InsightsUnveiled

It is important to consider the winter monsoon for 2 reasons:- a) It corresponds to the night cycle of the sea breeze & like the summer monsoon is an important component of the global monsoon. b) It has the capacity to generate seasonal rainfall over the southern part of Indian peninsula, Sri Lanka, Malaysia & Indonesia. The onset of winter monsoon is not clearly defined & at times there is no distinction between withdrawal of summer monsoon & the onset of winter monsoon. There is a period of transition of about a week for the winter rains to st in Tamil Nadu.Tamil Nadu experiences north-east monsoon from October to December. Intense convection over Indonesia generates precipitation & releases of latent heat subsequently. This is an ascend corresponding to the rising limb of the Hadley's cell. the ascending air spreads to the north & south which isn't possible for the ascending air over Tibet during the summer monsoon because the northwards air

It’s a term introduced by Bjerkness school in Norway(1918) to describe a sloping boundary plane or surface of separating 2 air masses that exhibit different meteorological properties or characteristics. the interface of which may be narrow & on a small scale when it is termed as a -frontal surface(eg.-warm front associated with depression) & may be broad & on scale of a frontal zone(eg.-Atlantic Polar Front). The different types of front are as follows:- 1) The Arctic Front:- this is a distinctive baroclinic zone separating the ice & snow of the high Arctic regions from the more moderate polar/tundra environments to the Pacific portion does move further south into N.W.North America in winter as the high Arctic freeze is acentuated by polar night. 2)P olar Front :-It's well known active zone of frontogenesis in Atlantic & pacific oceans. It’s quite variable depending on the seasonal distribution & extent of polar & tropical air masses. In t

Tropical cyclones are warm core vortex circulation of tropical region with a small diameter, often of an approximately circular shape, minimum surface pressure (<900mb 33m="33m" accompanied="accompanied" amp="amp" at="at" by="by" least="least" maximum="maximum" o:p="o:p" of="of" rains="rains" sec.="sec." standard="standard" thunderstorms="thunderstorms" torrential="torrential" winds="winds" with="with"> & are known by a variety of names.                                                               these storms cause havoc in the India, Bangladesh, Myanmar & hence, correct predictions are required for preventions for disaster management policy formulation. There are 3 distinct periods for occurrence of this storm:- 1) Pre-monsoon period; 2) Monsoon season leaving the months of June, July, August &

Dry adiabatic lapse rate is the decrease in temperature of an unsaturated air mass in it's vertical movement through a stable equilibrium  atmosphere where temperature is decreasing @ 1(degree)celcius/100m ascend.     Saturated adiabetic lapse rate is the decrease in temperature of a saturated air mass in it's vertical movement through the atmosphere where the decrease in temperature of a saturated air mass in it's vertical movement through the atmosphere where temperature decreases @ 0.4(degrees)C - 0.9(degrees)C ascend. At the altitudes SALR(Saturated Adiabetic Lapse Rate) has no independent existence in the sense that SALR=DALR(approximately)which is due to the fact that SALR depends on water vapour concentration & temperature.      When condensation takes place in a air parcel undergoing DALR,esults in decreased temperature due to expansion of air parcel since ENVIRONMENAL LAPSE RATE (ELR) is less than the DALR & emergence of SALR conversion air mass fro

Latent heat is the heat energy absorbed & held in storage in a liquid or solid & is subsequently released by the process of condensation.   When water is converted into steam, heat is required in the process. Once steam is formed this steam stores potential energy in the form of latent heat which amounts to 260 joules of energy per gram of water vapour laden air. As this mass of moisture laden air rises due to connection current atmospheric gasses mixes with the water vapour. Addition of solids increases the boiling point of water & addition of gasses decreases the boiling point. In the lower part of troposphere the concentration of dust particles & other suspended foreign bodies are high & it decreases with height. Atmosphere pressure also decreases with height. Decrease in atmospheric pressure followed with decrease in dust particles 7 other suspended foreign bodies are high & it decreases with height. Atmospheric pressure also decreases with height. Decr

Relative humidity is the ratio between the actual amount of water vapour present in the atmosphere at a given temperature & the maximum amount of water vapour that the atmosphere can retain at that temperature & is expressed as a percentage.       We know, A.P.=K*D*T where,A.P.=atmospheric pressure;K=constant=density & T=Temperature temperature is the index of heat contained in a substance.thus,when temperature increases density of air mass decreases so does the atmospheric pressure.Since,we are concerned with water vapour so vapour pressure would be a more appropriate term,Hence,it is the actual vapour pressure expressed as the percentage of saturation vapour pressure which would be possible at the same temperature. It(relative Humidity) is concerned with 2 variables:- a)actual water vapour in a given mass of air; b)Temperature of that mass of air,since this determines the capacity of the air to hold water vapour.this implies high temperature which is indicati

Pressure gradient is the amount of change in atmosphere pressure between 2 points & is depicted on the synoptic chart by the differential spacing of isobars(imaginary lines joining points on the map with equal barometric pressure)-a wide spacing indicates weak or gentle gradient (& therefore wind of low velocity) while narrow spacing indicates a steep gradient (& therefore winds of high velocity).Thus, when the wind is subjected to greater pressure on one side than on the other, this imbalance produces a net imbalanced force from a region of high pressure to the region of low pressure called the Pressure Gradient Force.                     Pressure gradient force=1/density of atmosphere*(rate of pressure change*over distance 'P' )/(rate of pressure change* in the direction 'X' ) This pressure difference between the two isobars cause the wind to blow as per Newton's second law f motion & if these differences are high wind velocity is high &

jet stream is narrow belt of high altitude (>12000m.) westerly winds in the troposphere whose speed varies between 10 Km./hr(in summer) to 184Km./hr(in winter),although velocities of over 370Km./hr. has been recorded occasionally. Their location & velocities have an important effect on travel times of flying aircraft especially in mid-latitude air routes. Westerlies are the wind system which dominates the zones between latitude 40(degrees)N/S & 70(degrees)N/S of the equator. The flows of air from the sub-tropical high pressure cells to the temperate zone of low pressure cell, thereby maintaining the fundamental meridional heat exchange mechanism.The prevailing wind direction in northern hemisphere is from south-west & in the northern hemisphere in the north-west.it is one of he strongest & most undisturbed airflows among the planetary winds. the velocity increases with height & the southern hemisphere westerlies are stronger than their northern hemespherial

An isotherm is an imaginary line drawn on a weather chart or map to join places of equal temperature. Temperature varies from season -as there is high temperature during summer & low temperature during winter with minor changes during transitionary seasons. We know that temperature is proportional to atmospheric pressure & inversely proportional to density.                                                        A.P.=K*D*T                                                           T=A.P*1/D where,A.P.=atmospheric pressure;K=constant;D=density;T=temperature      During the summer season in either of the hemisphere's the sun is vertically overhead of the tropic of cancer/capricorn.The land which has a low specific heat capacity & also being a bad conductor of heat re-radiates the heat to the atmosphere resulting in the spreading of molecules of atmospheric gases due to the heat energy. As molecules spread over a wide region it's pressure on the land becomes l

Hot deserts are located between 15(degrees) & 30(degrees)N/S of the equator on the western part of the continents where the trade winds are off-shore. As a result they don't contain moisture but contain heat which they are carrying away from the sub-tropical high pressure belts. Moreover, the whole of Arabia, N.W.India etc. region fall under the descending limb of the Walker Cell originating over Indonesia which makes these regions a "heat sink" as a result temperatures remain high & pressure low since, density is low as the heat energy is encouraging individual atoms & molecules to move away from each other by breaking away the inter-molecular force of attraction. The presence of cold currents have  a desiccating effect on the climate of these hot deserts aa they don't emit sensible or latent heat as they travel along like their warm counterparts. For eg.-cold canaries current & cold benguela current  flow along the western part of Africa, Californi

Blowing of strong trade wind have a frictional drag on warm surface water of ocean away from it's source environment resulting in divergence caused due to coriolis force.the removal of light warm water from the surface encourage upwelling of cold Benthos water to the surface as in for example-the Peruvian current (Humbolt current ) off-South America. Lapse rate steepening, instability & free convection over warm water is now being replaced by surface temperature inversion & stability.                                 The replacement of cold Peruvian current in the tropical pacific basin by incursion at periodic levels by a weak warm ocean current that flows south along the coast of Ecuador & Peru. This disruption is called El Nino commonly occurring during Christmas season. Southern Oscillation is a climatologically term referring to perturbation in the inter tropical general circulation, especially in the Indian Ocean & south pacific. The term was introduced

The obscurity by the surface layers of the atmosphere owing to the presence of water droplets formed by condensation, amplified by suspended particles of smoke & dust which occur.                     Fogs are classified as follows:- a) Advection Fog:- A fog formed when a relatively warm, moist & stable air mass moves laterally over a cooler surface thereby reducing the temperature of the lower layer of the air mass causing inversion of temperature until it reaches the dew point when condensation takes place. This may occur when warm maritime air moves over the cold landmass or when warm continental air mass moves of-shore across a cold ocean current.Eg.-Gulf stream meeting air above cold Labrador current near the grand banks of new foundland.                            It sometimes develops over a frozen, snow covered land mass in conjugation with radiation fog. If the air flow is too vigorous & beyond 8m/sec. in velocity then the fog will rise to form low altitud

It's a name given to the westerly winds of the low latitudes,caused when the north-east & south-east trade winds are deflected on the crossing the equator & develop a westerly component thereby becoming the equatorial westerlies whenever the inter-tropical convergence zone is more than 5 degree away from the equator.           The shifting of the position is related to the shifting of pressure belts 5(degree)N/S to 10(degree)N/S as per the movement of the sun & the amount of insolation received.When the sun is overhead the tropic of cancer,differential heating leads to a low pressure region over the north-west India,Arabia etc. which provokes ascending warm air causing lower air convergence thus, inviting the south-east trades( which are constant & carry moisture due to their path of motion over the seas/oceans) to cross the equator & get deflected to the right as per Ferrel's Law & Corriolis Force  & enters the Indian sub-continent as south-wes

Green house effect is an expression referring to the process to describe how short-ave radiation passes easily through the atmosphere to reach Earth’s surface whereas outgoing radiation passes easily through the atmosphere to reach Earth's surface whereas outgoing radiation is absorbed & reradiated by water vapor droplets & cabon-di-oxide.the burning of fossil fuel is a reason for the accentuation of this effect. The current annual increase of carbon-di-oxide is 0.4%. the effects of green house effect could be as follows:- 1) Future sea level rise: Environmental & Socio-political considerations two processes will contribute to the rise in mean sea level. An atmospheric warming of several degrees would warm the upper layer of the ocean, causing it to expand in volume like the liquid mercury in a hospital thermometer. Melting of mountain top glaciers would find it's ways into oceans by the increased run-off & such melting of mountain glaciers would raise

Easterly waves or eastern depressions are roughs of low pressure embedded in north-east trade winds & they move from east to west.They develop in broad convergence zone formed by an aggregation of several cloud clusters within ITCZ. Since,the resultant vigorous convection takes place too close to equator where Coriolis force is too weak to generate circular atmospheric motions & major synoptic-scale disturbances comparable with mid-latitude depressions.the tropical convection becomes associated with pronounced wave like undulations & thwart trade winds. These troughs alternate with high pressure ridges (divergence zones) with wavelengths between 2000Km & 4000 Km.these waves have a life span of upto 2 weeks & travel westwards  (in trade wind flow) 6(degrees) - 7 (degrees) long/day at a speed of 5 - 7 m/sec. ,in deep trade wind flow of the southern limb of the Azores & North Pacific sub-tropical highs .The shallow weak troughs extend from equator to the

Similarities between land & sea breeze are as follows:- 1) In land & sea breeze land & sea/ocean is involved.                                                                             Here, land (but subcontinent or apart of the subcontinent) & ocean/sea (never a lake or minor water body) is involved. 2)It is caused due to thermal contrast between land & sea due to differential specific heat capacity of land & water.                                                                          In Asian monsoon circulation, thermal contrasts during the different seasons (especially summer & winter when contrasts are maximum) between land & sea is it's cause, due to difference in specific heat capacity between land & water. 3)In land & sea breeze both horizontal & vertical heat transfers occur.                                                                  In Asian monsoon circulation, both horizontal & vertical heat trans