Numerical modeling of cloud and precipitation evolution and its connection with entropy
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| Опубліковано в: : | Геофизический журнал |
|---|---|
| Дата: | 2010 |
| Автори: | , |
| Формат: | Стаття |
| Мова: | Англійська |
| Опубліковано: |
Інститут геофізики ім. С.I. Субботіна НАН України
2010
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| Онлайн доступ: | https://nasplib.isofts.kiev.ua/handle/123456789/101197 |
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| Назва журналу: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Цитувати: | Numerical modeling of cloud and precipitation evolution and its connection with entropy / T. Belyi, A. Pirnach // Геофизический журнал. — 2010. — Т. 32, № 4. — С. 15-17. — Бібліогр.: 4 назв. — англ. |
Репозитарії
Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1860049891805364224 |
|---|---|
| author | Belyi, T. Pirnach, A. |
| author_facet | Belyi, T. Pirnach, A. |
| citation_txt | Numerical modeling of cloud and precipitation evolution and its connection with entropy / T. Belyi, A. Pirnach // Геофизический журнал. — 2010. — Т. 32, № 4. — С. 15-17. — Бібліогр.: 4 назв. — англ. |
| collection | DSpace DC |
| container_title | Геофизический журнал |
| first_indexed | 2025-12-07T16:59:47Z |
| format | Article |
| fulltext |
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Numerical modeling of cloud and precipitation evolution
and its connection with entropy
T. �����1, A. Pirnach2, 2010
1Institute of Geophysics, National Academy of Sciences of Ukraine, Kiev, Ukraine
tbelyi@mail.ru
2Ukrainian Hydrometeorological Institute, Kiev, Ukraine
hanna@uhmi.org.ua
A recent work devoted to sources of entropy con-
nected with mesoscale frontal cloudiness. Three-
dimensional nowacasting and forecasting numeri-
cal models developed in UHRI [Pirnach, 199�; 2008;
Belyi et al., 2009] for modeling of the winter and
summer frontal cloud systems were adapted for theo-
retical interpretation of the investigated phenomena.
The integration of full thermodynamic equations,
which included equations for air motion, water va-
por content, temperature transfer, the continuity and
thermodynamic state equations are used in these
models. Cloud microphysics is considered explicit-
ly by solving the kinetic equations for the droplet
and crystal size distribution. The size distribution
function of the cloud and precipitation particles is
formed due to cloud condensation nucleation, ice
nucleation, growth (evaporation) by deposition, and
freezing, riming, collection by raindrops of cloud
drops. Droplet and ice nucleation is accounted by
parameterization in the model. Cartesian coordi-
nates (�, �, �) and terrain-following sigma coordinates
, , have been used. In second case the system
of equation will be described as follows:
i
dSi F
dt
Si ,
( 1 )
/#�)-(% '0%.�+,#(� #(%1
�5 ���������
���
����������������������
0
wvu
,
RT
p ,
ki fqTwvuS ,,,,, �
8,...,2,1=i �� 3,2,1=k �
�, �, � are components of wind velocity across , ,
axis, which are directed on east, north and per-
pendicular to the ground surface respectively. �
are
describes separate physical processes: �
�
�
�
pre-
sented right parts of wind velocity projections, which
included Carioles parameter, free-fall acceleration,
pressure gradients and etc.; �
�
�
�
�describe heat
and moisture fluxes; �
�
�
represent processes of
droplets and crystal nucleation, cloud and precipi-
tation particles falling velocities, their transfer, con-
densation and coagulation processes etc; �
is
turbulent transfer; � and are pressure and densi-
ty;
is temperature; q is specific humidity; �
�
are
cloud particle size distribution functions.
A�splitting�method�had�been�used�for�sintegration�of
the system (1). The solution scheme was described
as follows:
6
1n
in
i F
t
S
, 6,...,2,1n �� 8,...,2,1i �
System (5) to split up on 6 equations as follows:
in
in F
t
S
, 6,...,2,1n .
�
��
presented�the�advection��convection�and�turbu-
lent�transfer ��
�
� included the pressure gradients
�
�
�included�Carioles acceleration ��
�
described a
vertical motion solution schemes;��
�
presented con-
densation processes; �
�included coagulation so-
lution schemes.
Entropy S calculated by relationship [Khrgian,
1969]:
constlnpCS ,
is potential temperature, �
�
is specific heat ca-
pacity at the constant pressure.
Production of entropy calculated by relationship
as follows:
pC
dt
d
dt
dS
.
Numerical simulation of atmospheric phenome-
na connected with atmospheric fronts and their
cloud systems that caused the damages events have
been fulfilled for several synoptic situations observed
in steppe part and mountain regions of Ukraine. Di-
agnostic and forecast models have been construc-
ted for mesoscale cloud formations followed by high
floods in Carpathian region. Numerical experiments
are carried out with aim to determine the role of
various dynamics and microphisics parameters in
formation of strong and catastrophic precipitation.
Series of numerical experiments have been carried
out with aim to research the key parameters caused
features of development of dangerous events and their
activity. Special numerical experiments have been
carried out with a main goal to research the temporal
and spatial distribution of entropy and its production.
Numerical study interaction between entropy and cloud
and precipitation had been carried out.
It is found, the unlimited growth of water and ice
supersaturation is possible if mechanisms of cloud
precipitation formation are insufficiently effective for pre-
cipitating of whole moisture. In turn, it can cause inten-
sive activation of cloud condensation nuclei and unli-
mited growth of large drops as well. Therefore the un-
limited growth of precipitation intensities may occur.
Some key parameters, meteorological conditions
and predictors caused the occurrence of dangerous
phenomena were defined. The main features of
strong precipitation have been noted as follows: in-
teraction of flows of different physical nature coming
from opposite directions; presence of ice supersa-
turation layers; strong vortical motions in single air
mass advanced to mountain ridge; chimney clouds
with ice tops and cirrus clouds above; high tropo-
pause achieved 10 km and more, strong ascending
and compensative descending motions; the neces-
sary combination of precipitation-forming mecha-
nisms.
Coupling modeling of evolution entropy and pre-
cipitation found their perfect agreement. Regions of
the low entropy coincided with regions of heavy pre-
cipitation. Regions with high entropy located in
cloudless space. Regions of the low entropy can to
be good predictors of heavy precipitation with a high
confidence probability.
References
Belyi T. A., Dudar C. M., Pirnach G. M. Numerical inves-
tigation effect on evolution of mesoscale cloud clus-
ters of different mechanisms of cloud and precipi-
tation formation caused heavy precipitation in Car-
���������
���
���������������������� ��
��� ��!"#�$%&'�("�%()�#*+#�' #(&"�&��&,#��-�%()� �)#..'(/
patian in 2008 during July 21—29 // Geophys. J. —
2009. — 31, � 6. — P. 107—123 (in Russian).
Khrgian �. Kh. Atmospheric physics. — Leningrad:
Hydrometeoisdat, 1969. — 647 p. (in Russian).
Pirnach A. M. Numerical modeling of clouds and pre-
cipitation in atmospheric frontal systems. — Kiev:
Nika-Center, 2008. — 294 p.
Pirnach A. M. The construction and application of nu-
merical models to the study of cloud dynamics and
the structure of winter frontal rainbands //
� At-
mospher. Res. — 1998. — 45—47. — P. 356—376.
|
| id | nasplib_isofts_kiev_ua-123456789-101197 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 0203-3100 |
| language | English |
| last_indexed | 2025-12-07T16:59:47Z |
| publishDate | 2010 |
| publisher | Інститут геофізики ім. С.I. Субботіна НАН України |
| record_format | dspace |
| spelling | Belyi, T. Pirnach, A. 2016-05-31T18:53:35Z 2016-05-31T18:53:35Z 2010 Numerical modeling of cloud and precipitation evolution and its connection with entropy / T. Belyi, A. Pirnach // Геофизический журнал. — 2010. — Т. 32, № 4. — С. 15-17. — Бібліогр.: 4 назв. — англ. 0203-3100 https://nasplib.isofts.kiev.ua/handle/123456789/101197 en Інститут геофізики ім. С.I. Субботіна НАН України Геофизический журнал Numerical modeling of cloud and precipitation evolution and its connection with entropy Article published earlier |
| spellingShingle | Numerical modeling of cloud and precipitation evolution and its connection with entropy Belyi, T. Pirnach, A. |
| title | Numerical modeling of cloud and precipitation evolution and its connection with entropy |
| title_full | Numerical modeling of cloud and precipitation evolution and its connection with entropy |
| title_fullStr | Numerical modeling of cloud and precipitation evolution and its connection with entropy |
| title_full_unstemmed | Numerical modeling of cloud and precipitation evolution and its connection with entropy |
| title_short | Numerical modeling of cloud and precipitation evolution and its connection with entropy |
| title_sort | numerical modeling of cloud and precipitation evolution and its connection with entropy |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/101197 |
| work_keys_str_mv | AT belyit numericalmodelingofcloudandprecipitationevolutionanditsconnectionwithentropy AT pirnacha numericalmodelingofcloudandprecipitationevolutionanditsconnectionwithentropy |