from theircorresponding pixels from E-OBS and ROCADA gridded datasets

    Name Stationcode

    Latitude(N)

    Longitude(E)

    Altitude(m.a.s.l.)

    Time seriescoverage

    Alba Iulia 15280 46.0639 23.5634 252 19792013

    Gura Portitei 15428 44.6901 29.0005 4 19862013

    Obarsia Lotrului 15297 45.4355 23.6308 1348 19762013

    Stana de Vale 15118 46.6898 22.6234 1108 19792013

    Targu Lapus 15047 47.4396 23.8722 375 19872013

    Tarnaveni (Bobohalma) 15165 46.3600 24.2259 525 19872013

    Nat Hazards

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  • Figure 3 shows the comparison of the aforementioned time series. As it could be seen,

    the ROCADA dataset comes closer to the raw station data. The temporal variability of

    precipitation is well estimated in all three datasets, especially at lower altitudes. At Stana

    de Vale weather station, located in the mountains, the precipitation values are highly

    underestimated by both gridded datasets, ROCADA providing the closest resemblance

    with the observations.

    In order to illustrate how closely the interpolation methods resemble the observations,

    Taylor diagrams were also used, as they are able to simultaneously represent three coef-

    ficients in one graph (Taylor 2001): standard deviations of measured and computed data as

    the radial distance from the graph origin, centered RMS difference indicating the distance

    from the point observed located on x-axis, and the correlation coefficient given by the

    Fig. 3 Comparison of the precipitation time series from ROCADA, E-OBS, APHRODITE and independentmeteorological stations at six locations, for January (top) and July (bottom)

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  • angle between the x-axis and the position vector. Figure 4 shows the Taylor diagram for

    precipitation data extracted at station locations from the three gridded datasets (the entire

    data series were considered when building the diagrams). Generally, the E-OBS and

    ROCADA datasets show reasonable performance in all cases. ROCADA has a better

    accuracy in terms of standard deviation, correlation and root-mean-square error. However,

    both datasets underestimate the amount of observed precipitation, as emphasized by the

    temporal variability plots from Fig. 3.

    Regarding the mean air temperature, the time series plots (Fig. 5) show a much closer

    resemblance between the station data and the time series extracted from the gridded

    datasets. As in the case of precipitation, the ROCADA dataset managed to better reproduce

    the local variability. The Taylor diagram (Fig. 6) shows that both gridded datasets per-

    formed well in all cases, with ROCADA having a better accuracy with respect to all three

    indicators of the diagramalthough, for two stations, the results were extremely close for

    the two datasets.

    However, it is worth mentioning that these results could be strongly influenced by the

    fact that, within ROCADA, all available precipitation data records with less than 30 %

    missing values were used, while in the E-OBS dataset only 28 Romanian weather stations

    were involved (www.ecad.eu/).

    For the other parameters (i.e., minimum and maximum air temperature, cloud cover,

    number of sunshine hours, air pressure, relative humidity, soil temperature), comparison

    plots between ROCADA and six independent stations (four in case of soil temperature) are

    available as electronic supplementary material.

    Fig. 4 Taylor diagrams of the precipitation time series from ROCADA, E-OBS and independentmeteorological stations at six locations

    Nat Hazards

    123

  • The comparison charts show that at the two mountain stations situated above

    1100 m.a.s.l. (Stana de Vale and Obarsia Lotrului), the minimum air temperature and the

    number of sunshine hours are both overestimated by ROCADA, while the maximum air

    temperature, air pressure and relative humidity are underestimated. Cloud cover is well

    reproduced for all sites. The same goes for soil temperature; however, it has to be men-

    tioned that there are no observations for soil temperature at stations above 1100 m.a.s.l.

    These differences that occur at higher elevations are mainly due to the interpolation

    method and to the averaging at the dimension of the grid cell. While we cannot expect a

    perfect fit of a time series from a weather station over the data from the related grid cell

    Fig. 5 Comparison of the mean air temperature time series from ROCADA, E-OBS and independentmeteorological stations at six locations, for January (top) and July (bottom)

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  • (averaged over 0.1 9 0.1 degrees), it is obvious that, at higher elevations, the values

    derived from ROCADA are less reliable in most cases.

    5 Conclusions and future work

    We presented the realization of a high-resolution, daily gridded climatic dataset for the

    Romanian territory, for nine meteorological variables, covering the period 19612013. The

    data were quality-controlled, homogenized and spatially interpolated using state-of-the-art

    methods implemented in MASH and MISH software packages. The dataset proved to

    capture well the orography and is suitable for studies on climatic variability, climate-

    related hazards, as well as for spatially distributed agro/bio-meteorological and hydro-

    logical models. The dataset is freely available on request at doi.pangaea.de/10.1594/

    PANGAEA.833627 (Birsan and Dumitrescu 2014b) and at www.euro4m.eu.

    Of course, any gridded dataset-based interpolation of local weather station has its

    limitations, at least because the values of a given parameter are averaged over a grid cell.

    We are aware that, due to low network station density, the data series might be over-

    smoothed (Daly 2006; Ensor and Robeson 2008; Hofstra et al. 2009), leading to a flat-

    tening of the extreme values, particularly concerning precipitation at higher elevations

    (e.g., Cheval et al. 2011).

    Future work on the dataset concerns five main issues: increasing the length of the time

    period; adding new parameters to the dataset (e.g., snow depth, wind speed); adding

    Fig. 6 Taylor diagrams of the mean air temperature time series from ROCADA, E-OBS and independentmeteorological stations at six locations

    Nat Hazards

    123

  • metadata within the homogenization process; increasing the spatial resolution for some

    parameters (first of all for precipitation); testing new spatial interpolation methods.

    Acknowledgments Dr. Tamas Szentimrey (Hungarian Meteorological Service) is kindly acknowledgedfor his help on the homogenization and interpolation software. We acknowledge the E-OBS dataset from theEU-FP6 project ENSEMBLES (http://ensembles-eu.metoffice.com) and the data providers in the ECA&Dproject (http://www.ecad.eu). The APHRODITE dataset was downloaded from www.chikyu.ac.jp/precip.We thank the two anonymous referees for their comments and suggestions, which led to an overall im-provement in the original manuscript. This work has been realized within the framework of the EU-FP7project EURO4 M, code: 242093 (www.euro4m.eu).

    References

    Balteanu D, Chendes V, Sima M, Enciu P (2010) A country-wide spatial assessment of landslide suscep-tibility in Romania. Geomorphology 124(34):102112. doi:10.1016/j.geomorph.2010.03.005

    Birsan MV (2013) Application of a distributed physically-based hydrological model on the upper river basinof Somesul Mare (Northern Romania). Rom. Rep Phys 65(4):14691478

    Birsan MV (2015) Trends in monthly natural streamflow in Romania and linkages to atmospheric circulationin the North Atlantic. Water Resour Manag. doi:10.1007/s11269-015-0999-6

    Birsan MV, Dumitrescu A (2014a) Snow variability in Romania in connection to large-scale atmosphericcirculation. Int J Climatol 34:134144. doi:10.1002/joc.3671

    Birsan MV, Dumitrescu A (2014b) ROCADA: Romanian daily gridded climatic dataset (19612013) V1.0.Administratia Nationala de Meteorologie, Bucuresti, Romania. doi:10.1594/PANGAEA.833627

    Birsan MV, Zaharia L, Chendes V, Branescu E (2012) Recent trends in streamflow in Romania(19762005). Rom Rep Phys 64(1):275280

    Birsan MV, Marin L, Dumitrescu A (2013) Seasonal changes in wind speed in Romania. Rom Rep Phys65(4):14791484

    Birsan MV, Dumitrescu A, Micu DM, Cheval S (2014a) Changes in annual temperature extremes in theCarpathians since AD 1961. Nat Hazards. doi:10.1007/s11069-014-1290-5

    Birsan MV, Zaharia L, Chendes V, Branescu E (2014b) Seasonal trends in Romanian streamflow. HydrolProcess 28:44964505. doi:10.1002/hyp.9961

    Busuioc A, Dobrinescu A, Birsan MV, Dumitrescu A, Orzan A (2014) Spatial and temporal variability ofclimate extremes in Romania and associated large-scale mechanisms. Int J Climatol. doi:10.1002/joc.4054

    Cheval S, Baciu M, Dumitrescu A, Breza T, Legates DR, Chendes V (2011) Climatologic adjustments tomonthly precipitation in Romania. Int J Climatol 31:704714. doi:10.1002/joc.2099

    Cheval S, Birsan MV, Dumitrescu A (2014a) Climate variability in the Carpathian Mountains region over1961-2010. Glob Planet Change 118:8596. doi:10.1016/j.gloplacha.2014.04.005

    Cheval S, Busuioc A, Dumitrescu A, Birsan MV (2014b) Spatiotemporal variability of the meteorologicaldrought in Romania using the standardized precipitation index (SPI). Clim Res 60:235348. doi:10.3354/cr01245

    Costa AC, Soares A (2009) Homogenization of climate data: review and new perspectives using geo-statistics. Math Geosci 41:291305. doi:10.1007/s11004-008-9203-3

    Croitoru AE, Piticar A, Dragota CS, Bursada DC (2013) Recent changes in reference evapotranspiration inRomania. Glob Planet Change 111:127136. doi:10.1016/j.gloplacha.2013.09.004

    Daly C (2006) Guidelines for assessing the suitability of spatial climate data sets. Int J Climatol 26:707721.doi:10.1002/joc.1322

    Dumitrescu A, Bojariu R, Birsan MV, Marin L, Manea A (2014) Recent climatic changes in Romania fromobservational data (19612013). Theor Appl Climatol. doi:10.1007/s00704-014-1290-0

    Ensor LA, Robeson SM (2008) Statistical characteristics of daily precipitation: comparisons of gridded andpoint datasets. J Appl Meteor Climatol 47:24682476. doi:10.1175/2008JAMC1757.1

    Haylock MR, Hofstra N, Klein Tank AMG, Klok EJ, Jones PD, New M (2008) A European daily high-resolution gridded dataset of surface temperature and precipitation. J Geophys Res (Atmos)113:D20119. doi:10.1029/2008JD10201

    Hofstra N, Haylock M, New M, Jones PD (2009) Testing E-OBS European high-resolution gridded datasetof daily precipitation and surface temperature. J Geophys Res 114:D21101. doi:10.1029/2009JD011799

    Nat Hazards

    123

  • Ionita M (2015) Interannual summer streamflow variability over Romania and its connection to large-scaleatmospheric circulation. Int J Climatol. doi:10.1002/joc.4278

    Ionita M, Chelcea S, Rimbu N, Adler MJ (2014) Spatial and temporal variability of winter streamflow overRomania and its relationship to large-scale atmospheric circulation. J Hydrol 519:13391349. doi:10.1016/j.jhydrol.2014.09.024

    Ionita M, Rimbu N, Chelcea S, Patrut S (2012) Multidecadal variability of summer temperature overRomania and its relation with Atlantic multidecadal oscillation. Theor Appl Climatol113(12):305315. doi:10.1007/s00704-012-0786-8

    Lakatos M, Szentimrey T, Bihari Z, Szalai S (2013) Creation of a homogenized climate database for theCarpathian region by applying the MASH procedure and the preliminary analysis of the data. Id}ojaras117(1):143158

    Marin L, Birsan MV, Bojariu R, Dumitrescu A, Micu DM, Manea A (2014) An overview of annual climaticchanges in Romania: trends in air temperature, precipitation, sunshine hours, cloud cover, relativehumidity and wind speed during the 19612013 period. Carpath J Earth Env 9(4):253258

    Micu D (2009) Snow pack in the Romanian Carpathians under changing climatic conditions. MeteorolAtmos Phys 105(12):116. doi:10.1007/s00703-009-0035-6

    Rimbu N, Stefan S, Necula C (2014) The variability of winter high temperature extremes in Romania and itsrelationship with large-scale atmospheric circulation. Theor Appl Climatol. doi:10.1007/s00704-014-1219-7

    Sluiter R (2012) Interpolation Methods for the Climate Atlas. Royal Netherlands Meteorological Institute(KNMI) Technical report TR-335. De Bilt, The Netherlands. http://www.knmi.nl/knmi-library/knmipubTR/TR335.pdf

    Spinoni J, Szalai S, Lakatos M, Szentimrey T, Bihari Z, Mihic D, Antofie T, Vogt J, Auer I, Hiebl J,Milkovic J, Stepanek P, Tolasz R, Zahradncek P, Nagy A, Nemeth A, Kovacs T, Kilar P, LimanowkaD, Pyrc R, Cheval S, Gyorgy D, Dumitrescu A, Matei M, Birsan MV, Dacic M, Petrovic P, Krzic A,Antolovic I, Nejedlik P, Statsny P, Kajaba P, Bochnicek O, Galo D, Mikulova K, Nabyvanets Y,Skrynyk O, Krakovska S, Gnatiuk N (2014) Climate of the Carpathian Region in 19612010: cli-matologies and trends of ten variables. Int J Climatol. doi:10.1002/joc.4059

    Stefanescu V, Stefan S, Georgescu F (2014) Spatial distribution of heavy precipitation in Romania between1980 and 2009. Meteorol Appl 21:684694. doi:10.1002/met.1391

    Szentimrey T (1999) Multiple Analysis of Series for Homogenization (MASH). Proceedings of the 2ndseminar for homogenization of surface climatological data. Budapest, Hungary. WMO, WCDMP-No.41: 2746

    Szentimrey T (2008) Development of MASH homogenization procedure for daily data. Proceedings of the5th seminar for homogenization and quality control in climatological databases, Budapest, Hungary,2006, WCDMP-No. 71: 123130

    Szentimrey T (2011) Manual of homogenization software MASHv3.03. Hungarian Meteorological ServiceSzentimrey T, Bihari Z (2004) Mathematical background of the spatial interpolation methods and the

    software MISH (Meteorological Interpolation based on surface homogenized data basis). Proceedingsof the conference on spatial interpolation in climatology and meteorology. COST-719 Meeting, Bu-dapest, Hungary, 2429 October 2004

    Szentimrey T, Bihari Z (2005) Manual of interpolation software MISHv1.01Szentimrey T, Bihari Z (2007) Mathematical background of the spatial interpolation methods and the

    software MISH (meteorological interpolation based on surface homogenized data basis), Proceedingsfrom the conference on spatial interpolation in climatology and meteorology, Budapest, Hungary,2004, COST Action 719, COST Office: 1727

    Taylor KE (2001) Summarizing multiple aspects of model performance in a single diagram. J Geophys Res106(D7):71837192. doi:10.1029/2000JD900719

    Tveito OE, Wegehenkel M, van der Wel F, Dobesch H (2006) The use of geographic information systems inclimatology and meteorology. COST Action 719 Final Report. w3.cost.eu/fileadmin/domain_files/METEO/Action_719/final_report/final_report-719.pdf

    Venema VKC, Mestre O, Aguilar E, Auer I, Guijarro JA, Domonkos P, Vertacnik G, Szentimrey T,Stepanek P, Zahradnicek P, Viarre J, Muller-Westermeier G, Lakatos M, Williams CN, Menne M,Lindau R, Rasol D, Rustemeier E, Kolokythas K, Marinova T, Andresen L, Acquaotta F, Fratianni S,Cheval S, Klancar M, Brunetti M, Gruber C, Prohom Duran M, Likso T, Esteban P, Brandsma T(2012) Benchmarking homogenization algorithms for monthly data. Clim Past 8:89115. doi:10.5194/cp-8-89-2012

    Yatagai A, Kamiguchi K, Arakawa O, Hamada A, Yasutomi N, Kitoh A (2012) APHRODITE: constructinga long-term daily gridded precipitation dataset for Asia based on a dense network of rain gauges. B AmMeteorol Soc 93:14011415. doi:10.1175/BAMS-D-11-00122.1

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    ROCADA: a gridded daily climatic dataset over Romania (1961--2013) for nine meteorological variablesAbstractIntroductionLocation and dataMethodsResults and discussionConclusions and future workAcknowledgmentsReferences