eChapters

Abstract

Gastrointestinal parasitic infections particularly Haemonchus contortus infection in goats is very common and found as major nematode infections in farm condition. To chalk out the control programme and to prevent the initiation of anthelmintic resistant parasites, it is essential to know well in advance the prevalence of H. contortus infection. During the year 2009, a study was undertaken on H. contortus infection in the goat farm of ICAR Research Complex for NEH Region, Umiam, Meghalaya, which is a subtropical hill area and bioclimatograph was prepared to predict the prevalence of H. contortus infection in goats of this area. Meteorological data of this area was collected to visualize the effect of temperature, rainfall and humidity. Bioclimatographs were prepared in which total rainfall (TRF) or relative humidity (RH) is plotted against the maximum temperature (T-max) or minimum temperature (T-min) for the months and the resultant points are joined by a closed curve. The lines constituted the windows on these bioclimatographs, indicating the limit of the climatic conditions most suitable for development and survival of exogenous stages of gastrointestinal nematodes.

Abstract

Aquaculture is facing the serious effects of climate change in the form of scarcity of water and shift in dissolved oxygen level leading to outbreak of diseases. In a study conducted in Farm facilities of ICAR, Tripura it was seen that rise in temperature do have significant effect on hematological and biochemical parameters of fish which are basic index of good health of any organism. Many different diseases occur in the farmers’ pond and which can be controlled. So some basic diseases and their controlling strategies have been pointed out that can lead to better management of fish diseases in pond condition.

Abstract

Climate change is a matter of great concern considering aquatic resources and the productivity. The likely impact of Climate Change is noted in the domain both in marine as well as estuarine capture fisheries, fresh water capture fisheries and freshwater aquaculture. Climate change is having a linkage with spread of fish diseases as increasing water temperature will shift the balance in favor of either the host or pathogen changing the frequency and distribution of diseases. There are a no of adaptation and mitigation measures in aquaculture in order to increase the productivity and properly maintain the survivability of many aquaculture species.

Abstract

The breeding potential of Ompok bimaculatus is declining day by day due to decrease of rainfall and increase of atmospheric temperature. As a result, the population of Ompok bimaculatus is significantly reducing in the fresh water bodies of Tripura.
 
The results of reproductive biology of O. bimaculatus were based on the fish samples collected from different locations of some rivers and Hurijala wetland of Tripura. Total weight of the sampled fish varied from 22 g to 171.50 g and the females had a greater weight and length than males. Total length of the males varied from 16.50 cm to 29.50 cm, while the females ranged from 17.0 cm to 33.0 cm. Female dominance over male was observed in the species. The ratio of males to females was 1:1.58. Significant correlation exists between fish length and weight in both males (R² = 0.943) and females (R² = 0.827).

Abstract

Climate change is a change in the distribution of weather over periods of time that range. The effect of climate change is now visible every where including animal farm industry. Projected temperature rise around 2-5oC by 2100 due to climate change is likely estrus, start estrus and decline in reproduction efficiency of livestock species Climate change may have a significant effect on livestock and other animals through is impact on diseases Zoonotic diseases which can be transmitted between vertebrate animals and humans are a matter of great concerns. There is an urgent need for adoption of integrated approaches towards mitigation of advance effects of climate change in animal production. There are nutritional strategies to reduce enteric methane production. Surveillance and monitoring with various adaption strategies are to be brought under purvision to reduce adverse impact of climatic variability in livestock 

Abstract

Climate change and variability can adversely affect the poultry production in India, because birds can only tolerate narrow temperature ranges. Thermal stress on poultry is major concern. Heat and clod stress can cause immunosuppression and make birds more prone to infectious diseases. Climate change affects the occurrence, distribution and prevalence of poultry diseases.  Nutritional strategies aimed to alleviate the negative effects of heat stress by maintaining feed intake, electrolyte and water balance or supplementation of micronutrients such as vitamins and minerals to satisfy the special needs during heat stress have been proven advantageous. Ventilation and cooling methods are essential for birds to survive high summertime temperatures. Tunnel ventilation coupled with evaporative cooling is very effective in keeping birds cool during hot weather. The increasing proportion of poultry production in tropic and subtropical region makes it necessary to reconsider the selection strategy and potential use of naked neck and frizzle genes for improving heat tolerance in chicken.

Abstract

Infertility in Livestock is a matter of great concern Anoestrous and repeat breeding in buffalo and bovines are two of the most serious reproductive problems affecting 30-40% of the total cattles and buffalo population on a conservative estimate our country is loosing 20-30 million tonnes of milk due to anestrus and repeat breading in cattle and buffaloes translating to a loss of Rs 40-50,000 crores annually. The used weak symptoms of estrus in the normal breeding season (September to February) become ever weaker during the hot month of summer. The incidences of silent heat is the lowest in December while the break is seen in the hot summer month of April. Summer infertility is also noticedin goat. During summer farmer experience a variety of reproductive problems such as an estrus extended weaning to eastern interiors, poor conception rates, higher unbryo mortality rates and low barrowing rates. There are strategies to ameliorate heat stress induced fertility problems and gonadotropin treatment can prevent seasonal infertility. There is a need to implement several techniques at the field level combining the glance of any detrimental impact on health and environment

Abstract

In order to estimate the irrigation need of the crop, stress degree day index computers from canopy and air temperature could be used. During rabi manon, two varieties (Seeta, Brassica Juncea) and (Benoy, Brassica Camperteris) were grown. The canopy temperature of the crop was measured on 45th, 60th  and 75th  days after sowing and stress degree day (SDDI) was also measured. About 67, 70 and 51 per cent activation between SDDI and dry matter production could be explained at 45, 60 and 75 DAS of the crop growth period. Reflectance by mustard canopy was 940 measured. Late sown crop reflected less radiation with the advancement of growth. Extinction coefficient was also measured and the increase in the value of extinction coefficient upon irrigation showed canopy development and better utilization of increasing radiation by the crop. 

Abstarct

The Photosynthetically Active Radiation (PAR) measure of radiant power is important in evaluating the effect of light on plant growth. The photosynthetic response correlates better with the number of photons than with energy. This is expected because photosynthesis is a photochemical conversion where each molecule is activated by the absorption of one photon in the primary photochemical process. PAR is defined in terms of photon (quantum) flux, specifically, the number of moles of photons in the radiant energy between 400 nm and 700nm. One mole of photons is 6.0222 x 1023 photons ( 6.0222 x 1023 is Avagadro’s Number). The Phtotssynthetic Photon Flux Density (PPFD), i.e. the photon irridiance, is expressed in moles per squre meter and per second (formerly, Einsteins per squre meter and per second). The absorption of PAR by wheat varieties increased from 7.30 h to 11.30 h followed by a decline at 13.30 h at CRI, tillering and milking stages.

Abstract

Mushroom has a great potential in India. Its production is gradually increasing at the annual rate of 7%. The total mushroom production in India is 1.13 million tones and on the other hand, mushroom production annually in china is 18.2 million tones. There are a no. 07 wild mushroom available in the world and medicinal properties much as anti Candida, anti tumor (including cervical, uterine, stomach cancer) and antis viral are rotally present. Of the entire wild mushroom tested, T. glolulum has the highest amount of protein, ask, Calcium, phosphorus and iron. A total of 172 wild mushrooms have been reported home NE India and majority of the wild mushroom is of the order Agaricales. There is a need to make a concerted study of the mushroom biodiversity and its use for economic activity.

Abstract

Three villages were selected randomly representing the flood affected areas of Dhemaji district of Assam. Analysed data on climatic parameters like rainfall(mm), temperature(oC), potential evapotranspiration (mm), relative humidity (%) of last 10 years collected authentic sources and depth of ground water table  was collected from the well water depth from the three villages for twelve months showed that the length of growing period was more than 300 days and during July to September the ground water table is above the soil surface i.e. there is flood in this period, but during January to March, it is very low and water becomes inadequate for growing crops. Other climatic parameters are most suitable for both Kharif and Rabi crops, but annual flooding affects the crop during July to September. From the study it was concluded that short duration varieties of different crops like that of paddy, pulses, oilseeds etc. may be grown at pre and post flood condition.

Abstract

India has diversified agro-climatic conditions with significant variability in climatic factors viz, rainfall pattern, temperature, humidity, sunshine hours and wind speed etc. A no of fruit crops and vegetable crops are grown in India with significant differences in climatic requirements for sustainable growth and production of these crops. Attempt has also been made to have off season production of horticultural crops. Weather variability could also play a pivotal role in disease and pest incidence. So, forecasting of yield along with disease pest incidence should be given top priority to save the crop from weather vagaries and increase the crop productivity.

Abstract

Global warming is predicted to have significant effects in global potato production. Like many crops, potaoes are likely to be affected by changes in atmospheric carbon dioxide, temperature and precipitatiom, as well as interations between these factors. As well as affecting potatoes directly, climate change will also affect the distributions and populations of many potato diseases and pests. Potato is one of the world’s most important food crops. Potato prodcution must be adapted to climate change to aviod reductions in crop yields. Potato plants and potato crop are predicted to benefit from increased carbon dioxide concentrations in the atmosphere. The major benefit of increased atmospheric carbon dioxide for potatoes (and other plants) is an increase in thier photosynthetic rates which can increase their growth rates. Potato crop yields are also predicted to benefit because potates partition more starch to the ediable tubers under elevated carbon dioxides levels. Higher levels of atmospheric carbon dioxide also results in potatoes having to open thier stomata less to take up equal amount of carbon dioxide for photosynthesis, which means loss through transpiration from stomata. As a result the water use efficiency (the amount of carbon assimilated per unit water lost) of potato plants is predicted to increase.

Abstract

Rice being the major food crop in the world requires a serious attention to protect the crop from variable pest attack under change in climatic scenario. More then 100 species of insects have been recored as rice pest affecting the productivity as well as maintaining sustainability in rice production. Bio-control agents for the control of rice pests are to be systematically evaluted. More than 1500 species of pathogens are formulated as microbiological insecticides. So our current awareness in pest- pathogen-abiotic interactions should be made use in designing the crop protection strategy.

Abstract

Mulberry is a fast growing deciduous woody perennial plant. It has a deep root system. the leaves are simple, alternative, stipulate, petiolate, entire or lobed. The number of lobes varies from one to five. Plants are generally dioecious. Inflorescence is catkin with pendent or drooping peduncle bearing unisexual flowers. Inflorescence is always auxiliary. Male catkins are usually longer than the female catkins. Male flowers are loosely arranged and after shedding the pollen, the inflorescence dries and falls off. These are four presistent parianth lobes and four stamens implexed in bud. Female Inflorescence is usually short and the flowers are very compactly arranged. There are four presistent parianth lobes. The ovary is one-celled and the stigma is bilid. The chief pollinating agent in mulberry is wind. Mulberry fruit is a sorosis, mainly violet black in  colour. 

Abstract

As such in search of alternative to chemical insecticides against insect pest of rice resulted in identifying white muscardine fungus, Beauveria bassiana an entomopathogen out of several entomogenous fungi prevalent in rice ecosystem as the potential mycoinsecticides. The fungus has 78-87% virulence against rice hispa with  LC 50 value of 90.16. Under field situations it is required that the effectiveness of the bioagents are enhanced by combining them with compatible pesticides. A sublethal dose of a pesticide  would make the insect physiologically weak which makes it much more susceptible to the attack of the entomogenous organisms. In view of this, compatibility test was conducted with 14 different commonly applied insecticides at two different doses i.e., recommended and half of the recommended dose. In small scale field trial chloropyriphos at half of the recommended dose along with B. bassiana was the best treatment in controlling the pest along with increased yield of the crop consecutively for two years.

Abstract

Tripura is expected to be highly prone to the consequences to climate change because of its geo-ecological fragility, strategic location, its trans-boundary river basins and its inherent socio-economic instabilities.  Environmental security and sustainability of the state is and will be greatly challenged by the impacts of climate change in coming years.
Climate and weather can substantially influence the development and distribution of insects.

Introduction

India is believed to be the native of several economic plant species which have spread to various part of the world. While agriculture continuous to stagnate in underdevelopment and insufficiency in food production. India enjoys variable climatic conditions and multiplicity of topographic feature, elevation and rainfall. The climatic conditions and soil type are so diversified that the various combinations of these factors favor unlimited production of a wide variety of crop plants. Now started move and rapid changes are taking place largely as results of bio-technology to advance scientific agriculture. Bio-technological approaches introduction of genetically modified in plant protection. A small percentage of former are well educated on the advantages of scientific forming and are adopting newer technique at limited extent.

Abstract

Pest damage is an age old problem of Indian agriculture. The increased accumulation of green house gases always changes the climatic conditions that have potential effects in increasing pest population.  The insect pests are cold-blooded animals and their body temperature varies with the surrounding temperature. Thus, any change in the climate and weather is bound to influence the activity of pests. The pests are directly influenced by temperature, precipitation, humidity, wind speed and other environmental factors in terms of their occurrence, development, reproduction, distribution, migration and adaptation. In many cases the insect out breaks which classified as gradient out breaks are not self-driven but are entirely dependent on external environmental conditions. For example, the number of aphids has frequently been shown to be correlated with several environmental factors. Such correlations indicate an understanding of aphid out breaks. The increased temperature as a result of climate change has several implications for agricultural pests. These are as follows: (i) changes in population growth rates, (ii) increased number of generations, (iii) extension of development season, (iv) extension of geographical range, (v) increased over wintering, (vi) changes in crop-pest synchrony, (vii) changes in interspecific interactions, (vii) increased risk of invasion by migrant pests, (ix) introduction of alternate hosts, and (x) availability of over wintering hosts.

Abstract

The present experiment was conducted to study the influence of weather parameters on the population dynamics of insect pests of rice during 2009-10 at ICAR-RC for NEH Region, Mizoram Centre, Kolasib, Mizoram. The result of the study indicated that, the mean populations of peak abundance of major insect pests rice crops during August were stem borer, flea beetle and gundhi bug. The Correlation studies showed that stem borer population a significant positively correlation was observed with maximum and minimum relative humidity. Nevertheless non significant negative correlation was obtained with maximum and minimum temperature. The finding of the present study indicated a positive non significant correlation with maximum relative humidity, maximum and minimum temperature where as negative insignificant correlation with rainfall and minimum relative humidity with flea beetle population. The highest minimum temperature showed a positive significant correlation with the Monolepta.

Abstract

Climate change or elements of variability is a matter of great concern production positive, negative or natural impact on pest dynamics because of the specific nature of interactions of host, the pest and the environment. New pest such as Rice Whorl maggot, Flea beetal in rice/soybean and bark eating beetle in citrus are emerging with the change in climate pattern. Pest outbreaks in epemic form such as Rice hispa and rice ear cutting caterpillar are also noted. Location specific IPM packages with an emphasis on biological control are the need of the hour considering the threat of environmental pollution. The ecosystem diversification along with the study on natural enemies, spiders and coccinellids may be brought under purview.

Abstract

Climate is changing naturally at its own pace, since the beginning of evolution of earth, 4–5 billion years ago, but presently it has gained momentum due to inadvertent anthropogenic disturbances. Global climate is changing and it can have serious implications for our food security through its direct and indirect effects on crops, soils, live stocks, fisheries and pests. In the developing countries including India there has been relatively less attention paid to this topic in an integrated manner. Agriculture is the largest human activity in the world which depends on climatic parameters. We can manipulate soil, water and nutrient management practices but manipulation of climate is beyond our control. It influences crop-pest equilibrium. More than 50% differences in yield are due to climatic variation. Different causes of climate change are: A) Natural cause: Earth orbit, Global warming, Mountains, Sun, and Volcano. B) Anthropogenic cause: Global warming, Deforestation, Change in land use pattern. Climate change is a present reality and a major risk for future generations. Implementing energy conservation methods and utilizing renewable resource such as green power (power from moon, hydrogen fuel, nuclear power, sewage power, geothermal power and power of the mighty sun). Government should also encourage the use of mass transit; provide tax rebates for people who buy low and no pollution vehicles and subsidies to fossil fuels and the nuclear industries.

Abstract

Under Ministry of Earth Sciences, India Meteorological Department has launched District level Agro-meteorological Advisory Services in June 2008. The agro-advisory bulletins containing the forecast on rainfall cloud cover, wind direction and speed aid minimum and maximum temperature with their likely impact on crops are in use twice in a week.

Abstract

An attempt has been made in this paper to study probability model for modeling of spell distribution & Weather Cycles during the monsoon period (June to September) at Cochbehar, West Bengal. The daily rainfall data of 31 years (1970 to 2000), recorded at Cochbehar have been analyzed. In this study, it was found that daily rainfall during monsoon period follows Markov Chain model. Markov dependent truncated geometric distribution model is best fitted for studying the Dry spells, Wet spells & Weather Cycles during the monsoon period.

Abstract

Climate change and its various forms of variability are  a global phenomenon and are definitely a threat to our civilization. The change in climatic variables, being  uncertain in nature  has an impact on productivity of agriculture and other allied sectors thus producing a detrimental  effect on the fragile ecosystem prevailed in the North East India. Low or high atmospheric CO2  concentration, temperture fluctuations , rainfall and soil moisture variations, sunshine hours , soil temperature variability ,altogether considered as climatic complex could have impact on field crops, vegetables, fruit crops, animal and aquaculture productivity in a diversified way.Technological modalities in the domain of resilience in agriculture pertainining to natural resource management , crop production and livestock /fisheries  need to implemented in a holistic  manner so as to have institutional interventions to take the resilient measures in the doorstep of the farming community and such measures will be the  weapon for the people to face the challenges of climatic uncertaintity

Abstract

The north eastern region of India, consisting of the eight states of Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland, Sikkim and Tripura, has an area of 255 090 km2 with a vigorous monsoon dominated climatic and a dynamic hydro-geomorphic regimes. Endowed with a sub-tropical type of monsoonal climate, the region shows remarkable variability of weather and climate on a regional scale. It possesses about 30% of the total water resources potential and about 41 % of the total hydropower potential of India. The per capita and per hectare availability of water in this region is the highest in the country. The problems of environment degradation in the northeastern areas of India are, primarily impacted by demographic pressure, urbanization, natural disasters, soil erosion and land degradation. The region is visited by the southwest monsoons which make it one of the wettest areas in South Asia as well as highly frequented by the water induced disasters. The rapid melting of glaciers is initially expected to first contribute to excessive water flow and flooding in the region. Eventually with the full loss of glaciers, the shortage, when it comes, will likely arrive much more abruptly in time; with water systems going from plenty to want in perhaps a few decades or less.

Zenith : The point directly overhead on the celestial sphere.
 
Zenith Angle : The angle formed by the local line perpendicular to the surface on which the radiation falls, and the position of the Sun in the sky from which the incident ray falls. 

Year : The time taken by the earth to revolve once in its orbit round the sun.

Yellow Snow : Snow which has a yellow or golden colour due to the presence of pine or cypress pollen in it.

Xlokk : The name of a hot, dry wind that blows regularly in Malta.
X-rays : The electromagnetic radiation in the wave length region below 100 angstroms.

Walker Circulation : A thermally driven longitudinal cellular circulation over equatorial oceans, particularly Pacific Ocean, Peruvian coast, etc. These circulations rise in the West and sink in the East.
 
Warm Air : If the temperature of air is relatively warm as compared to an underlying surface or another adjacent air column or within itself, then the air is said to be warm air.

Warm Front : A front whose movement is such that the warmer air mass is replacing colder air mass.
 
Warm Sector : The state of lower troposphere in between a warm front and the following cold front. 

Vacuum : A space in which there is no air or gas. This is more an imaginary situation. This term indicate the air or any other gases at the minimum possible pressure in a space.
 
Validation : Model validation in its simplest form is a comparison between simulated and observed values. Validation is determining whether the model works with totally independent data sets or not and whether it accurately predicts growth, yield and processes by comparing the values predicted by the model with those obtained from the real experiment.

Ultraviolet Radiation : Ultraviolet radiation (UV) is one form of radiant energy coming from the sun. The sun emits a range of energy known as the electromagnetic spectrum. The various forms of energy, or radiation, are classified according to wavelength (measured in nanometers (nm) where one nm is a millionth of a millimeter). The shorter the wavelength, the more energetic is the radiation. In order of decreasing energy, the principal forms of radiation are gamma rays, X-rays, UV (ultraviolet radiation), visible light, infrared radiation, microwaves, and radio waves. Ultraviolet, which is invisible, is so named because it occurs next to violet in the visible light spectrum. Ultraviolet radiation contains the wavelengths between 30 and 400 nm. The UV band is divided into three sub-bands in regard to its biological impacts :

Taiga (Boreal Forest) : The open northern part of the coniferous forest. Taiga also refers to sub-polar climate.
 
Tail Wind : The wind that assists the further movement of an object by blowing in the same direction in which the object is actually moving.
 
Tangent Arc : An arc of light tangent to a halo. It forms by refraction of light through ice crystals.
 
Tcu : An abbreviation sometimes used to denote a towering cumulus cloud (cumulus congestus).
 
Teleconnections : A linkage between weather changes occurring in widely separated regions of the world. 

Saffir-Simpson Scale : A scale relating a hurricane’s central pressure and winds to the possible damage it is capable of inflicting.
 
Sand Storm : An ensemble of particles of dust or sand energetically lifted to great heights by a strong and turbulent wind.
 
Santa Ana Wind : A warm, dry wind that blows into southern California from the east off the elevated desert plateau. Its warmth is derived from compressional heating.
 
Satellite Imagery : Images formed from data collected by a weather satellite that reveal visual information on the nature of the atmosphere such as the flow of water vapour, the development and movement of weather systems, or the distribution of the temperatures of cloud tops or the earth’s surface.

Saturated Adiabat : Any statistically valid thermodynamic diagram on a graph related to adiabatic change under saturated conditions of an air parcel. 

Rabi : The winter crop season in India from November to April. Main crops grown in rabi comprise wheat, mustard, etc.

Rad : The ‘rad’ is the unit of radiation dose and is defined as the total absorbed dose of 100 ergs of energy per gram of tissue in a unit time.

Radar : An electronic instrument used to detect objects (such as falling precipitation) by their ability to reflect and scatter microwaves back to a receiver. The radar is used for detecting tropical cyclones and monitoring their course as they approach the coast.
 
Radar sonde : A system in which both meteorological and wind data may be obtained, as in radiosonde.

Radiance : Radiant flux per unit area per unit solid angle. Radiance has unit of watts per meter per meter per steradian. The radiance of a perfectly diffuse surface (Lambertian) is independent of the viewing angle.

Q₁₀ : The number of times the rate of a process (physical, chemical or physiological) increases with a 10^ºC increase in temperature. If the rate of the process is doubled Q₁₀ is 2. Q₁₀ for respiration is 2 to 3.

Quantum : Unit of energy emitted by a photon.

Quantum Flux Density : The number of quanta from a source, incident on a unit area of a small surface situated in a perpendicular direction.

Quantum Irradiance : The number of quanta from a source incident on a unit area of a surface. This differs from the ‘quantum flux density’ as far as direction is concerned.

Pan Coefficient (Kp) : It is the ratio between reference evapotranspiration (ET_o ) and water loss by evaporation from an open water surface of a pan (E_pan ).
    K_p = ET_o / E_pan

Peat soil : An organic soil containing more than 50 per cent organic matter.

Pan Evaporation : is the value of evaporation from an open pan evaporimeter (usually from standard USWB, class ‘A’ pan evaporimeter) during a day or specified period at a place.

Parcel : A volume of air small enough to contain uniform distribution of its meteorological properties and large enough to remain relatively self-contained and respond to all meteorological processes.

Oasis effect : Vertical energy transfer from the air to the crop. It is the exchange of heat between a growing crop and hot air whereby air over the crop is cooled.
 
Observation : In meteorology, the evaluation of one or more meteorological elements, such as temperature, pressure, or wind, that describe the state of the atmosphere, either at the earth’s surface or aloft. An observer is one who records the evaluations of the meteorological elements.
 
Occluded Front : Also known as an occlusion, it is a complex front formed when a cold front overtakes a warm front. It develops when three thermally different air masses conflict. The type of frontal boundary they create depends on the manner in which they meet.

Nanometre : The unit of length specifically applied to wavelengths of radiation. This is equal to ten Angstrom units or 10-9 meters.

Net Assimilation Rate (NAR) : It is increase in dry weight of plant per unit leaf area per unit time. NAR is calculated from the following equation : 

Macroclimate : It deals with the study of atmosphere over large areas of the earth and with the large scale atmospheric motions that cause weather. It helps in forecasting weather. OR Climate of a continent or over the complete globe.
 
Macrometeorology : A branch of meteorology concerned with the study of large scale meteorological phenomena over a continent or the entire globe.

Macroscale : The meteorological scale covering an area ranging from the size of a continent to the entire globe.
 
Marine climate : Almost similar and on many occasions used as a synonym to maritime climate. The climate is basically influenced by adjacent seas and oceans.
 
Maritime Climate : The climate experienced in areas and regions near the oceans and seas. It is characterised by hot dry summers and mild wet winters. The diurnal variations of temperature are small and air is with high relative humidity.

Lake Effect : The effect of any lake in modifying the weather and climate along its shore and inland which depends on the size of the lake. In some areas such as the North American Great Lakes, lake effect refers to snowfall generated by the lake on the downwind shore.

Lake Effect Snowfall : Snowfalls along the lee shore of a lake or downwind some distance from the shore caused by the modification of cold, subfreezing air by the relatively warmer lake water. The intensity of the lake-effect snowfall depends upon several factors : the temperature contrast between the lake surface and the air passing over it, the over-water distance the air has traversed (the fetch), and the regional weather situation. 

Katabatic Wind : Downslope gravitational flow of the colder, denser air beneath the warmer, lighter air results and comprises the katabatic wind. It is also known as the drainage wind or mountain wind.

Kelvin Temperature Scale : An absolute temperature scale in which the zero point is absolute zero. The scale is based upon the triple point of pure water and the size of the degree is same as on the celsius scale. So the 273.16 K = 0°C. That means the freezing point of water is 273.16 K and boiling point of water is 373.16 K, etc. This is more commonly called as the absolute.

January Thaw : A period of mild weather, usually following a cold spell, which often occurs in late January in the eastern regions of North America, particularly around the Great Lakes region, New England and the Canadian Maritime Provinces. The thaw is associated with a strong flow of warm air northward from the Gulf of Mexico on southerly winds on the back of a high pressure system.

Jet Stream : A relatively narrow band of high-speed winds, generally greater than 50 knots (57 mph or 93 kmph), found in the upper troposphere above regions of strong horizontal temperature contrasts such as fronts. The major jet streams are the subtropical jet and the polar jet stream.

Joule : The unit of work or energy. In mechanical systems, this is the work done when a force of one Newton displaces the point of application by a distance of one metre in the direction of force. In electrical systems, a joule is the equivalent of moving one coulomb through a potential difference of one volt. One joule is equal to one watt per second

Ice Caps : A perennial ice/snow cover over an extensive area of land or sea, found only around the two geographic poles.

Ice Columns : Ice crystals resembling stubby pencils rather than the delicate branched snowflake shape. Columns typically form in the temperature ranges -5° C to -8° C (23° F to 18° F) and below -25° C ( -13° F). They are long in comparison to their hexagonal cross-section.

Ice Crystals : 1) Hexagonal (6-sided) crystals that form upon freezing of water, may be in one of several shapes : stars, needles, plates, columns or combinations of these forms. 2) Precipitation in the form of slowly falling, singular or unbranched ice needles, columns, or plates, may be called diamond dust.

Ice Fog : Fog composed of minute ice particles that occur in very low temperatures (typically - 30°C or - 22°F & below) under clear, calm conditions in the polar latitudes. 

Haboob : Sudanese name for duststorm or sandstorm with strong winds that carry small particles of dirt or sand into the air, particularly severe in areas of drought.
 
Habitat : A place where a plant or a community of plants or a crop is existing.

Hadley Cell : A mean thermally driven atmospheric circulation in which warm air rises and flows away from the equator at upper level and descends at the tropics. Wind moves from the tropics back to equator poleward. In many cases this term is also referred to as ‘Hadley circulation’.

Hail : Solid precipitation in the form of balls or pieces if ice (hailstones) with diameter ranging from 5 mm to 50 mm or even more. 
Hailstorm : A storm, often too long and severe, consisting largely of hail or frozen rain drops ranging in diameter from 5 mm to 10 mm or more. 

Gale : Wind of force 8 or above blowing continuously and damaging trees, houses etc.

General Circulation : The average general distribution of wind in motion on the Earth. This general circulation includes the scientific description of atmospheric dynamics not only statistically but also from the point of view of physics. The global wind systems like westerlies, trades, etc., are the examples of general circulation.

General Circulation Model : At present, there are different models in vogue, to explain the general circulation of the atmosphere. If the general circulation is modelled in a three dimensional procedure, then it is known as a general circulation model.

Geopotential : The potential energy per unit mass of a body due to the earth’s gravitational field referred to an arbitrary zero.

Fahrenheit Temperature Scale : A temperature scale having freezing point of water as 32 degrees and the boiling point equal to 212 degrees at standard atmospheric pressure. 
    Degree F = (Degree C x 1.8) + 32
    Degree C = (Degree F - 32)/1.8

Fair Weather : Fine sky. Appearance of cirrus or cumulus cover is in fair amount but not covering the sky totally.

Fetch : The distance over which a wind of nearly constant direction has blown, usually over a consistent surface such as water or a forest or a field. Most often the fetch is applied to a distance over water and used to determine the height of wind-generated waves.
 
Fine Weather : A blue and cloudless sky. Even if a few cirrus clouds are noticed, they do not express any vertical development.

Earthquake : A sudden, transient motion or trembling of the earth’s crust, resulting from the waves in the earth caused by faulting of the rocks or by volcanic activity.
    
Easterlies : Usually applied to the broad patterns of persistent winds with an easterly component, such as the easterly trade winds.

Easterly Wave : A wave like disturbance, of the tropospheric easterlies of low latitude. These are synoptic scale and occur in the region of intertropical convergence zone.

Ecoclimate : Climate under crop canopy is called eco-climate. 

Edaphic : A term pertaining to the influence or relationship of soil or other similar media to plant growth in contrast to atmospheric influences. 

Daily Maximum Temperature : As per the IMD guidelines, the maximum temperature recorded in a 24 hour period at any given place or location.

Daily Mean Temperature : The average of the values observed during a day (at any regular intervals or maximum and minimum) of temperature.

Daily Minimum Temperature : As per the IMD guidelines, the minimum temperature recorded in a 24 hour period at any given place or location.

Daily Range of Temperature : The range of temperature (between maximum and minimum) recorded as per IMD guidelines in 24 hour period.

C3 Plant : A plant in which the first product of CO₂ fixation is the 3-carbon compound; phosphoglyceric acid and is comparatively photosynthetically less efficient than C4 plants e.g. wheat, rice, barley etc. 
C4 Plant : A plant in which the first product of CO₂ fixation is the 4-carbon compound oxalo acetic acid (OAA) and is photosynthetically more efficient than C3 plants e.g. sugarcane, maize etc.
Calibration : Calibration with respect to models refers to the adjustments made to model parameters so as to give the most accurate comparison between simulated results and results obtained from field measurements. 
Calm : Absence of appreciable wind : On the Beaufort Scale of wind force calm is accorded the figure 0 and has a wind speed equivalent or less than 1 knot.