HONOLULU - Thousands are expected to gather at a Honolulu beach on Monday to float candlelit lanterns on the ocean in remembrance of loved ones and to pay tribute to ancestors.

The Japanese Buddhist sect Shinnyo-en organizes the annual Memorial Day ceremony. Now in its 13th year, the event is expected to draw about 40,000 people to Ala Moana Beach Park.

In a year marked by natural disasters, the thoughts of many are expected to be on friends and family who lost their lives in the March 11 earthquake and tsunamis in Japan and the tornadoes that ripped through Missouri, Alabama and other parts of the US mainland in recent months.

Participants write the names of those they are honoring and a short message on the lanterns before setting them in the water at sunset. Some write prayers, others write poems.

Part of the ceremony's appeal is the beauty of the lanterns slowly drifting off in the water as the sun sets in the horizon.

Those participating say the ritual also helps them cope with the loss of a loved one, as though physically setting the lantern in the water helps them spiritually let go of someone they're mourning. They also speak of the power that comes from sharing the experience with thousands of others around them.

"Lantern floating touches your heart. It doesn't matter who you are, it doesn't matter what religion you come from, it doesn't matter what culture, what you believe in," said Roy Ho, the executive director of the Na Lei Aloha Foundation, a social services organization founded by Shinnyo-en that helps organize the event.

In Japan, the centuries-old tradition is generally observed in July or August to coincide with obon, the season when ancestors are honored. In Hawaii, Shinnyo-en holds a ceremony on Memorial Day, in the hopes this will help it win wider acceptance among the public.

Shinnyo-en's leader, Her Holiness Shinso Ito, said having the event on Memorial Day blends American and Japanese cultures.

"I thought there would be harmony if they combined, and it would be nice if harmony spread just a little bit more in the world," Ito said in an interview before the ceremony.

The event has gained a broad following since 1999, when 7,000 - many of them Shinnyo-en members from Japan - gathered at Keehi Lagoon next to the airport. It's since grown six-fold, draws participants of many faiths and backgrounds, and has moved to a larger beach park in the center of town. A television station now broadcasts the ceremony live in Hawaii.

Leaders of various religious denominations in Honolulu - representing the Catholic diocese, a Jewish temple, the Episcopal diocese, and other Buddhist sects - attend. A few help set flame to a giant torch called the Light of Harmony during the ceremony.

Shinnyo-en has prepared 3,000 lanterns. Volunteers are due to collect the lanterns after they're floated so they don't drift out to sea. Shinnyo-en plans to respectfully recondition them so they may be used again next year.