258 articles
Quaternary Ice Age divisions
The Quaternary Ice Age divisions are the glacial and interglacial subdivisions of the Pleistocene, classically the four Alpine ice ages Günz, Mindel, Riss, and Würm.
Rain shadow
A rain shadow, also called the rain shadow effect, is a region of reduced precipitation on the lee side of a mountain, where descending air warms and dries.
Rasputitsa
Rasputitsa (распу́тица), also bezdorozhye/bezdorizhzhia, is the twice-yearly spring-thaw and autumn-rain mud season of Russia, Belarus, and Ukraine, when unpaved roads become impassable; it shaped Napoleon's 1812 retreat and WWII Eastern Front operations.
Regional climate model
A regional climate model (RCM) is a limited-area atmospheric model driven at its edges by a global climate model, downscaling coarse global projections into regional detail for climate studies.
Roman Warm Period
The Roman Warm Period, also called the Roman Climate Optimum, was a warm, wet, stable Mediterranean climate phase from about 200 BCE to 150 CE.
Sahel drought
The Sahel drought was a prolonged period of abnormally low rainfall across the semi-arid Sahel from the late 1960s through the 1990s, among the most extreme droughts on record.
Seasonal lag
Seasonal lag is the delay between the time of maximum solar input and the time of a location's warmest or coldest temperatures, larger over ocean than land.
Semi-arid climate
The semi-arid climate, or steppe climate (Köppen BS), is a dry climate intermediate between humid and arid, with aridity index 0.2 to 0.5, supporting grassland and scrub.
Simoom
Simoom (Arabic: سموم, samūm, "poison wind"), also spelled simoon or samoom, is a hot, dry, dust-laden desert wind of the Sahara, the Levant, and Arabia, briefly reaching 54 °C.
Snow drought
Snow drought is a period of abnormally little snowpack for the time of year, of two types: dry, from low precipitation, and warm, from warm temperatures.
Snow in Australia
Snow in Australia falls mainly on the Australian Alps between Melbourne and Canberra and the highlands of Tasmania, with declining snow depths since the late 1950s.
Snow in Florida
Snow in Florida is a rare but recurring winter phenomenon, first documented in 1774, falling almost entirely in the Panhandle during Arctic air outbreaks.
Snow line
A snow line is the minimum elevation at which snow lies on the ground or a glacier; on glaciers, it separates bright snow from darker firn or ice.
Southern Annular Mode
The Southern Annular Mode, also called the Antarctic Oscillation, is the leading pattern of Southern Hemisphere climate variability, a north-south shift of the westerly winds circling Antarctica.
Standardized Precipitation Evapotranspiration Index
The Standardized Precipitation Evapotranspiration Index (SPEI) is a multiscalar drought index, proposed in 2010, that measures drought from the climatic water balance of precipitation minus potential evapotranspiration over chosen time scales.
Standardized Precipitation Index
The Standardized Precipitation Index (SPI) is a drought index expressing precipitation over periods like 3 or 12 months as a standardized departure from local climatological norms.
Sturtian glaciation
The Sturtian glaciation was a global Snowball Earth glaciation of the Cryogenian Period, from about 717 to 660 million years ago, the longest in Earth history.
Subarctic climate
The subarctic climate, also called boreal climate, is a high-latitude continental climate with long, cold winters and one to three months averaging above 10 °C, underlying the boreal forest.
Subtropical climate
A subtropical climate is a climate zone between the tropics and temperate latitudes, typically found on eastern sides of continents between 20° and 35° latitude.
Subtropics
The subtropics, or subtropical zone, are the climatic zones between the tropics and temperate regions, roughly 20 to 40 degrees of latitude in each hemisphere.
Summer
Summer is the warmest of the four temperate seasons, occurring when a hemisphere tilts toward the Sun; it spans June to August in the Northern Hemisphere.
Summit Camp
Summit Camp, or Summit Station, is the NSF-funded year-round U.S. research station near the apex of the Greenland Ice Sheet at 3,210 m, established 1989 for the GISP2 ice core, operated by Battelle ARO, distinct from same-named places in Nevada, Idaho, and Pennsylvania.
Sunshine duration
Sunshine duration, or sunshine hours, is a climatological quantity defined by the WMO as the time direct solar irradiance exceeds 120 W/m², measured in hours at climate stations.
Super El Niño events
Super El Niño events are exceptionally strong El Niños in which central equatorial Pacific sea temperatures reach 2 °C above normal, recorded in 1982/1983, 1997/1998, 2015/2016, and 2026.
Temperate climate
A temperate climate is a middle-latitude climate with no extreme season, defined in the Köppen-Geiger scheme as group C and subdivided into humid subtropical, marine west coast, and Mediterranean types.
Temperature in Canada
Temperature in Canada: surface air temperature regime measured by Environment and Climate Change Canada. Official extremes −63°C at Snag (1947) and 45°C at Midale; national warming of 2.4°C since 1948, about twice the global rate.
Timeline of glaciation
The timeline of glaciation, or list of ice ages, covers Earth's five major glacial periods, from the Huronian glaciation 2.4 billion years ago to the ongoing Quaternary.
Toarcian Oceanic Anoxic Event
The Toarcian Oceanic Anoxic Event, also called the Jenkyns Event, was an episode of global warming and ocean deoxygenation about 183 million years ago in the Early Jurassic.
Trewartha climate classification
The Trewartha climate classification, often called the Köppen–Trewartha classification, is a 1966 modification of the Köppen system by geographer Glenn Trewartha, subdividing middle latitudes into temperature-based groups.
Tropical climate
A tropical climate is a continually hot climate of equatorial and tropical regions with considerable precipitation, forming Köppen group A with all months above 18 °C.