Editing Northern Hemisphere (section)

==Geography and climate==
During the 2.5 million years of the [[Pleistocene]], numerous cold phases called [[Glacial period|glacials]] ([[Quaternary glaciation|Quaternary ice age]]), or significant advances of continental ice sheets, in [[Europe]] and [[North America]], occurred at intervals of approximately 40,000 to 100,000 years. The long glacial periods were separated by more temperate and shorter [[interglacial]]s which lasted about 10,000–15,000 years. The last cold episode of the [[last glacial period]] ended about 10,000 years ago.<ref>{{cite magazine|url=https://www.nationalgeographic.com/science/prehistoric-world/quaternary|title=Quaternary Period|magazine=National Geographic|date=2017-01-06|access-date=2022-05-06|archive-date=2020-11-29|archive-url=https://web.archive.org/web/20201129042714/https://www.nationalgeographic.com/science/prehistoric-world/quaternary/|url-status=dead}}</ref> Earth is currently in an interglacial period of [[Quaternary|the Quaternary]], called the [[Holocene]].<ref>{{cite news |title=How long can we expect the present Interglacial period to last? |url=https://www.usgs.gov/faqs/how-long-can-we-expect-present-interglacial-period-last |work=U.S. Department of the Interior |access-date=2022-05-06 |archive-date=2022-07-26 |archive-url=https://web.archive.org/web/20220726044340/http://www.usgs.gov/faqs/how-long-can-we-expect-present-interglacial-period-last |url-status=live }}</ref> The glaciations that occurred during the glacial period covered many areas of the Northern Hemisphere.

[[File:Northern icesheet hg.png|thumb|Northern hemisphere glaciation during the last [[ice age]]s. The setup of 3 to 4 kilometer thick ice sheets caused a [[sea level rise|sea level lowering]] of about 120&nbsp;m.]]
The [[Arctic]] is a region around the [[North Pole]] (90° [[latitude]]). Its climate is characterized by cold winters and cool summers. Precipitation mostly comes in the form of snow. Areas inside the [[Arctic Circle]] (66°34′ latitude) experience some days in summer when the Sun never sets, and some days during the winter when it never rises. The duration of these phases varies from one day for locations right on the Arctic Circle to several months near the Pole, which is the middle of the Northern Hemisphere. Between the Arctic Circle and the [[Tropic of Cancer]] (23°26′ latitude) lies the [[Northern temperate zone]]. The changes in these regions between summer and winter are generally mild, rather than extreme hot or cold. However, a temperate climate can have very unpredictable weather.

[[Tropics|Tropical]] regions (between the Tropic of Cancer and the Equator, 0° latitude) are generally hot all year round and tend to experience a [[Wet season|rainy season]] during the summer months, and a [[dry season]] during the winter months.

[[File:Snow covered mountains in Mount Robson (Unsplash).jpg|thumb|[[Canadian Rockies]] in North America]]
In the Northern Hemisphere, objects moving across or above the surface of the Earth tend to turn to the right because of the [[Coriolis effect]]. As a result, large-scale horizontal flows of air or water tend to form clockwise-turning [[Ocean gyre|gyres]].<ref name= USDoC>{{Cite web|last=US Department of Commerce|first=National Oceanic and Atmospheric Administration|title=Boundary Currents – Currents: NOAA's National Ocean Service Education|url=https://oceanservice.noaa.gov/education/tutorial_currents/04currents3.html|access-date=2020-07-31|website=oceanservice.noaa.gov|language=EN-US|archive-date=2010-05-15|archive-url=https://web.archive.org/web/20100515015346/https://oceanservice.noaa.gov/education/tutorial_currents/04currents3.html|url-status=live}}</ref> These are best seen in ocean circulation patterns in the [[Atlantic Ocean|North Atlantic]] and [[Pacific Ocean|North Pacific]] oceans.<ref name= USDoC/> Within the Northern Hemisphere, oceanic currents can change the weather patterns that affect many factors within the north coast.<ref>{{cite web |url= https://oceanexplorer.noaa.gov/facts/climate.html|title=How does the ocean affect climate and weather on land? |author=<!--Not stated--> |date= |website=NOAA Ocean Exploration |publisher=U.S. Department of Commerce |access-date=21 November 2023 |quote=}}</ref> For the same reason, flows of air down toward the northern surface of the Earth tend to spread across the surface in a clockwise pattern. Thus, clockwise air circulation is characteristic of [[high pressure]] weather cells in the Northern Hemisphere. Conversely, air rising from the northern surface of the Earth (creating a region of low pressure) tends to draw air toward it in a counterclockwise pattern. [[Tropical cyclone|Hurricanes]] and [[tropical cyclone|tropical storms]] (massive low-pressure systems) spin counterclockwise in the Northern Hemisphere.<ref>{{Cite web|title=Hurricanes: Science and Society: Primary Circulation|url=http://www.hurricanescience.org/science/science/primarycirculation/|access-date=2021-08-11|website=www.hurricanescience.org|archive-date=2010-12-28|archive-url=https://web.archive.org/web/20101228015456/http://www.hurricanescience.org/science/science/primarycirculation/|url-status=live}}</ref>

The shadow of a sundial moves clockwise on latitudes north of the [[subsolar point]] and anticlockwise to the south. During the day at these latitudes, the Sun tends to rise to its maximum at a southerly position. Between the Tropic of Cancer and the Equator, the Sun can be seen to the north, directly overhead, or to the south at noon, depending on the time of year. In the Southern Hemisphere, the midday Sun is predominantly in the north.

When viewed from the Northern Hemisphere, the [[Moon]] appears inverted compared to a view from the Southern Hemisphere.<ref>{{cite web|url=http://curious.astro.cornell.edu/our-solar-system/46-our-solar-system/the-moon/observing-the-moon/135-does-the-moon-look-different-in-the-northern-and-southern-hemispheres-beginner|title=Does the Moon look different in the northern and southern hemispheres? (Beginner) – Curious About Astronomy? Ask an Astronomer|author=Laura Spitler|work=cornell.edu|access-date=10 November 2015|archive-date=4 November 2015|archive-url=https://web.archive.org/web/20151104012834/http://curious.astro.cornell.edu/our-solar-system/46-our-solar-system/the-moon/observing-the-moon/135-does-the-moon-look-different-in-the-northern-and-southern-hemispheres-beginner|url-status=live}}</ref><ref>{{cite web|title=Perspective of the Moon from the Northern and Southern Hemispheres|url=http://epod.usra.edu/blog/2011/09/perspective-of-the-moon-from-the-northern-and-southern-hemispheres.html|access-date=22 October 2013|archive-url=https://web.archive.org/web/20170909070809/http://epod.usra.edu/blog/2011/09/perspective-of-the-moon-from-the-northern-and-southern-hemispheres.html|archive-date=9 September 2017|url-status=dead}}</ref> The North Pole faces away from the [[Galactic Center]] of the [[Milky Way]]. This results in the Milky Way being sparser and dimmer in the Northern Hemisphere compared to the Southern Hemisphere, making the Northern Hemisphere more suitable for deep-space observation, as it is not "blinded" by the Milky Way.{{citation needed|date=August 2015}}