Air humidity in Cracow (Poland) in the period 1863-2007 – daily data quality control and...

Air humidity in Cracow (Poland) in Air humidity in Cracow (Poland) in the period 1863-2007 – daily data the period 1863-2007 – daily data

quality control and homogenization quality control and homogenization methodsmethods

Agnieszka Wypych, Katarzyna PiotrowiczAgnieszka Wypych, Katarzyna PiotrowiczInstitute of Geography and Spatial ManagementInstitute of Geography and Spatial Management

Jagiellonian UniversityJagiellonian University

Krakow - location

Krakow lies in the southern part of Poland on the Vistula River in a valley at the foot of the Carpathian Plateau, 219 meters above sea level.

The city covers an area of 327 sq meters.

Neighbourhood of Krakow with the Wieliczka Foothils and the Krakow Upland, located 200-250 metres higher, results

in modification of many climate features within the town area.

AIR HUMIDITY – DATA QUALITY CONTROL

The Sniadecki CollegiumThe Sniadecki Collegium

The station was established as early as in 1792 by Jan The station was established as early as in 1792 by Jan SSniadecki niadecki

as partas part of theof the Astronomical ObservatoryAstronomical Observatory


The Historical Station is located 12m a.g.l. (NNW)


Since 1826 meteorological measurements have been conducted: 1. Permanently in the same place

Krakow – city developement

before 1792in 1792in 1915in 1941in 1951in 1973in 1986

2. With nearly unchanged surroundings


1847


2007


3. According to contemporary meteorological Instructions

The hours of observation and methods of calculating the mean daily air temperature in Krakow

Since 1826 meteorological measurements have been conducted:


* Krakow local time is put back at 20 minutes in relation to Central-European time. Measurements were performed in Krakow local time between 6-7 a.m, 2-3 p.mand about 9 p.m., that is Central-European time: 5.40-6.40 a.m., 1.40-2.40 p.m. and about 8.40. p.m.

(t1+t7+t13+t19)/4Cental- European1, 7, 13, 191971- to today

(t7+t13+2t21)/4Cental- European7, 13, 211957- 1970

(t7+t14+2t21)/4Krakowlocal7, 14, 211912- 1956


(t6+t14+t22)/3Cental- European6, 14, 221892- 1902

(t6+t14+t22)/3Krakowlocal6, 14, 221837- 1891

(t7+t12+t21)/3Krakowlocal7, 12, 15, 211826- 1836

(t6+t14+t21)/3Krakowlocal*6- 7, 14- 15, about 211792- 1825

Method of calculating the

mean dailyTime of observation

The hours of observation

Years

* Krakow local time is put back at 20 minutes in relation to Central-European time. Measurements were performed in Krakow local time between 6-7 a.m, 2-3 p.mand about 9 p.m., that is Central-European time: 5.40-6.40 a.m., 1.40-2.40 p.m. and about 8.40. p.m.

(t1+t7+t13+t19)/4Cental- European1, 7, 13, 191971- to today


(t7+t14+2t21)/4Krakowlocal7, 14, 211912- 1956


(t6+t14+t22)/3Cental- European6, 14, 221892- 1902

(t6+t14+t22)/3Krakowlocal6, 14, 221837- 1891

(t7+t12+t21)/3Krakowlocal7, 12, 15, 211826- 1836

(t6+t14+t21)/3Krakowlocal*6- 7, 14- 15, about 211792- 1825

Method of calculating the

mean dailyTime of observation

The hours of observation

Years

The only measurement The only measurement series to have undergone series to have undergone homogeneity testing thus homogeneity testing thus far are series of air far are series of air temperature,temperature, atmospheric atmospheric pressure and precipitation. pressure and precipitation.

Fluctuation of climate in Krakow Fluctuation of climate in Krakow (1792-1995)(1792-1995)

Secular change of climate on the basis of Secular change of climate on the basis of the Krakow meteorological series …the Krakow meteorological series …

Janina Trepińska (ed.)Janina Trepińska (ed.)


Saussure HigrometerSaussure Higrometer Higrometer - XIX century Higrometer - XIX century

Air humidity measurements have begun

20 May 1792 (19 May 1792)


Psychrometric measurements - Psychrometric measurements - 18341834

Permanent data - December Permanent data - December 18621862

1863 – 2007 (144 years)1863 – 2007 (144 years)

The homogeneity of air humidity parameters has not been The homogeneity of air humidity parameters has not been investigated, mainly due to the methodical difficulties investigated, mainly due to the methodical difficulties related to the analysis of numerical material.related to the analysis of numerical material.


RESEARCH PURPOSERESEARCH PURPOSE

EExamine the quality of Cracow’s air humidity xamine the quality of Cracow’s air humidity measurementmeasurement seriesseries..

Daily values of selected air humidity parameters Daily values of selected air humidity parameters calculated on the basis ofcalculated on the basis of psychometric measurementspsychometric measurements (1863-2007) – morning, noon, evening observation time(1863-2007) – morning, noon, evening observation time

DATADATA


METHODSMETHODS

- Psychrometric measurements values qualityPsychrometric measurements values quality- Air humidity parameters calculating methodsAir humidity parameters calculating methods- Series homogeneizationSeries homogeneization


AA comparison of air temperature (T), whose comparison of air temperature (T), whose homogeneity hahomogeneity hass previously been checked, with the previously been checked, with the appropriate readings of a wet bulb thermometer (T’). appropriate readings of a wet bulb thermometer (T’).

TThe missing data concerning the state of the he missing data concerning the state of the cambric during the measurements cambric during the measurements - - water/ice water/ice ((completedcompleted))

Air humidity measurements - Air humidity measurements - methodical difficultiesmethodical difficulties- psychrometer localisation: distance from vegetation, psychrometer localisation: distance from vegetation, water water reservoirsreservoirs- wet-bulb thermometer moisteingwet-bulb thermometer moisteing- wind speed (ventilation)wind speed (ventilation)

Temperature measurements – different thermal scales Temperature measurements – different thermal scales (recalculated)(recalculated)


CCambric ambric state state during the measurements during the measurements - - water/icewater/ice

Psychrometric formulas (-10Psychrometric formulas (-10ooC) – (+8C) – (+8ooC)C)

Frequency of Frequency of iceice//waterwater cambic state (Krakow 1971-2000) cambic state (Krakow 1971-2000)

Statistics (1971-2000)Statistics (1971-2000)

0%

20%

40%

60%

80%

100%

<-5.0;-4.0) <-4.0;-3.0) <-3.0;-2.0) <-2.0;-1.0) <-1.0;0.0) 0.0 (0.0;1.0> (1.0;2.0> (2.0;3.0> (3.0;4.0> (4.0;5.0>

temperature (oC)

frequency


Statistics (1863-1900)Statistics (1863-1900)

Difference (%) between relative air humidity values counted Difference (%) between relative air humidity values counted using „ice formulas” and „water formulas” (-5using „ice formulas” and „water formulas” (-5ŁŁttŁŁ5)5)

Error range Error range (%)(%)

-5

-4

-3

-2

-1

0

1

2

3

4

5

<-5.0;-4.0) <-4.0;-3.0) <-3.0;-2.0) <-2.0;-1.0) <-1.0;0.0) 0.0 (0.0;1.0> (1.0;2.0> (2.0;3.0> (3.0;4.0> (4.0;5.0>

temperature (oC)

diff erence (%)


CCambric ambric state state during the measurements during the measurements - - water/icewater/ice

Psychrometric formulas (-10Psychrometric formulas (-10ooC) – (+8C) – (+8ooC)C)

Statistics (1863-1900)Statistics (1863-1900) (1971-(1971-2000)2000)

(-5(-5ooC) – (+5C) – (+5ooC) C)

Missing dataMissing data

t<-3t<-3ooC - iceC - ice

-3-3ooC<t<-2C<t<-2ooC – iceC – ice (t’<-2(t’<-2ooC)C)

-1,9-1,9ooC<t<1,9C<t<1,9ooC C compared with compared with weather weather conditionsconditionst>2t>2ooC - waterC - water

VValuealuess of air humidity parameters of air humidity parameters - p - psychsychrrometric ometric models, identical for the entire seriesmodels, identical for the entire series


Psychrometric formulasPsychrometric formulasmodyfied: G. Magnus (1844); M. Robitzsch (1928); O. Tatens modyfied: G. Magnus (1844); M. Robitzsch (1928); O. Tatens

(1930)(1930)

)'(7946,0' ttEte

'235

'4366,710107,6'

t

tEt

'5,265

'5,910107,6'

t

tEt

)'(7060,0' ttEte

water

ice

Extreme cases, which gave rise to doubtsExtreme cases, which gave rise to doubts – compared with – compared with the records the records about the state of the atmosphere:about the state of the atmosphere:

- - circulation conditions, circulation conditions,

- - the occurrence of foehn the occurrence of foehn

- - atmospheric phenomena atmospheric phenomena


Homogeneity testHomogeneity test


Air humidity values – no visible inhomogeneity Air humidity values – no visible inhomogeneity ((modified form of SNHT Alexanderssonmodified form of SNHT Alexandersson)

The The controversial values controversial values - - further verificationfurther verification Corrections of numerical data Corrections of numerical data - - not performednot performed

CONCLUSIONCONCLUSION

The content of air vapour in the air is a result of the The content of air vapour in the air is a result of the interaction of numerous factors and processes, which interaction of numerous factors and processes, which need to be taken into account before correcting the need to be taken into account before correcting the values. values.

In light of the lack other objective possibilities of In light of the lack other objective possibilities of verification of air humidity in Krakow, the analysed verification of air humidity in Krakow, the analysed data were considered as relatively homogeneous.data were considered as relatively homogeneous.


Long term course of the relative air humidity (f%) in Krakow Long term course of the relative air humidity (f%) in Krakow (1863-2007)(1863-2007)

y = -0,0648x + 82,061

60

70

80

90

100

1860 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000years

f (%)


Long term course of the number of Long term course of the number of very wet (fvery wet (fłł86%)86%) and and dry dry (f(fŁŁ55%)55%) days in Krakow (1863-2007) days in Krakow (1863-2007)

0

50

100

150

200

1860 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

number of days

Thank you Thank you

for for

your attentionyour attention

Air humidity in Cracow (Poland) in the period 1863-2007 – daily data quality control and...

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