Spring (hydrology)A spring is a natural exit point at which groundwater emerges out of the aquifer and flows onto the top of the Earth's crust (pedosphere) to become surface water. It is a component of the hydrosphere, as well as a part of the water cycle. Springs have long been important for humans as a source of fresh water, especially in arid regions which have relatively little annual rainfall. Springs are driven out onto the surface by various natural forces, such as gravity and hydrostatic pressure.
Urban runoffUrban runoff is surface runoff of rainwater, landscape irrigation, and car washing created by urbanization. Impervious surfaces (roads, parking lots and sidewalks) are constructed during land development. During rain, storms, and other precipitation events, these surfaces (built from materials such as asphalt and concrete), along with rooftops, carry polluted stormwater to storm drains, instead of allowing the water to percolate through soil.
Effects of climate changeClimate change affects the physical environment, ecosystems and human societies. Changes in the climate system include an overall warming trend, more extreme weather and rising sea levels. These in turn impact nature and wildlife, as well as human settlements and societies. The effects of human-caused climate change are broad and far-reaching, especially if significant climate action is not taken. The projected and observed negative impacts of climate change are sometimes referred to as the climate crisis.
Climate variability and changeClimate variability includes all the variations in the climate that last longer than individual weather events, whereas the term climate change only refers to those variations that persist for a longer period of time, typically decades or more. Climate change may refer to any time in Earth's history, but the term is now commonly used to describe contemporary climate change. Since the Industrial Revolution, the climate has increasingly been affected by human activities.
Discharge (hydrology)In hydrology, discharge is the volumetric flow rate (in m3/h or ft3/h) of water transported through a given cross-sectional area. It includes any suspended solids (e.g. sediment), dissolved chemicals (e.g. CaCO3(aq)), or biologic material (e.g. diatoms) in addition to the water itself. Terms may vary between disciplines. For example, a fluvial hydrologist studying natural river systems may define discharge as streamflow, whereas an engineer operating a reservoir system may equate it with outflow, contrasted with inflow.
Climate of IndiaThe climate of India consists of a wide range of weather conditions across a vast geographic scale and varied topography. Based on the Köppen system, India hosts six major climatic sub types, ranging from arid deserts in the west, alpine tundra and glaciers in the north, and humid tropical regions supporting rain forests in the southwest and the island territories. Many regions have starkly different microclimates, making it one of the most climatically diverse countries in the world.
Climate sensitivityClimate sensitivity is a measure of how much Earth's surface will cool or warm after a specified factor causes a change in its climate system, such as how much it will warm for a doubling in the atmospheric carbon dioxide () concentration. In technical terms, climate sensitivity is the average change in global mean surface temperature in response to a radiative forcing, which drives a difference between Earth's incoming and outgoing energy.
Arctic sea ice declineSea ice in the Arctic has declined in recent decades in area and volume due to climate change. It has been melting more in summer than it refreezes in winter. Global warming, caused by greenhouse gas forcing is responsible for the decline in Arctic sea ice. The decline of sea ice in the Arctic has been accelerating during the early twenty‐first century, with a decline rate of 4.7% per decade (it has declined over 50% since the first satellite records). It is also thought that summertime sea ice will cease to exist sometime during the 21st century.
Spring (season)Spring, also known as springtime, is one of the four temperate seasons, succeeding winter and preceding summer. There are various technical definitions of spring, but local usage of the term varies according to local climate, cultures and customs. When it is spring in the Northern Hemisphere, it is autumn in the Southern Hemisphere and vice versa. At the spring (or vernal) equinox, days and nights are approximately twelve hours long, with daytime length increasing and nighttime length decreasing as the season progresses until the Summer Solstice in June (Northern Hemisphere) and December (Southern Hemisphere).
Ice coreAn ice core is a core sample that is typically removed from an ice sheet or a high mountain glacier. Since the ice forms from the incremental buildup of annual layers of snow, lower layers are older than upper ones, and an ice core contains ice formed over a range of years. Cores are drilled with hand augers (for shallow holes) or powered drills; they can reach depths of over two miles (3.2 km), and contain ice up to 800,000 years old. The physical properties of the ice and of material trapped in it can be used to reconstruct the climate over the age range of the core.
September equinoxThe September equinox (or southward equinox) is the moment when the Sun appears to cross the celestial equator, heading southward. Because of differences between the calendar year and the tropical year, the September equinox may occur anytime from September 21 to 24. At the equinox, the Sun as viewed from the equator rises due east and sets due west. Before the Southward equinox, the Sun rises and sets more northerly, and afterwards, it rises and sets more southerly.
Air massIn meteorology, an air mass is a volume of air defined by its temperature and humidity. Air masses cover many hundreds or thousands of square miles, and adapt to the characteristics of the surface below them. They are classified according to latitude and their continental or maritime source regions. Colder air masses are termed polar or arctic, while warmer air masses are deemed tropical. Continental and superior air masses are dry, while maritime and monsoon air masses are moist.
