December Signals Summer Solstice for American Samoa and Jarvis Island

Summary: December signals a summer solstice for American Samoa and Jarvis Island but a winter solstice for the rest of the United States.

remnants of an old shipwreck on Jarvis Island, one of only two U.S. Southern Hemisphere possessions; May 2012: NOAA Coral Reef Ecosystem Division-Mission Blog, Public Domain, via NOAA CRED

December signals a summer solstice for American Samoa and Jarvis Island as the only two U.S. possessions in the Southern Hemisphere but a winter solstice for the rest of the United States in the Northern Hemisphere.

Earth’s axial tilt away from the sun accounts for opposite seasons in the Northern and Southern Hemispheres. The December solstice favors the Southern Hemisphere with the south polar terminus of axis tilting toward the sun. The December tilt yields greater surface receipt of direct rays of sunlight by the Southern Hemisphere than by the Northern Hemisphere. Consequently, the favorable tilt announces astronomical summer in the Southern Hemisphere.

The December solstice disfavors the Northern Hemisphere with the north polar terminus of Earth’s imaginary axis tilting away from the sun. The decreased surface receipt of direct rays of sunlight by the Northern Hemisphere on the December solstice initiates astronomical winter in the Northern Hemisphere.

The United States mostly lies in the Northern Hemisphere. All U.S. states and all except two territories occupy the Northern Hemisphere.

American Samoa and Jarvis Island uniquely occupy the Southern Hemisphere. Both islands are located in the South Pacific Ocean. The U.S. Central Intelligence Agency (CIA) gives geographic coordinates of 14 degrees 20 minutes south latitude and 170 degrees west longitude for American Samoa. The CIA geographic coordinates for Jarvis Island are 0 degrees 22 minutes south latitude and 160 degrees 1 minute west longitude.

The instant of the 2019 December solstice takes place Sunday, Dec. 22, at 04:19 Coordinated Universal Time (UTC), the world’s primary time standard. Negative and positive offsets express local time zone differences with respect to UTC. Negative offsets represent time zones that are earlier than UTC. Positive offsets reference time zones that are later than UTC.

American Samoa and Jarvis Island have offsets of UTC-11. Local time in American Samoa and Jarvis Island lags 11 hours behind UTC.

The instant of the 2019 December solstice happens Saturday, Dec. 21, at 5:19 p.m. Samoa Standard Time (SST). Located northeast of American Samoa, Jarvis Island observes the instant of the 2019 December solstice at the exact same time.

The December solstice occurs as the second of two annual solstices. The year’s first solstice happens in June. The June solstice reverses the December solstice’s astronomical seasons. The Northern Hemisphere knows the June solstice as a summer solstice. In the Southern Hemisphere, the June solstice marks astronomical winter.

According to Coordinated Universal Time, the instant of the June solstice happened Friday, June 21, at 15:54 (3:54 p.m.). American Samoa placed the opening of astronomical winter in 2019 at 4:54 a.m. SST, Friday, June 21. Jarvis Island shared in the time and date of the June solstice with American Samoa. The rest of the United States, meanwhile, knew the June solstice as a summer solstice.

The United States comprises 50 states; a federal district, Washington, D.C. (District of Columbia); 16 territories. Five of the territories are permanently inhabited: American Samoa, Guam and the Commonwealth of the Northern Mariana Islands in the Pacific Ocean; the Commonwealth of Puerto Rico and the Virgin Islands of the United States in the Caribbean Sea-North Atlantic Ocean.

Eleven territories have no native or permanent population. Eight are located in the Pacific Ocean: Baker Island, Howland Island, Jarvis Island, Johnston Atoll, Kingman Reef, Midway Atoll, Palmyra Atoll and Wake Island. Three lie in the North Atlantic Ocean’s Caribbean Sea: Bajo Nuevo Bank, Navassa Island and Serranilla Bank.

The takeaway for the December signal of the summer solstice for American Samoa and Jarvis Island is that the United States primarily occupies the Northern Hemisphere, with American Samoa and Jarvis Island as the only U.S. possessions in the Southern Hemisphere.

view through coastal vegetation of Fagatele Bay National Marine Sanctuary (NMS), Tutuila Island, American Samoa: Kip Evans, Public Domain, via NOAA Photo Library

Acknowledgment

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

Image credits:

remnants of an old shipwreck on Jarvis Island, one of only two U.S. Southern Hemisphere possessions; May 2012: NOAA Coral Reef Ecosystem Division-Mission Blog, Public Domain, via NOAA CRED @ http://noaacred.blogspot.com/2012/05/open-boat-films-field-notes-part-ii.html

view through coastal vegetation of Fagatele Bay National Marine Sanctuary (NMS), Tutuila Island, American Samoa: Kip Evans, Public Domain, via NOAA Photo Library @ https://www.photolib.noaa.gov/htmls/sanc0310.htm

For further information:

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

Marriner, Derdriu. “2019 Winter Solstice Happens Sunday, Dec. 22, in Northern Hemisphere.” Earth and Space News. Wednesday. Dec. 11, 2019.
Available @ https://earth-and-space-news.blogspot.com/2019/12/2019-winter-solstice-happens-sunday-dec.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/2018/12/american-samoa-has-summer-solstice-as.html

Marriner, Derdriu. “June Signals Winter Solstice for American Samoa and Jarvis Island.” Earth and Space News. Wednesday, June 19, 2019.
Available @ https://earth-and-space-news.blogspot.com/2019/06/june-signals-winter-solstice-for.html

Marriner, Derdriu. "Northern Latitudes Have Least Amount of Daylight Near December Solstice." Earth and Space News. Wednesday, Dec. 4, 2019.
Available @ https://earth-and-space-news.blogspot.com/2019/12/northern-latitudes-have-least-amount-of.html

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