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Noctilucent cloud
Noctilucent clouds, also called polar mesospheric clouds, are the highest clouds on Earth, thin ice clouds near the mesopause that shine at night in summer.
Nocturnal tornado
A nocturnal tornado is a tornado that occurs between sunset and sunrise, when it is hardest to see and about 2.5 times as likely to kill.
Nommo Valles
Nommo Valles: 200 km-wide channel system (vallis) on Venus at 40.7S, 87.3E, IAU-approved 2000, named for Dogon water deities of Mali; not detectable in Magellan radar imagery.
Nor'easter
A nor'easter is a powerful coastal storm that moves up the East Coast of North America, bringing strong northeast winds, heavy snow or rain, and coastal flooding.
NorESM
NorESM, the Norwegian Earth System Model, is a coupled Earth system model developed in Norway since 2007; its simulations feature in IPCC reports and CMIP6.
Normal fault
A normal fault is a dip-slip fault on which the hanging wall moves downward relative to the footwall, forming where the crust is pulled apart by extension.
Normal moveout
Normal moveout (NMO) is a seismic data processing correction that time-shifts each trace in a CMP gather by an offset-dependent amount, flattening reflections for stacking.
North
North is one of the four cardinal directions: true north toward the geographic North Pole, magnetic north where a compass points, and grid north on maps.
North American blizzard of 1996
The North American blizzard of 1996, commonly called the Blizzard of '96, was a severe nor'easter that struck the eastern United States from January 6 to 8, 1996.
North American Mesoscale Model
The North American Mesoscale Model (NAM) is a regional numerical weather prediction system run by NCEP four times daily, providing mesoscale forecast guidance to meteorologists across North America.
North American monsoon
The North American monsoon is a seasonal shift in winds that brings summer rain to northern Mexico and the southwestern US, peaking in July and August.
North American Plate
The North American Plate is a major tectonic plate covering most of North America, Greenland, and Atlantic floor, bounded by the San Andreas Fault and Cascadia subduction zone.
North Anatolian Fault
The North Anatolian Fault (NAF) is a major right-lateral strike-slip fault in northern Turkey, about 1,200 km long, marking the boundary between the Anatolian and Eurasian plates.
North Atlantic Current
The North Atlantic Current, also called the North Atlantic Drift, is a warm ocean current that continues the Gulf Stream northeastward from the Grand Banks toward the British Isles.
North Atlantic Deep Water
North Atlantic Deep Water is a cold, salty water mass formed in the subpolar North Atlantic and Nordic Seas that flows southward and ventilates the deep ocean.
North Atlantic garbage patch
The North Atlantic garbage patch, or Atlantic Garbage Patch, is a zone of floating plastic debris, mostly microplastics, in the North Atlantic Subtropical Gyre near Bermuda.
North Atlantic oscillation
The North Atlantic oscillation (NAO) is a fluctuation in atmospheric pressure between the Azores High and the Icelandic Low that shapes winter weather across Europe and eastern North America.
North Atlantic storm track
The North Atlantic storm track is the band where extratropical cyclones form and travel, downstream of the jet stream, bringing winter windstorms, heavy precipitation, and storm surges to western Europe.
North Pacific High
The North Pacific High, or North Pacific Subtropical High (NPSH), is a semi-permanent high-pressure system over the North Pacific, strongest in summer between about 15°N and 45°N.
North Pacific Intermediate Water
North Pacific Intermediate Water (NPIW) is the low-salinity water mass of the North Pacific, a salinity minimum at depths of roughly 300–800 m, sourced mainly from the Sea of Okhotsk.
North Pacific Oscillation
The North Pacific Oscillation (NPO) is a recurring north-south seesaw in sea level pressure over the North Pacific, tied to shifts of the Aleutian low and to ENSO.
North Sea flood of 1953
The North Sea flood of 1953, known in the Netherlands as the Watersnoodramp, killed 1,836 Dutch people and more than 300 in England on 1 February 1953.
Northeastern United States blizzard of 1978
The Northeastern United States blizzard of 1978, often called the Blizzard of '78, was a nor'easter that struck New England on February 5-7, 1978, paralyzing Boston for about a week.
Northwest Africa 7034
Northwest Africa 7034, nicknamed "Black Beauty", is a Martian meteorite found in Morocco's Sahara in 2011 that founded a new class of water-rich Martian breccias.
Norwegian Continental Shelf
The Norwegian Continental Shelf is the seabed area under Norwegian jurisdiction in the North Sea, Norwegian Sea, and Barents Sea, and Western Europe's most important petroleum province.
Notice to Mariners
A Notice to Mariners is a periodic publication issued by national hydrographic offices announcing corrections to nautical charts, such as new dangers to navigation and changes to aids to navigation.
NovaGold Resources
NovaGold Resources is a Vancouver, British Columbia gold development company whose principal asset is a majority interest in the Donlin Gold project, a large undeveloped deposit in southwestern Alaska.
November 2014 Bering Sea cyclone
The November 2014 Bering Sea cyclone was an extratropical storm from the remnants of Typhoon Nuri that deepened to 924 millibars, among the strongest North Pacific cyclones recorded.
Nowcasting
Nowcasting is the production of detailed weather forecasts from the present to 6 hours ahead, defined by the WMO and built mainly from weather radar observations.
Nuclear magnetic resonance logging
Nuclear magnetic resonance logging is a well-logging technique that measures hydrogen in rock pore space to determine fluids, porosity, and permeability, with tools lowered into the borehole.