The following mission descriptions come from a short book on the history of the 9th Bombardment Group, which can be found as a PDF download here (if the link doesn't work, let me know). The 9th Bombardment Group was one of two extant and retrained groups assigned to the 313th Bomb Wing (the other being the 6th). The other two bombardment groups in the 313th Wing, the 504th and 505th, were newly-constituted units. The 509th Composite Group, which handled the atomic bombings of Hiroshima and Nagasaki, was assigned to the 313th Bombardment Wing for command and control purposes in June 1945.

• Constituted as the 313th Bombardment Wing (Very Heavy) on 15 April 1944

• Activated on 23 April 1944

• Inactivated on 15 June 1948

• Assigned Second Air Force, 23 April-8 June 1944

• Assigned XXI Bomber Command, 8 June 1944-16 July 1945

• Assigned Twentieth Air Force, 16 July 1945-13 March 1946

• Assigned Thirteenth Air Force, 13 March 1946-15 June 1948

It appears a couple of the dates and figures in your grandfather's journal might be slightly off from what was officially recorded, so I have included descriptions of the most probable missions. In the book, there is a list of personnel that served in the group, group crews, and aircraft that flew on each mission; you likely will find your grandfather's name, as well as his aircraft and crew. The document is downloadable directly from the link and is searchable.

these aircraft

The last three letters of the aircraft's serial number. Aircraft were assigned serial numbers by the Army Air Forces in the sequence in which they were purchased.

T in the "Alt[itude]?

In thousands of feet, for example, "15T" would mean 15,000 feet. "1/2T" is 500 feet.

the munition types?

As written verbatim in your grandfather's journal;

100# fire

M47 incendiary bomb, which could be filled with either napalm, white phosphorus, or a mixture of both for a burning effect on wooden buildings (Japanese cities, with "cottage industry" scattered among civilian houses, were particularly vulnerable to this type of attack).

4000#

4,000-pound general purpose AN-M56 demolition bomb, usually utilized for extreme blast effect on fortified structures like submarine pens.

500# CL

Most likely the 500-pound M17 aimable incendiary cluster, filled with 110 4-pound M69 incendiary (napalm) bomblets.

500# G.P.

500-pound general-purpose demolition bomb. By this point in the war, the most likely candidate would have been the AN-M64 500-pound bomb, which replaced stocks of the earlier AN-M43 bomb beginning in 1943.

These are the mission descriptions from the book that most closely match the entries in your grandfather's journal;

62.) July 19 CHOSHI URBAN AREA. Of 45 a/c on hand, 34 were scheduled and airborne. At night from 10,400' by radar, 30 a/c dropped 259 tons which destroyed 43% of that city. No crew casualties or a/c damage.

63.) July 24 TSU URBAN AREA. Of 44 a/c on hand, 42 were scheduled and 41 airborne. At night from 11,000', 36 a/c dropped 299 tons of IB which, along with 75 other B-29’s bombs, destroyed .84 square miles, 57% of that city. No crew casualties or a/c damage.

65.) July 28 UJI-YAMADA URBAN AREA. Of 46 a/c on hand, 34 were scheduled and 33 airborne. At night from 12,400', 32 a/c dropped 271 tons of IB which, along with 71 other B-29’s bombs, destroyed .36 square miles, 39% of that city. No crew casualties or a/c damage.

66.) Aug. 1 NAGAOKA URBAN AREA. (To celebrate the 38th anniversary of the establishment of an army air unit—an AAF birthday of sorts—the command was ordered to make a “maximum effort,” with the goal of 800 B-29s in the air; 836 were airborne and 784 struck targets.) Of 48 a/c on hand, 48 were scheduled; 47 were airborne, bombed Japan, and returned to Tinian safely—the 9th’s greatest operational achievement! At night from 12,000', 43 dropped 322 tons of IB which, along with the 82 other B-29’s bombs, destroyed 1.33 square miles, 65.5% of that city. Four a/c dropped 31 tons on targets of opportunity. No crew casualties or a/c damage.

69.) Aug. 8 YAWATA URBAN AREA. Of 48 a/c on hand, 30 were scheduled and airborne. By daylight from 20,000', by radar due to cloud cover, 29 a/c dropped 161 tons of IB which, along with 192 other B-29’s bombs, destroyed 1.22 square miles, 21% of that city. Keller’s aircraft was badly damaged by flak. He guided it to an open area of the ocean where the crew bailed out. Keller, after bailing out, was struck by the aircraft and killed. Nelson’s and Tulloch’s crews “buddied” Keller’s, dropped extra life rafts, and did their best to get rescue seaplanes or submarines to the area but, eventually, to no avail. The 10 surviving crew members, after drifting on life rafts for a week, were captured, mistreated, and imprisoned about the time Japan capitulated; they were released and repatriated a few weeks later.

70.) Aug. 14 MARIFU RAILROAD YARDS. Of 45 a/c on hand, 42 were scheduled for this “maximum effort” mission, and 41 were airborne. By daylight from 16,600', 37 a/c dropped 264 tons of GP which, along with 67 other B-29’s bombs, destroyed 92% of those railroad yards. No crew casualties or a/c damage. The last major combat mission.

71.) Aug. 14 KUMAGAYA URBAN AREA. Of 45 a/c on hand, 4 were scheduled and airborne; At night from 14,000', 3 a/c dropped 25 tons of IB which along with 90 other B-29’s bombs, destroyed 1.3 square miles, 65% of that city. No crew casualties or a/c damage. Last combat mission.

72.) Aug. 30 DISPLAY OF POWER. To support psychologically the arrival in Japan of U.S. troops and General MacArthur and other surrender officials, this mission, a fly-over of Tokyo, was ordered. Of 48 a/c on hand, 11 were scheduled; 10 were airborne and completed the mission.

74.) Sept. 1 PRISONER OF WAR SUPPLIES. (This mission was to drop food, medicine, clothing, and other supplies to known prisoner of war camps.) Of 48 a/c on hand, 20 were scheduled and airborne. Sixteen completed their missions.