Earth and Space News: 2019 March equinox U.S. time zones

Showing posts with label 2019 March equinox U.S. time zones. Show all posts

Wednesday, March 20, 2019

March Signals Autumn Equinox for American Samoa and Jarvis Island

Summary: March signals an autumn equinox for American Samoa and Jarvis, the only two U.S. possessions in the Southern Hemisphere.

NASA’s DC-8 flying laboratory’s stop in American Samoa in summer 2016, during first round of Atom (Atmospheric Tomography) flights: NASA photo, Public Domain, via NASA

March signals an autumn equinox for American Samoa and Jarvis, the only two U.S. possessions located in the Southern Hemisphere.

Location north or south of the equator determines the seasonal significance of Earth’s annual pair of equinoxes (Latin: aequus, “equal” + nox, “night”). The March equinox announces spring in the Northern Hemisphere and autumn in the Southern Hemisphere. September’s equinox opens autumn in the Northern Hemisphere and spring in the Southern Hemisphere.

The United States primarily occupies the Northern Hemisphere. Two possessions, however, lie in the Southern Hemisphere. American Samoa and Jarvis Island both occupy the Southern Hemisphere.

American Samoa’s CIA (Central Intelligence Agency) geographic coordinates of 14 degrees 20 minutes south latitude and 170 degrees west longitude situate the unincorporated U.S. territory in the South Pacific Ocean. Swains Island is American Samoa’s northernmost island. The U.S. Department of the Interior gives geographic coordinates of 11 degrees 3 minutes south latitude and 170 degrees 55 minutes west longitude for the privately owned atoll.

American Samoa observes Samoa Standard Time year-round. The 2019 March equinox ushers in astronomical autumn in American Samoa. The unincorporated, South Pacific, U.S. territory experiences the instant of the 2019 autumn equinox Wednesday, March 20, at 10:58 SST.

Jarvis Island’s CIA geographic coordinates of 0 degrees 22 minutes south latitude and 160 degrees 1 minute west longitude situate the unincorporated, unorganized U.S. territory in the South Pacific Ocean. The uninhabited coral island is located almost halfway between Hawaii and New Zealand’s associated state, the self-governing Cook Islands.

The U.S. Central Intelligence Agency’s Map of Standard Time Zones of the World, as of May 2018, places Jarvis Island within the UTC-11 offset, indicating the local time on Jarvis Island lags 11 hours behind Coordinated Universal Time. Jarvis Island observes standard time year-round. As with American Samoa, the 2019 autumn equinox begins Wednesday, March 20, at 10:58 a.m. on Jarvis Island.

The International Organization for Standardization (ISO) is a non-governmental organization, headquartered in Geneva, Switzerland. ISO Code 3166-1 standardizes names of countries and their subdivisions. The ISO assigns the statistical designation of United States Minor Outlying Islands (USMOI) to nine of the 14 U.S. insular areas.

Jarvis Island joins Baker Island, Howland Island, Johnston Atoll, Kingman Reed, Midway Atoll, Navassa Island, Palmyra Atoll and Wake Island as U.S. Minor Outlying Islands. Navassa Island is the only USMOI in the Caribbean Sea. Navassa Island’s CIA geographic coordinates are 18 degrees 25 minutes north latitude and 75 degrees 2 minutes west longitude. The Pacific Ocean claims Jarvis Island and the seven other minor outlying islands.

Except for Jarvis Island, the U.S. Minor Outlying Islands experience the March equinox as a spring equinox. Kingman’s Reef, Midway Atoll and Palmyra Atoll share the same UTC-11 offset with Jarvis Island. They experience the March event as a spring equinox at 10:58 a.m.

Kingman Reef and Palmyra Atoll are located south of Hawaii, in the Northern Line Islands. Kingman Reef’s CIA coordinates are 6 degrees 23 minutes north latitude, 162 degrees 25 minutes west longitude. Palmyra Atoll’s CIA coordinates are 5 degrees 53 minutes north latitude, 162 degrees 5 minutes west longitude.

Johnston Atoll has a UTC-10 offset on the CIA’s May 2018 world time zone map. The 2019 spring equinox takes place at 11:58 a.m. for Johnston Atoll. Johnston Atoll’s CIA coordinates are 16 degrees 45 minutes north latitude, 169 degrees 31 minutes west longitude.

The CIA’s May 2018 world time zone map designates UTC-12 offsets for Baker and Howland Islands. The 2019 spring equinox happens at 9:58 a.m. for both Central Pacific, uninhabited atolls.

Baker Island’s CIA coordinates are 0 degrees 13 minutes north latitude, 176 degrees 28 minutes west longitude. Howland Island’s CIA coordinates are 0 degrees 48 minutes north latitude, 176 degrees 38 minutes west longitude.

Except for Wake Island, the U.S. Minor Outlying Islands experiences the instant of the 2019 March equinox on Wednesday, March 20. Wake Island lies west of the International Date Line. The coral atoll comprising the three islands of Peale, Wake and Wilkes has an offset of UTC+12. The 2019 spring equinox happens Thursday, March 21, at 9:58 a.m., according to the Wake Island Time Zone. Wake Island’s CIA coordinates are 19 degrees 17 minutes north latitude, 166 degrees 39 minutes east longitude.

The takeaways for the 2019 March equinox are that American Samoa has an autumn equinox, along with Jarvis Island, as the only U.S. possessions in the Southern Hemisphere and that Wake Island is the only one of the nine U.S. Minor Outlying Islands with a Thursday, March 21, date for the equinoctial event.

Jarvis Island's western shore, with day beacon (white; right) and U.S. Fish and Wildlife Service’s No Trespassing sign (orange-brown; left); Central Pacific Ocean; Thursday, Oct. 16, 2003, 21:15: Joann94024 at English Wikipedia, Public Domain, via Wikimedia Commons

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

NASA’s DC-8 flying laboratory’s stop in American Samoa in summer 2016, during first round of Atom (Atmospheric Tomography) flights: NASA photo, Public Domain, via NASA @ https://www.nasa.gov/centers/armstrong/news/newsreleases/2017/17-02.html

Cole, Steve; Ellen Gray. “NASA Round-the-World Science Mission Stops in New Zealand.” NASA > NASA Centers and Facilities > Armstrong Flight Research Center > Media Resources > News Releases. Jan. 31, 2017. Last updated June 27, 2018.
Available via NASA @ https://www.nasa.gov/centers/armstrong/news/newsreleases/2017/17-02.html

Marriner, Derdriu. “2017 Spring Equinox Happens Monday, March 20, in Northern Hemisphere.” Earth and Space News. Wednesday, March 15, 2017.
Available @ https://earth-and-space-news.blogspot.com/2017/03/2017-spring-equinox-happens-monday.html

Marriner, Derdriu. “2018 Northern Hemisphere Spring Equinox Happens Tuesday, March 20.” Earth and Space News. Wednesday, March 14, 2018.
Available @ https://earth-and-space-news.blogspot.com/2018/03/2018-northern-hemisphere-spring-equinox.html

Marriner, Derdriu. "2019 Northern Hemisphere Spring Equinox Happens Wednesday, March 20." Earth and Space News. Wednesday, March 13, 2019.
Available @ https://earth-and-space-news.blogspot.com/2019/03/2019-northern-hemisphere-spring-equinox.html

Marriner, Derdriu. “American Samoa Has Autumn Equinox While United States Has Spring Equinox.” Earth and Space News. Wednesday, March 1, 2017.
Available @ https://earth-and-space-news.blogspot.com/2017/03/american-samoa-has-autumn-equinox-while.html

Marriner, Derdriu. “American Samoa Has Summer Solstice As Rest of U.S. Has Winter Solstice.” Earth and Space News. Wednesday, Dec. 12, 2018.
Available @ https://earth-and-space-news.blogspot.com/2017/03/american-samoa-has-autumn-equinox-while.html

Marriner, Derdriu. "March Equinox Astronomically Opens Northern Spring and Southern Autumn." Earth and Space News. Wednesday, March 6, 2019.
Available @ https://earth-and-space-news.blogspot.com/2019/03/march-equinox-astronomically-opens.html

Time And Date. “Time Zones in the United States.” Time And Date > Time Zones > World > United States.
Available @ https://www.timeanddate.com/time/zone/usa

U.S. Central Intelligence Agency. “Field Listing: Geographic Coordinates.” Central Intelligence Agency > Library > Publications > The World Factbook.
Available @ https://www.cia.gov/library/publications/the-world-factbook/fields/2011.html

U.S. Central Intelligence Agency. “Standard Time Zones of the World, May 2018.” Central Intelligence Agency > Library > Publications > The World Factbook.
Available @ https://www.cia.gov/library/publications/the-world-factbook/graphics/ref_maps/physical/pdf/standard_time_zones_of_the_world.pdf

U.S. Department of the Interior-Office of Insular Affairs. A Brief History of Swains Island in American Samoa.
Available via Internet Archive Wayback Machine @ https://web.archive.org/web/20120208205101/http://www.doi.gov/oia/Islandpages/swainsis.htm

U.S.N.O. Astronomical Applications Department. “Equinoxes.” U.S. Naval Observatory Astronomical Applications Department > Information Center > Phenomena of the Sun and Moon > Length of Day and Night at the Equinoxes.
Available @ http://aa.usno.navy.mil/faq/docs/equinoxes.php

U.S.N.O. Astronomical Applications Department. “U.S. Time Zones.” U.S. Naval Observatory Astronomical Applications Department > Information Center > Time > What Are the U.S. Time Zones?
Available @ http://aa.usno.navy.mil/faq/docs/us_tzones.php

Van Tilburg, Hans K.; David J. Herdrich; Rhonda Suka; Matthew Lawrence; Christopher Filimoehala; Stephanie Gandulla. Unlocking the Secrets of Swains Island: A Maritime Heritage Resources Survey, September 2013. Maritime Heritage Program Series Number 6. Silver Spring MD: NOAA Office of National Marine Sanctuaries, 2015.
Available via ResearchGate @ https://www.researchgate.net/publication/280311217_Unlocking_the_Secrets_of_Swains_Island_a_Maritime_Heritage_Resources_Survey

Wednesday, March 13, 2019

2019 Northern Hemisphere Spring Equinox Happens Wednesday, March 20

Summary: The 2019 Northern Hemisphere spring equinox happens Wednesday, March 20, at 21:58 Coordinated Universal Time (5:58 p.m. Eastern Daylight Time).

view of March 20, 2011, equinox from space; SEVIRI (Spinning Enchanced Visible and Infrared Imager) on EUMETSAT’s Meteosat-9 satellite: NASA Earth Observatory, via NASA GSFC (Goddard Space Flight Center) Scientific Visualization Studio

The 2019 Northern Hemisphere spring equinox happens Wednesday, March 20, at 21:58 Coordinated Universal Time (5:58 p.m. Eastern Daylight Time), according to the U.S. Naval Observatory Astronomical Applications Department.

The Northern Hemisphere’s spring equinox occurs annually in March and pairs with the northern autumn equinox, which occurs in September. The U.S. Naval Observatory’s Astronomical Applications Department website explains the significance of the annual equinoxes (Latin: aequus, “equal” + nox, “night”): “On the day of an equinox, the geometric center of the Sun’s disk crosses the equator, and this point is above the horizon for 12 hours everywhere on the Earth.”

Point Udall, St. Croix, United States Virgin Islands (USVI), claims the easternmost point of all U.S. territory, by direction of travel. Point Udall’s geographic coordinates are 17 degrees 45 minutes 19 minutes north latitude and 64 degrees 33 minutes 54 seconds west longitude. Officially known as the Virgin Islands of the United States, the unincorporated and organized U.S. territory in the Caribbean Sea joins the Commonwealth of Puerto Rico in observing Atlantic Standard Time (AST) year-round.

AST’s UTC (Coordinated Universal Time) offset, UTC-4, reflects the time zone’s lag of four hours behind UTC. The 2019 Northern Hemisphere spring equinox takes place Wednesday, March 20, at 5:58 p.m. AST.

Pochnoi Point, Semisopochnoi Island, in Alaska’s Aleutian Islands, claims the easternmost longitudinal point of all U.S. territory. Pochnoi Point lies at 51 degrees 57 minutes 42 degrees north latitude and 179 degrees 46 minutes 23 seconds east longitude. The portion of Alaska’s Aleutian Islands lying west of 169 degrees 30 minutes west longitude observes Hawaii-Aleutian Time. The 2019 spring equinox starts at 12:58 p.m. HDT (also abbreviated as HADT).

Point Udall, Orote Peninsula, Guam, claims the westernmost point of all U.S. territory, by direction of travel. The geographic coordinates for Point Udall, also known as Orote Point, are 13 degrees 26 minutes 51 seconds north latitude and 144 degrees 37 minutes 5.5 seconds east longitude. The unincorporated and organized U.S. Territory of Guam observes Chamorro Standard Time year-round. The 2019 spring equinox begins Thursday, March 21, at 07:58 a.m. ChST.

Amatignak Island in Alaska’s Aleutian Islands claims the westernmost longitudinal point of all U.S. territory. Amatignak Island lies at 51 degrees 16 minutes 7 seconds north latitude and 179 degrees 8 minutes 55 seconds west longitude. Falling with the Hawaii-Aleutian time zone, Amatignak Island experiences the instant of the 2019 spring equinox at 12:58 p.m. HDT.

Six time zones convert the instant of the 2019 Northern Hemisphere spring equinox to local time in the continental United States. The continental United States encompasses the District of Columbia (Washington, D.C.); the 48 contiguous states, known as the lower 48; Alaska.

The continental United States mostly observes standard time annually for eight months and daylight saving time for four months. The switch to daylight saving time happens well before the Northern Hemisphere’s spring equinox occurs. Daylight saving time takes effect at 2 a.m. on the second Sunday in March.

Three of the four time zones observed in the lower 48 switch to daylight saving time prior to the March equinox. The spring equinox commences at 5:58 p.m. EDT, 4:58 p.m. Central Daylight Time, 3:58 p.m. Mountain Daylight Time and 2:58 p.m. Pacific Daylight Time.

Most of Arizona remains on Mountain Standard Time throughout the year. The 2019 spring equinox begins at 2:58 p.m. MST. On Navajo tribal lands, where daylight saving time is observed, the 2019 spring equinox starts at 3:58 MDT.

Alaska claims uniqueness as the only U.S. state that is part of the continental United States but not part of the contiguous United States. The northernmost of the continental U.S. states also likens to 12 other states in splits between time zones. In addition to Alaska, time zone splits take place in Florida, Idaho, Indiana, Kansas, Kentucky, Michigan, Nebraska, North Dakota, Oregon, South Dakota, Tennessee and Texas.

Alaska observes daylight saving time in both of the state’s time zones. Alaska Daylight Time places the instant of the 2019 spring equinox at 1:58 p.m. for mainland Alaska and most of Alaska’s Aleutian Islands. The 2019 spring equinox begins at 12:58 p.m. HDT for the portion of Alaska’s Aleutian Islands to the west of 169 degrees 30 minutes west longitude.

The Hawaiian Islands observe standard time year-round. The 2019 spring equinox occurs at 11:58 a.m., according to HAST.

The takeaway for the 2019 Northern Hemisphere spring equinox, which happens Wednesday, March 20, at 21:58 Coordinated Universal Time (5:58 p.m. Eastern Daylight Time), is that the annual astronomical event occurs during daylight saving time (DST) for most of the continental United States but during standard time for most of Arizona as well as for Hawaii and U.S. territories.

Map of the standard time zones of the 50 U.S. states indicates 13 split time zone states (Alaska, Florida, Idaho, Indiana, Kansas, Kentucky, Michigan, Nebraska, North Dakota, Oregon, South Dakota, Tennessee, Texas) one standard time zone only state (Hawaii) and one mostly standard time zone state (Arizona); The National Atlas of the United States of America: U.S. Department of the Interior-U.S. Geological Survey, via U.S. Naval Observatory Astronomical Applications Department

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

view of March 20, 2011, equinox from space; SEVIRI (Spinning Enchanced Visible and Infrared Imager) on EUMETSAT’s (European Organisation for the Exploitation of Meteorological Satellites) Meteosat-9 satellite: NASA Earth Observatory, via NASA GSFC (Goddard Space Flight Center) Scientific Visualization Studio @ https://svs.gsfc.nasa.gov/11353

Espenak, Fred. “Solstices and Equinoxes: 2001 to 2100 Greenwich Mean Time.” AstroPixels > Ephemeris.
Available @ http://www.astropixels.com/ephemeris/soleq2001.html

Marriner, Derdriu. “First Point of Aries for Spring Equinox Actually Happens in Pisces.” Earth and Space News. Wednesday, March 8, 2017.
Available @ https://earth-and-space-news.blogspot.com/2017/03/first-point-of-aries-for-spring-equinox.html

Time And Date. “Time Zones in the United States.” Time And Date > Time Zones > World > United States.
Available @ https://www.timeanddate.com/time/zone/usa

U.S.N.O. Astronomical Applications Department. “Comparative Lengths of Days and Nights.” U.S. Naval Observatory Astronomical Applications Department > Information Center > Phenomena of the Sun and Moon > Lengths of Longest and Shortest Days.
Available @ http://aa.usno.navy.mil/faq/docs/longest_day.php

U.S.N.O. Astronomical Applications Department. “Daylight Time.” U.S. Naval Observatory Astronomical Applications Department > Information Center > Time > When Does Daylight Time Begin and End?
Available @ http://aa.usno.navy.mil/faq/docs/daylight_time.php

U.S.N.O. Astronomical Applications Department. “Earth’s Seasons and Apsides.” U.S. Naval Observatory Astronomical Applications Department > Data Services > Equinoxes, Solstices, Perihelion, and Aphelion.
Available @ http://aa.usno.navy.mil/data/docs/EarthSeasons.php

U.S.N.O. Astronomical Applications Department. “Equinox.” U.S. Naval Observatory Astronomical Applications Department > Information Center > Terms Used on This Website > The Astronomical Almanac Online.
Available @ http://asa.usno.navy.mil/SecM/Glossary.html#_E

U.S.N.O. Astronomical Applications Department. “Universal Time.” U.S. Naval Observatory Astronomical Applications Department > Information Center > Time > Universal Time and Greenwich Mean Time.
Available @ http://aa.usno.navy.mil/faq/docs/UT.php